Epidemiology, clinical presentation and pathology of vasospasm

Symptomatic vasospasme or delayed cerebral ischemia associated with arterio graphic evidence of arterial constriction is currently the most important c ause of morbidity after acute subarachnoid hemorrhage. Symptomatic vasospas m usually develops between 4 and 12 days after subarachnoid hemorrhage. The re is typically a gradual deterioration of the level of consciousness accom panied by focal neurological deficits. 30% of patients who survived aneurys mal SAH develop delayed cerebral ischemia secondary to vasospasm. Vasospasm produces cerebral ischemia and infarction by hemodynamic mechanisms. Vasos pasm is an important independant predictor of poor outcome after aneurysmal SAH. Other conditions than aneurysmal subarachnoid hemorrhage such as trauma, tu mors, unruptured aneurysms, meningitis and ruptured AVM may be associated w ith vasospasm.