Cortical Spreading Depression and Ischemia in Neurocritical Patients.

Spreading depolarization in cerebral cortex is associated with swelling of neurons, distortion of dendritic spines, massive ion translocation with a large change of the slow electrical potential, and silencing of brain electrical activity. The term spreading depression represents a wave of spontaneous activity of the electrocorticogram that propagates through contiguous cerebral gray matter at a characteristic velocity. Spreading depression is a consequence of cortical spreading depolarization. Therefore, spreading depolarization is not always accompanied by spreading depression and the terms are not synonymous.