@article{MTMT:34610438, title = {Effects of transcranial magnetic stimulation on the human brain recorded with intracranial electrocorticography}, url = {https://m2.mtmt.hu/api/publication/34610438}, author = {Wang, Jeffrey B. and Hassan, Umair and Bruss, Joel E. and Oya, Hiroyuki and Uitermarkt, Brandt D. and Trapp, Nicholas T. and Gander, Phillip E. and Howard, Matthew A. and Keller, Corey J. and Boes, Aaron D.}, doi = {10.1038/s41380-024-02405-y}, journal-iso = {MOL PSYCHIATR}, journal = {MOLECULAR PSYCHIATRY}, unique-id = {34610438}, issn = {1359-4184}, abstract = {Transcranial magnetic stimulation (TMS) is increasingly used as a noninvasive technique for neuromodulation in research and clinical applications, yet its mechanisms are not well understood. Here, we present the neurophysiological effects of TMS using intracranial electrocorticography (iEEG) in neurosurgical patients. We first evaluated safety in a gel-based phantom. We then performed TMS-iEEG in 22 neurosurgical participants with no adverse events. We next evaluated intracranial responses to single pulses of TMS to the dorsolateral prefrontal cortex (dlPFC) (N = 10, 1414 electrodes). We demonstrate that TMS is capable of inducing evoked potentials both locally within the dlPFC and in downstream regions functionally connected to the dlPFC, including the anterior cingulate and insular cortex. These downstream effects were not observed when stimulating other distant brain regions. Intracranial dlPFC electrical stimulation had similar timing and downstream effects as TMS. These findings support the safety and promise of TMS-iEEG in humans to examine local and network-level effects of TMS with higher spatiotemporal resolution than currently available methods.}, year = {2024}, eissn = {1476-5578} } @article{MTMT:34227757, title = {An orexigenic subnetwork within the human hippocampus}, url = {https://m2.mtmt.hu/api/publication/34227757}, author = {Barbosa, D.A.N. and Gattas, S. and Salgado, J.S. and Kuijper, F.M. and Wang, A.R. and Huang, Y. and Kakusa, B. and Leuze, C. and Luczak, A. and Rapp, P. and Malenka, R.C. and Hermes, D. and Miller, K.J. and Heifets, B.D. and Bohon, C. and McNab, J.A. and Halpern, C.H.}, doi = {10.1038/s41586-023-06459-w}, journal-iso = {NATURE}, journal = {NATURE}, volume = {621}, unique-id = {34227757}, issn = {0028-0836}, year = {2023}, eissn = {1476-4687}, pages = {381-388} } @article{MTMT:34281661, title = {An orexigenic subnetwork within the human hippocampus}, url = {https://m2.mtmt.hu/api/publication/34281661}, author = {Barbosa, Daniel A. N. and Gattas, Sandra and Salgado, Juliana S. and Kuijper, Fiene Marie and Wang, Allan R. and Huang, Yuhao and Kakusa, Bina and Leuze, Christoph and Luczak, Artur and Rapp, Paul and Malenka, Robert C. and Hermes, Dora and Miller, Kai J. and Heifets, Boris D. and Bohon, Cara and Mcnab, Jennifer A. and Halpern, Casey H.}, doi = {10.1038/s41586-023-06459}, journal-iso = {NATURE}, journal = {NATURE}, unique-id = {34281661}, issn = {0028-0836}, abstract = {Only recently have more specific circuit-probing techniques become available to inform previous reports implicating the rodent hippocampus in orexigenic appetitive processing1-4. This function has been reported to be mediated at least in part by lateral hypothalamic inputs, including those involving orexigenic lateral hypothalamic neuropeptides, such as melanin-concentrating hormone5,6. This circuit, however, remains elusive in humans. Here we combine tractography, intracranial electrophysiology, cortico-subcortical evoked potentials, and brain-clearing 3D histology to identify an orexigenic circuit involving the lateral hypothalamus and converging in a hippocampal subregion. We found that low-frequency power is modulated by sweet-fat food cues, and this modulation was specific to the dorsolateral hippocampus. Structural and functional analyses of this circuit in a human cohort exhibiting dysregulated eating behaviour revealed connectivity that was inversely related to body mass index. Collectively, this multimodal approach describes an orexigenic subnetwork within the human hippocampus implicated in obesity and related eating disorders.An appetite-regulating subnetwork in humans involving the lateral hypothalamus and the dorsolateral hippocampus is implicated in obesity and related eating disorders.}, year = {2023}, eissn = {1476-4687}, orcid-numbers = {Bohon, Cara/0000-0001-9978-3727} } @article{MTMT:33893852, title = {Quantitative approaches to guide epilepsy surgery from intracranial EEG}, url = {https://m2.mtmt.hu/api/publication/33893852}, author = {Bernabei, John M. and Li, Adam and Revell, Andrew Y. and Smith, Rachel J. and Gunnarsdottir, Kristin M. and Ong, Ian Z. and Davis, Kathryn A. and Sinha, Nishant and Sarma, Sridevi and Litt, Brian}, doi = {10.1093/brain/awad007}, journal-iso = {BRAIN}, journal = {BRAIN}, unique-id = {33893852}, issn = {0006-8950}, abstract = {Over the past 10 years, the drive to improve outcomes from epilepsy surgery has stimulated widespread interest in methods to quantitatively guide epilepsy surgery from intracranial EEG (iEEG). Many patients fail to achieve seizure freedom, in part due to the challenges in subjective iEEG interpretation. To address this clinical need, quantitative iEEG analytics have been developed using a variety of approaches, spanning studies of seizures, interictal periods, and their transitions, and encompass a range of techniques including electrographic signal analysis, dynamical systems modeling, machine learning and graph theory. Unfortunately, many methods fail to generalize to new data and are sensitive to differences in pathology and electrode placement. Here, we critically review selected literature on computational methods of identifying the epileptogenic zone from iEEG. We highlight shared methodological challenges common to many studies in this field and propose ways that they can be addressed. One fundamental common pitfall is a lack of open-source, high-quality data, which we specifically address by sharing a centralized high-quality, well-annotated, multicentre dataset consisting of >100 patients to support larger and more rigorous studies. Ultimately, we provide a road map to help these tools reach clinical trials and hope to improve the lives of future patients.Bernabei et al. provide an update on quantitative methods for guiding epilepsy surgery using intracranial EEG. They identify challenges which have prevented successful clinical translation of these methods, and offer potential solutions, including the release of a new dataset with more than 100 patients to support larger and more rigorous studies.}, keywords = {EPILEPSY; neurosurgery; data-sharing; intracranial-EEG}, year = {2023}, eissn = {1460-2156}, orcid-numbers = {Li, Adam/0000-0001-8421-365X; Sinha, Nishant/0000-0002-2090-4889} } @article{MTMT:33893851, title = {Event-related causality in stereo-EEG discriminates syntactic processing of noun phrases and verb phrases}, url = {https://m2.mtmt.hu/api/publication/33893851}, author = {Cometa, Andrea and d'Orio, Piergiorgio and Revay, Martina and Bottoni, Franco and Repetto, Claudia and Russo, Giorgio Lo and Cappa, Stefano F. and Moro, Andrea and Micera, Silvestro and Artoni, Fiorenzo}, doi = {10.1088/1741-2552/accaa8}, journal-iso = {J NEURAL ENG}, journal = {JOURNAL OF NEURAL ENGINEERING}, volume = {20}, unique-id = {33893851}, issn = {1741-2560}, abstract = {Objective. Syntax involves complex neurobiological mechanisms, which are difficult to disentangle for multiple reasons. Using a protocol able to separate syntactic information from sound information we investigated the neural causal connections evoked by the processing of homophonous phrases, i.e. with the same acoustic information but with different syntactic content. These could be either verb phrases (VP) or noun phrases. Approach. We used event-related causality from stereo-electroencephalographic recordings in ten epileptic patients in multiple cortical and subcortical areas, including language areas and their homologous in the non-dominant hemisphere. The recordings were made while the subjects were listening to the homophonous phrases. Main results. We identified the different networks involved in the processing of these syntactic operations (faster in the dominant hemisphere) showing that VPs engage a wider cortical and subcortical network. We also present a proof-of-concept for the decoding of the syntactic category of a perceived phrase based on causality measures. Significance. Our findings help unravel the neural correlates of syntactic elaboration and show how a decoding based on multiple cortical and subcortical areas could contribute to the development of speech prostheses for speech impairment mitigation.}, keywords = {Connectivity; Speech; SYNTAX; decoding; Partial directed coherence; SEEG; event-related causality}, year = {2023}, eissn = {1741-2552}, orcid-numbers = {Cometa, Andrea/0000-0002-5771-0316} } @article{MTMT:33865809, title = {Quantifying trial-by-trial variability during cortico-cortical evoked potential mapping of epileptogenic tissue}, url = {https://m2.mtmt.hu/api/publication/33865809}, author = {Cornblath, Eli J. J. and Lucas, Alfredo and Armstrong, Caren and Greenblatt, Adam S. S. and Stein, Joel M. M. and Hadar, Peter N. N. and Raghupathi, Ramya and Marsh, Eric and Litt, Brian and Davis, Kathryn A. A. and Conrad, Erin C. C.}, doi = {10.1111/epi.17528}, journal-iso = {EPILEPSIA}, journal = {EPILEPSIA}, volume = {64}, unique-id = {33865809}, issn = {0013-9580}, abstract = {ObjectiveMeasuring cortico-cortical evoked potentials (CCEPs) is a promising tool for mapping epileptic networks, but it is not known how variability in brain state and stimulation technique might impact the use of CCEPs for epilepsy localization. We test the hypotheses that (1) CCEPs demonstrate systematic variability across trials and (2) CCEP amplitudes depend on the timing of stimulation with respect to endogenous, low-frequency oscillations. MethodsWe studied 11 patients who underwent CCEP mapping after stereo-electroencephalography electrode implantation for surgical evaluation of drug-resistant epilepsy. Evoked potentials were measured from all electrodes after each pulse of a 30 s, 1 Hz bipolar stimulation train. We quantified monotonic trends, phase dependence, and standard deviation (SD) of N1 (15-50 ms post-stimulation) and N2 (50-300 ms post-stimulation) amplitudes across the 30 stimulation trials for each patient. We used linear regression to quantify the relationship between measures of CCEP variability and the clinical seizure-onset zone (SOZ) or interictal spike rates. ResultsWe found that N1 and N2 waveforms exhibited both positive and negative monotonic trends in amplitude across trials. SOZ electrodes and electrodes with high interictal spike rates had lower N1 and N2 amplitudes with higher SD across trials. Monotonic trends of N1 and N2 amplitude were more positive when stimulating from an area with higher interictal spike rate. We also found intermittent synchronization of trial-level N1 amplitude with low-frequency phase in the hippocampus, which did not localize the SOZ. SignificanceThese findings suggest that standard approaches for CCEP mapping, which involve computing a trial-averaged response over a .2-1 Hz stimulation train, may be masking inter-trial variability that localizes to epileptogenic tissue. We also found that CCEP N1 amplitudes synchronize with ongoing low-frequency oscillations in the hippocampus. Further targeted experiments are needed to determine whether phase-locked stimulation could have a role in localizing epileptogenic tissue.}, keywords = {EPILEPSY; Hippocampal theta; seizure; Cortico-cortical evoked potentials; epileptic spikes; ONSET ZONE}, year = {2023}, eissn = {1528-1167}, pages = {1021-1034}, orcid-numbers = {Lucas, Alfredo/0000-0001-9439-735X} } @article{MTMT:34539630, title = {Identification of epileptic networks with graph convolutional network incorporating oscillatory activities and evoked synaptic responses}, url = {https://m2.mtmt.hu/api/publication/34539630}, author = {Dou, Y. and Xia, J. and Fu, M. and Cai, Y. and Meng, X. and Zhan, Y.}, doi = {10.1016/j.neuroimage.2023.120439}, journal-iso = {NEUROIMAGE}, journal = {NEUROIMAGE}, volume = {284}, unique-id = {34539630}, issn = {1053-8119}, year = {2023}, eissn = {1095-9572} } @article{MTMT:34170893, title = {Electrical Stimulation of Temporal and Limbic Circuitry Produces Distinct Responses in Human Ventral Temporal Cortex}, url = {https://m2.mtmt.hu/api/publication/34170893}, author = {Huang, H. and Gregg, N.M. and Valencia, G.O. and Brinkmann, B.H. and Lundstrom, B.N. and Worrell, G.A. and Miller, K.J. and Hermes, D.}, doi = {10.1523/JNEUROSCI.1325-22.2023}, journal-iso = {J NEUROSCI}, journal = {JOURNAL OF NEUROSCIENCE}, volume = {43}, unique-id = {34170893}, issn = {0270-6474}, abstract = {The human ventral temporal cortex (VTC) is highly connected to integrate visual perceptual inputs with feedback from cognitive and emotional networks. In this study, we used electrical brain stimulation to understand how different inputs from multiple brain regions drive unique electrophysiological responses in the VTC. We recorded intracranial EEG data in 5 patients (3 female) implanted with intracranial electrodes for epilepsy surgery evaluation. Pairs of electrodes were stimulated with single-pulse electrical stimulation, and corticocortical evoked potential responses were measured at electrodes in the collateral sulcus and lateral occipitotemporal sulcus of the VTC. Using a novel unsupervised machine learning method, we uncovered 2-4 distinct response shapes, termed basis profile curves (BPCs), at each measurement electrode in the 11-500 ms after stimulation interval. Corticocortical evoked potentials of unique shape and high amplitude were elicited following stimulation of several regions and classified into a set of four consensus BPCs across subjects. One of the consensus BPCs was primarily elicited by stimulation of the hippocampus; another by stimulation of the amygdala; a third by stimulation of lateral cortical sites, such as the middle temporal gyrus; and the final one by stimulation of multiple distributed sites. Stimulation also produced sustained high-frequency power decreases and low-frequency power increases that spanned multiple BPC categories. Characterizing distinct shapes in stimulation responses provides a novel description of connectivity to the VTC and reveals significant differences in input from cortical and limbic structures.}, year = {2023}, eissn = {1529-2401}, pages = {4434-4447} } @article{MTMT:34227755, title = {Lateralization of the hippocampus: A review of molecular, functional, and physiological properties in health and disease}, url = {https://m2.mtmt.hu/api/publication/34227755}, author = {Nemati, S.S. and Sadeghi, L. and Dehghan, G. and Sheibani, N.}, doi = {10.1016/j.bbr.2023.114657}, journal-iso = {BEHAV BRAIN RES}, journal = {BEHAVIOURAL BRAIN RESEARCH}, volume = {454}, unique-id = {34227755}, issn = {0166-4328}, year = {2023}, eissn = {1872-7549} } @article{MTMT:34079558, title = {Reliability and Validity of Transcranial Magnetic Stimulation–Electroencephalography Biomarkers}, url = {https://m2.mtmt.hu/api/publication/34079558}, author = {Parmigiani, S. and Ross, J.M. and Cline, C.C. and Minasi, C.B. and Gogulski, J. and Keller, C.J.}, doi = {10.1016/j.bpsc.2022.12.005}, journal-iso = {BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGINING}, journal = {BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING}, volume = {In press}, unique-id = {34079558}, issn = {2451-9022}, abstract = {Noninvasive brain stimulation and neuroimaging have revolutionized human neuroscience with a multitude of applications, including diagnostic subtyping, treatment optimization, and relapse prediction. It is therefore particularly relevant to identify robust and clinically valuable brain biomarkers linking symptoms to their underlying neural mechanisms. Brain biomarkers must be reproducible (i.e., have internal reliability) across similar experiments within a laboratory and be generalizable (i.e., have external reliability) across experimental setups, laboratories, brain regions, and disease states. However, reliability (internal and external) is not alone sufficient; biomarkers also must have validity. Validity describes closeness to a true measure of the underlying neural signal or disease state. We propose that these metrics, reliability and validity, should be evaluated and optimized before any biomarker is used to inform treatment decisions. Here, we discuss these metrics with respect to causal brain connectivity biomarkers from coupling transcranial magnetic stimulation (TMS) with electroencephalography (EEG). We discuss controversies around TMS-EEG stemming from the multiple large off-target components (noise) and relatively weak genuine brain responses (signal), as is unfortunately often the case in noninvasive human neuroscience. We review the current state of TMS-EEG recordings, which consist of a mix of reliable noise and unreliable signal. We describe methods for evaluating TMS-EEG biomarkers, including how to assess internal and external reliability across facilities, cognitive states, brain networks, and disorders and how to validate these biomarkers using invasive neural recordings or treatment response. We provide recommendations to increase reliability and validity, discuss lessons learned, and suggest future directions for the field. © 2022}, keywords = {Reliability; VALIDITY; Electroencephalography (EEG); Transcranial magnetic stimulation (TMS); TMS-EEG; Transcranial magnetic stimulation–evoked potentials (TEP)}, year = {2023}, eissn = {2451-9030}, pages = {In press} } @article{MTMT:34132462, title = {Brain network communication: concepts, models and applications}, url = {https://m2.mtmt.hu/api/publication/34132462}, author = {Seguin, Caio and Sporns, Olaf and Zalesky, Andrew}, doi = {10.1038/s41583-023-00718-5}, journal-iso = {NAT REV NEUROSCI}, journal = {NATURE REVIEWS NEUROSCIENCE}, volume = {24}, unique-id = {34132462}, issn = {1471-003X}, abstract = {Developments in connectomics and network neuroscience over the past 20 years have led to new ways of investigating communication in complex brain networks. In this Review, Seguin, Sporns and Zalesky discuss the current landscape of models of brain network communication. Understanding communication and information processing in nervous systems is a central goal of neuroscience. Over the past two decades, advances in connectomics and network neuroscience have opened new avenues for investigating polysynaptic communication in complex brain networks. Recent work has brought into question the mainstay assumption that connectome signalling occurs exclusively via shortest paths, resulting in a sprawling constellation of alternative network communication models. This Review surveys the latest developments in models of brain network communication. We begin by drawing a conceptual link between the mathematics of graph theory and biological aspects of neural signalling such as transmission delays and metabolic cost. We organize key network communication models and measures into a taxonomy, aimed at helping researchers navigate the growing number of concepts and methods in the literature. The taxonomy highlights the pros, cons and interpretations of different conceptualizations of connectome signalling. We showcase the utility of network communication models as a flexible, interpretable and tractable framework to study brain function by reviewing prominent applications in basic, cognitive and clinical neurosciences. Finally, we provide recommendations to guide the future development, application and validation of network communication models.}, keywords = {ORGANIZATION; DYNAMICS; PROPAGATION; Robustness; SMALL-WORLD; INFORMATION-FLOW; resting-state; STATE FUNCTIONAL CONNECTIVITY; connectomics}, year = {2023}, eissn = {1471-0048}, pages = {557-574}, orcid-numbers = {Seguin, Caio/0000-0001-9384-6336} } @article{MTMT:34227756, title = {Signatures of Electrical Stimulation Driven Network Interactions in the Human Limbic System}, url = {https://m2.mtmt.hu/api/publication/34227756}, author = {Valencia, G.O. and Gregg, N.M. and Huang, H. and Lundstrom, B.N. and Brinkmann, B.H. and Attia, T.P. and Van, Gompel J.J. and Bernstein, M.A. and In, M.-H. and Huston, J. III and Worrell, G.A. and Miller, K.J. and Hermes, D.}, doi = {10.1523/JNEUROSCI.2201-22.2023}, journal-iso = {J NEUROSCI}, journal = {JOURNAL OF NEUROSCIENCE}, volume = {43}, unique-id = {34227756}, issn = {0270-6474}, year = {2023}, eissn = {1529-2401}, pages = {6697-6711} } @article{MTMT:34225839, title = {Human anterior thalamic stimulation evoked cortical potentials align with intrinsic functional connectivity}, url = {https://m2.mtmt.hu/api/publication/34225839}, author = {Wu, D. and Schaper, F.L.W.V.J. and Jin, G. and Qi, L. and Du, J. and Wang, X. and Wang, Y. and Xu, C. and Wang, X. and Yu, T. and Fox, M.D. and Ren, L.}, doi = {10.1016/j.neuroimage.2023.120243}, journal-iso = {NEUROIMAGE}, journal = {NEUROIMAGE}, volume = {277}, unique-id = {34225839}, issn = {1053-8119}, year = {2023}, eissn = {1095-9572} } @article{MTMT:34610439, title = {Single-pulse electrical stimulation artifact removal using the novel matching pursuit-based artifact reconstruction and removal method (MPARRM)}, url = {https://m2.mtmt.hu/api/publication/34610439}, author = {Xie, Tao and Foutz, Thomas J. and Adamek, Markus and Swift, James R. and Inman, Cory S. and Manns, Joseph R. and Leuthardt, Eric C. and Willie, Jon T. and Brunner, Peter}, doi = {10.1088/1741-2552/ad1385}, journal-iso = {J NEURAL ENG}, journal = {JOURNAL OF NEURAL ENGINEERING}, volume = {20}, unique-id = {34610439}, issn = {1741-2560}, abstract = {Objective. Single-pulse electrical stimulation (SPES) has been widely used to probe effective connectivity. However, analysis of the neural response is often confounded by stimulation artifacts. We developed a novel matching pursuit-based artifact reconstruction and removal method (MPARRM) capable of removing artifacts from stimulation-artifact-affected electrophysiological signals. Approach. To validate MPARRM across a wide range of potential stimulation artifact types, we performed a bench-top experiment in which we suspended electrodes in a saline solution to generate 110 types of real-world stimulation artifacts. We then added the generated stimulation artifacts to ground truth signals (stereoelectroencephalography signals from nine human subjects recorded during a receptive speech task), applied MPARRM to the combined signal, and compared the resultant denoised signal with the ground truth signal. We further applied MPARRM to artifact-affected neural signals recorded from the hippocampus while performing SPES on the ipsilateral basolateral amygdala in nine human subjects. Main results. MPARRM could remove stimulation artifacts without introducing spectral leakage or temporal spread. It accommodated variable stimulation parameters and recovered the early response to SPES within a wide range of frequency bands. Specifically, in the early response period (5-10 ms following stimulation onset), we found that the broadband gamma power (70-170 Hz) of the denoised signal was highly correlated with the ground truth signal ( R=0.98 +/- 0.02 , Pearson), and the broadband gamma activity of the denoised signal faithfully revealed the responses to the auditory stimuli within the ground truth signal with 94%+/- 1.47% sensitivity and 99%+/- 1.01% specificity. We further found that MPARRM could reveal the expected temporal progression of broadband gamma activity along the anterior-posterior axis of the hippocampus in response to the ipsilateral amygdala stimulation. Significance. MPARRM could faithfully remove SPES artifacts without confounding the electrophysiological signal components, especially during the early-response period. This method can facilitate the understanding of the neural response mechanisms of SPES.}, keywords = {Matching pursuit; Early response; CCEP; CCSR; single-pulse electrical stimulation; broadband gamma; stimulation artifact removal}, year = {2023}, eissn = {1741-2552} } @inproceedings{MTMT:34227766, title = {Difference in Network Effects of Pulsatile and Galvanic Stimulation}, url = {https://m2.mtmt.hu/api/publication/34227766}, author = {Adkisson, P. and Fridman, G.Y. and Steinhardt, C.R.