ALPHA(1) ANTITRYPSIN DEFICIENCY IN INTRACRANIAL ANEURYSMS AND CERVICAL ARTERY DISSECTION

The pathogenesis of ruptured intracranial aneurysms and cervical arter y dissections is poorly understood but may be similar in these two dis orders. We report four patients with alpha(1)-antitrypsin deficiency w ho developed a ruptured intracranial aneurysm or spontaneous dissectio n of the cervical internal carotid artery. Three patients were heteroz ygous for the deficient allele (PiMZ or PiGZ) and one was homozygous ( PiZZ). A deficiency of alpha(1)-antitrypsin or one of the other protea se inhibitors could result in degradation of the arterial wall through an imbalance between proteolytic enzymes and their inhibitors, thereb y predisposing the arterial wall to dissection or aneurysm formation.