Epidemiology of intracranial aneurysm and subarachnoid hemorrhage.

Intracranial aneurysmal hemorrhage is a common but devastating condition associated with significant morbidity and mortality. Epidemiologic studies have identified risk factors associated with this condition. Genetic factors involve family history and the presence of certain heritable connective tissue disorders such as Ehlers-Danlos syndrome, Marfan's syndrome, neurofibromatosis, and polycystic kidney disease. Acquired factors include traumatic brain injury, sepsis, smoking, and hypertension. Management of these patients consists of prevention, patient screening, and prophylactic aneurysm repair.