}, booktitle = {2022 44th Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC)}, doi = {10.1109/EMBC48229.2022.9871812}, volume = {2022-July}, unique-id = {34227766}, year = {2022}, pages = {3093-3099} } @article{MTMT:33001901, title = {Anesthetic modulations dissociate neuroelectric characteristics between sensory-evoked and spontaneous activities across bilateral rat somatosensory cortical laminae}, url = {https://m2.mtmt.hu/api/publication/33001901}, author = {Baek, Kwangyeol and Park, Chae Ri and Jang, Siwan and Shim, Woo Hyun and Kim, Young Ro}, doi = {10.1038/s41598-022-13759-0}, journal-iso = {SCI REP}, journal = {SCIENTIFIC REPORTS}, volume = {12}, unique-id = {33001901}, issn = {2045-2322}, year = {2022}, eissn = {2045-2322} } @article{MTMT:33007471, title = {Functional connectivity and epileptogenicity of nodular heterotopias: A single-pulse stimulation study}, url = {https://m2.mtmt.hu/api/publication/33007471}, author = {Boulogne, Sebastien and Pizzo, Francesca and Chatard, Benoit and Roehri, Nicolas and Catenoix, Helene and Ostrowsky-Coste, Karine and Giusiano, Bernard and Guenot, Marc and Carron, Romain and Bartolomei, Fabrice and Rheims, Sylvain}, doi = {10.1111/epi.17168}, journal-iso = {EPILEPSIA}, journal = {EPILEPSIA}, volume = {63}, unique-id = {33007471}, issn = {0013-9580}, abstract = {Objective Nodular heterotopias (NHs) are malformations of cortical development associated with drug-resistant focal epilepsy with frequent poor surgical outcome. The epileptogenic network is complex and can involve the nodule, the overlying cortex, or both. Single-pulse electrical stimulation (SPES) during stereo-electroencephalography (SEEG) allows the investigation of functional connectivity between the stimulated and responsive cortices by eliciting cortico-cortical evoked potentials (CCEPs). We used SPES to analyze the NH connectome and its relation to the epileptogenic network organization. Methods We retrospectively studied 12 patients with NH who underwent 1 Hz or 0.2 Hz SPES of NH during SEEG. Outbound connectivity (regions where CCEPs were elicited by NH stimulation) and inbound connectivity (regions where stimulation elicited CCEPs in the NH) were searched. SEEG channels were then classified as "heterotopic" (located within the NH), "connected" (located in normotopic cortex and showing connectivity with the NH), and "unconnected." We used the epileptogenicity index (EI) to quantify implication of channels in the seizure-onset zone and to classify seizures as heterotopic, normotopic, and normo-heterotopic. Results One hundred thirty-five outbound and 72 inbound connections were found. Three patients showed connectivity between hippocampus and NH, and seven patients showed strong internodular connectivity. A total of 39 seizures were analyzed: 23 normo-heterotopic, 12 normotopic, and 4 heterotopic. Logistic regression found that "connected" channels were significantly (p = 8.4e-05) more likely to be epileptogenic than "unconnected" channels (odds ratio 4.71, 95% confidence interval (CI) [2.17, 10.21]) and heterotopic channels were also significantly (p = .024) more epileptogenic than "unconnected" channels (odds ratio 3.29, 95% CI [1.17, 9.23]). Significance SPES reveals widespread connectivity between NH and normotopic regions. Those connected regions show higher epileptogenicity. SPES might be useful to assess NH epileptogenic network.}, keywords = {EPILEPSY; functional connectivity; Cortico-cortical evoked potentials; Nodular heterotopia; epileptogenicity}, year = {2022}, eissn = {1528-1167}, pages = {961-973}, orcid-numbers = {Pizzo, Francesca/0000-0001-6345-1288; Roehri, Nicolas/0000-0002-6948-1055} } @article{MTMT:33007467, title = {Network connectivity predicts effectiveness of responsive neurostimulation in focal epilepsy}, url = {https://m2.mtmt.hu/api/publication/33007467}, author = {Fan, Joline M. and Lee, Anthony T. and Kudo, Kiwamu and Ranasinghe, Kamalini G. and Morise, Hirofumi and Findlay, Anne M. and Kirsch, Heidi E. and Chang, Edward F. and Nagarajan, Srikantan S. and Rao, Vikram R.}, doi = {10.1093/braincomms/fcac104}, journal-iso = {BRAIN COMMUN}, journal = {BRAIN COMMUNICATIONS}, volume = {4}, unique-id = {33007467}, abstract = {Responsive neurostimulation is a promising treatment for drug-resistant focal epilepsy; however, clinical outcomes are highly variable across individuals. The therapeutic mechanism of responsive neurostimulation likely involves modulatory effects on brain networks; however, with no known biomarkers that predict clinical response, patient selection remains empiric. This study aimed to determine whether functional brain connectivity measured non-invasively prior to device implantation predicts clinical response to responsive neurostimulation therapy. Resting-state magnetoencephalography was obtained in 31 participants with subsequent responsive neurostimulation device implantation between 15 August 2014 and 1 October 2020. Functional connectivity was computed across multiple spatial scales (global, hemispheric, and lobar) using pre-implantation magnetoencephalography and normalized to maps of healthy controls. Normalized functional connectivity was investigated as a predictor of clinical response, defined as percent change in self-reported seizure frequency in the most recent year of clinic visits relative to pre-responsive neurostimulation baseline. Area under the receiver operating characteristic curve quantified the performance of functional connectivity in predicting responders (>= 50% reduction in seizure frequency) and non-responders (<50%). Leave-one-out cross-validation was furthermore performed to characterize model performance. The relationship between seizure frequency reduction and frequency-specific functional connectivity was further assessed as a continuous measure. Across participants, stimulation was enabled for a median duration of 52.2 (interquartile range, 27.0-62.3) months. Demographics, seizure characteristics, and responsive neurostimulation lead configurations were matched across 22 responders and 9 non-responders. Global functional connectivity in the alpha and beta bands were lower in non-responders as compared with responders (alpha, p(fdr) < 0.001; beta, p(fdr) < 0.001). The classification of responsive neurostimulation outcome was improved by combining feature inputs; the best model incorporated four features (i.e. mean and dispersion of alpha and beta bands) and yielded an area under the receiver operating characteristic curve of 0.970 (0.919-1.00). The leave-one-out cross-validation analysis of this four-feature model yielded a sensitivity of 86.3%, specificity of 77.8%, positive predictive value of 90.5%, and negative predictive value of 70%. Global functional connectivity in alpha band correlated with seizure frequency reduction (alpha, P = 0.010). Global functional connectivity predicted responder status more strongly, as compared with hemispheric predictors. Lobar functional connectivity was not a predictor. These findings suggest that non-invasive functional connectivity may be a candidate personalized biomarker that has the potential to predict responsive neurostimulation effectiveness and to identify patients most likely to benefit from responsive neurostimulation therapy. Follow-up large-cohort, prospective studies are required to validate this biomarker. These findings furthermore support an emerging view that the therapeutic mechanism of responsive neurostimulation involves network-level effects in the brain.To prognosticate outcomes with neurostimulation for epilepsy, Fan et al. investigate functional network connectivity measured non-invasively with magnetoencephalography as a novel biomarker for effectiveness of responsive neurostimulation (RNS) therapy. Resting-state functional connectivity in alpha and beta frequency bands predicted response to subsequent RNS therapy and correlated with seizure frequency reduction.}, keywords = {neuromodulation; functional connectivity; magnetoencephalography; Imaginary Coherence; RNS system}, year = {2022}, eissn = {2632-1297} } @article{MTMT:33007469, title = {A brain atlas of axonal and synaptic delays based on modelling of cortico-cortical evoked potentials}, url = {https://m2.mtmt.hu/api/publication/33007469}, author = {Lemarechal, Jean-Didier and Jedynak, Maciej and Trebaul, Lena and Boyer, Anthony and Tadel, Francois and Bhattacharjee, Manik and Deman, Pierre and Tuyisenge, Viateur and Ayoubian, Leila and Hugues, Etienne and Chanteloup-Foret, Blandine and Saubat, Carole and Zouglech, Raouf and Mejia, Gina Catalina Reyes and Tourbier, Sebastien and Hagmann, Patric and Adam, Claude and Barba, Carmen and Bartolomei, Fabrice and Blauwblomme, Thomas and Curot, Jonathan and Dubeau, Francois and Francione, Stefano and Garces, Mercedes and Hirsch, Edouard and Landre, Elizabeth and Liu, Sinclair and Maillard, Louis and Metsahonkala, Eeva-Liisa and Mindruta, Ioana and Nica, Anca and Pail, Martin and Petrescu, Ana Maria and Rheims, Sylvain and Rocamora, Rodrigo and Schulze-Bonhage, Andreas and Szurhaj, William and Taussig, Delphine and Valentin, Antonio and Wang, Haixiang and Kahane, Philippe and George, Nathalie and David, Olivier}, doi = {10.1093/brain/awab362}, journal-iso = {BRAIN}, journal = {BRAIN}, volume = {145}, unique-id = {33007469}, issn = {0006-8950}, abstract = {Epilepsy presurgical investigation may include focal intracortical single-pulse electrical stimulations with depth electrodes, which induce cortico-cortical evoked potentials at distant sites because of white matter connectivity. Cortico-cortical evoked potentials provide a unique window on functional brain networks because they contain sufficient information to infer dynamical properties of large-scale brain connectivity, such as preferred directionality and propagation latencies. Here, we developed a biologically informed modelling approach to estimate the neural physiological parameters of brain functional networks from the cortico-cortical evoked potentials recorded in a large multicentric database. Specifically, we considered each cortico-cortical evoked potential as the output of a transient stimulus entering the stimulated region, which directly propagated to the recording region. Both regions were modelled as coupled neural mass models, the parameters of which were estimated from the first cortico-cortical evoked potential component, occurring before 80 ms, using dynamic causal modelling and Bayesian model inversion. This methodology was applied to the data of 780 patients with epilepsy from the F-TRACT database, providing a total of 34 354 bipolar stimulations and 774 445 cortico-cortical evoked potentials. The cortical mapping of the local excitatory and inhibitory synaptic time constants and of the axonal conduction delays between cortical regions was obtained at the population level using anatomy-based averaging procedures, based on the Lausanne2008 and the HCP-MMP1 parcellation schemes, containing 130 and 360 parcels, respectively. To rule out brain maturation effects, a separate analysis was performed for older (>15 years) and younger patients (<15 years). In the group of older subjects, we found that the cortico-cortical axonal conduction delays between parcels were globally short (median = 10.2 ms) and only 16% were larger than 20 ms. This was associated to a median velocity of 3.9 m/s. Although a general lengthening of these delays with the distance between the stimulating and recording contacts was observed across the cortex, some regions were less affected by this rule, such as the insula for which almost all efferent and afferent connections were faster than 10 ms. Synaptic time constants were found to be shorter in the sensorimotor, medial occipital and latero-temporal regions, than in other cortical areas. Finally, we found that axonal conduction delays were significantly larger in the group of subjects younger than 15 years, which corroborates that brain maturation increases the speed of brain dynamics. To our knowledge, this study is the first to provide a local estimation of axonal conduction delays and synaptic time constants across the whole human cortex in vivo, based on intracerebral electrophysiological recordings.}, keywords = {Cortico-cortical evoked potential; Dynamic causal modelling; Neural mass models; axonal conduction delay; synaptic time constant}, year = {2022}, eissn = {1460-2156}, pages = {1653-1667}, orcid-numbers = {Jedynak, Maciej/0000-0003-1876-5485; David, Olivier/0000-0003-0776-0216} } @article{MTMT:33231072, title = {Distinct roles of theta and gamma rhythms in inter-areal interaction in human visual cortex revealed by cortico-cortical evoked potentials}, url = {https://m2.mtmt.hu/api/publication/33231072}, author = {Luo, Lu and Chen, Guanpeng and Li, Siqi and Wang, Jing and Wang, Qian and Fang, Fang}, doi = {10.1016/j.brs.2022.07.056}, journal-iso = {BRAIN STIMUL}, journal = {BRAIN STIMULATION}, volume = {15}, unique-id = {33231072}, issn = {1935-861X}, year = {2022}, eissn = {1876-4754}, pages = {1048-1050}, orcid-numbers = {Luo, Lu/0000-0002-7223-4143} } @article{MTMT:33167383, title = {Advances in human intracranial electroencephalography research, guidelines and good practices}, url = {https://m2.mtmt.hu/api/publication/33167383}, author = {Mercier, Manuel R. and Dubarry, Anne-Sophie and Tadel, Francois and Avanzini, Pietro and Axmacher, Nikolai and Cellier, Dillan and Del Vecchio, Maria and Hamilton, Liberty S. and Hermes, Dora and Kahana, Michael J. and Knight, Robert T. and Llorens, Anais and Megevand, Pierre and Melloni, Lucia and Miller, Kai J. and Piai, Vitoria and Puce, Aina and Ramsey, Nick F. and Schwiedrzik, Caspar M. and Smith, Sydney E. and Stolk, Arjen and Swann, Nicole C. and Vansteensel, Mariska J. and Voytek, Bradley and Wang, Liang and Lachaux, Jean-Philippe and Oostenveld, Robert}, doi = {10.1016/j.neuroimage.2022.119438}, journal-iso = {NEUROIMAGE}, journal = {NEUROIMAGE}, volume = {260}, unique-id = {33167383}, issn = {1053-8119}, abstract = {Since the second-half of the twentieth century, intracranial electroencephalography (iEEG), including both electrocorticography (ECoG) and stereo-electroencephalography (sEEG), has provided an intimate view into the human brain. M the interface between fundamental research and the clinic, iEEG provides both high temporal resolution and high spatial specificity but comes with constraints, such as the individual's tailored sparsity of electrode sampling. Over the years, researchers in neuroscience developed their practices to make the most of the iEEG approach. Here we offer a critical review of iEEG research practices in a didactic framework for newcomers, as well addressing issues encountered by proficient researchers. The scope is threefold: (i) review common practices in iEEG research, (H) suggest potential guidelines for working with iEEG data and answer frequently asked questions based on the most widespread practices, and (Hi) based on current neurophysiological knowledge and methodologies, pave the way to good practice standards in iEEG research. The organization of this paper follows the steps of iEEG data processing. The first section contextualizes iEEG data collection. The second section focuses on localization of intracranial electrodes. The third section highlights the main pre-processing steps. The fourth section presents iEEG signal analysis methods. The fifth section discusses statistical approaches. The sixth section draws some unique perspectives on iEEG research. Finally, to ensure a consistent nomenclature throughout the manuscript and to align with other guidelines, e.g., Brain Imaging Data Structure (BIDS) and the OHBM Committee on Best Practices in Data Analysis and Sharing (COBIDAS), we provide a glossary to disambiguate terms related to iEEG research.}, keywords = {ECoG; Electrocorticogram; event-related potentials; neuroimaging; time-frequency analysis; Neurosciences; DEEP-BRAIN-STIMULATION; stereotactic electroencephalography; SEEG; HUMAN SENSORIMOTOR CORTEX; Intracranial recording in humans; Good research practice; PULSE ELECTRICAL-STIMULATION; GUIDED RADIOFREQUENCY THERMOCOAGULATION; ELECTROCORTICOGRAPHIC SPECTRAL-ANALYSIS; MULTIVARIATE PATTERN-ANALYSIS; RESISTANT FOCAL EPILEPSY}, year = {2022}, eissn = {1095-9572}, orcid-numbers = {Mercier, Manuel R./0000-0001-6358-4734; Dubarry, Anne-Sophie/0000-0002-6096-4835; Tadel, Francois/0000-0001-5726-7126; Hermes, Dora/0000-0002-8683-8909; Piai, Vitoria/0000-0002-4860-5952} } @article{MTMT:33231077, title = {Movement-dependent electrical stimulation for volitional strengthening of cortical connections in behaving monkeys}, url = {https://m2.mtmt.hu/api/publication/33231077}, author = {Moorjani, Samira and Walvekar, Sarita and Fetz, Eberhard E. and Perlmutter, Steve I}, doi = {10.1073/pnas.2116321119}, journal-iso = {P NATL ACAD SCI USA}, journal = {PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, volume = {119}, unique-id = {33231077}, issn = {0027-8424}, abstract = {Correlated activity of neurons can lead to long-term strengthening or weakening of the connections between them. In addition, the behavioral context, imparted by execution of physical movements or the presence of a reward, can modulate the plasticity induced by Hebbian mechanisms. In the present study, we have combined behavior and induced neuronal correlations to strengthen connections in the motor cortex of adult behaving monkeys. Correlated activity was induced using an electrical-conditioning protocol in which stimuli gated by voluntary movements were used to produce coactivation of neurons at motor-cortical sites involved in those movements. Delivery of movement-dependent stimulation resulted in small increases in the strength of associated cortical connections immediately after conditioning. Remarkably, when paired with further repetition of the movements that gated the conditioning stimuli, there were substantially larger gains in the strength of cortical connections, which occurred in a use-dependent manner, without delivery of additional conditioning stimulation. In the absence of such movements, little change was observed in the strength of motor-cortical connections. Performance of the motor behavior in the absence of conditioning also did not produce any changes in connectivity. Our results show that combining movement-gated stimulation with further natural use of the "conditioned" pathways after stimulation ends can produce use-dependent strengthening of connections in adult primates, highlighting an important role for behavior in cortical plasticity. Our data also provide strong support for combining movement-gated stimulation with use-dependent physical rehabilitation for strengthening connections weakened by a stroke or spinal cord injury.}, keywords = {BEHAVIOR; Movement; USE-DEPENDENT PLASTICITY; Cortical plasticity; electrical conditioning}, year = {2022}, eissn = {1091-6490}, orcid-numbers = {Moorjani, Samira/0000-0002-1812-121X} } @article{MTMT:32961414, title = {Simultaneous stereo-EEG and high-density scalp EEG recordings to study the effects of intracerebral stimulation parameters}, url = {https://m2.mtmt.hu/api/publication/32961414}, author = {Parmigiani, S. and Mikulan, E. and Russo, S. and Sarasso, S. and Zauli, F. M. and Rubino, A. and Cattani, A. and Fecchio, M. and Giampiccolo, D. and Lanzone, J. and D'Orio, P. and Del Vecchio, M. and Avanzini, P. and Nobili, L. and Sartori, I and Massimini, M. and Pigorini, A.}, doi = {10.1016/j.brs.2022.04.007}, journal-iso = {BRAIN STIMUL}, journal = {BRAIN STIMULATION}, volume = {15}, unique-id = {32961414}, issn = {1935-861X}, abstract = {Background: Cortico-cortical evoked potentials (CCEPs) recorded by stereo-electroencephalography (SEEG) are a valuable tool to investigate brain reactivity and effective connectivity. However, invasive recordings are spatially sparse since they depend on clinical needs. This sparsity hampers systematic comparisons across-subjects, the detection of the whole-brain effects of intracortical stimulation, as well as their relationships to the EEG responses evoked by non-invasive stimuli. Objective: To demonstrate that CCEPs recorded by high-density electroencephalography (hd-EEG) provide additional information with respect SEEG alone and to provide an open, curated dataset to allow for further exploration of their potential. Methods: The dataset encompasses SEEG and hd-EEG recordings simultaneously acquired during Single Pulse Electrical Stimulation (SPES) in drug-resistant epileptic patients (N 1/4 36) in whom stimulations were delivered with different physical, geometrical, and topological parameters. Differences in CCEPs were assessed by amplitude, latency, and spectral measures. Results: While invasively and non-invasively recorded CCEPs were generally correlated, differences in pulse duration, angle and stimulated cortical area were better captured by hd-EEG. Further, intracranial stimulation evoked site-specific hd-EEG responses that reproduced the spectral features of EEG responses to transcranial magnetic stimulation (TMS). Notably, SPES, albeit unperceived by subjects, elicited scalp responses that were up to one order of magnitude larger than the responses typically evoked by sensory stimulation in awake humans. Conclusions: CCEPs can be simultaneously recorded with SEEG and hd-EEG and the latter provides a reliable descriptor of the effects of SPES as well as a common reference to compare the whole-brain}, keywords = {single pulse electrical stimulation; CCEP; stereo-EEG; Stimulation parameters; scalp hd-EEG}, year = {2022}, eissn = {1876-4754}, pages = {664-675} } @article{MTMT:33007466, title = {Complex negative emotions induced by electrical stimulation of the human hypothalamus}, url = {https://m2.mtmt.hu/api/publication/33007466}, author = {Parvizi, Josef and Veit, Michael J. and Barbosa, Daniel A. N. and Kucyi, Aaron and Perry, Claire and Parker, Jonathon J. and Shivacharan, Rajat S. and Chen, Fengyixuan and Yih, Jennifer and Gross, James J. and Fisher, Robert and McNab, Jennifer A. and Falco-Walter, Jessica and Halpern, Casey H.}, doi = {10.1016/j.brs.2022.04.008}, journal-iso = {BRAIN STIMUL}, journal = {BRAIN STIMULATION}, volume = {15}, unique-id = {33007466}, issn = {1935-861X}, abstract = {Background: Stimulation of the ventromedial hypothalamic region in animals has been reported to cause attack behavior labeled as sham-rage without offering information about the internal affective state of the animal being stimulated. Objective: To examine the causal effect of electrical stimulation near the ventromedial region of the human hypothalamus on the human subjective experience and map the electrophysiological connectivity of the hypothalamus with other brain regions. Methods: We examined a patient (Subject S20_150) with intracranial electrodes implanted across 170 brain regions, including the hypothalamus. We combined direct electrical stimulation with tractography, cortico-cortical evoked potentials (CCEP), and functional connectivity using resting state intracranial electroencephalography (EEG). Results: Recordings in the hypothalamus did not reveal any epileptic abnormalities. Electrical stimulations near the ventromedial hypothalamus induced profound shame, sadness, and fear but not rage or anger. When repeated single-pulse stimulations were delivered to the hypothalamus, significant responses were evoked in the amygdala, hippocampus, ventromedial-prefrontal and orbitofrontal cortices, anterior cingulate, as well as ventral-anterior and dorsal-posterior insula. The time to first peak of these evoked responses varied and earliest propagations correlated best with the measures of resting-state EEG connectivity and structural connectivity. Conclusion: This patient's case offers details about the affective state induced by the stimulation of the human hypothalamus and provides causal evidence relevant to current theories of emotion. The complexity of affective state induced by the stimulation of the hypothalamus and the profile of hypothalamic electrophysiological connectivity suggest that the hypothalamus and its connected structures ought to be seen as causally important for human affective experience. (c) 2022 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).}, keywords = {DEPRESSION; EEG; affect; emotion; FEELINGS; subjectivity; Hypothalamic nuclei; VMH nucleus of hypothalamus}, year = {2022}, eissn = {1876-4754}, pages = {615-623}, orcid-numbers = {Perry, Claire/0000-0002-9324-0518; Fisher, Robert/0000-0003-0287-613X} } @article{MTMT:33006199, title = {Improved speech hearing in noise with invasive electrical brain stimulation}, url = {https://m2.mtmt.hu/api/publication/33006199}, author = {Patel, Prachi and Khalijhinejad, Bahar and Herrero, Jose L. and Bickel, Stephan and Mehta, Ashesh D. and Mesgarani, Nima}, doi = {10.1523/JNEUROSCI.1468-21.2022}, journal-iso = {J NEUROSCI}, journal = {JOURNAL OF NEUROSCIENCE}, volume = {42}, unique-id = {33006199}, issn = {0270-6474}, abstract = {Speech perception in noise is a challenging everyday task with which many listeners have difficulty. Here, we report a case in which electrical brain stimulation of implanted intracranial electrodes in the left planum temporale (PT) of a neurosurgical patient significantly and reliably improved subjectivequality (up to 50%) and objective intelligibility (up to 97%) of speech in noise perception. Stimulation resulted in a selective enhancement of speech sounds compared to the background noises. Thereceptive fields of the PT sites whose stimulation improved speech perception were tuned to spectrally broad and rapidly changing sounds. Corticocortical evoked potential analysis revealed that the PT sites were located between the sites in Heschl's gyrus (HG) and the superior temporal gyrus (STG). Moreover, the discriminability of speech from nonspeech sounds increased in population neural responses from HG to the PT to the STG sites. These findings causally implicate the PT in background noise suppression and may point to a novel potential neuroprosthetic solution to assist in the challenging task of speech perception in noise.SignificanceSpeech perception in noise remains a challenging task for many individuals. Here, we present a case in which the electrical brain stimulation of intracranially implanted electrodes in the planum temporale of a neurosurgical patient significantly improved both the subjective quality (up to 50%) and objective intelligibility (up to 97%) of speech perception in noise. Stimulation resulted in a selective enhancement of speech sounds compared to the background noises. Our local and network-level functional analyses placed the planum temporale sites in between the sites in the primary auditory areas in Heschl's gyrus and nonprimary auditory areas in the superior temporal gyrus. These findings causally implicate planum temporale in acoustic scene analysis and suggest potential neuroprosthetic applications to assist hearing in noise.