Role of vertebral artery hypoplasia in migraine.

The role of cerebral hypoperfusion in the posterior circulation has not been clearly established in migraine. The purpose of this study was to determine the role of vertebral artery (VA) hypoplasia in the pathogenesis of migraine. We studied the extracranial part of VA in 59 migraine patients (17 with and 42 without aura) using color Doppler. In migraine with aura, 29% of patients had hypoplastic VA, and in migraine without aura 7%. In migraine with aura, mean diameter of the right VA was 2.7+/-0.7 mm, and of the left 3.3+/-0.7 mm; in migraine without aura mean diameter was 3.1+/-0.5 mm on the right, and 3.3+/-0.6 on the left. In migraine with aura, mean systolic blood flow velocity was 55+/-16 cm/s on the right, 60+/-17 cm/s on the left, in migraine without aura 57+/-18 cm/s on the right, 57+/-18 cm/s on the left. We observed higher frequency of hypoplastic VA in migraine with aura, suggesting that hypoplasia of VA may be an additional factor which can lead to hypoperfusion in the posterior circulation during the aura phase.