Terminal spreading depolarizations causing electrocortical silencing prior to clinical brain death: case report

Abstract

The authors report on a 57-year-old woman in whom progression to brain death occurred on day 9 after aneurysmal subarachnoid hemorrhage without evidence of significant brain edema or vasospasm. Neuromonitoring demonstrated that brain death was preceded by a series of cortical spreading depolarizations that occurred in association with progressive hypoxic episodes. The depolarizations induced final electrical silence in the cortex and ended with a terminal depolarization that persisted > 7 hours. To the authors' knowledge, this is the first report of terminal spreading depolarization in the human brain prior to clinical brain death and major cardiopulmonary failure.

Keywords: DC = direct current; ECoG = electrocorticography; ICP = intracranial pressure; NUP = negative ultraslow potential; SD = spreading depolarization; SpO2 = peripheral capillary oxygen saturation; aSAH = aneurysmal subarachnoid hemorrhage; brain death; electrocorticography; electrophysiology; ptiO2 = brain tissue partial pressure of oxygen; spreading depolarization; subarachnoid hemorrhage; vascular disorders.