}, keywords = {auditory cortex; human electrophysiology}, year = {2022}, eissn = {1529-2401} } @article{MTMT:33006200, title = {Local and distant cortical responses to single pulse intracranial stimulation in the human brain are differentially modulated by specific stimulation parameters}, url = {https://m2.mtmt.hu/api/publication/33006200}, author = {Paulk, Angelique C. and Zelmann, Rina and Crocker, Britni and Widge, Alik S. and Dougherty, Darin D. and Eskandar, Emad N. and Weisholtz, Daniel S. and Richardson, R. Mark and Cosgrove, G. Rees and Williams, Ziv M. and Cash, Sydney S.}, doi = {10.1016/j.brs.2022.02.017}, journal-iso = {BRAIN STIMUL}, journal = {BRAIN STIMULATION}, volume = {15}, unique-id = {33006200}, issn = {1935-861X}, abstract = {Background: Electrical neuromodulation via direct electrical stimulation (DES) is an increasingly common therapy for a wide variety of neuropsychiatric diseases. Unfortunately, therapeutic efficacy is inconsistent, likely due to our limited understanding of the relationship between the massive stimulation parameter space and brain tissue responses.Objective: To better understand how different parameters induce varied neural responses, we systematically examined single pulse-induced cortico-cortico evoked potentials (CCEP) as a function of stimulation amplitude, duration, brain region, and whether grey or white matter was stimulated.Methods: We measured voltage peak amplitudes and area under the curve (AUC) of intracranially recorded stimulation responses as a function of distance from the stimulation site, pulse width, current injected, location relative to grey and white matter, and brain region stimulated (N = 52, n = 719 stimulation sites).Results: Increasing stimulation pulse width increased responses near the stimulation location. Increasing stimulation amplitude (current) increased both evoked amplitudes and AUC nonlinearly. Locally (<15 mm), stimulation at the boundary between grey and white matter induced larger responses. In contrast, for distant sites (>15 mm), white matter stimulation consistently produced larger responses than stimulation in or near grey matter. The stimulation location-response curves followed different trends for cingulate, lateral frontal, and lateral temporal cortical stimulation.Conclusion: These results demonstrate that a stronger local response may require stimulation in the grey-white boundary while stimulation in the white matter could be needed for network activation. Thus, stimulation parameters tailored for a specific anatomical-functional outcome may be key to advancing neuromodulatory therapy. (C) 2022 The Authors. Published by Elsevier Inc.}, keywords = {CORTEX; human; white matter; nonlinear; single pulse electrical stimulation}, year = {2022}, eissn = {1876-4754}, pages = {491-508} } @article{MTMT:34227767, title = {Lesion-Behavior Awake Mapping with Direct Cortical and Subcortical Stimulation}, url = {https://m2.mtmt.hu/api/publication/34227767}, author = {Ries, S.K. and Jordan, K. and Knight, R.T. and Berger, M.}, doi = {10.1007/978-1-0716-2225-4_14}, journal-iso = {NEUROMETHODS}, journal = {NEUROMETHODS}, volume = {180}, unique-id = {34227767}, issn = {0893-2336}, year = {2022}, eissn = {1940-6045}, pages = {257-270} } @article{MTMT:33231075, title = {Mapping effective connectivity of human amygdala subdivisions with intracranial stimulation}, url = {https://m2.mtmt.hu/api/publication/33231075}, author = {Sawada, Masahiro and Adolphs, Ralph and Dlouhy, Brian J. and Jenison, Rick L. and Rhone, Ariane E. and Kovach, Christopher K. and Greenlee, Jeremy D. W. and Howard, Matthew A. III and Oya, Hiroyuki}, doi = {10.1038/s41467-022-32644-y}, journal-iso = {NAT COMMUN}, journal = {NATURE COMMUNICATIONS}, volume = {13}, unique-id = {33231075}, issn = {2041-1723}, abstract = {The amygdala is known to be engaged in emotional and autonomic function, yet the detailed functional connectivity of the human amygdala remains unclear. Here, the authors examine effective connectivity in the amygdala of patients with epilepsy using direct focal electrical stimulation.The primate amygdala is a complex consisting of over a dozen nuclei that have been implicated in a host of cognitive functions, individual differences, and psychiatric illnesses. These functions are implemented through distinct connectivity profiles, which have been documented in animals but remain largely unknown in humans. Here we present results from 25 neurosurgical patients who had concurrent electrical stimulation of the amygdala with intracranial electroencephalography (electrical stimulation tract-tracing; es-TT), or fMRI (electrical stimulation fMRI; es-fMRI), methods providing strong inferences about effective connectivity of amygdala subdivisions with the rest of the brain. We quantified functional connectivity with medial and lateral amygdala, the temporal order of these connections on the timescale of milliseconds, and also detail second-order effective connectivity among the key nodes. These findings provide a uniquely detailed characterization of human amygdala functional connectivity that will inform functional neuroimaging studies in healthy and clinical populations.}, year = {2022}, eissn = {2041-1723}, orcid-numbers = {Adolphs, Ralph/0000-0002-8053-9692; Oya, Hiroyuki/0000-0002-1733-5478} } @article{MTMT:33007472, title = {Intracranial electroencephalographic biomarker predicts effective responsive neurostimulation for epilepsy prior to treatment}, url = {https://m2.mtmt.hu/api/publication/33007472}, author = {Scheid, Brittany H. and Bernabei, John M. and Khambhati, Ankit N. and Mouchtaris, Sofia and Jeschke, Jay and Bassett, Dani S. and Becker, Danielle and Davis, Kathryn A. and Lucas, Timothy and Doyle, Werner and Chang, Edward F. and Friedman, Daniel and Rao, Vikram R. and Litt, Brian}, doi = {10.1111/epi.17163}, journal-iso = {EPILEPSIA}, journal = {EPILEPSIA}, volume = {63}, unique-id = {33007472}, issn = {0013-9580}, abstract = {Objective Despite the overall success of responsive neurostimulation (RNS) therapy for drug-resistant focal epilepsy, clinical outcomes in individuals vary significantly and are hard to predict. Biomarkers that indicate the clinical efficacy of RNS-ideally before device implantation-are critically needed, but challenges include the intrinsic heterogeneity of the RNS patient population and variability in clinical management across epilepsy centers. The aim of this study is to use a multicenter dataset to evaluate a candidate biomarker from intracranial electroencephalographic (iEEG) recordings that predicts clinical outcome with subsequent RNS therapy. Methods We assembled a federated dataset of iEEG recordings, collected prior to RNS implantation, from a retrospective cohort of 30 patients across three major epilepsy centers. Using ictal iEEG recordings, each center independently calculated network synchronizability, a candidate biomarker indicating the susceptibility of epileptic brain networks to RNS therapy. Results Ictal measures of synchronizability in the high-gamma band (95-105 Hz) significantly distinguish between good and poor RNS responders after at least 3 years of therapy under the current RNS therapy guidelines (area under the curve = .83). Additionally, ictal high-gamma synchronizability is inversely associated with the degree of therapeutic response. Significance This study provides a proof-of-concept roadmap for collaborative biomarker evaluation in federated data, where practical considerations impede full data sharing across centers. Our results suggest that network synchronizability can help predict therapeutic response to RNS therapy. With further validation, this biomarker could facilitate patient selection and help avert a costly, invasive intervention in patients who are unlikely to benefit.}, keywords = {MULTICENTER; neuromodulation; functional connectivity; network neuroscience; Synchronizability}, year = {2022}, eissn = {1528-1167}, pages = {652-662}, orcid-numbers = {Mouchtaris, Sofia/0000-0002-6095-4549; Becker, Danielle/0000-0002-4792-8055} } @article{MTMT:33167384, title = {Time-frequency signatures evoked by single-pulse deep brain stimulation to the subcallosal cingulate}, url = {https://m2.mtmt.hu/api/publication/33167384}, author = {Smith, Ezra E. and Choi, Ki Sueng and Veerakumar, Ashan and Obatusin, Mosadoluwa and Howell, Bryan and Smith, Andrew H. and Tiruvadi, Vineet and Crowell, Andrea L. and Riva-Posse, Patricio and Alagapan, Sankaraleengam and Rozell, Christopher J. and Mayberg, Helen S. and Waters, Allison C.}, doi = {10.3389/fnhum.2022.939258}, journal-iso = {FRONT HUM NEUROSCI}, journal = {FRONTIERS IN HUMAN NEUROSCIENCE}, volume = {16}, unique-id = {33167384}, issn = {1662-5161}, abstract = {Precision targeting of specific white matter bundles that traverse the subcallosal cingulate (SCC) has been linked to efficacy of deep brain stimulation (DBS) for treatment resistant depression (TRD). Methods to confirm optimal target engagement in this heterogenous region are now critical to establish an objective treatment protocol. As yet unexamined are the time-frequency features of the SCC evoked potential (SCC-EP), including spectral power and phase-clustering. We examined these spectral features-evoked power and phase clustering-in a sample of TRD patients (n = 8) with implanted SCC stimulators. Electroencephalogram (EEG) was recorded during wakeful rest. Location of electrical stimulation in the SCC target region was the experimental manipulation. EEG was analyzed at the surface level with an average reference for a cluster of frontal sensors and at a time window identified by prior study (50-150 ms). Morlet wavelets generated indices of evoked power and inter-trial phase clustering. Enhanced phase clustering at theta frequency (4-7 Hz) was observed in every subject and was significantly correlated with SCC-EP magnitude, but only during left SCC stimulation. Stimulation to dorsal SCC evinced stronger phase clustering than ventral SCC. There was a weak correlation between phase clustering and white matter density. An increase in evoked delta power (2-4 Hz) was also coincident with SCC-EP, but was less consistent across participants. DBS evoked time-frequency features index mm-scale changes to the location of stimulation in the SCC target region and correlate with structural characteristics implicated in treatment optimization. Results also imply a shared generative mechanism (inter-trial phase clustering) between evoked potentials evinced by electrical stimulation and evoked potentials evinced by auditory/visual stimuli and behavioral tasks. Understanding how current injection impacts downstream cortical activity is essential to building new technologies that adapt treatment parameters to individual differences in neurophysiology.}, keywords = {Deep brain stimulation; stimulation evoked potential; single pulse electrical stimulation; subcallosal cingulate; time frequency analyses; treatment resistant depression (TRD); inter-trial phase clustering; perturbation mapping}, year = {2022}, eissn = {1662-5161} } @article{MTMT:33687758, title = {Stimulating native seizures with neural resonance: a new approach to localize the seizure onset zone}, url = {https://m2.mtmt.hu/api/publication/33687758}, author = {Smith, Rachel J. and Hays, Mark A. and Kamali, Golnoosh and Coogan, Christopher and Crone, Nathan E. and Kang, Joon Y. and Sarma, Sridevi V}, doi = {10.1093/brain/awac214}, journal-iso = {BRAIN}, journal = {BRAIN}, volume = {145}, unique-id = {33687758}, issn = {0006-8950}, abstract = {Successful outcomes in epilepsy surgery rely on the accurate localization of the seizure onset zone. Localizing the seizure onset zone is often a costly and time-consuming process wherein a patient undergoes intracranial EEG monitoring, and a team of clinicians wait for seizures to occur. Clinicians then analyse the intracranial EEG before each seizure onset to identify the seizure onset zone and localization accuracy increases when more seizures are captured. In this study, we develop a new approach to guide clinicians to actively elicit seizures with electrical stimulation. We propose that a brain region belongs to the seizure onset zone if a periodic stimulation at a particular frequency produces large amplitude oscillations in the intracranial EEG network that propagate seizure activity. Such responses occur when there is 'resonance' in the intracranial EEG network, and the resonant frequency can be detected by observing a sharp peak in the magnitude versus frequency response curve, called a Bode plot. To test our hypothesis, we analysed single-pulse electrical stimulation response data in 32 epilepsy patients undergoing intracranial EEG monitoring. For each patient and each stimulated brain region, we constructed a Bode plot by estimating a transfer function model from the intracranial EEG 'impulse' or single-pulse electrical stimulation response. The Bode plots were then analysed for evidence of resonance. First, we showed that when Bode plot features were used as a marker of the seizure onset zone, it distinguished successful from failed surgical outcomes with an area under the curve of 0.83, an accuracy that surpassed current methods of analysis with cortico-cortical evoked potential amplitude and cortico-cortical spectral responses. Then, we retrospectively showed that three out of five native seizures accidentally triggered in four patients during routine periodic stimulation at a given frequency corresponded to a resonant peak in the Bode plot. Last, we prospectively stimulated peak resonant frequencies gleaned from the Bode plots to elicit seizures in six patients, and this resulted in an induction of three seizures and three auras in these patients. These findings suggest neural resonance as a new biomarker of the seizure onset zone that can guide clinicians in eliciting native seizures to more quickly and accurately localize the seizure onset zone. Inducing seizures with electrical stimulation could help clinicians localize the seizure onset zone in patients with epilepsy. Smith et al. present a novel method based on neural resonance that can guide clinicians in actively eliciting seizures, thereby expediting the intracranial monitoring process for seizure localization.}, keywords = {RESPONSES; HUMAN BRAIN; CORTEX; FREQUENCY; functional connectivity; Clinical Neurology; Cortical stimulation; Cortico-cortical evoked potentials; Neocortical epilepsy; seizure induction; single-pulse electrical stimulation; PULSE ELECTRICAL-STIMULATION; dynamical network model; CORTICOCORTICAL EVOKED-POTENTIALS}, year = {2022}, eissn = {1460-2156}, pages = {3886-3900}, orcid-numbers = {Smith, Rachel J./0000-0001-7142-0684; Hays, Mark A./0000-0001-7800-9302} } @article{MTMT:32961415, title = {Neuromonitoring of the language pathways using cortico-cortical evoked potentials: a systematic review and meta-analysis}, url = {https://m2.mtmt.hu/api/publication/32961415}, author = {Titov, Oleg and Bykanov, Andrey and Pitskhelauri, David and Danilov, Gleb}, doi = {10.1007/s10143-021-01718-8}, journal-iso = {NEUROSURG REV}, journal = {NEUROSURGICAL REVIEW}, volume = {45}, unique-id = {32961415}, issn = {0344-5607}, abstract = {Cortico-cortical evoked potentials (CCEPs) are a surge in activity of one cortical zone caused by stimulation of another cortical zone. Recording of CCEP may be a useful method of intraoperative monitoring of the brain pathways, particularly of the language-related tracts. We aimed to conduct a systematic review and meta-analysis, dedicated to the clinical question: Does the CCEP recording effectively predict the postoperative speech deficits in neurosurgical patients? We conducted language-restricted PubMed, Google Scholar, Scopus, and Cochrane database search for eligible studies of CCEP published until March 2021. There were 4 articles (3 case series and 1 case report), which met our inclusion/exclusion criteria. A total of 32 patients (30 cases of tumors and 2 cavernomas) included in the analysis were divided into two cohorts - quantitative and qualitative, in accordance with the method of evaluating changes in the amplitude of CCEP after the lesion resection and postoperative alterations in speech function. Quantitative variables were studied using the Spearman rank correlation coefficient. Categorical variables were compared in groups by Fisher's exact test. We found a strong positive correlation between the decrease in the N1 wave amplitude and the severity of postoperative speech deficits (quantitative cohort: r = 0.57, p = 0.01; qualitative cohort: p = 0.02). Thus, the CCEP method using the N1 wave amplitude as a marker enables to effectively predict postoperative speech outcomes. Nevertheless, the low level of evidence for the included works indicated the necessity for additional research on this issue.}, keywords = {Brain; CORTEX; Connectivity; LANGUAGE; connectome; Cortico-cortical evoked potentials}, year = {2022}, eissn = {1437-2320}, pages = {1883-1894} } @article{MTMT:33229822, title = {Distinct connectivity patterns in human medial parietal cortices: Evidence from standardized connectivity map using cortico-cortical evoked potential}, url = {https://m2.mtmt.hu/api/publication/33229822}, author = {Togo, Masaya and Matsumoto, Riki and Usami, Kiyohide and Kobayashi, Katsuya and Takeyama, Hirofumi and Nakae, Takuro and Shimotake, Akihiro and Kikuchi, Takayuki and Yoshida, Kazumichi and Matsuhashi, Masao and Kunieda, Takeharu and Miyamoto, Susumu and Takahashi, Ryosuke and Ikeda, Akio}, doi = {10.1016/j.neuroimage.2022.119639}, journal-iso = {NEUROIMAGE}, journal = {NEUROIMAGE}, volume = {263}, unique-id = {33229822}, issn = {1053-8119}, abstract = {The medial parietal cortices are components of the default mode network (DMN), which are active in the resting state. The medial parietal cortices include the precuneus and the dorsal posterior cingulate cortex (dPCC). Few studies have mentioned differences in the connectivity in the medial parietal cortices, and these differences have not yet been precisely elucidated. Electrophysiological connectivity is essential for understanding cortical function or functional differences. Since little is known about electrophysiological connections from the medial parietal cortices in humans, we evaluated distinct connectivity patterns in the medial parietal cortices by constructing a standardized connectivity map using cortico-cortical evoked potential (CCEP). This study included nine patients with partial epilepsy or a brain tumor who underwent chronic intracranial electrode placement covering the medial parietal cortices. Single-pulse electrical stimuli were delivered to the medial parietal cortices (38 pairs of electrodes). Responses were standardized using the z-score of the baseline activity, and a response density map was constructed in the Montreal Neurological Institutes (MNI) space. The precuneus tended to connect with the inferior parietal lobule (IPL), the occipital cortex, superior parietal lobule (SPL), and the dorsal premotor area (PMd) (the four most active regions, in descending order), while the dPCC tended to connect to the middle cingulate cortex, SPL, precuneus, and IPL. The connectivity pattern differs significantly between the precuneus and dPCC stimulation ( p < 0.05). Regarding each part of the medial parietal cortices, the distributions of parts of CCEP responses resembled those of the functional connectivity database. Based on how the dPCC was connected to the medial frontal area, SPL, and IPL, its connectivity pattern could not be explained by DMN alone, but suggested a mixture of DMN and the frontoparietal cognitive network. These findings improve our understanding of the connectivity profile within the medial parietal cortices. The electrophysiological connectivity is the basis of propagation of electrical activities in patients with epilepsy. In addition, it helps us to better understand the epileptic network arising from the medial parietal cortices.}, keywords = {default mode network; posterior cingulate cortex; Precuneus; Medial parietal cortices; Cortico-cortical evoked potential (CCEP)}, year = {2022}, eissn = {1095-9572}, orcid-numbers = {Usami, Kiyohide/0000-0003-2257-8279; Nakae, Takuro/0000-0002-3574-1744; Kikuchi, Takayuki/0000-0002-6295-5510; Yoshida, Kazumichi/0000-0002-8898-079X} } @article{MTMT:33231079, title = {Phase-based causality analysis with partial mutual information from mixed embedding}, url = {https://m2.mtmt.hu/api/publication/33231079}, author = {Vlachos, Ioannis and Kugiumtzis, Dimitris and Palus, Milan}, doi = {10.1063/5.0087910}, journal-iso = {CHAOS}, journal = {CHAOS}, volume = {32}, unique-id = {33231079}, issn = {1054-1500}, abstract = {Instantaneous phases extracted from multivariate time series can retain information about the relationships between the underlying mechanisms that generate the series. Although phases have been widely used in the study of nondirectional coupling and connectivity, they have not found similar appeal in the study of causality. Herein, we present a new method for phase-based causality analysis, which combines ideas from the mixed embedding technique and the information-theoretic approach to causality in coupled oscillatory systems. We then use the introduced method to investigate causality in simulated datasets of bivariate, unidirectionally paired systems from combinations of Rossler, Lorenz, van der Pol, and Mackey-Glass equations. We observe that causality analysis using the phases can capture the true causal relation for coupling strength smaller than the analysis based on the amplitudes can capture. On the other hand, the causality estimation based on the phases tends to have larger variability, which is attributed more to the phase extraction process than the actual phase-based causality method. In addition, an application on real electroencephalographic data from an experiment on elicited human emotional states reinforces the usefulness of phases in causality identification. Published under an exclusive license by AIP Publishing.}, year = {2022}, eissn = {1089-7682}, orcid-numbers = {Palus, Milan/0000-0001-8474-1436} } @article{MTMT:33007468, title = {Physiologically informed neuromodulation}, url = {https://m2.mtmt.hu/api/publication/33007468}, author = {Wendt, Karen and Denison, Timothy and Foster, Gaynor and Krinke, Lothar and Thomson, Alix and Wilson, Saydra and Widge, Alik S.}, doi = {10.1016/j.jns.2021.120121}, journal-iso = {J NEUROL SCI}, journal = {JOURNAL OF THE NEUROLOGICAL SCIENCES}, volume = {434}, unique-id = {33007468}, issn = {0022-510X}, abstract = {The rapid evolution of neuromodulation techniques includes an increasing amount of research into stimulation paradigms that are guided by patients' neurophysiology, to increase efficacy and responder rates. Treatment personalisation and target engagement have shown to be effective in fields such as Parkinson's disease, and closed-loop paradigms have been successfully implemented in cardiac defibrillators. Promising avenues are being explored for physiologically informed neuromodulation in psychiatry. Matching the stimulation frequency to individual brain rhythms has shown some promise in transcranial magnetic stimulation (TMS). Matching the phase of those rhythms may further enhance neuroplasticity, for instance when combining TMS with electroencephalographic (EEG) recordings. Resting-state EEG and event-related potentials may be useful to demonstrate connectivity between stimulation sites and connected areas. These techniques are available today to the psychiatrist to diagnose underlying sleep disorders, epilepsy, or lesions as contributing factors to the cause of depression. These technologies may also be useful in assessing the patient's brain network status prior to deciding on treatment options. Ongoing research using invasive recordings may allow for future identification of mood biomarkers and network structure. A core limitation is that biomarker research may currently be limited by the internal heterogeneity of psychiatric disorders according to the current DSM-based classifications. New approaches are being developed and may soon be validated. Finally, care must be taken when incorporating closed loop capabilities into neuromodulation systems, by ensuring the safe operation of the system and understanding the physiological dynamics. Neurophysiological tools are rapidly evolving and will likely define the next generation of neuromodulation therapies.