Reversible cerebral vasoconstriction syndrome.

Reversible cerebral vasoconstriction syndrome is characterized by severe headaches with or without focal neurologic deficits and/or seizures, and segmental constriction of cerebral arteries that resolves within 3 months. This increasingly recognized syndrome is supposedly due to a transient disturbance in the control of cerebral vascular tone with sympathetic overactivity. It can cause stroke in the young. It affects mainly middle-aged women. More than half the cases occur after exposure to vasoactive substances or during postpartum. The manifestations have a monophasic course, without new clinical symptom after 4 weeks, and range from pure cephalalgic forms with recurrent thunderclap headaches over 1-2 weeks to rare catastrophic forms with multiple hemorrhagic and ischemic strokes, brain edema and death. Diagnosis may be hampered by the dynamic nature of clinicoradiological features. Convexity subarachnoid hemorrhage or stroke may occur a few days after initial normal imaging, and cerebral vasoconstriction is maximal on angiography 2-3 weeks after clinical onset. Symptomatic treatment includes rest and removal of vasoactive substances. Nimodipine has been proposed to reduce thunderclap headaches within 48 hours, but has no proven effect on the hemorrhagic and ischemic complications.