Alpha-1-antitrypsin deficiency in spontaneous intracranial arterial dissections.

alpha 1-Antitrypsin deficiency has been associated with a variety of vascular disorders including arterial aneurysms, spontaneous extracranial arterial dissections, and arterial fibromuscular dysplasia. We determined the distribution of alpha 1-antitrypsin phenotypes in patients with intracranial arterial dissections, a rare cause of subarachnoid hemorrhage. The study population consisted of 4 consecutive patients with subarachnoid hemorrhage due to spontaneous intracranial arterial dissections. The vertebral artery was involved in 3 patients and the posterior inferior cerebellar artery in 1 patient. Three of these 4 patients were found to have a heterozygous alpha 1-antitrypsin deficiency (PiMZ or PiMS phenotypes). These data support previous studies suggesting that patients with alpha 1-antitrypsin deficiency may be at an increased risk of developing spontaneous arterial dissections.