}, keywords = {Electroencephalography; neuromodulation; Deep brain stimulation; transcranial magnetic stimulation; brain-state dependent stimulation; Biomarkers in psychiatry}, year = {2022}, eissn = {1878-5883} } @article{MTMT:32277679, title = {Local and distant responses to single pulse electrical stimulation reflect different forms of connectivity}, url = {https://m2.mtmt.hu/api/publication/32277679}, author = {Crocker, Britni and Ostrowski, Lauren and Williams, Ziv M. and Dougherty, Darin D. and Eskandar, Emad N. and Widge, Alik S. and Chu, Catherine J. and Cash, Sydney S. and Paulk, Angelique C.}, doi = {10.1016/j.neuroimage.2021.118094}, journal-iso = {NEUROIMAGE}, journal = {NEUROIMAGE}, volume = {237}, unique-id = {32277679}, issn = {1053-8119}, abstract = {Measuring connectivity in the human brain involves innumerable approaches using both noninvasive (fMRI, EEG) and invasive (intracranial EEG or iEEG) recording modalities, including the use of external probing stimuli, such as direct electrical stimulation. To examine how different measures of connectivity correlate with one another, we compared 'passive' measures of connectivity during resting state conditions to the more 'active' probing measures of connectivity with single pulse electrical stimulation (SPES). We measured the network engagement and spread of the cortico-cortico evoked potential (CCEP) induced by SPES at 53 out of 104 total sites across the brain, including cortical and subcortical regions, in patients with intractable epilepsy (N = 11) who were undergoing intracranial recordings as a part of their clinical care for identifying seizure onset zones. We compared the CCEP network to functional, effective, and structural measures of connectivity during a resting state in each patient. Functional and effective connectivity measures included correlation or Granger causality measures applied to stereoEEG (sEEGs) recordings. Structural connectivity was derived from diffusion tensor imaging (DTI) acquired before intracranial electrode implant and monitoring (N = 8). The CCEP network was most similar to the resting state voltage correlation network in channels near to the stimulation location. In contrast, the distant CCEP network was most similar to the DTI network. Other connectivity measures were not as similar to the CCEP network. These results demonstrate that different connectivity measures, including those derived from active stimulation-based probing, measure different, complementary aspects of regional interrelationships in the brain.}, keywords = {Connectivity; diffusion tensor imaging; Intracranial; SEEG; direct electrical stimulation}, year = {2021}, eissn = {1095-9572}, orcid-numbers = {Ostrowski, Lauren/0000-0002-8377-4751} } @article{MTMT:32277694, title = {Towards linking diffusion MRI based macro- and microstructure measures with cortico-cortical transmission in brain tumor patients}, url = {https://m2.mtmt.hu/api/publication/32277694}, author = {Filipiak, Patryk and Almairac, Fabien and Papadopoulo, Theodore and Fontaine, Denys and Mondot, Lydiane and Chanalet, Stephane and Deriche, Rachid and Clerc, Maureen and Wassermann, Demian}, doi = {10.1016/j.neuroimage.2020.117567}, journal-iso = {NEUROIMAGE}, journal = {NEUROIMAGE}, volume = {226}, unique-id = {32277694}, issn = {1053-8119}, abstract = {We aimed to link macro- and microstructure measures of brain white matter obtained from diffusion MRI with effective connectivity measures based on a propagation of cortico-cortical evoked potentials induced with intrasurgical direct electrical stimulation. For this, we compared streamline lengths and log-transformed ratios of streamlines computed from presurgical diffusion-weighted images, and the delays and amplitudes of N1 peaks recorded intrasurgically with electrocorticography electrodes in a pilot study of 9 brain tumor patients. Our results showed positive correlation between these two modalities in the vicinity of the stimulation sites (Pearson coefficient 0.54 +/- 0.13 for N1 delays, and 0.47 +/- 0.23 for N1 amplitudes), which could correspond to the neural propagation via U-fibers. In addition, we reached high sensitivities (0.78 +/- 0.07) and very high specificities (0.93 +/- 0.03) in a binary variant of our comparison. Finally, we used the structural connectivity measures to predict the effective connectivity using a multiple linear regression model, and showed a significant role of brain microstructure-related indices in this relation.}, keywords = {tractography; Effective connectivity; Structural connectivity; Cortico-cortical evoked potentials; direct electrical stimulation; Brain white matter microstructure}, year = {2021}, eissn = {1095-9572}, orcid-numbers = {Papadopoulo, Theodore/0000-0002-1643-9988; Deriche, Rachid/0000-0002-4643-8417; Wassermann, Demian/0000-0001-5194-6056} } @article{MTMT:32277683, title = {Single-pulse electrical stimulation methodology in freely moving rat}, url = {https://m2.mtmt.hu/api/publication/32277683}, author = {Gronlier, Eloise and Vendramini, Estelle and Volle, Julien and Wozniak-Kwasniewska, Agata and Santos, Noelia Anton and Coizet, Veronique and Duveau, Venceslas and David, Olivier}, doi = {10.1016/j.jneumeth.2021.109092}, journal-iso = {J NEUROSCI METH}, journal = {JOURNAL OF NEUROSCIENCE METHODS}, volume = {353}, unique-id = {32277683}, issn = {0165-0270}, abstract = {Background: Cortico-cortical evoked potentials (CCEP) are becoming popular to infer brain connectivity and cortical excitability in implanted refractory epilepsy patients. Our goal was to transfer this methodology to the freely moving rodent.New method: CCEP were recorded on freely moving Sprague-Dawley rats, from cortical and subcortical areas using depth electrodes. Electrical stimulation was applied using 1 ms biphasic current pulse, cathodic first, at a frequency of 0.5 Hz, with intensities ranging from 0.2 to 0.8 mA. Data were then processed in a similar fashion to human clinical studies, which included epoch selection, artefact correction and smart averaging.Results: For a large range of tested intensities, we recorded CCEPs with very good signal to noise ratio and reproducibility between animals, without any behavioral modification. The CCEP were composed of different components according to recorded and stimulated sites, similarly to human recordings. Comparison with existing methods: We minimally adapted a clinically-motivated methodology to a freely moving rodent model to achieve high translational relevance of future preclinical studies.Conclusions: Our results indicate that the CCEP methodology can be applied to freely moving rodents and transferred to preclinical research. This will be of interest to address various neuroscientific questions, in physiological and pathological conditions.}, keywords = {rodent; local field potential (LFP); Cortico-cortical evoked potentials (CCEP); intracranial electroencephalography (iEEG); Direct electrical stimulation (DES)}, year = {2021}, eissn = {1872-678X}, orcid-numbers = {David, Olivier/0000-0003-0776-0216} } @article{MTMT:32277272, title = {Effective connectivity among the hippocampus, amygdala, and temporal neocortex in epilepsy patients: A cortico-cortical evoked potential study}, url = {https://m2.mtmt.hu/api/publication/32277272}, author = {Guo, Zhihao and Zhao, Baotian and Hu, Wenhan and Zhang, Chao and Wang, Xiu and Wang, Yao and Liu, Chang and Mo, Jiajie and Sang, Lin and Ma, Yanshan and Shao, Xiaoqiu and Zhang, Jianguo and Zhang, Kai}, doi = {10.1016/j.yebeh.2020.107661}, journal-iso = {EPILEPSY BEHAV}, journal = {EPILEPSY & BEHAVIOR}, volume = {115}, unique-id = {32277272}, issn = {1525-5050}, abstract = {Objective: Mesial temporal lobe epilepsy (MTLE) is one of the most common types of intractable epilepsy. The hippocampus and amygdala are two crucial structures of the mesial temporal lobe and play important roles in the epileptogenic network of MTLE. This study aimed to explore the effective connectivity among the hippocampus, amygdala, and temporal neocortex and to determine whether differences in effective connectivity exist between MTLE patients and non-MTLE patients.Methods: This study recruited 20 patients from a large cohort of drug-resistant epilepsy patients, of whom 14 were MTLE patients. Single-pulse electrical stimulation (SPES) was performed to acquire cortico-cortical evoked potentials (CCEPs). The root mean square (RMS) was used as the metric of the magnitude of CCEP to represent the effective connectivity. We then conducted paired and independent sample t-tests to assess the directionality of the effective connectivity.Results: In both MTLE patients and non-MTLE patients, the directional connectivity from the amygdala to the hippocampus was stronger than that from the hippocampus to the amygdala (P < 0.01); the outward connectivity from the amygdala to the cortex was stronger than the inward connectivity from the cortex to the amygdala (P < 0.01); the amygdala had stronger connectivity to the neocortex than the hippocampus (P < 0.01). In MTLE patients, the neocortex had stronger connectivity to the hippocampus than to the amygdala (P < 0.01). No significant differences in directional connectivity were noted between the two groups.Conclusions: A unique effective connectivity pattern among the hippocampus, amygdala, and temporal neocortex was identified through CCEPs analysis. This study may aid in our understanding of physiological and pathological networks in the brain and inspire neurostimulation protocols for neurological and psychiatric disorders. (C) 2020 Elsevier Inc. All rights reserved.}, keywords = {hippocampus; Effective connectivity; CCEP; mTLE; amygdala}, year = {2021}, eissn = {1525-5069}, orcid-numbers = {Guo, Zhihao/0000-0002-4713-1337} } @article{MTMT:33007475, title = {Neurobehavioural comorbidities of epilepsy: towards a network-based precision taxonomy}, url = {https://m2.mtmt.hu/api/publication/33007475}, author = {Hermann, Bruce P. and Struck, Aaron F. and Busch, Robyn M. and Reyes, Anny and Kaestner, Erik and McDonald, Carrie R.}, doi = {10.1038/s41582-021-00555-z}, journal-iso = {NAT REV NEUROL}, journal = {NATURE REVIEWS NEUROLOGY}, volume = {17}, unique-id = {33007475}, issn = {1759-4758}, abstract = {Cognitive and behavioural comorbidities are prevalent in childhood and adult epilepsies and impose a substantial human and economic burden. Over the past century, the classic approach to understanding the aetiology and course of these comorbidities has been through the prism of the medical taxonomy of epilepsy, including its causes, course, characteristics and syndromes. Although this 'lesion model' has long served as the organizing paradigm for the field, substantial challenges to this model have accumulated from diverse sources, including neuroimaging, neuropathology, neuropsychology and network science. Advances in patient stratification and phenotyping point towards a new taxonomy for the cognitive and behavioural comorbidities of epilepsy, which reflects the heterogeneity of their clinical presentation and raises the possibility of a precision medicine approach. As we discuss in this Review, these advances are informing the development of a revised aetiological paradigm that incorporates sophisticated neurobiological measures, genomics, comorbid disease, diversity and adversity, and resilience factors. We describe modifiable risk factors that could guide early identification, treatment and, ultimately, prevention of cognitive and broader neurobehavioural comorbidities in epilepsy and propose a road map to guide future research.This Review offers a novel theoretical perspective on the neurobehavioural comorbidities of adult and childhood epilepsy, involving new analytical approaches, derivation of new taxonomies and consideration of the diverse forces that influence cognition and behaviour in individuals with epilepsy.}, year = {2021}, eissn = {1759-4766}, pages = {731-746} } @article{MTMT:32219280, title = {Impact of gyral geometry on cortical responses to surface electrical stimulation: insights from experimental and modeling studies}, url = {https://m2.mtmt.hu/api/publication/32219280}, author = {Kudela, Pawel and Anderson, William S.}, doi = {10.1088/1741-2552/ac1ed3}, journal-iso = {J NEURAL ENG}, journal = {JOURNAL OF NEURAL ENGINEERING}, volume = {18}, unique-id = {32219280}, issn = {1741-2560}, abstract = {Objective. Invasive simultaneous stimulation and recording from intracranial electrodes and microwire arrays were used to investigate direct cortical responses to single pulses of electrical stimulation in humans. Approach. Microwire contacts measured surface potentials in cortical microdomains at a distance of 2-6 mm from the intracranial electrode. Direct cortical responses to stimulation (<20 ms) consisted of a larger surface negative potentials. Main results. The latencies of these responses were directly or inversely correlated with distances between the intracranial electrode and microwire contacts. We hypothesize that surface negative potentials reflected local synchronous depolarization of apical dendrites of pyramidal neurons in cortical microdomains in the superficial cortical layer and resulted from the activation of gray matter axons that delivered excitatory inputs to apical dendrites after cortical stimulation. We further hypothesized that the positive or inverse distance-latency correlations of the recorded negative responses were measured depending on whether activation of neurons originated at one (crown) or multiple (crown, lip, bank) sites throughout the gyrus simultaneously. The inverse distance-latency correlations then reflected the spatiotemporal superposition of different nearby sources of neuronal recruitment in the gyrus. To prove this hypothesis, we built an anatomically informed and biophysically realistic cortical network model and simulated early responses of cortical neurons to electrical stimulation in this cortical network model. The model simulations yielded negative potentials in simulated microdomains in the cortical model consistent with those recorded from humans. The model predicted sensitivity of cortical responses to the alignment of the stimulating electrode and microwire array with respect to the cortical gyrus and confirmed that gyral geometry has a major impact on direct neuronal recruitment, the timing, and the time course of neuronal activation in cortical microdomains. Significance. In this work, we demonstrated how the high-resolution forward network models can be used for better understanding and detailed prediction of cortical stimulation effects. Accurate predictive modeling tools are needed for the progress of brain stimulation therapies.}, keywords = {cortical electrical stimulation; early cortical responses; multicompartment model; cortical network model}, year = {2021}, eissn = {1741-2552} } @article{MTMT:32277693, title = {Intracerebral electrical stimulations of the temporal lobe: A stereoelectroencephalography study}, url = {https://m2.mtmt.hu/api/publication/32277693}, author = {Mariani, Valeria and Balestrini, Simona and Gozzo, Francesca and Pelliccia, Veronica and Mai, Roberto and Francione, Stefano and Sartori, Ivana and Cardinale, Francesco and Tassi, Laura}, doi = {10.1111/ejn.15377}, journal-iso = {EUR J NEUROSCI}, journal = {EUROPEAN JOURNAL OF NEUROSCIENCE}, volume = {54}, unique-id = {32277693}, issn = {0953-816X}, abstract = {The functional anatomy of the anteromesial portion of the temporal lobe and its involvement in epilepsy can be explored by means of intracerebral electrical stimulations. Here, we aimed to expand the knowledge of its physiological and pathophysiological symptoms by conducting the first large-sample systematic analysis of 1529 electrical stimulations of this anatomical region. We retrospectively analysed all clinical manifestations induced by intracerebral electrical stimulations in 173 patients with drug-resistant focal epilepsy with at least one electrode implanted in this area. We found that high-frequency stimulations were more likely to evoke electroclinical manifestations (p < .0001) and also provoked 'false positive' seizures. Multimodal symptoms were associated with EEG electrical modification (after discharge) (p < .0001). Visual symptoms were not associated with after discharge (p = .0002) and were mainly evoked by stimulation of the hippocampus (p = .009) and of the parahippocampal gyrus (p = .0212). 'False positive seizures' can be evoked by stimulation of the hippocampus, parahippocampal gyrus and amygdala, likely due to their intrinsic low epileptogenic threshold. Visual symptoms evoked in the hippocampus and parahippocampal gyrus, without EEG changes, are physiological symptoms and suggest involvement of these areas in the visual ventral stream. Our findings provide meaningful guidance in the interpretation of intracranial EEG studies of the temporal lobe.}, keywords = {Temporal lobe epilepsy; epilepsy surgery; stereo-EEG; clinical neurophysiology; visual stream}, year = {2021}, eissn = {1460-9568}, pages = {5368-5383}, orcid-numbers = {Mariani, Valeria/0000-0003-0476-2283; Balestrini, Simona/0000-0001-5639-1969; Sartori, Ivana/0000-0001-5659-0730; Cardinale, Francesco/0000-0002-5141-9202; Tassi, Laura/0000-0002-0632-7296} } @article{MTMT:33006203, title = {Basis profile curve identification to understand electrical stimulation effects in human brain networks}, url = {https://m2.mtmt.hu/api/publication/33006203}, author = {Miller, Kai J. and Mueller, Klaus-Robert and Hermes, Dora}, doi = {10.1371/journal.pcbi.1008710}, journal-iso = {PLOS COMPUT BIOL}, journal = {PLOS COMPUTATIONAL BIOLOGY}, volume = {17}, unique-id = {33006203}, issn = {1553-734X}, abstract = {Brain networks can be explored by delivering brief pulses of electrical current in one area while measuring voltage responses in other areas. We propose a convergent paradigm to study brain dynamics, focusing on a single brain site to observe the average effect of stimulating each of many other brain sites. Viewed in this manner, visually-apparent motifs in the temporal response shape emerge from adjacent stimulation sites. This work constructs and illustrates a data-driven approach to determine characteristic spatiotemporal structure in these response shapes, summarized by a set of unique "basis profile curves " (BPCs). Each BPC may be mapped back to underlying anatomy in a natural way, quantifying projection strength from each stimulation site using simple metrics. Our technique is demonstrated for an array of implanted brain surface electrodes in a human patient. This framework enables straightforward interpretation of single-pulse brain stimulation data, and can be applied generically to explore the diverse milieu of interactions that comprise the connectome.}, year = {2021}, eissn = {1553-7358}, orcid-numbers = {Mueller, Klaus-Robert/0000-0002-3861-7685} } @article{MTMT:33007473, title = {Electrocorticography reveals thalamic control of cortical dynamics following traumatic brain injury}, url = {https://m2.mtmt.hu/api/publication/33007473}, author = {Mofakham, Sima and Fry, Adam and Adachi, Joseph and Stefancin, Patricia L. and Duong, Tim Q. and Saadon, Jordan R. and Winans, Nathan J. and Sharma, Himanshu and Feng, Guanchao and Djuric, Petar M. and Mikell, Charles B.}, doi = {10.1038/s42003-021-02738-2}, journal-iso = {COMMUN BIOL}, journal = {COMMUNICATIONS BIOLOGY}, volume = {4}, unique-id = {33007473}, abstract = {To begin to uncover the mechanisms underlying the return of consciousness following traumatic brain injury, Mofakham et al. recorded local field potentials from depth cortical regions in these patients. They found that thalamic input to the cortex plays a role in mediating the cortical dynamics associated with recovery of consciousness.The return of consciousness after traumatic brain injury (TBI) is associated with restoring complex cortical dynamics; however, it is unclear what interactions govern these complex dynamics. Here, we set out to uncover the mechanism underlying the return of consciousness by measuring local field potentials (LFP) using invasive electrophysiological recordings in patients recovering from TBI. We found that injury to the thalamus, and its efferent projections, on MRI were associated with repetitive and low complexity LFP signals from a highly structured phase space, resembling a low-dimensional ring attractor. But why do thalamic injuries in TBI patients result in a cortical attractor? We built a simplified thalamocortical model, which connotes that thalamic input facilitates the formation of cortical ensembles required for the return of cognitive function and the content of consciousness. These observations collectively support the view that thalamic input to the cortex enables rich cortical dynamics associated with consciousness.}, year = {2021}, eissn = {2399-3642}, orcid-numbers = {Mofakham, Sima/0000-0002-4509-6080} } @inproceedings{MTMT:32277266, title = {Intracortical microstimulation of somatosensory cortex generates evoked responses in motor cortex}, url = {https://m2.mtmt.hu/api/publication/32277266}, author = {Osborn, Luke E. and McMullen, David P. and Christie, Breanne P. and Kudela, Pawel and Thomas, Tessy M. and Thompson, Margaret C. and Nickl, Robert W. and Anaya, Manuel and Srihari, Sahana and Crone, Nathan E. and Wester, Brock A. and Celnik, Pablo A. and Cantarero, Gabriela L. and Tenore, Francesco V and Fifer, Matthew S.}, booktitle = {2021 10th International IEEE/EMBS Conference on Neural Engineering (NER)}, doi = {10.1109/NER49283.2021.9441123}, unique-id = {32277266}, abstract = {The complex nature of neural connections throughout the cerebral cortex has led to broad interest in understanding cortical functional networks of tactile perception and sensorimotor integration. Cortico-cortical evoked potentials (CCEPs) can be used as physiological markers to study and map cerebral networks in the brain. In a human participant with bi-hemispheric microelectrode array implants in sensorimotor regions of the brain, we found that intracortical microstimulation (ICMS) of the primary somatosensory cortex can lead to evoked responses in the motor cortex in the same hemisphere, indicating connectivity between these sensorimotor regions. Single ICMS pulses were not consciously perceived, but elicited a rapid evoked potential approximately 20 ms after stimulus onset. Multi-pulse ICMS trains, perceived as tactile sensations in the thumb, sustained over an approximately 33 ms period, led to a delayed evoked response roughly 80 ms after stimulus onset. This work is important not only for better understanding the functional relationship between cortical areas, specifically somatosensory and motor cortices, but also to provide insight on pathways where neuromodulation techniques could be employed for rehabilitation or mitigation of sensorimotor neurodegenerative effects.}, year = {2021}, pages = {53-56} } @article{MTMT:33007474, title = {Closed-loop neuromodulation in an individual with treatment-resistant depression}, url = {https://m2.mtmt.hu/api/publication/33007474}, author = {Scangos, Katherine W. and Khambhati, Ankit N. and Daly, Patrick M. and Makhoul, Ghassan S. and Sugrue, Leo P. and Zamanian, Hashem and Liu, Tony X. and Rao, Vikram R. and Sellers, Kristin K. and Dawes, Heather E. and Starr, Philip A. and Krystal, Andrew D. and Chang, Edward F.}, doi = {10.1038/s41591-021-01480-w}, journal-iso = {NAT MED}, journal = {NATURE MEDICINE}, volume = {27}, unique-id = {33007474}, issn = {1078-8956}, abstract = {Deep brain stimulation is a promising treatment for neuropsychiatric conditions such as major depression. It could be optimized by identifying neural biomarkers that trigger therapy selectively when symptom severity is elevated. We developed an approach that first used multi-day intracranial electrophysiology and focal electrical stimulation to identify a personalized symptom-specific biomarker and a treatment location where stimulation improved symptoms. We then implanted a chronic deep brain sensing and stimulation device and implemented a biomarker-driven closed-loop therapy in an individual with depression. Closed-loop therapy resulted in a rapid and sustained improvement in depression. Future work is required to determine if the results and approach of this n-of-1 study generalize to a broader population.