[Reversible cerebral vasoconstriction syndrome].
The reversible cerebral vasoconstriction syndrome (RCVS) is an under-estimated transient acute cerebrovascular disorder. It has long been mistaken as central nervous system vasculitis whereas it is now believed to result from an acute but prolonged vasospasm of cerebral arteries. This disorder can be precipitated by postpartum or vasoactive drug. However, it occurs spontaneously in a significant number of cases. The characteristic clinico-radiological presentation and disease course of the RCVS has been delineated only recently. Mean age at onset is 40-45 years, with a female predominance. A provocative factor can be identified in 12-60% out of the patients. Clinical presentation is predominantly marked by recurrent thunderclap headaches, but can be complicated with focal neurological deficit or seizures. Brain imaging is normal in most cases, but can reveal hemorrhagic or ischemic complications. Cortical subarachnoid hemorrhage is a suggestive finding. A posterior reversible encephalopathy syndrome (PRES) can be seen occasionally. Cerebral angiography reveals multifocal arterial narrowing with string and bead appearance. Cerebrospinal fluid reveals no or mild abnormalities. The disease resumes spontaneously within several days to weeks, whereas vasoconstriction reverses within 1 to 3 months. This clinico-radiological presentation should be promptly recognized in order to avoid unnecessary investigations and aggressive treatment, and lead to search for a triggering factor. Further studies are required in order to clarify the precipitating role of several drugs, and clinical trials are needed to reduce the occurrence of strokes.