37 - Reversible Cerebral Vasoconstriction Syndromes

Abstract

The term reversible cerebral vasoconstriction syndrome (RCVS) refers to a group of conditions manifesting with segmental narrowing and dilatation of multiple intracranial arteries, usually heralded by a sudden, severe (thunderclap) headache. The vast majority of patients report recurrences of thunderclap headache over a span of days to weeks. Inpatient case series show that approximately one-third to one-half can develop neurologic deficits that are typically mild and related to complications such as ischemic or hemorrhagic stroke, convexity subarachnoid hemorrhage, or brain edema. Yet, the clinical outcome remains favorable in over 90% to 95% of patients. The intracranial vascular abnormalities resolve spontaneously within a few weeks. RCVS has been associated with numerous conditions including pregnancy and vasoconstrictive drug exposure; however, its pathophysiology remains relatively unknown. There appears to be significant overlap with primary thunderclap headache and posterior reversible leukoencephalopathy syndrome. Management involves pain relief, removal of any identified vasoconstrictive factors, calcium-channel blockers to relieve headaches, and avoidance of glucocorticoids since they can significantly worsen outcome. Intra-arterial vasodilator infusion has been attempted to treat severe vasoconstriction, with variable success. Over the last two decades RCVS multiple groups have characterized the clinical and imaging features, and shown how to distinguish RCVS from mimics such as primary cerebral vasculitis and aneurysmal subarachnoid hemorrhage. The recently developed RCVS2 score provides up to 99% specificity and 90% sensitivity for diagnosing RCVS upon initial presentation. These advances have enabled the prompt recognition and diagnosis of RCVS, resulting in improved management.