}, year = {2021}, eissn = {1546-170X}, pages = {1696-+} } @article{MTMT:32277692, title = {Effective connectivity differs between focal cortical dysplasia types I and II}, url = {https://m2.mtmt.hu/api/publication/32277692}, author = {Shahabi, Hossein and Taylor, Kenneth and Hirfanoglu, Tugba and Koneru, Shreekanth and Bingaman, William and Kobayashi, Katsuya and Kobayashi, Masako and Joshi, Anand and Leahy, Richard M. and Mosher, John C. and Bulacio, Juan and Nair, Dileep}, doi = {10.1111/epi.17064}, journal-iso = {EPILEPSIA}, journal = {EPILEPSIA}, volume = {62}, unique-id = {32277692}, issn = {0013-9580}, abstract = {Objective To determine whether brain connectivity differs between focal cortical dysplasia (FCD) types I and II. Methods We compared cortico-cortical evoked potentials (CCEPs) as measures of effective brain connectivity in 25 FCD patients with drug-resistant focal epilepsy who underwent intracranial evaluation with stereo-electroencephalography (SEEG). We analyzed the amplitude and latency of CCEP responses following ictal-onset single-pulse electrical stimulation (iSPES). Results In comparison to FCD type II, patients with type I demonstrated significantly larger responses in the electrodes near the ictal-onset zone (<50 mm). These findings persisted when controlling for the location of the epileptogenic zone, as noted in patients with temporal lobe epilepsies, as well as controlling for seizure type, as noted in patients with focal to bilateral tonic-clonic seizures (FBTCS). In type II, the root mean square (RMS) of CCEP responses dropped substantially from the early segment (10-60 ms) to the middle and late segments (60-600 ms). The middle and late CCEP latency segments showed the largest differences between FCD types I and II. Significance Focal cortical dysplasia type I may have a greater degree of cortical hyperexcitability as compared with FCD type II. In addition, FCD type II displays a more restrictive area of hyperexcitability in both temporal and spatial domains. In patients with FBTCS and type I FCD, the increased amplitudes of RMS in the middle and late CCEP periods appear consistent with the cortico-thalamo-cortical network involvement of FBTCS. The notable differences in degree and extent of hyperexcitability may contribute to the different postsurgical seizure outcomes noted between these two pathological substrates.}, keywords = {EPILEPSY; BRAIN NETWORKS; Cortico-cortical evoked potentials; SEEG; Focal cortical dysplasia}, year = {2021}, eissn = {1528-1167}, pages = {2753-2765} } @article{MTMT:33007470, title = {Six-dimensional dynamic tractography atlas of language connectivity in the developing brain}, url = {https://m2.mtmt.hu/api/publication/33007470}, author = {Sonoda, Masaki and Silverstein, Brian H. and Jeong, Jeong-Won and Sugiura, Ayaka and Nakai, Yasuo and Mitsuhashi, Takumi and Rothermel, Robert and Luat, Aimee F. and Sood, Sandeep and Asano, Eishi}, doi = {10.1093/brain/awab225}, journal-iso = {BRAIN}, journal = {BRAIN}, volume = {144}, unique-id = {33007470}, issn = {0006-8950}, abstract = {During a verbal conversation, our brain moves through a series of complex linguistic processing stages: sound decoding, semantic comprehension, retrieval of semantically coherent words, and overt production of speech outputs. Each process is thought to be supported by a network consisting of local and long-range connections bridging between major cortical areas. Both temporal and extratemporal lobe regions have functional compartments responsible for distinct language domains, including the perception and production of phonological and semantic components.This study provides quantitative evidence of how directly connected inter-lobar neocortical networks support distinct stages of linguistic processing across brain development. Novel six-dimensional tractography was used to intuitively visualize the strength and temporal dynamics of direct inter-lobar effective connectivity between cortical areas activated during each linguistic processing stage.We analysed 3401 non-epileptic intracranial electrode sites from 37 children with focal epilepsy (aged 5-20 years) who underwent extra-operative electrocorticography recording. Principal component analysis of auditory naming-related high-gamma modulations determined the relative involvement of each cortical area during each linguistic processing stage. To quantify direct effective connectivity, we delivered single-pulse electrical stimulation to 488 temporal and 1581 extratemporal lobe sites and measured the early cortico-cortical spectral responses at distant electrodes. Mixed model analyses determined the effects of naming-related high-gamma co-augmentation between connecting regions, age, and cerebral hemisphere on the strength of effective connectivity independent of epilepsy-related factors.Direct effective connectivity was strongest between extratemporal and temporal lobe site pairs, which were simultaneously activated between sentence offset and verbal response onset (i.e. response preparation period); this connectivity was approximately twice more robust than that with temporal lobe sites activated during stimulus listening or overt response. Conversely, extratemporal lobe sites activated during overt response were equally connected with temporal lobe language sites. Older age was associated with increased strength of inter-lobar effective connectivity especially between those activated during response preparation. The arcuate fasciculus supported approximately two-thirds of the direct effective connectivity pathways from temporal to extratemporal auditory language-related areas but only up to half of those in the opposite direction. The uncinate fasciculus consisted of <2% of those in the temporal-to-extratemporal direction and up to 6% of those in the opposite direction. We, for the first time, provided an atlas which quantifies and animates the strength, dynamics, and direction specificity of inter-lobar neural communications between language areas via the white matter pathways. Language-related effective connectivity may be strengthened in an age-dependent manner even after the age of 5.}, keywords = {intracranial electroencephalography; Cortico-cortical evoked potentials; high-gamma activity; Paediatric epilepsy surgery; dynamic DWI tractography}, year = {2021}, eissn = {1460-2156}, pages = {3340-3354}, orcid-numbers = {Sonoda, Masaki/0000-0002-4612-5728; Asano, Eishi/0000-0001-8391-4067} } @article{MTMT:32961416, title = {Temporal order of signal propagation within and across intrinsic brain networks}, url = {https://m2.mtmt.hu/api/publication/32961416}, author = {Veit, Mike J. and Kucyi, Aaron and Hu, Wenhan and Zhang, Chao and Zhao, Baotian and Guo, Zhihao and Yang, Bowen and Sava-Segal, Clara and Perry, Claire and Zhang, Jianguo and Zhang, Kai and Parvizi, Josef}, doi = {10.1073/pnas.2105031118}, journal-iso = {P NATL ACAD SCI USA}, journal = {PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, volume = {118}, unique-id = {32961416}, issn = {0027-8424}, abstract = {We studied the temporal dynamics of activity within and across functional MRI (fMRI)-derived nodes of intrinsic resting-state networks of the human brain using intracranial electroencephalography (iEEG) and repeated single-pulse electrical stimulation (SPES) in neurosurgical subjects implanted with intracranial electrodes. We stimulated and recorded from 2,133 and 2,372 sites, respectively, in 29 subjects. We found that N1 and N2 segments of the evoked responses are associated with intra- and internetwork communications, respectively. In a separate cognitive experiment, evoked electrophysiological responses to visual target stimuli occurred with less temporal separation across pairs of electrodes that were located within the same fMRI-defined resting-state networks compared with those located across different resting-state networks. Our results suggest intranetwork prior to internetwork information processing at the subsecond timescale.}, keywords = {human; Event related potentials; Intracranial EEG; CCEP; gradual-onset continuous performance task}, year = {2021}, eissn = {1091-6490}, orcid-numbers = {Zhao, Baotian/0000-0003-0920-6825; Guo, Zhihao/0000-0002-4713-1337; Sava-Segal, Clara/0000-0002-3010-3858; Perry, Claire/0000-0002-9324-0518} } @article{MTMT:32277695, title = {Modelling and prediction of the dynamic responses of large-scale brain networks during direct electrical stimulation}, url = {https://m2.mtmt.hu/api/publication/32277695}, author = {Yang, Yuxiao and Qiao, Shaoyu and Sani, Omid G. and Sedillo, J. Isaac and Ferrentino, Breonna and Pesaran, Bijan and Shanechi, Maryam M.}, doi = {10.1038/s41551-020-00666-w}, journal-iso = {NAT BIOMED ENG}, journal = {NATURE BIOMEDICAL ENGINEERING}, volume = {5}, unique-id = {32277695}, issn = {2157-846X}, abstract = {Direct electrical stimulation can modulate the activity of brain networks for the treatment of several neurological and neuropsychiatric disorders and for restoring lost function. However, precise neuromodulation in an individual requires the accurate modelling and prediction of the effects of stimulation on the activity of their large-scale brain networks. Here, we report the development of dynamic input-output models that predict multiregional dynamics of brain networks in response to temporally varying patterns of ongoing microstimulation. In experiments with two awake rhesus macaques, we show that the activities of brain networks are modulated by changes in both stimulation amplitude and frequency, that they exhibit damping and oscillatory response dynamics, and that variabilities in prediction accuracy and in estimated response strength across brain regions can be explained by an at-rest functional connectivity measure computed without stimulation. Input-output models of brain dynamics may enable precise neuromodulation for the treatment of disease and facilitate the investigation of the functional organization of large-scale brain networks.}, year = {2021}, eissn = {2157-846X}, orcid-numbers = {Pesaran, Bijan/0000-0003-4116-0038} } @article{MTMT:31425921, title = {Non-invasive inference of information flow using diffusion MRI, functional MRI, and MEG}, url = {https://m2.mtmt.hu/api/publication/31425921}, author = {Deslauriers-Gauthier, Samuel and Costantini, Isa and Deriche, Rachid}, doi = {10.1088/1741-2552/ab95ec}, journal-iso = {J NEURAL ENG}, journal = {JOURNAL OF NEURAL ENGINEERING}, volume = {17}, unique-id = {31425921}, issn = {1741-2560}, abstract = {Objective. To infer information flow in the white matter of the brain and recover cortical activity using functional MRI, diffusion MRI, and MEG without a manual selection of the white matter connections of interest.Approach. A Bayesian network which encodes the priors knowledge of possible brain states is built from imaging data. Diffusion MRI is used to enumerate all possible connections between cortical regions. Functional MRI is used to prune connections without manual intervention and increase the likelihood of specific regions being active. MEG data is used as evidence into this network to obtain a posterior distribution on cortical regions and connections.Main results. We show that our proposed method is able to identify connections associated with the a sensory-motor task. This allows us to build the Bayesian network with no manual selection of connections of interest. Using sensory-motor MEG evoked response as evidence into this network, our method identified areas known to be involved in a visuomotor task. In addition, information flow along white matter fiber bundles connecting those regions was also recovered.Significance. Current methods to estimate white matter information flow are extremely invasive, therefore limiting our understanding of the interaction between cortical regions. The proposed method makes use of functional MRI, diffusion MRI, and M/EEG to infer communication between cortical regions, therefore opening the door to the non-invasive exploration of information flow in the white matter.}, keywords = {functional MRI; BRAIN NETWORKS; DIFFUSION MRI; information flow; MEG}, year = {2020}, eissn = {1741-2552}, orcid-numbers = {Deslauriers-Gauthier, Samuel/0000-0003-2781-121X; Deriche, Rachid/0000-0002-4643-8417} } @article{MTMT:30868010, title = {Reorganization of Large-Scale Functional Networks during Low-Frequency Electrical Stimulation of the Cortical Surface}, url = {https://m2.mtmt.hu/api/publication/30868010}, author = {File, Bálint and Nánási, Tibor and Tóth, E. and Bokodi, Virág and Tóth, Brigitta and Hajnal, Boglárka Zsófia and Balogh-Kardos, Zsófia Klára and Entz, László and Erőss, Loránd and Ulbert, István and Fabó, Dániel}, doi = {10.1142/S0129065719500229}, journal-iso = {INT J NEURAL SYST}, journal = {INTERNATIONAL JOURNAL OF NEURAL SYSTEMS}, volume = {30}, unique-id = {30868010}, issn = {0129-0657}, year = {2020}, eissn = {1793-6462}, orcid-numbers = {Erőss, Loránd/0000-0002-5796-5546; Ulbert, István/0000-0001-9941-9159; Fabó, Dániel/0000-0001-5141-5351} } @article{MTMT:31689181, title = {Epileptogenic network of focal epilepsies mapped with cortico-cortical evoked potentials}, url = {https://m2.mtmt.hu/api/publication/31689181}, author = {Guo, Zhi-hao and Zhao, Bao-tian and Toprani, Sheela and Hu, Wen-han and Zhang, Chao and Wang, Xiu and Sang, Lin and Ma, Yan-shan and Shao, Xiao-qiu and Razavi, Babak and Parvizi, Josef and Fisher, Robert and Zhang, Jian-guo and Zhang, Kai}, doi = {10.1016/j.clinph.2020.08.012}, journal-iso = {CLIN NEUROPHYSIOL}, journal = {CLINICAL NEUROPHYSIOLOGY}, volume = {131}, unique-id = {31689181}, issn = {1388-2457}, abstract = {Objective: The goal of this study was to investigate the spatial extent and functional organization of the epileptogenic network through cortico-cortical evoked potentials (CCEPs) in patients being evaluated with intracranial stereoelectroencephalography.Methods: Weretrospectively included 25 patients. Wedivided the recorded sites into three regions: epileptogenic zone (EZ); propagation zone (PZ); and noninvolved zone (NIZ). The root mean square of the amplitudes was calculated to reconstruct effective connectivity network. Wealso analyzed the N1/N2 amplitudes to explore the responsiveness influenced by epileptogenicity. Prognostic analysis was performed by comparing intra-region and inter-region connectivity between seizure-free and non-seizure-free groups.Results: Our results confirmed that stimulation of the EZ caused the strongest responses on other sites within and outside the EZ. Moreover, wefound a hierarchical connectivity pattern showing the highest connectivity strength within EZ, and decreasing connectivity gradient from EZ, PZ to NIZ. Prognostic analysis indicated a stronger intra-EZ connection in the seizure-free group.Conclusion: The EZ showed highest excitability and dominantly influenced other regions. Quantitative CCEPs can be useful in mapping epileptic networks and predicting surgical outcome.Significance: The generated computational connectivity model may enhance our understanding of epileptogenic networks and provide useful information for surgical planning and prognosis prediction. (C) 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.}, keywords = {focal epilepsy; Effective connectivity; Epileptogenic network; CCEPs}, year = {2020}, eissn = {1872-8952}, pages = {2657-2666} } @article{MTMT:31425920, title = {On analysis of inputs triggering large nonlinear neural responses Slow-fast dynamics in the Wendling neural mass model}, url = {https://m2.mtmt.hu/api/publication/31425920}, author = {Hebbink, Jurgen and van Gils, Stephan A. and Meijer, Hil G. E.}, doi = {10.1016/j.cnsns.2019.105103}, journal-iso = {COMMUN NONLIN SCI NUMER SIMULAT}, journal = {COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION}, volume = {83}, unique-id = {31425920}, issn = {1007-5704}, abstract = {Many applications in neuroscience, such as electrical and magnetic stimulation, can be modelled as short transient input to non-linear dynamical systems. In excitable systems, small input yields more or less linear responses, while for increasing stimulation strength large non-linear responses may show up suddenly. A challenging task is to determine the transition between the two different response types.In this work we consider such a transition between normal and pathological responses in a model of coupled Wendling neural masses as we encountered in a previous study. First, the different timescales of inhibition in this model allow a slow-fast analysis. This reveals two different dynamical regimes for the systems' response. Second, the two response types are separated by a high-dimensional stable manifold of a saddle slow manifold. Large pathological responses appear if the fast subsystem escapes from this manifold to another attractor. The typical fast oscillations seen during the pathological responses are explained by the bifurcation diagram of the fast subsystem. Under normal conditions these oscillations are suppressed by slow inhibition. External stimulation temporarily releases the fast subsystem from this slow inhibition. The critical response can be formulated as a boundary value problem with one free parameter and can be used to study the dependency of the transition between the two response types upon the system parameters. (C) 2019 Elsevier B.V. All rights reserved.}, keywords = {neural mass model; Cortical stimulation; Non-linear response; Slow-fast analysis}, year = {2020}, eissn = {1878-7274} } @article{MTMT:31023490, title = {Pathological responses to single-pulse electrical stimuli in epilepsy: The role of feedforward inhibition}, url = {https://m2.mtmt.hu/api/publication/31023490}, author = {Hebbink, Jurgen and Huiskamp, Geertjan and van Gils, Stephan A. and Leijten, Frans S. S. and Meijer, Hil G. E.}, doi = {10.1111/ejn.14562}, journal-iso = {EUR J NEUROSCI}, journal = {EUROPEAN JOURNAL OF NEUROSCIENCE}, volume = {51}, unique-id = {31023490}, issn = {0953-816X}, abstract = {Delineation of epileptogenic cortex in focal epilepsy patients may profit from single-pulse electrical stimulation during intracranial EEG recordings. Single-pulse electrical stimulation evokes early and delayed responses. Early responses represent connectivity. Delayed responses are a biomarker for epileptogenic cortex, but up till now, the precise mechanism generating delayed responses remains elusive. We used a data-driven modelling approach to study early and delayed responses. We hypothesized that delayed responses represent indirect responses triggered by early response activity and investigated this for 11 patients. Using two coupled neural masses, we modelled early and delayed responses by combining simulations and bifurcation analysis. An important feature of the model is the inclusion of feedforward inhibitory connections. The waveform of early responses can be explained by feedforward inhibition. Delayed responses can be viewed as second-order responses in the early response network which appear when input to a neural mass falls below a threshold forcing it temporarily to a spiking state. The combination of the threshold with noisy background input explains the typical stochastic appearance of delayed responses. The intrinsic excitability of a neural mass and the strength of its input influence the probability at which delayed responses to occur. Our work gives a theoretical basis for the use of delayed responses as a biomarker for the epileptogenic zone, confirming earlier clinical observations. The combination of early responses revealing effective connectivity, and delayed responses showing intrinsic excitability, makes single-pulse electrical stimulation an interesting tool to obtain data for computational models of epilepsy surgery.}, keywords = {focal epilepsy; neural mass model; single-pulse electrical stimulation; delayed responses; early responses}, year = {2020}, eissn = {1460-9568}, pages = {1122-1136} } @article{MTMT:33255128, title = {Transfer Function Models for the Localization of Seizure Onset Zone From Cortico-Cortical Evoked Potentials}, url = {https://m2.mtmt.hu/api/publication/33255128}, author = {Kamali, Golnoosh and Smith, Rachel June and Hays, Mark and Coogan, Christopher and Crone, Nathan E. and Kang, Joon Y. and Sarma, Sridevi V.}, doi = {10.3389/fneur.2020.579961}, journal-iso = {FRONT NEUR}, journal = {FRONTIERS IN NEUROLOGY}, volume = {11}, unique-id = {33255128}, issn = {1664-2295}, abstract = {Surgical resection of the seizure onset zone (SOZ) could potentially lead to seizure-freedom in medically refractory epilepsy patients. However, localizing the SOZ can be a time consuming and tedious process involving visual inspection of intracranial electroencephalographic (iEEG) recordings captured during passive patient monitoring. Cortical stimulation is currently performed on patients undergoing invasive EEG monitoring for the main purpose of mapping functional brain networks such as language and motor networks. We hypothesized that evoked responses from single pulse electrical stimulation (SPES) can also be used to localize the SOZ as they may express the natural frequencies and connectivity of the iEEG network. To test our hypothesis, we constructed patient specific transfer function models from the evoked responses recorded from 22 epilepsy patients that underwent SPES evaluation and iEEG monitoring. We then computed the frequency and connectivity dependent "peak gain" of the system as measured by the H infinity norm from systems theory. We found that in cases for which clinicians had high confidence in localizing the SOZ, the highest peak gain transfer functions with the smallest "floor gain" (gain at which the dipped H infinity 3dB below DC gain) corresponded to when the clinically annotated SOZ and early spread regions were stimulated. In more complex cases, there was a large spread of the peak-to-floor (PF) ratios when the clinically annotated SOZ was stimulated. Interestingly for patients who had successful surgeries, our ratio of gains, agreed with clinical localization, no matter the complexity of the case. For patients with failed surgeries, the PF ratio did not match clinical annotations. Our findings suggest that transfer function gains and their corresponding frequency responses computed from SPES evoked responses may improve SOZ localization and thus surgical outcomes.}, keywords = {STIMULATION; SYSTEM; RESPONSES; EPILEPSY; Connectivity; surgery; High-frequency oscillations; Clinical Neurology; Neocortical epilepsy; CCEPs; SPES; PULSE ELECTRICAL-STIMULATION; HUMAN TEMPORAL-LOBE; IDENTIFY EPILEPTOGENIC CORTEX}, year = {2020}, eissn = {1664-2295}, orcid-numbers = {Hays, Mark/0000-0001-7800-9302} } @article{MTMT:31686218, title = {A systematic exploration of parameters affecting evoked intracranial potentials in patients with epilepsy}, url = {https://m2.mtmt.hu/api/publication/31686218}, author = {Kundu, Bornali and Davis, Tyler S. and Philip, Brian and Smith, Elliot H. and Arain, Amir and Peters, Angela and Newman, Blake and Butson, Christopher R. and Rolston, John D.}, doi = {10.1016/j.brs.2020.06.002}, journal-iso = {BRAIN STIMUL}, journal = {BRAIN STIMULATION}, volume = {13}, unique-id = {31686218}, issn = {1935-861X}, abstract = {Background: Brain activity is constrained by and evolves over a network of structural and functional connections. Corticocortical evoked potentials (CCEPs) have been used to measure this connectivity and to discern brain areas involved in both brain function and disease. However, how varying stimulation parameters influences the measured CCEP across brain areas has not been well characterized. Objective: To better understand the factors that influence the amplitude of the CCEPs as well as evoked gamma-band power (70-150 Hz) resulting from single-pulse stimulation via cortical surface and depth electrodes. Methods: CCEPs from 4370 stimulation-response channel pairs were recorded across a range of stimulation parameters and brain regions in 11 patients undergoing long-term monitoring for epilepsy. A generalized mixed-effects model was used to model cortical response amplitudes from 5 to 100 ms post-stimulation. Results: Stimulation levels <5.5 mA generated variable CCEPs with low amplitude and reduced spatial spread. Stimulation at >= 5.5 mA yielded a reliable and maximal CCEP across stimulation-response pairs over all regions. These findings were similar when examining the evoked gamma-band power. The amplitude of both measures was inversely correlated with distance. CCEPs and evoked gamma power were largest when measured in the hippocampus compared with other areas. Larger CCEP size and evoked gamma power were measured within the seizure onset zone compared with outside this zone.Conclusion: These results will help guide future stimulation protocols directed at quantifying network connectivity across cognitive and disease states. (C) 2020 The Authors. Published by Elsevier Inc.