Résumé
"Reversible cerebral vasoconstriction syndrome" (RCVS) is a recently described entity that is mainly characterized by the association of severe ("thunderclap") headaches with or without additional neurological symptoms and diffuse, multifocal, segmental narrowings involving large and medium-sized cerebral arteries. By definition, angiographic abnormalities disappear within 3 months. The clinical course is usually benign, with a higher prevalence in young women. RCVS is idiopathic in the majority of the cases. However, recent papers have outlined the role of precipitating factors, including the use of vasoactive substances. Some patients, nevertheless, have a more severe clinical course with transient or permanent ischemic events. Hemorrhagic complications appear to have been underestimated. They are usually restricted to circumscribed cortical subarachnoid hemorrhage, in the absence of any ruptured cerebral aneurysm. This limited bleeding is unlikely at the origin of the diffuse vasoconstriction. The finding of an unruptured cerebral aneurysm in RCVS patients is probably incidental. An overlap is possible between RCVS and other syndromes such as posterior reversible encephalopathy syndrome. There is no standardized treatment regimen for RCVS patients. It appears rational to further investigate the efficacy and safety of the calcium-channel antagonist nimodipine.