In neurocritical care, the gold standard method is intracranial pressure (ICP) monitoring
for the patient's lifesaving. Since it is an invasive method, it is desirable to use
an alternative, noninvasive technique. The computerized real-time invasive cerebral
blood flow (CBF) autoregulation (AR) monitoring calculates the status of CBF AR, called
the pressure reactivity index (PRx). Studies documented that the electrical impedance
of the head (Rheoencephalography – REG) can detect the status of CBF AR (REGx) and
ICP noninvasively. We aimed to test REG to reflect ICP and CBF AR.