}, keywords = {GAMMA; POWER; Stereoelectroencephalography (SEEG); Corticocortical evoked potential (CCEP); Single-pulse electrical stimulation (SPES)}, year = {2020}, eissn = {1876-4754}, pages = {1232-1244} } @article{MTMT:33255170, title = {Information Integration and Mesoscopic Cortical Connectivity during Propofol Anesthesia}, url = {https://m2.mtmt.hu/api/publication/33255170}, author = {Liang, Zhenhu and Cheng, Lei and Shao, Shuai and Jin, Xing and Yu, Tao and Sleigh, Jamie W. and Li, Xiaoli}, doi = {10.1097/ALN.0000000000003015}, journal-iso = {ANESTHESIOLOGY}, journal = {ANESTHESIOLOGY}, volume = {132}, unique-id = {33255170}, issn = {0003-3022}, abstract = {Background: The neurophysiologic mechanisms of propofol-induced loss of consciousness have been studied in detail at the macro (scalp electroencephalogram) and micro (spiking or local field potential) scales. However, the changes in information integration and cortical connectivity during propofol anesthesia at the mesoscopic level (the cortical scale) are less clear. Methods: The authors analyzed electrocorticogram data recorded from surgical patients during propofol-induced unconsciousness (n = 9). A new information measure, genuine permutation cross mutual information, was used to analyze how electrocorticogram cross-electrode coupling changed with electrode-distances in different brain areas (within the frontal, parietal, and temporal regions, as well as between the temporal and parietal regions). The changes in cortical networks during anesthesia-at nodal and global levels-were investigated using clustering coefficient, path length, and nodal efficiency measures. Results: In all cortical regions, and in both wakeful and unconscious states (early and late), the genuine permutation cross mutual information and the percentage of genuine connections decreased with increasing distance, especially up to about 3 cm. The nodal cortical network metrics (the nodal clustering coefficients and nodal efficiency) decreased from wakefulness to unconscious state in the cortical regions we analyzed. In contrast, the global cortical network metrics slightly increased in the early unconscious state (the time span from loss of consciousness to 200 s after loss of consciousness), as compared with wakefulness (normalized average clustering coefficient: 1.05 +/- 0.01 vs. 1.06 +/- 0.03, P = 0.037; normalized average path length: 1.02 +/- 0.01 vs. 1.04 +/- 0.01, P = 0.021). Conclusions: The genuine permutation cross mutual information reflected propofol-induced coupling changes measured at a cortical scale. Loss of consciousness was associated with a redistribution of the pattern of information integration; losing efficient global information transmission capacity but increasing local functional segregation in the cortical network.}, keywords = {Brain; NETWORK; EEG; Electroencephalogram; SYNCHRONIZATION; Consciousness; GRAPH-THEORETICAL ANALYSIS; Permutation entropy; intraoperative electrocorticography}, year = {2020}, eissn = {1528-1175}, pages = {504-524}, orcid-numbers = {Li, Xiaoli/0000-0003-1359-5130} } @article{MTMT:31425916, title = {Utilizing High-Density Electroencephalography and Motion Capture Technology to Characterize Sensorimotor Integration While Performing Complex Actions}, url = {https://m2.mtmt.hu/api/publication/31425916}, author = {Mazurek, Kevin A. and Richardson, David and Abraham, Nicholas and Foxe, John J. and Freedman, Edward G.}, doi = {10.1109/TNSRE.2019.2941574}, journal-iso = {IEEE T NEUR SYS REH}, journal = {IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING}, volume = {28}, unique-id = {31425916}, issn = {1534-4320}, abstract = {Studies of sensorimotor integration often use sensory stimuli that require a simple motor response, such as a reach or a grasp. Recent advances in neural recording techniques, motion capture technologies, and time-synchronization methods enable studying sensorimotor integration using more complex sensory stimuli and performed actions. Here, we demonstrate that prehensile actions that require using complex sensory instructions for manipulating different objects can be characterized using high-density electroencephalography and motion capture systems. In 20 participants, we presented stimuli in different sensory modalities (visual, auditory) containing different contextual information about the object with which to interact. Neural signals recorded near motor cortex and posterior parietal cortex discharged based on both the instruction delivered and object manipulated. Additionally, kinematics of the wrist movements could be discriminated between participants. These findings demonstrate a proof-of-concept behavioral paradigm for studying sensorimotor integration of multidimensional sensory stimuli to perform complex movements. The designed framework will prove vital for studying neural control of movements in clinical populations in which sensorimotor integration is impaired due to information no longer being communicated correctly between brain regions (e.g. stroke). Such a framework is the first step towards developing a neural rehabilitative system for restoring function more effectively.}, keywords = {Electroencephalography (EEG); Kinematic Analysis; sensorimotor integration; grasping; reaching; mobile brain; body integration (MoBI); motion capture (Mocap)}, year = {2020}, eissn = {1558-0210}, pages = {287-296}, orcid-numbers = {Richardson, David/0000-0002-5696-6045; Abraham, Nicholas/0000-0002-6216-2828} } @article{MTMT:31685308, title = {Connectivity Gradient in the Human Left Inferior Frontal Gyrus: Intraoperative Cortico-Cortical Evoked Potential Study}, url = {https://m2.mtmt.hu/api/publication/31685308}, author = {Nakae, Takuro and Matsumoto, Riki and Kunieda, Takeharu and Arakawa, Yoshiki and Kobayashi, Katsuya and Shimotake, Akihiro and Yamao, Yukihiro and Kikuchi, Takayuki and Aso, Toshihiko and Matsuhashi, Masao and Yoshida, Kazumichi and Ikeda, Akio and Takahashi, Ryosuke and Ralph, Matthew A. Lambon and Miyamoto, Susumu}, doi = {10.1093/cercor/bhaa065}, journal-iso = {CEREB CORTEX}, journal = {CEREBRAL CORTEX}, volume = {30}, unique-id = {31685308}, issn = {1047-3211}, abstract = {In the dual-stream model of language processing, the exact connectivity of the ventral stream to the anterior temporal lobe remains elusive. To investigate the connectivity between the inferior frontal gyrus (IFG) and the lateral part of the temporal and parietal lobes, we integrated spatiotemporal profiles of cortico-cortical evoked potentials (CCEPs) recorded intraoperatively in 14 patients who had undergone surgical resection for a brain tumor or epileptic focus. Four-dimensional visualization of the combined CCEP data showed that the pars opercularis (Broca's area) is connected to the posterior temporal cortices and the supramarginal gyrus, whereas the pars orbitalis is connected to the anterior lateral temporal cortices and angular gyrus. Quantitative topographical analysis of CCEP connectivity confirmed an anterior-posterior gradient of connectivity from IFG stimulus sites to the temporal response sites. Reciprocality analysis indicated that the anterior part of the IFG is bidirectionally connected to the temporal or parietal area. This study shows that each IFG subdivision has different connectivity to the temporal lobe with an anterior-posterior gradient and supports the classical connectivity concept of Dejerine; that is, the frontal lobe is connected to the temporal lobe through the arcuate fasciculus and also a double fan-shaped structure anchored at the limen insulae.}, keywords = {Cortico-cortical evoked potential; 4D visualization; dual-stream language model; fronto-temporal radiation}, year = {2020}, eissn = {1460-2199}, pages = {4633-4650} } @article{MTMT:31295717, title = {In vivo-assessment of the human temporal network: Evidence for asymmetrical effective connectivity}, url = {https://m2.mtmt.hu/api/publication/31295717}, author = {Novitskaya, Y. and Dümpelmann, M. and Vlachos, A. and Reinacher, P.C. and Schulze-Bonhage, A.}, doi = {10.1016/j.neuroimage.2020.116769}, journal-iso = {NEUROIMAGE}, journal = {NEUROIMAGE}, volume = {214}, unique-id = {31295717}, issn = {1053-8119}, keywords = {Adult; Adolescent; Female; Middle Aged; Male; hippocampus; EPILEPSY; ARTICLE; human; priority journal; cohort analysis; nuclear magnetic resonance imaging; evoked cortical response; Parahippocampal Gyrus; clinical article; Temporal Lobe; Young Adult; in vivo study; clinical assessment; brain asymmetry; ASYMMETRY; nerve cell network; functional connectivity; spatiotemporal analysis; Effective connectivity; CCEP; neuromuscular electrical stimulation; Human temporal lobe; Reciprocal connectivity; amygdala}, year = {2020}, eissn = {1095-9572} } @article{MTMT:31422817, title = {Comparing connectivity metrics in cortico-cortical evoked potentials using synthetic cortical response patterns}, url = {https://m2.mtmt.hu/api/publication/31422817}, author = {Prime, David and Woolfe, Matthew and Rowlands, David and O'Keefe, Steven and Dionisio, Sasha}, doi = {10.1016/j.jneumeth.2019.108559}, journal-iso = {J NEUROSCI METH}, journal = {JOURNAL OF NEUROSCIENCE METHODS}, volume = {334}, unique-id = {31422817}, issn = {0165-0270}, abstract = {Background: Cortico-Cortical Evoked Potentials (CCEPs) are a novel low frequency stimulation method used for brain mapping during intracranial epilepsy investigations. Only a handful of metrics have been applied to CCEP data to infer connectivity, and no comparison as to which is best has been performed.New method: We implement a novel method which involved superimposing synthetic cortical responses onto stereoelectroencephalographic (SEEG) data, and use this to compare several metric's ability to detect the simulated patterns. In this we compare two commonly employed metrics currently used in CCEP analysis against eight time series similarity metrics (TSSMs), which have been widely used in machine learning and pattern matching applications.Results: Root Mean Square (RMS), a metric commonly employed in CCEP analysis, was sensitive to a wide variety of response patterns, but insensitive to simulated epileptiform patterns. Autoregressive (AR) coefficients calculated by Burg's method were also sensitive to a wide range of patterns, but were extremely sensitive to epileptiform patterns. Other metrics which employed elastic warping techniques were less sensitive to the simulated response patterns. Comparison with existing methods: Our study is the first to compare CCEP connectivity metrics against one-another. Our results found that RMS, which has been used in many CCEP studies previously, was the most sensitive metric across a wide range of patterns.Conclusions: Our novel method showed that RMS is a robust and sensitive measure, validating much of the findings of the SEEG-CCEP literature to date. Autoregressive coefficients may also be a useful metric to investigate epileptic networks.}, keywords = {Signal processing; Pattern matching; Similarity metrics; Effective connectivity; root mean square; Cortico-cortical evoked potentials; CCEP; stereo-EEG}, year = {2020}, eissn = {1872-678X}, orcid-numbers = {Prime, David/0000-0003-4034-0977; Woolfe, Matthew/0000-0002-6504-953X; Dionisio, Sasha/0000-0003-0870-6094} } @article{MTMT:31425919, title = {Anomaly Detection of Moderate Traumatic Brain Injury Using Auto-Regularized Multi-Instance One-Class SVM}, url = {https://m2.mtmt.hu/api/publication/31425919}, author = {Rasheed, Waqas and Tang, Tong Boon}, doi = {10.1109/TNSRE.2019.2948798}, journal-iso = {IEEE T NEUR SYS REH}, journal = {IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING}, volume = {28}, unique-id = {31425919}, issn = {1534-4320}, abstract = {Detection and quantification of functional deficits due to moderate traumatic brain injury (mTBI) is crucial for clinical decision-making and timely commencement of functional therapy. In this work, we explore magnetoencephalography (MEG) based functional connectivity features i.e. magnitude squared coherence(MSC) and phase lag index (PLI) to quantify synchronized brain activity patterns as a means to detect functional deficits. We propose a multi-instance one-class support vector machine (SVM) model generated from a healthy control population. Any dispersion from the decision boundary of the model would be identified as an anomaly instance of mTBI case (Glasgow Coma Scale, GCS score between 9 and 13). The decision boundary was optimized by considering the closest anomaly (GCS = 13) from the negative class as a support vector. Validated against magnetic resonance imaging (MRI) data, the proposed model at high beta band yielded an accuracy of 94.19% and a sensitivity of 90.00%, when tested with our mTBI dataset. The results support the suggestion of multi-instance one-class SVM for the detection of mTBI.}, keywords = {machine learning; Anomaly detection; Medical diagnosis; Neurorehabilitation; Neural imaging}, year = {2020}, eissn = {1558-0210}, pages = {83-93}, orcid-numbers = {Tang, Tong Boon/0000-0002-5721-6828} } @article{MTMT:31689443, title = {Spatially confined responses of mouse visual cortex to intracortical magnetic stimulation from micro-coils}, url = {https://m2.mtmt.hu/api/publication/31689443}, author = {Ryu, Sang Baek and Paulk, Angelique C. and Yang, Jimmy C. and Ganji, Mehran and Dayeh, Shadi A. and Cash, Sydney S. and Fried, Shelley I and Lee, Seung Woo}, doi = {10.1088/1741-2552/abbd22}, journal-iso = {J NEURAL ENG}, journal = {JOURNAL OF NEURAL ENGINEERING}, volume = {17}, unique-id = {31689443}, issn = {1741-2560}, abstract = {Objective. Electrical stimulation via microelectrodes implanted in cortex has been suggested as a potential treatment for a wide range of neurological disorders. Despite some success however, the effectiveness of conventional electrodes remains limited, in part due to an inability to create specific patterns of neural activity around each electrode and in part due to challenges with maintaining a stable interface. The use of implantable micro-coils to magnetically stimulate the cortex has the potential to overcome these limitations because the asymmetric fields from coils can be harnessed to selectively activate some neurons, e.g. vertically-oriented pyramidal neurons while avoiding others, e.g. horizontally-oriented passing axons. In vitro experiments have shown that activation is indeed confined with micro-coils but their effectiveness in the intact brain of living animals has not been evaluated. Approach. To assess the efficacy of stimulation, a 128-channel custom recording microelectrode array was positioned on the surface of the visual cortex (ECoG) in anesthetized mice and responses to magnetic and electric stimulation were compared. Stimulation was delivered from electrodes or micro-coils implanted through a hole in the center of the recording array at a rate of 200 pulses per second for 100 ms. Main results. Both electric and magnetic stimulation reliably elicited cortical responses, although activation from electric stimulation was spatially expansive, often extending more than 1 mm from the stimulation site, while activation from magnetic stimulation was typically confined to a similar to 300 mu m diameter region around the stimulation site. Results were consistent for stimulation of both cortical layer 2/3 and layer 5 as well as across a range of stimulus strengths. Significance. The improved focality with magnetic stimulation suggests that the effectiveness of cortical stimulation can be improved. Improved focality may be particularly attractive for cortical prostheses that require high spatial resolution, e.g. devices that target sensory cortex, as it may lead to improved acuity.}, keywords = {Primary visual cortex; visual prosthesis; micro-magnetic stimulation; implantable micro-coil; micro-electrocorticography (µ; -ECoG)}, year = {2020}, eissn = {1741-2552}, orcid-numbers = {Ryu, Sang Baek/0000-0002-1466-871X; Lee, Seung Woo/0000-0003-4070-809X} } @article{MTMT:31295716, title = {Dynamic tractography: Integrating cortico-cortical evoked potentials and diffusion imaging}, url = {https://m2.mtmt.hu/api/publication/31295716}, author = {Silverstein, B.H. and Asano, E. and Sugiura, A. and Sonoda, M. and Lee, M.-H. and Jeong, J.-W.}, doi = {10.1016/j.neuroimage.2020.116763}, journal-iso = {NEUROIMAGE}, journal = {NEUROIMAGE}, volume = {215}, unique-id = {31295716}, issn = {1053-8119}, keywords = {electrocorticography; Effective connectivity; epilepsy surgery; Functional brain mapping; diffusion-weighted imaging tractography; Cortico-cortical evoked potentials (CCEP)}, year = {2020}, eissn = {1095-9572} } @article{MTMT:31689444, title = {Models of communication and control for brain networks: distinctions, convergence, and future outlook}, url = {https://m2.mtmt.hu/api/publication/31689444}, author = {Srivastava, Pragya and Nozari, Erfan and Kim, Jason Z. and Ju, Harang and Zhou, Dale and Becker, Cassiano and Pasqualetti, Fabio and Pappas, George J. and Bassett, Danielle S.}, doi = {10.1162/netn_a_00158}, journal-iso = {NETW NEUROSCI}, journal = {NETWORK NEUROSCIENCE}, volume = {4}, unique-id = {31689444}, issn = {2472-1751}, abstract = {Author SummaryModels of communication in brain networks have been essential in building a quantitative understanding of the relationship between structure and function. More recently, control-theoretic models have also been applied to brain networks to quantify the response of brain networks to exogenous and endogenous perturbations. Mechanistically, both of these frameworks investigate the role of interregional communication in determining the behavior and response of the brain. Theoretically, both of these frameworks share common features, indicating the possibility of combining the two approaches. Drawing on a large body of past and ongoing works, this review presents a discussion of convergence and distinctions between the two approaches, and argues for the development of integrated models at the confluence of the two frameworks, with potential applications to various topics in neuroscience.Recent advances in computational models of signal propagation and routing in the human brain have underscored the critical role of white-matter structure. A complementary approach has utilized the framework of network control theory to better understand how white matter constrains the manner in which a region or set of regions can direct or control the activity of other regions. Despite the potential for both of these approaches to enhance our understanding of the role of network structure in brain function, little work has sought to understand the relations between them. Here, we seek to explicitly bridge computational models of communication and principles of network control in a conceptual review of the current literature. By drawing comparisons between communication and control models in terms of the level of abstraction, the dynamical complexity, the dependence on network attributes, and the interplay of multiple spatiotemporal scales, we highlight the convergence of and distinctions between the two frameworks. Based on the understanding of the intertwined nature of communication and control in human brain networks, this work provides an integrative perspective for the field and outlines exciting directions for future work.}, keywords = {Integrated models; Nonlinear control; CAUSALITY; system identification; BRAIN DYNAMICS; Communication models; Linear control; Spatiotemporal scales in brain; Control models for brain networks; Time-varying control}, year = {2020}, eissn = {2472-1751}, pages = {1122-1159}, orcid-numbers = {Zhou, Dale/0000-0001-9240-1327} } @article{MTMT:31689442, title = {Characterizing and predicting cortical evoked responses to direct electrical stimulation of the human brain}, url = {https://m2.mtmt.hu/api/publication/31689442}, author = {Steinhardt, Cynthia R. and Sacre, Pierre and Sheehan, Timothy C. and Wittig, John H. and Inati, Sara K. and Sarma, Sridevi and Zaghloul, Kareem A.}, doi = {10.1016/j.brs.2020.05.001}, journal-iso = {BRAIN STIMUL}, journal = {BRAIN STIMULATION}, volume = {13}, unique-id = {31689442}, issn = {1935-861X}, abstract = {Background: Direct electrical stimulation of the human brain has been used to successfully treat several neurological disorders, but the precise effects of stimulation on neural activity are poorly understood. Characterizing the neural response to stimulation, however, could allow clinicians and researchers to more accurately predict neural responses, which could in turn lead to more effective stimulation for treatment and to fundamental knowledge regarding neural function.Objective: Here we use a linear systems approach in order to characterize the response to electrical stimulation across cortical locations and then to predict the responses to novel inputs.Methods: We use intracranial electrodes to directly stimulate the human brain with single pulses of stimulation using amplitudes drawn from a random distribution. Based on the evoked responses, we generate a simple model capturing the characteristic response to stimulation at each cortical site. Results: We find that the variable dynamics of the evoked response across cortical locations can be captured using the same simple architecture, a linear time-invariant system that operates separately on positive and negative input pulses of stimulation. We demonstrate that characterizing the response to stimulation using this simple and tractable model of evoked responses enables us to predict the responses to subsequent stimulation with single pulses with novel amplitudes, and the compound response to stimulation with multiple pulses.Conclusion: Our data suggest that characterizing the response to stimulation in an approximately linear manner can provide a powerful and principled approach for predicting the response to direct electrical stimulation. (C) 2020 The Author(s). Published by Elsevier Inc.}, keywords = {linear system identification; Electrical brain stimulation; Cortical evoked response; human cortex}, year = {2020}, eissn = {1876-4754}, pages = {1218-1225}, orcid-numbers = {Sacre, Pierre/0000-0002-7228-1628} } @article{MTMT:31406151, title = {Four-dimensional map of direct effective connectivity from posterior visual areas}, url = {https://m2.mtmt.hu/api/publication/31406151}, author = {Sugiura, A. and Silverstein, B.H. and Jeong, J.-W. and Nakai, Y. and Sonoda, M. and Motoi, H. and Asano, E.}, doi = {10.1016/j.neuroimage.2020.116548}, journal-iso = {NEUROIMAGE}, journal = {NEUROIMAGE}, volume = {210}, unique-id = {31406151}, issn = {1053-8119}, year = {2020}, eissn = {1095-9572} } @article{MTMT:31425917, title = {Mapping short-latency cortical responses to electrical stimulation of thalamic motor nuclei by increasing sampling rate - A technical report}, url = {https://m2.mtmt.hu/api/publication/31425917}, author = {Toth, Emilia and Chaitanya, Ganne and Pati, Sandipan}, doi = {10.1016/j.clinph.2019.10.015}, journal-iso = {CLIN NEUROPHYSIOL}, journal = {CLINICAL NEUROPHYSIOLOGY}, volume = {131}, unique-id = {31425917}, issn = {1388-2457}, year = {2020}, eissn = {1872-8952}, pages = {142-144} } @article{MTMT:31425918, title = {A Single-Chip Bidirectional Neural Interface With High-Voltage Stimulation and Adaptive Artifact Cancellation in Standard CMOS}, url = {https://m2.mtmt.hu/api/publication/31425918}, author = {Uehlin, John P. and Smith, William Anthony and Pamula, Venkata Rajesh and Pepin, Eric P. and Perlmutter, Steve and Sathe, Visvesh and Rudell, Jacques Christophe}, doi = {10.1109/JSSC.2020.2991524}, journal-iso = {IEEE J SOLID-ST CIRC}, journal = {IEEE JOURNAL OF SOLID-STATE CIRCUITS}, volume = {55}, unique-id = {31425918}, issn = {0018-9200}, abstract = {A single-chip, bidirectional brain-computer interface (BBCI) enables neuromodulation through simultaneous neural recording and stimulation. This article presents a prototype BBCI application-specified integrated circuit (ASIC) consisting of a 64-channel time-multiplexed recording frontend, an area-optimized four-channel high-voltage compliant stimulator, and electronics to support the concurrent multichannel stimulus artifact cancellation. Stimulator power generation is integrated on a chip, providing +/- 11-V compliance from low-voltage supplies with a resonant charge pump. Highfrequency (similar to 3 GHz) self-resonant clocking is used to reduce the pumping capacitor area while suppressing the associated switching losses. A 32-tap least mean square (LMS)-based digital adaptive filter achieves 60-dB artifact suppression, enabling simultaneous neural stimulation and recording. The entire chip occupies 4 mm(2) in a 65-nm low power (LP) process and is powered by 2.5-/1.2-V supplies, dissipating 205 mu W in recording and 142 mu W in the stimulation and cancellation back-ends. The stimulation output drivers achieve 31% dc-dc efficiency at a maximum output power of 24 mW.}, keywords = {electrical stimulation; Brain-computer interfaces; neural recording; Artifact cancellation; time-division multiplexing}, year = {2020}, eissn = {1558-173X}, pages = {1749-1761} } @article{MTMT:31023491, title = {Direct Electrical Stimulation in Electrocorticographic Brain-Computer Interfaces: Enabling Technologies for Input to Cortex}, url = {https://m2.mtmt.hu/api/publication/31023491}, author = {Caldwell, David J. and Ojemann, Jeffrey G. and Rao, Rajesh P. N.