Cortical spreading depression and estrogen.

Cortical spreading depression (CSD) is an electrophysiological phenomenon characterized by a wave of excitation followed by inhibition. The aura phase that precedes migraine headache in about 20-30% of migraineurs shares overlapping characteristics with CSD. Studies of rare autosomal-dominant forms of migraine with aura provide strong evidence that the threshold for evoking CSD and aura are related to neuronal excitability. Although the relationship between CSD and migraine without aura is not completely understood, the molecular abnormalities that predispose to migraine with aura illustrate the importance of physiologic events associated with neuronal hyperexcitability, and provide a basis for understanding a more generalized view of migraine.