Transient global amnesia and migraine.

Twelve patients with transient global amnesia (TGA) had prior migraines (six classical and six common). In three patients, classic migrainous phenomena accompanied TGA, and in nine patients severe headache accompanied the amnestic attack. Migrainous vascular dysfunction in the dominant posterior cerebral artery territory could explain TGA: (1) The pathophysiology and transient nature of TGA have led many to postulate posterior circulation vascular disease; migraine is a vascular disorder with a posterior circulation bias. (2) TGA and migraine share common precipitants. (3) Migraine differs from arteriosclerotic ischemia; the repetitive queries of TGA are absent in amnestic stroke. (4) TGA and migraine are usually benign.