}, doi = {10.3389/fnins.2019.00804}, journal-iso = {FRONT NEUROSCI-SWITZ}, journal = {FRONTIERS IN NEUROSCIENCE}, volume = {13}, unique-id = {31023491}, issn = {1662-4548}, abstract = {Electrocorticographic brain computer interfaces (ECoG-BCIs) offer tremendous opportunities for restoring function in individuals suffering from neurological damage and for advancing basic neuroscience knowledge. ECoG electrodes are already commonly used clinically for monitoring epilepsy and have greater spatial specificity in recording neuronal activity than techniques such as electroencephalography (EEG). Much work to date in the field has focused on using ECoG signals recorded from cortex as control outputs for driving end effectors. An equally important but less explored application of an ECoG-BCI is directing input into cortex using ECoG electrodes for direct electrical stimulation (DES). Combining DES with ECoG recording enables a truly bidirectional BCI, where information is both read from and written to the brain. We discuss the advantages and opportunities, as well as the barriers and challenges presented by using DES in an ECoG-BCI. In this article, we review ECoG electrodes, the physics and physiology of DES, and the use of electrical stimulation of the brain for the clinical treatment of disorders such as epilepsy and Parkinson's disease. We briefly discuss some of the translational, regulatory, financial, and ethical concerns regarding ECoG-BCIs. Next, we describe the use of ECoG-based DES for providing sensory feedback and for probing and modifying cortical connectivity. We explore future directions, which may draw on invasive animal studies with penetrating and surface electrodes as well as non-invasive stimulation methods such as transcranial magnetic stimulation (TMS). We conclude by describing enabling technologies, such as smaller ECoG electrodes for more precise targeting of cortical areas, signal processing strategies for simultaneous stimulation and recording, and computational modeling and algorithms for tailoring stimulation to each individual brain.}, keywords = {electrocorticography; neuromodulation; brain-computer interface (BCI); intracranial electrodes; direct electrical stimulation; plasticity induction; neuroprosthetic; sensory restoration}, year = {2019}, eissn = {1662-453X} } @article{MTMT:30388857, title = {A quantitative method for evaluating cortical responses to electrical stimulation}, url = {https://m2.mtmt.hu/api/publication/30388857}, author = {Crowther, Lawrence J. and Brunner, Peter and Kapeller, Christoph and Guger, Christoph and Kamada, Kyousuke and Bunch, Marjorie E. and Frawley, Bridget K. and Lynch, Timothy M. and Ritaccio, Anthony L. and Schalk, Gerwin}, doi = {10.1016/j.jneumeth.2018.09.034}, journal-iso = {J NEUROSCI METH}, journal = {JOURNAL OF NEUROSCIENCE METHODS}, volume = {311}, unique-id = {30388857}, issn = {0165-0270}, abstract = {Background: Electrical stimulation of the cortex using subdurally implanted electrodes can causally reveal structural connectivity by eliciting cortico-cortical evoked potentials (CCEPs). While many studies have demonstrated the potential value of CCEPs, the methods to evaluate them were often relatively subjective, did not consider potential artifacts, and did not lend themselves to systematic scientific investigations.}, keywords = {electrocorticography; Connectivity; electrical stimulation; Cortico-cortical evoked potentials}, year = {2019}, eissn = {1872-678X}, pages = {67-75}, orcid-numbers = {Brunner, Peter/0000-0002-2588-2754} } @article{MTMT:31021978, title = {A Comparison of Evoked and Non-evoked Functional Networks}, url = {https://m2.mtmt.hu/api/publication/31021978}, author = {Hebbink, Jurgen and van Blooijs, Dorien and Huiskamp, Geertjan and Leijten, Frans S. S. and van Gils, Stephan A. and Meijer, Hil G. E.}, doi = {10.1007/s10548-018-0692-1}, journal-iso = {BRAIN TOPOGR}, journal = {BRAIN TOPOGRAPHY}, volume = {32}, unique-id = {31021978}, issn = {0896-0267}, abstract = {The growing interest in brain networks to study the brain's function in cognition and diseases has produced an increase in methods to extract these networks. Typically, each method yields a different network. Therefore, one may ask what the resulting networks represent. To address this issue we consider electrocorticography (ECoG) data where we compare three methods. We derive networks from on-going ECoG data using two traditional methods: cross-correlation (CC) and Granger causality (GC). Next, connectivity is probed actively using single pulse electrical stimulation (SPES). We compare the overlap in connectivity between these three methods as well as their ability to reveal well-known anatomical connections in the language circuit. We find that strong connections in the CC network form more or less a subset of the SPES network. GC and SPES are related more weakly, although GC connections coincide more frequently with SPES connections compared to non-existing SPES connections. Connectivity between the two major hubs in the language circuit, Broca's and Wernicke's area, is only found in SPES networks. Our results are of interest for the use of patient-specific networks obtained from ECoG. In epilepsy research, such networks form the basis for methods that predict the effect of epilepsy surgery. For this application SPES networks are interesting as they disclose more physiological connections compared to CC and GC networks.}, keywords = {electrocorticography; functional connectivity; BRAIN NETWORKS; Cortico-cortical evoked potentials; single pulse electrical stimulation}, year = {2019}, eissn = {1573-6792}, pages = {405-417}, orcid-numbers = {van Blooijs, Dorien/0000-0002-7998-414X} } @article{MTMT:31020318, title = {Intracortical Dynamics Underlying Repetitive Stimulation Predicts Changes in Network Connectivity}, url = {https://m2.mtmt.hu/api/publication/31020318}, author = {Huang, Yuhao and Hajnal, Boglárka Zsófia and Entz, László and Fabó, Dániel and Herrero, Jose L. and Mehta, Ashesh D. and Keller, Corey J.}, doi = {10.1523/JNEUROSCI.0535-19.2019}, journal-iso = {J NEUROSCI}, journal = {JOURNAL OF NEUROSCIENCE}, volume = {39}, unique-id = {31020318}, issn = {0270-6474}, abstract = {Targeted stimulation can be used to modulate the activity of brain networks. Previously we demonstrated that direct electrical stimulation produces predictable poststimulation changes in brain excitability. However, understanding the neural dynamics during stimulation and its relationship to poststimulation effects is limited but critical for treatment optimization. Here, we applied 10 Hz direct electrical stimulation across several cortical regions in 14 human subjects (6 males) implanted with intracranial electrodes for seizure monitoring. The stimulation train was characterized by a consistent increase in high gamma (70 -170 Hz) power. Immediately post-train, low-frequency (1-8 Hz) power increased, resulting in an evoked response that was highly correlated with the neural response during stimulation. Using two measures of network connectivity, corticocortical evoked potentials (indexing effective connectivity), and theta coherence (indexing functional connectivity), we found a stronger response to stimulation in regions that were highly connected to the stimulation site. In these regions, repeated cycles of stimulation trains and rest progressively altered the stimulation response. Finally, after just 2 min (similar to 10%) of repetitive stimulation, we were able to predict poststimulation connectivity changes with high disc rim inability. Together, this work reveals a relationship between stimulation dynamics and poststimulation connectivity changes in humans. Thus, measuring neural activity during stimulation can inform future plasticity-inducing protocols.}, keywords = {electrocorticography; PLASTICITY; electrical stimulation; neuromodulation; Cortico-cortical evoked potentials; Repetitive stimulation}, year = {2019}, eissn = {1529-2401}, pages = {6122-6135}, orcid-numbers = {Fabó, Dániel/0000-0001-5141-5351} } @article{MTMT:31023489, title = {Association of Cortical Stimulation-Induced Seizure With Surgical Outcome in Patients With Focal Drug-Resistant Epilepsy}, url = {https://m2.mtmt.hu/api/publication/31023489}, author = {Oderiz, Carolina Cuello and von Ellenrieder, Nicolas and Dubeau, Francois and Eisenberg, Ariella and Gotman, Jean and Hall, Jeffery and Hincapie, Ana-Sofia and Hoffmann, Dominique and Job, Anne-Sophie and Khoo, Hui Ming and Minotti, Lorella and Olivier, Andre and Kahane, Phillippe and Frauscher, Birgit}, doi = {10.1001/jamaneurol.2019.1464}, journal-iso = {JAMA NEUROL}, journal = {JAMA NEUROLOGY}, volume = {76}, unique-id = {31023489}, issn = {2168-6149}, abstract = {Key PointsQuestionIs seizure induction by cortical stimulation during intracranial electroencephalography associated with good surgical outcome in patients with focal drug-resistant epilepsy? FindingsIn this cohort study of 103 patients with focal drug-resistant epilepsy, cortical stimulation induced typical electroclinical seizures in 59 patients (57.3%). Induction of seizures was associated with better surgical outcome; a higher percentage of resected contacts from the seizure-onset zone informed by cortical stimulation, similar to that of spontaneous seizures, was associated with better surgical outcome. MeaningCortical stimulation appears to be reliable in identifying the cortical area responsible for seizure generation and to be associated with surgical outcome.ImportanceCortical stimulation is used during presurgical epilepsy evaluation for functional mapping and for defining the cortical area responsible for seizure generation. Despite wide use of cortical stimulation, the association between cortical stimulation-induced seizures and surgical outcome remains unknown. ObjectiveTo assess whether removal of the seizure-onset zone resulting from cortical stimulation is associated with a good surgical outcome. Design, Setting, and ParticipantsThis cohort study used data from 2 tertiary epilepsy centers: Montreal Neurological Institute in Montreal, Quebec, Canada, and Grenoble-Alpes University Hospital in Grenoble, France. Participants included consecutive patients (n=103) with focal drug-resistant epilepsy who underwent stereoelectroencephalography between January 1, 2007, and January 1, 2017. Participant selection criteria were cortical stimulation during implantation, subsequent open surgical procedure with a follow-up of 1 or more years, and complete neuroimaging data sets for superimposition between intracranial electrodes and the resection. Main Outcomes and MeasuresCortical stimulation-induced typical electroclinical seizures, the volume of the surgical resection, and the percentage of resected electrode contacts inducing a seizure or encompassing the cortical stimulation-informed and spontaneous seizure-onset zones were identified. These measures were correlated with good (Engel class I) and poor (Engel classes II-IV) surgical outcomes. Electroclinical characteristics associated with cortical stimulation-induced seizures were analyzed. ResultsIn total, 103 patients were included, of whom 54 (52.4%) were female, and the mean (SD) age was 31(11) years. Fifty-nine patients (57.3%) had cortical stimulation-induced seizures. The percentage of patients with cortical stimulation-induced electroclinical seizures was higher in the good outcome group than in the poor outcome group (31 of 44 [70.5%] vs 28 of 59 [47.5%]; P=.02). The percentage of the resected contacts encompassing the cortical stimulation-informed seizure-onset zone correlated with surgical outcome (median [range] percentage in good vs poor outcome: 63.2% [0%-100%] vs 33.3% [0%-84.6%]; Spearman rho =0.38; P=.003). A similar result was observed for spontaneous seizures (median [range] percentage in good vs poor outcome: 57.1% [0%-100%] vs 32.7% [0%-100%]; Spearman rho =0.32; P=.002). Longer elapsed time since the most recent seizure was associated with a higher likelihood of inducing seizures (>24 hours: 64.7% vs <24 hours: 27.3%; P=.04). Conclusions and RelevanceSeizure induction by cortical stimulation appears to identify the epileptic generator as reliably as spontaneous seizures do; this finding might lead to a more time-efficient intracranial presurgical investigation of focal epilepsy as the need to record spontaneous seizures is reduced.This cohort study examines the cortical stimulation of the epileptogenic zone and its association with good or poor outcomes in patients with focal epilepsy.}, year = {2019}, eissn = {2168-6157}, pages = {1070-1078}, orcid-numbers = {Khoo, Hui Ming/0000-0002-4039-0520} } @article{MTMT:30513083, title = {Cross-subject network investigation of the EEG microstructure: A sleep spindles study}, url = {https://m2.mtmt.hu/api/publication/30513083}, author = {Sakellariou, Dimitris F. and Koutroumanidis, Michalis and Richardson, Mark P. and Kostopoulos, George K.}, doi = {10.1016/j.jneumeth.2018.11.001}, journal-iso = {J NEUROSCI METH}, journal = {JOURNAL OF NEUROSCIENCE METHODS}, volume = {312}, unique-id = {30513083}, issn = {0165-0270}, abstract = {Background: The microstructural EEG elements and their functional networks relate to many neurophysiological functions of the brain and can reveal abnormalities. Despite the blooming variety of methods for estimating connectivity in the EEG of a single subject, a common pitfall is seen in relevant studies; grand averaging is used for estimating the characteristic connectivity patterns of a group of subjects. This averaging may distort results and fail to account for the internal variability of connectivity results across the subjects of a group.}, keywords = {PATTERN RECOGNITION; Graph theory; PCA; EEG networks; EEG microstructure; Sleep spindle networks}, year = {2019}, eissn = {1872-678X}, pages = {16-26} } @article{MTMT:31023488, title = {Mapping Structure-Function Relationships in the Brain}, url = {https://m2.mtmt.hu/api/publication/31023488}, author = {Snyder, Abraham Z. and Bauer, Adam Q.}, doi = {10.1016/j.bpsc.2018.10.005}, journal-iso = {BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGINING}, journal = {BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING}, volume = {4}, unique-id = {31023488}, issn = {2451-9022}, abstract = {Mapping the structural and functional connectivity of the brain is a major focus of systems neuroscience research and will help to identify causally important changes in neural circuitry responsible for behavioral dysfunction. Several methods for examining brain activity in humans have been extended to rodent and monkey models in which molecular and genetic manipulations exist for linking to human disease. In this review, which is part of a special issue focused on bridging brain connectivity information across species and spatiotemporal scales, we address mapping brain activity and neural connectivity in rodents using optogenetics in conjunction with either functional magnetic resonance imaging or optical intrinsic signal imaging. We chose to focus on these techniques because they are capable of reporting spontaneous or evoked hemodynamic activity most closely linked to human neuroimaging studies. We discuss the capabilities and limitations of blood-based imaging methods, usage of optogenetic techniques to map neural systems in rodent models, and other powerful mapping techniques for examining neural connectivity over different spatial and temporal scales. We also discuss implementing strategies for mapping brain connectivity in humans with both basic and clinical applications, and conclude with how cross-species mapping studies can be utilized to influence preclinical imaging studies and clinical practices alike.}, keywords = {transcranial magnetic stimulation; functional connectivity; Functional Neuroimaging; optogenetics; Effective connectivity; Structural connectivity}, year = {2019}, eissn = {2451-9030}, pages = {510-521} } @article{MTMT:33255133, title = {Inferring Cortical Connectivity From ECoG Signals Using Graph Signal Processing}, url = {https://m2.mtmt.hu/api/publication/33255133}, author = {Tavildar, Siddhi and Mogen, Brian and Zanos, Stavros and Seeman, Stephanie C. and Perlmutter, Steve I and Fetz, Eberhard and Ashrafi, Ashkan}, doi = {10.1109/ACCESS.2019.2934490}, journal-iso = {IEEE ACCESS}, journal = {IEEE ACCESS}, volume = {7}, unique-id = {33255133}, issn = {2169-3536}, abstract = {A novel method to characterize connectivity between sites in the cerebral cortex of primates is proposed in this paper. Connectivity graphs for two macaque monkeys are inferred from Electrocorticographic (ECoG) activity recorded while the animals were alert. The locations of ECoG electrodes are considered as nodes of the graph, the coefficients of the auto-regressive (AR) representation of the signals measured at each node are considered as the signal on the graph and the connectivity strengths between the nodes are considered as the edges of the graph. Maximization of the graph smoothness defined from the Laplacian quadratic form is used to infer the connectivity map (adjacency matrix of the graph). The cortical evoked potential (CEP) map was obtained by stimulating different electrodes and recording the evoked potentials at the other electrodes. The maps obtained by the graph inference and the traditional method of spectral coherence are compared with the CEP map. The results show that the proposed method provides a description of cortical connectivity that is more similar to the stimulation-based measures than spectral coherence. The results are also tested by the surrogate map analysis in which the CEP map is randomly permuted and the distribution of the errors is obtained. It is shown that error between the two maps is comfortably outside the surrogate map error distribution. This indicates that the similarity between the map calculated by the graph inference and the CEP map is statistically significant.}, keywords = {methodology; EEG; electrocorticography; RECORDINGS; DEPENDENCE; COHERENCE; network analysis; functional connectivity; Engineering, Electrical & Electronic; Computer Science, Information Systems; graph signal processing; Brain connectivity; Brain connectivity; Electrocorticography (ECoG); cortical connectivity; graph learning}, year = {2019}, eissn = {2169-3536}, pages = {109349-109362}, orcid-numbers = {Ashrafi, Ashkan/0000-0001-7073-0883} } @article{MTMT:31581020, title = {Inferring Cortical Connectivity From ECoG Signals Using Graph Signal Processing}, url = {https://m2.mtmt.hu/api/publication/31581020}, author = {Tavildar, Siddhi and Mogen, Brian and Zanos, Stavros and Seeman, Stephanie C. and Perlmutter, Steve I. and Fetz, Eberhard and Ashrafi, Ashkan}, doi = {10.1109/ACCESS.2019.2934490}, journal-iso = {IEEE ACCESS}, journal = {IEEE ACCESS}, volume = {7}, unique-id = {31581020}, issn = {2169-3536}, abstract = {A novel method to characterize connectivity between sites in the cerebral cortex of primates is proposed in this paper. Connectivity graphs for two macaque monkeys are inferred from Electrocorticographic (ECoG) activity recorded while the animals were alert. The locations of ECoG electrodes are considered as nodes of the graph, the coefficients of the auto-regressive (AR) representation of the signals measured at each node are considered as the signal on the graph and the connectivity strengths between the nodes are considered as the edges of the graph. Maximization of the graph smoothness defined from the Laplacian quadratic form is used to infer the connectivity map (adjacency matrix of the graph). The cortical evoked potential (CEP) map was obtained by stimulating different electrodes and recording the evoked potentials at the other electrodes. The maps obtained by the graph inference and the traditional method of spectral coherence are compared with the CEP map. The results show that the proposed method provides a description of cortical connectivity that is more similar to the stimulation-based measures than spectral coherence. The results are also tested by the surrogate map analysis in which the CEP map is randomly permuted and the distribution of the errors is obtained. It is shown that error between the two maps is comfortably outside the surrogate map error distribution. This indicates that the similarity between the map calculated by the graph inference and the CEP map is statistically significant.}, keywords = {Animals; functional magnetic resonance imaging; Electroencephalography; Electrodes; Signal processing; COHERENCE; electric potential; Neural signal processing; graph signal processing; Brain connectivity; Electrocorticography (ECoG); cortical connectivity; graph learning}, year = {2019}, eissn = {2169-3536}, pages = {109349-109362} } @article{MTMT:31021975, title = {The neural tides of sleep and consciousness revealed by single-pulse electrical brain stimulation}, url = {https://m2.mtmt.hu/api/publication/31021975}, author = {Usami, Kiyohide and Korzeniewska, Anna and Matsumoto, Riki and Kobayashi, Katsuya and Hitomi, Takefumi and Matsuhashi, Masao and Kunieda, Takeharu and Mikuni, Nobuhiro and Kikuchi, Takayuki and Yoshida, Kazumichi and Miyamoto, Susumu and Takahashi, Ryosuke and Ikeda, Akio and Crone, Nathan E.}, doi = {10.1093/sleep/zsz050}, journal-iso = {SLEEP}, journal = {SLEEP}, volume = {42}, unique-id = {31021975}, issn = {0161-8105}, abstract = {Wakefulness and sleep arise from global changes in brain physiology that may also govern the flow of neural activity between cortical regions responsible for perceptual processing versus planning and action. To test whether and how the sleep/wake cycle affects the overall propagation of neural activity in large-scale brain networks, we applied single-pulse electrical stimulation (SPES) in patients implanted with intracranial EEG electrodes for epilepsy surgery. SPES elicited cortico-cortical spectral responses at high-gamma frequencies (CCSRHG, 80-150 Hz), which indexes changes in neuronal population firing rates. Using event-related causality (ERC) analysis, we found that the overall patterns of neural propagation among sites with CCSRHG were different during wakefulness and different sleep stages. For example, stimulation of frontal lobe elicited greater propagation toward parietal lobe during slow-wave sleep than during wakefulness. During REM sleep, we observed a decrease in propagation within frontal lobe, and an increase in propagation within parietal lobe, elicited by frontal and parietal stimulation, respectively. These biases in the directionality of large-scale cortical network dynamics during REM sleep could potentially account for some of the unique experiential aspects of this sleep stage. Together these findings suggest that the regulation of conscious awareness and sleep is associated with differences in the balance of neural propagation across large-scale frontal-parietal networks.}, keywords = {Brain Waves; Effective connectivity; human electrocorticography; high-gamma activity; causal interactions}, year = {2019}, eissn = {1550-9109}, orcid-numbers = {Matsumoto, Riki/0000-0003-3985-9210} } @article{MTMT:30512872, title = {Monitoring Corticocortical Evoked Potentials During Intracranial Vascular Surgery}, url = {https://m2.mtmt.hu/api/publication/30512872}, author = {Yoshimoto, Tetsuyuki and Maruichi, Katsuhiko and Itoh, Yasuhiro and Takamiya, Soichiro and Kaneko, Tetsuya}, doi = {10.1016/j.wneu.2018.10.179}, journal-iso = {WORLD NEUROSURG}, journal = {WORLD NEUROSURGERY}, volume = {122}, unique-id = {30512872}, issn = {1878-8750}, abstract = {BACKGROUND: Monitoring of corticocortical evoked potentials (CCEPs) during brain tumor surgery of patients under anesthesia was recently reported to be effective in assisting in preservation of speech function. The aim of this study was to investigate whether CCEPs can be reproducibly measured between the frontal and temporal lobes during standard intracranial vascular surgery under general anesthesia; whether dynamic changes in CCEPs caused by reduced focal cerebral blood flow can be measured; and whether CCEPs can be used to monitor speech function, particularly associated with the left side of the brain.