Reversible Cerebral Vasoconstriction Syndrome: Recognition and Treatment.

Reversible cerebral vasoconstriction syndrome (RCVS) is a rare but increasingly recognized disorder with over 500 cases published in the literature. The condition is characterized by recurrent severe thunderclap headaches with or without other neurological symptoms and diffuse segmental narrowing of the cerebral arteries which is reversible within 3 months. RCVS may occur spontaneously but in over 50% of cases, it is associated with various other conditions, including vasoactive medications or illicit drugs and the post-partum state. One third to a half of cases develop hemorrhagic or ischemic brain lesions or a combination of both. Posterior reversible encephalopathy syndrome (PRES) often occurs in association with RCVS and the conditions are likely to share a common pathophysiology. The pathogenesis of RCVS remains uncertain but autonomic dysregulation, oxidative stress, and genetic predisposition are postulated. Significant differential diagnoses include subarachnoid hemorrhage (SAH) due to aneurysmal rupture, cervical artery dissection, and primary angiitis of the central nervous system (PACNS). Although there is no proven treatment, calcium channel antagonists including nimodipine and verapamil have been administered with reported reduction of headache intensity but without effect on the time course of cerebral vasoconstriction. Glucocorticoids have been reported as an independent predictor of worse outcome and should be avoided. The cornerstone of RCVS management remains largely supportive with bed rest and analgesics and removal of precipitating factors. Invasive neurointerventional techniques should be reserved for severe deteriorating cases. The condition is usually benign and self-limited and the majority of patients have a favorable outcome but around 5-10% are left with permanent neurological deficits and rare cases may die. This review details the importance of the early recognition of this increasingly described condition and current treatment recommendations.