Vasospasm After Subarachnoid Hemorrhage

Abstract

Aneurysmal subarachnoid hemorrhage is associated with high rates of morbidity and mortality. In patients who survive the initial hemorrhage, post-hemorrhage complications account for the majority of the morbidity and mortality. Among these complications in the sequelae of the disease, cerebral vasospasm represents a major contributor to the final clinical outcome. Post-hemorrhage neurological deterioration after aneurysmal subarachnoid hemorrhage can often be attributed to delayed cerebral ischemia stemming from prolonged cerebral vasospasm, reduced cerebral blood flow, oxygen delivery, and secondary ischemic injury. As such, the timely detection, screening, diagnosis, and management of cerebral vasospasm can limit delayed cerebral ischemia and improve outcome in patients with subarachnoid hemorrhage. The diagnosis of vasospasm is a multifaceted approach that encompasses the clinical examination in conjunction with supportive neuroradiologic investigations. Among these, transcranial Doppler represents a noninvasive and readily accessible diagnostic tool to screen and diagnose cerebral vasospasm. Furthermore, TCD can also be used in the titration of interventional therapies aimed at improving cerebral blood flow in the setting of vasospasm using induced hypertensive therapy or systemic milrinone. The use of TCD in such a setting requires a multidisciplinary approach that enables experienced personnel to conduct examinations in a reproducible manner upon which therapeutic intervention can be based. This chapter reviews the diagnosis, prevention, and management of delayed cerebral ischemia and arterial vasospasm after aneurysmal subarachnoid hemorrhage.