}, keywords = {ISCHEMIA; BYPASS; clipping; CCEP; Speech function}, year = {2019}, eissn = {1878-8769}, pages = {E947-E954} } @article{MTMT:31023487, title = {Cortico-Cortical Evoked Potentials in Children With Tuberous Sclerosis Complex Using Stereo-Electroencephalography}, url = {https://m2.mtmt.hu/api/publication/31023487}, author = {Yu, Xiaoman and Ding, Ping and Yuan, Liu and Zhang, Juncheng and Liang, Shuangshuang and Zhang, Shaohui and Liu, Na and Liang, Shuli}, doi = {10.3389/fneur.2019.01093}, journal-iso = {FRONT NEUR}, journal = {FRONTIERS IN NEUROLOGY}, volume = {10}, unique-id = {31023487}, issn = {1664-2295}, abstract = {Objectives: Patients with tuberous sclerosis complex (TSC) present multiple cortical tubers in the brain, which are responsible for epilepsy. It is still difficult to localize the epileptogenic tuber. The value of cortico-cortical evoked potentials (CCEPs) was assessed in epileptogenic tuber localization in patients with TSC using stereo-electroencephalography (SEEG). Methods: Patients with TSC who underwent SEEG and CCEP examination in preoperative evaluation during 2014-2017 and reached postoperative seizure freedom at 1-year follow-up were enrolled in this study (n = 11). CCEPs were conducted by stimulating every two adjacent contacts of SEEG electrodes and recording on other contacts of SEEG electrodes in one epileptogenic tuber and its early-stage propagating tuber, and their perituberal cortexes in each patient. The CCEP was defined as positive when N1 and/or N2 wave presented, and then the occurrence rates of positive CCEPs were then compared among different tubers and perituberal regions. Results: Occurrence rates of positive CCEP from epileptogenic tubers to early propagating tubers and epileptogenic tubers to perituberal cortexes were 100%, which were significantly higher than the occurrence rates of CCEP between other locations. The occurrence rates of CCEP from peripheral portions of epileptogenic tubers to peripheral portions of early propagating tubers or perituberal cortexes were 100%, which were significant higher than the occurrence rates of CCEP from peripheral regions of early propagating tubers to peripheral portions of epileptogenic tubers, from the central part of early propagating tuber to central portions of epileptogenic tubers, or from perituberal cortexes to the center part of epileptogenic tubers. Conclusion: Epileptogenic tubers presented much more diffusive connectivity with other tubers and perituberal cortexes than any other connectivity relationships across propagating tubers, and the peripheral region of epileptogenic tubers presented the greatest connectivity with propagating tubers and perituberal cortexes. CCEP can be an effective tool in epileptogenic tuber localization in patients with TSC.}, keywords = {NETWORK; preoperative evaluation; Cortico-cortical evoked potential; tuberous sclerosis complex; stereo-electroencephalography}, year = {2019}, eissn = {1664-2295} } @article{MTMT:27555162, title = {Characterizing EEG Cortical Dynamics and Connectivity with Responses to Single Pulse Electrical Stimulation (SPES)}, url = {https://m2.mtmt.hu/api/publication/27555162}, author = {Alarcon, Gonzalo and Jimenez-Jimenez, Diego and Valentin, Antonio and Martin-Lopez, David}, doi = {10.1142/S0129065717500575}, journal-iso = {INT J NEURAL SYST}, journal = {INTERNATIONAL JOURNAL OF NEURAL SYSTEMS}, volume = {28}, unique-id = {27555162}, issn = {0129-0657}, year = {2018}, eissn = {1793-6462} } @article{MTMT:30387619, title = {A neural mass model to predict electrical stimulation evoked responses in human and non-human primate brain}, url = {https://m2.mtmt.hu/api/publication/30387619}, author = {Basu, Ishita and Crocker, Britni and Farnes, Kara and Robertson, Madeline M. and Paulk, Angelique C. and Vallejo, Deborah I. and Dougherty, Darin D. and Cash, Sydney S. and Eskandar, Emad N. and Kramer, Mark M. and Widge, Alik S.}, doi = {10.1088/1741-2552/aae136}, journal-iso = {J NEURAL ENG}, journal = {JOURNAL OF NEURAL ENGINEERING}, volume = {15}, unique-id = {30387619}, issn = {1741-2560}, abstract = {Objective. Deep brain stimulation (DBS) is a valuable tool for ameliorating drug resistant pathologies such as movement disorders and epilepsy. DBS is also being considered for complex neuro-psychiatric disorders, which are characterized by high variability in symptoms and slow responses that hinder DBS setting optimization. The objective of this work was to develop an in silico platform to examine the effects of electrical stimulation in regions neighboring a stimulated brain region. Approach. We used the Jansen-Rit neural mass model of single and coupled nodes to simulate the response to a train of electrical current pulses at different frequencies (10-160 Hz) of the local field potential recorded in the amygdala and cortical structures in human subjects and a non-human primate. Results. We found that using a single node model, the evoked responses could be accurately modeled following a narrow range of stimulation frequencies. Including a second coupled node increased the range of stimulation frequencies whose evoked responses could be efficiently modeled. Furthermore, in a chronic recording from a non-human primate, features of the in vivo evoked response remained consistent for several weeks, suggesting that model re-parameterization for chronic stimulation protocols would be infrequent. Significance. Using a model of neural population activity, we reproduced the evoked response to cortical and subcortical stimulation in human and non-human primate. This modeling framework provides an environment to explore, safely and rapidly, a wide range of stimulation settings not possible in human brain stimulation studies. The model can be trained on a limited dataset of stimulation responses to develop an optimal stimulation strategy for an individual patient.}, keywords = {Deep brain stimulation; neural mass model; stimulation evoked response}, year = {2018}, eissn = {1741-2552} } @article{MTMT:27302990, title = {Intracranial Electrophysiology of the Human Default Network}, url = {https://m2.mtmt.hu/api/publication/27302990}, author = {Fox, Kieran C R and Foster, Brett L and Kucyi, Aaron and Daitch, Amy L and Parvizi, Josef}, doi = {10.1016/j.tics.2018.02.002}, journal-iso = {TRENDS COGN SCI}, journal = {TRENDS IN COGNITIVE SCIENCES}, volume = {22}, unique-id = {27302990}, issn = {1364-6613}, year = {2018}, eissn = {1879-307X}, pages = {307-324} } @article{MTMT:27555163, title = {Induction and Quantification of Excitability Changes in Human Cortical Networks}, url = {https://m2.mtmt.hu/api/publication/27555163}, author = {Keller, Corey J and Huang, Yuhao and Herrero, Jose L and Fini, Maria E and Du, Victor and Lado, Fred A and Honey, Christopher J and Mehta, Ashesh D}, doi = {10.1523/JNEUROSCI.1088-17.2018}, journal-iso = {J NEUROSCI}, journal = {JOURNAL OF NEUROSCIENCE}, volume = {38}, unique-id = {27555163}, issn = {0270-6474}, year = {2018}, eissn = {1529-2401}, pages = {S384-S398} } @article{MTMT:27302993, title = {Neurophysiological and cognitive impairment following repeated sports concussion injuries in retired professional rugby league players}, url = {https://m2.mtmt.hu/api/publication/27302993}, author = {Pearce, Alan J and Rist, Billymo and Fraser, Clare L and Cohen, Adrian and Maller, Jerome J}, doi = {10.1080/02699052.2018.1430376}, journal-iso = {BRAIN INJURY}, journal = {BRAIN INJURY}, volume = {32}, unique-id = {27302993}, issn = {0269-9052}, year = {2018}, eissn = {1362-301X}, pages = {498-505} } @article{MTMT:27302994, title = {Considerations in performing and analyzing the responses of cortico-cortical evoked potentials in stereo-EEG}, url = {https://m2.mtmt.hu/api/publication/27302994}, author = {Prime, David and Rowlands, David and O'Keefe, Steven and Dionisio, Sasha}, doi = {10.1111/epi.13939}, journal-iso = {EPILEPSIA}, journal = {EPILEPSIA}, volume = {59}, unique-id = {27302994}, issn = {0013-9580}, year = {2018}, eissn = {1528-1167}, pages = {16-26} } @article{MTMT:30387617, title = {Direct Cortical Recordings Suggest Temporal Order of Task-Evoked Responses in Human Dorsal Attention and Default Networks}, url = {https://m2.mtmt.hu/api/publication/30387617}, author = {Raccah, Omri and Daitch, Amy L. and Kucyi, Aaron and Parvizi, Josef}, doi = {10.1523/JNEUROSCI.0079-18.2018}, journal-iso = {J NEUROSCI}, journal = {JOURNAL OF NEUROSCIENCE}, volume = {38}, unique-id = {30387617}, issn = {0270-6474}, abstract = {The past decade has seen a large number of neuroimaging studies focused on the anticorrelated functional relationship between the default mode network (DMN) and the dorsal attention network (DAN). Due principally to the low temporal resolution of functional neuroimaging modalities, the fast-neuronal dynamics across these networks remain poorly understood. Here we report novel human intracranial electrophysiology data from six neurosurgical patients ( four males) with simultaneous coverage of well characterized nodes of the DMN and DAN. Subjects performed an arithmetic processing task, shown previously to evoke reliable deactivations (below baseline) in the DMN, and activations in the DAN. In this cohort, we show that DMN deactivations lag DAN activations by approximately 200 ms. Our findings suggest a clear temporal order of processing across the two networks during the current task and place the DMN further than the DAN in a plausible information-processing hierarchy.}, keywords = {electrocorticography; default mode network; Intracranial EEG; dorsal attention network; network neuroscience}, year = {2018}, eissn = {1529-2401}, pages = {10305-10313} } @article{MTMT:30387609, title = {Critical Language Areas Show Increased Functional Connectivity in Human Cortex}, url = {https://m2.mtmt.hu/api/publication/30387609}, author = {Rolston, John D. and Chang, Edward F.}, doi = {10.1093/cercor/bhx271}, journal-iso = {CEREB CORTEX}, journal = {CEREBRAL CORTEX}, volume = {28}, unique-id = {30387609}, issn = {1047-3211}, abstract = {Electrocortical stimulation (ECS) mapping is routinely used to identify critical language sites before resective neurosurgery. The precise locations of these sites are highly variable across patients, occurring in the frontal, temporal, and parietal lobes-it is this variability that necessitates individual patient mapping. But why these particular anatomical sites are so privileged in each patient is unknown. We hypothesized that critical language sites have greater functional connectivity with nearby cortex than sites without critical functions, since they serve as central nodes within the language network. Functional connectivity across language, motor, and cleared sites was measured in 15 patients undergoing electrocortiographic (ECoG) mapping for epilepsy surgery. Critical language sites had significantly higher connectivity than sites without critical functions (P = 0.001), and this also held for motor sites (P = 0.022). These data support the hypothesis that critical language sites are highly connected within the local cortical network, perhaps explaining why their disruption with ECS leads to transient disturbances in language function. It is our hope that improved understanding of the mechanisms of ECS will permit improved surgical planning and perhaps contribute to the understanding of normal language physiology.}, keywords = {electrocorticography; electrical stimulation; Speech; Mapping; alpha band}, year = {2018}, eissn = {1460-2199}, pages = {4161-4168} } @article{MTMT:27302991, title = {Understanding the Hierarchical Organization of Large-Scale Networks Based on Temporal Modulations in Patterns of Neural Connectivity}, url = {https://m2.mtmt.hu/api/publication/27302991}, author = {Shafi, Reema}, doi = {10.1523/JNEUROSCI.3503-17.2018}, journal-iso = {J NEUROSCI}, journal = {JOURNAL OF NEUROSCIENCE}, volume = {38}, unique-id = {27302991}, issn = {0270-6474}, year = {2018}, eissn = {1529-2401}, pages = {3154-3156} } @article{MTMT:30387610, title = {Probabilistic functional tractography of the human cortex revisited}, url = {https://m2.mtmt.hu/api/publication/30387610}, author = {Trebaul, Lena and Deman, Pierre and Tuyisenge, Viateur and Jedynak, Maciej and Hugues, Etienne and Rudrauf, David and Bhattacharjee, Manik and Tadel, Francois and Chanteloup-Foret, Blandine and Saubat, Carole and Mejia, Gina Catalina Reyes and Adam, Claude and Nica, Anca and Pail, Martin and Dubeau, Francois and Rheims, Sylvain and Trebuchon, Agnes and Wang, Haixiang and Liu, Sinclair and Blauwblomme, Thomas and Garces, Mercedes and De Palma, Luca and Valentin, Antonio and Metsahonkala, Eeva-Liisa and Petrescu, Ana Maria and Landre, Elizabeth and Szurhaj, William and Hirsch, Edouard and Valton, Luc and Rocamora, Rodrigo and Schulze-Bonhage, Andreas and Mindruta, Ioana and Francione, Stefano and Maillard, Louis and Taussig, Delphine and Kahane, Philippe and David, Olivier}, doi = {10.1016/j.neuroimage.2018.07.039}, journal-iso = {NEUROIMAGE}, journal = {NEUROIMAGE}, volume = {181}, unique-id = {30387610}, issn = {1053-8119}, abstract = {In patients with pharmaco-resistant focal epilepsies investigated with intracranial electroencephalography (iEEG), direct electrical stimulations of a cortical region induce cortico-cortical evoked potentials (CCEP) in distant cerebral cortex, which properties can be used to infer large scale brain connectivity. In 2013, we proposed a new probabilistic functional tractography methodology to study human brain connectivity. We have now been revisiting this method in the F-TRACT project (f-tract.eu) by developing a large multicenter CCEP database of several thousand stimulation runs performed in several hundred patients, and associated processing tools to create a probabilistic atlas of human cortico-cortical connections. Here, we wish to present a snapshot of the methods and data of F-TRACT using a pool of 213 epilepsy patients, all studied by stereo-encephalography with intracerebral depth electrodes. The CCEPs were processed using an automated pipeline with the following consecutive steps: detection of each stimulation run from stimulation artifacts in raw intracranial EEG (iEEG) files, bad channels detection with a machine learning approach, model-based stimulation artifact correction, robust averaging over stimulation pulses. Effective connectivity between the stimulated and recording areas is then inferred from the properties of the first CCEP component, i.e. onset and peak latency, amplitude, duration and integral of the significant part. Finally, group statistics of CCEP features are implemented for each brain parcel explored by iEEG electrodes. The localization (coordinates, white/gray matter relative positioning) of electrode contacts were obtained from imaging data (anatomical MRI or CT scans before and after electrodes implantation). The iEEG contacts were repositioned in different brain parcellations from the segmentation of patients' anatomical MRI or from templates in the MNI coordinate system. The F-TRACT database using the first pool of 213 patients provided connectivity probability values for 95% of possible intrahemispheric and 56% of interhemispheric connections and CCEP features for 78% of intrahemisheric and 14% of interhemispheric connections. In this report, we show some examples of anatomo-functional connectivity matrices, and associated directional maps. We also indicate how CCEP features, especially latencies, are related to spatial distances, and allow estimating the velocity distribution of neuronal signals at a large scale. Finally, we describe the impact on the estimated connectivity of the stimulation charge and of the contact localization according to the white or gray matter. The most relevant maps for the scientific community are available for download on f-tract. eu (David et al., 2017) and will be regularly updated during the following months with the addition of more data in the F-TRACT database. This will provide an unprecedented knowledge on the dynamical properties of large fiber tracts in human.}, keywords = {EPILEPSY; Brain atlas; Intracranial electroencephalogram; Cortico-cortical evoked potentials; Connectivity mapping}, year = {2018}, eissn = {1095-9572}, pages = {414-429}, orcid-numbers = {David, Olivier/0000-0003-0776-0216} } @article{MTMT:27302992, title = {Automatic bad channel detection in intracranial electroencephalographic recordings using ensemble machine learning}, url = {https://m2.mtmt.hu/api/publication/27302992}, author = {Tuyisenge, Viateur and Trebaul, Lena and Bhattacharjee, Manik and Chanteloup-Foret, Blandine and Saubat-Guigui, Carole and Mindruta, Ioana and Rheims, Sylvain and Maillard, Louis and Kahane, Philippe and Taussig, Delphine and David, Olivier}, doi = {10.1016/j.clinph.2017.12.013}, journal-iso = {CLIN NEUROPHYSIOL}, journal = {CLINICAL NEUROPHYSIOLOGY}, volume = {129}, unique-id = {27302992}, issn = {1388-2457}, year = {2018}, eissn = {1872-8952}, pages = {548-554}, orcid-numbers = {David, Olivier/0000-0003-0776-0216} } @article{MTMT:30387618, title = {Evoked directional network characteristics of epileptogenic tissue derived from single pulse electrical stimulation}, url = {https://m2.mtmt.hu/api/publication/30387618}, author = {van Blooijs, Dorien and Leijten, Frans S. S. and van Rijen, Peter C. and Meijer, Hil G. E. and Huiskamp, Geertjan J. M.}, doi = {10.1002/hbm.24309}, journal-iso = {HUM BRAIN MAPP}, journal = {HUMAN BRAIN MAPPING}, volume = {39}, unique-id = {30387618}, issn = {1065-9471}, abstract = {We investigated effective networks constructed from single pulse electrical stimulation (SPES) in epilepsy patients who underwent intracranial electrocorticography. Using graph analysis, we compared network characteristics of tissue within and outside the epileptogenic area. In 21 patients with subdural electrode grids (1 cm interelectrode distance), we constructed a binary, directional network derived from SPES early responses (<100 ms). We calculated in-degree, out-degree, betweenness centrality, the percentage of bidirectional, receiving and activating connections, and the percentage of connections toward the (non-)epileptogenic tissue for each node in the network. We analyzed whether these network measures were significantly different in seizure onset zone (SOZ)-electrodes compared to non-SOZ electrodes, in resected area (RA)-electrodes compared to non-RA electrodes, and in seizure free compared to not seizure-free patients. Electrodes in the SOZ/RA showed significantly higher values for in-degree and out-degree, both at group level, and at patient level, and more so in seizure-free patients. These differences were not observed for betweenness centrality. There were also more bidirectional and fewer receiving connections in the SOZ/RA in seizure-free patients. It appears that the SOZ/RA is densely connected with itself, with only little input arriving from non-SOZ/non-RA electrodes. These results suggest that meso-scale effective network measures are different in epileptogenic compared to normal brain tissue. Local connections within the SOZ/RA are increased and the SOZ/RA is relatively isolated from the surrounding cortex. This offers the prospect of enhanced prediction of epilepsy-prone brain areas using SPES.}, keywords = {EPILEPSY; electrocorticography; surgery; bidirectional network; epileptogenic zone; single pulse electrical stimulation}, year = {2018}, eissn = {1097-0193}, pages = {4611-4622}, orcid-numbers = {van Blooijs, Dorien/0000-0002-7998-414X} } @article{MTMT:30387613, title = {Test-retest reliability of a stimulation-locked evoked response to deep brain stimulation in subcallosal cingulate for treatment resistant depression}, url = {https://m2.mtmt.hu/api/publication/30387613}, author = {Waters, Allison C. and Veerakumar, Ashan and Choi, Ki Sueng and Howell, Bryan and Tiruvadi, Vineet and Bijanki, Kelly R. and Crowell, Andrea and Riva-Posse, Patricio and Mayberg, Helen S.}, doi = {10.1002/hbm.24327}, journal-iso = {HUM BRAIN MAPP}, journal = {HUMAN BRAIN MAPPING}, volume = {39}, unique-id = {30387613}, issn = {1065-9471}, abstract = {Deep brain stimulation (DBS) to the subcallosal cingulate cortex (SCC) is an emerging therapy for treatment resistant depression. Precision targeting of specific white matter fibers is now central to the model of SCC DBS treatment efficacy. A method to confirm SCC DBS target engagement is needed to reduce procedural variance across treatment providers and to optimize DBS parameters for individual patients. We examined the reliability of a novel cortical evoked response that is time-locked to a 2 Hz DBS pulse and shows the propagation of signal from the DBS target. The evoked response was detected in four individuals as a stereotyped series of components within 150 ms of a 6 V DBS pulse, each showing coherent topography on the head surface. Test-retest reliability across four repeated measures over 14 months met or exceeded standards for valid test construction in three of four patients. Several observations in this pilot sample demonstrate the prospective utility of this method to confirm surgical target engagement and instruct parameter selection. The topography of an orbital frontal component on the head surface showed specificity for patterns of forceps minor activation, which may provide a means to confirm DBS location with respect to key white matter structures. A divergent cortical response to unilateral stimulation of left (vs. right) hemisphere underscores the need for feedback acuity on the level of a single electrode, despite bilateral presentation of therapeutic stimulation. Results demonstrate viability of this method to explore patient-specific cortical responsivity to DBS for brain-circuit pathologies.}, keywords = {Deep brain stimulation; treatment resistant depression; Cortico-cortical evoked potential; forceps minor; stimulation evoked potential; subcallosal cingulate cortex; white matter tractography}, year = {2018}, eissn = {1097-0193}, pages = {4844-4856} } @article{MTMT:30387621, title = {Phase-Locked Stimulation during Cortical Beta Oscillations Produces Bidirectional Synaptic Plasticity in Awake Monkeys}, url = {https://m2.mtmt.hu/api/publication/30387621}, author = {Zanos, Stavros and Rembado, Irene and Chen, Daofen and Fetz, Eberhard E.}, doi = {10.1016/j.cub.2018.07.009}, journal-iso = {CURR BIOL}, journal = {CURRENT BIOLOGY}, volume = {28}, unique-id = {30387621}, issn = {0960-9822}, abstract = {The functional role of cortical beta oscillations, if any, remains unresolved. During oscillations, the periodic fluctuation in excitability of entrained cells modulates transmission of neural impulses and periodically enhances synaptic interactions. The extent to which oscillatory episodes affect activity-dependent synaptic plasticity remains to be determined. In nonhuman primates, we delivered single-pulse electrical cortical stimulation to a "stimulated'' site in sensorimotor cortex triggered on a specific phase of ongoing beta (12-25 Hz) field potential oscillations recorded at a separate "triggering'' site. Corticocortical connectivity from the stimulated to the triggering site as well as to other (non-triggering) sites was assessed by cortically evoked potentials elicited by test stimuli to the stimulated site, delivered outside of oscillatory episodes. In separate experiments, connectivity was assessed by intracellular recordings of evoked excitatory postsynaptic potentials. The conditioning paradigm produced transient (1-2 s long) changes in connectivity between the stimulated and the triggering site that outlasted the duration of the oscillatory episodes. The direction of the plasticity effect depended on the phase from which stimulation was triggered: potentiation in depolarizing phases, depression in hyperpolarizing phases. Plasticity effects were also seen at non-triggering sites that exhibited oscillations synchronized with those at the triggering site. These findings indicate that cortical beta oscillations provide a spatial and temporal substrate for short-term, activity-dependent synaptic plasticity in primate neocortex and may help explain the role of oscillations in attention, learning, and cortical reorganization.}, year = {2018}, eissn = {1879-0445}, pages = {2515-+} } @article{MTMT:30387620, title = {The effectiveness of cortico-cortical evoked potential in detecting seizure onset zones}, url = {https://m2.mtmt.hu/api/publication/30387620}, author = {Zhang, Nan and Zhang, Bingqing and Rajah, Gary B. and Geng, Xiaokun and Singh, Rasanjeet and Yang, Yanfeng and Yan, Xiupeng and Li, Zhe and Zhou, Wenjing and Ding, Yuchuan and Sun, Wei}, doi = {10.1080/01616412.2018.1454092}, journal-iso = {NEUROL RES}, journal = {NEUROLOGICAL RESEARCH}, volume = {40}, unique-id = {30387620}, issn = {0161-6412}, abstract = {Objective:The aim of the study was to evaluate the parameters for localizing the seizure onset zone in refractory epilepsy patients using cortico-cortical evoked potentials (CCEP).}, keywords = {RMS; CCEP; medically refractory epilepsy; seizure onset zone; seizure propagation zone}, year = {2018}, eissn = {1743-1328}, pages = {480-490} } @article{MTMT:26910907, title = {Are the Neural Correlates of Consciousness in the Front or in the Back of the Cerebral Cortex? Clinical and Neuroimaging Evidence}, url = {https://m2.mtmt.hu/api/publication/26910907}, author = {Boly, Melanie and Massimini, Marcello and Tsuchiya, Naotsugu and Postle, Bradley R and Koch, Christof and Tononi, Giulio}, doi = {10.1523/JNEUROSCI.3218-16.2017}, journal-iso = {J NEUROSCI}, journal = {JOURNAL OF NEUROSCIENCE}, volume = {37}, unique-id = {26910907}, issn = {0270-6474}, year = {2017}, eissn = {1529-2401}, pages = {9603-9613} } @article{MTMT:26556208, title = {Stable functional networks exhibit consistent timing in the human brain}, url = {https://m2.mtmt.hu/api/publication/26556208}, author = {Chapeton, Julio I and Inati, Sara K and Zaghloul, Kareem A}, doi = {10.1093/brain/aww337}, journal-iso = {BRAIN}, journal = {BRAIN}, volume = {140}, unique-id = {26556208}, issn = {0006-8950}, year = {2017}, eissn = {1460-2156}, pages = {628-640} } @{MTMT:31406154, title = {Connectomics in Patients with Temporal Lobe Epilepsy}, url = {https://m2.mtmt.hu/api/publication/31406154}, author = {Donos, Cristian and Barborica, Andrei and Mindruta, Ioana and Maliia, Mihai and Popa, Irina and Ciurea, Jean}, booktitle = {THE PHYSICS OF THE MIND AND BRAIN DISORDERS}, doi = {10.1007/978-3-319-29674-6_20}, unique-id = {31406154}, year = {2017}, pages = {447-468} }