Neurológiai betegségek (pl. Alzheimer-kór, Huntington-kór, Parkinson-kór)
We investigated the functional network reorganization caused by low-frequency electrical
stimulation (LFES) of human brain cortical surface. Intracranial EEG data from subdural
grid positions were analyzed in 16 pre-surgery epileptic patients. LFES was performed
by injecting current pulses (10[Formula: see text]mA, 0.2[Formula: see text]ms pulse
width, 0.5[Formula: see text]Hz, 25 trials) into all adjacent electrode contacts.
Dynamic functional connectivity analysis was carried out on two frequency bands (low:
1–4[Formula: see text]Hz; high: 10–40[Formula: see text]Hz) to investigate the early,
high frequency and late, low frequency responses elicited by the stimulation. The
centralization increased in early compared to late responses, suggesting a more prominent
role of direct neural links between primarily activated areas and distant brain regions.
Injecting the current into the seizure onset zone (SOZ) evoked a more integrated functional
topology during the early (N1) period of the response, whereas during the late (N2)
period — regardless of the stimulation site — the connectedness of the SOZ was elevated
compared to the non-SOZ tissue. The abnormal behavior of the epileptic sub-network
during both part of the responses supports the idea of the pathogenic role of impaired
inhibition and excitation mechanisms in epilepsy.
