Spreading depression



Cortical spreading depression is a wave of hyperactivity followed by a wave of inhibition, usually in the visual cortex.

The term is used by neuroscientists to represent at least one of the following cortical processes:
 * The spreading of a self-propagating wave of cellular depolarization in the cerebral cortex.
 * The spreading of a wave of ischemia passing through an area of cortex.
 * The spreading of a wave of vasoconstriction following vasodilation of contiguous cortical arterioles.

The scintillating scotoma of migraine in humans may be related to the neurophysiologic phenomenon termed the spreading depression of Leão.

The spreading depression wave progresses across the cortex at approximately 3.6 mm/minute.