Cerebral aneurysms and cervical artery dissection: Neurological complications and genetic associations.

Dissections and aneurysms are two of the more common nonatherosclerotic arteriopathies of the cerebrovascular system and a significant contributor to neurovascular complications, particularly in the young. Specifically, ruptured intracranial aneurysms (IA) account for nearly 500,000 cases of subarachnoid hemorrhage annually with a 30-day mortality approaching 40% and survivors suffering often permanent neurologic deficits and disability. Unruptured IAs require dedicated assessment of risk and often warrant serial radiologic monitoring. Cervical artery dissection, affecting the carotid and vertebral arteries, accounts for nearly 20% of strokes in young and middle-aged adults. While approximately 70% of cervical artery dissection (CeAD) cases present with stroke or TIA, additional neurologic complications include severe headache and neck pain, oculosympathetic defect (i.e., partial Horner's syndrome), acute vestibular syndrome, and rarely lower cranial nerve palsies. Both aneurysms and dissections of the cerebrovascular system may occur frequently in patients with syndromic connective tissue disorders; however, the majority of cases are spontaneously occurring or mildly heritable with both polygenic and environmental associations. Fibromuscular dysplasia, in particular, is commonly associated with both risk of CeAD and IA formation. Further research is needed to better understand the pathophysiology of both IA and CeAD to better understand risk, improve treatments, and prevent devastating neurologic complications.