Le syndrome de vasoconstriction cérébrale réversible

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by severe headaches, as well as vasoconstriction of cerebral arteries, which resolves spontaneously in one to three months. This condition has a moderate female preponderance. The mean age of onset is around 45 years. About 60% of the cases are secondary, mainly occurring during postpartum and/or after exposure to vasoactive substances. The main clinical presentation includes multiple recurrent thunderclap headaches over one to three weeks. The major complications of RCVS are localized cortical subarachnoid hemorrhages (cSAH) (20-25%) and parenchymal strokes (5-10%). Complications occur with different time courses: hemorrhages (cSAH and intracerebral hemorrhages), and posterior reversible encephalopathy syndrome are early events occurring during the first week, while ischemic events including TIAs and cerebral infarcts occur significantly later, during the second week. Diagnosis requires the demonstration of the “string and beads” aspect of cerebral arteries by a cerebral angiogram (MRA, CTA or conventional) and the demonstration of the complete or marked normalisation of arteries by a repeat angiogram performed within 12 weeks of onset. Treatment is based on nimodipine that seems to reduce thunderclap headaches within 48 h. However, nimodipine has not proven any efficacy against the hemorrhagic and ischemic complications of RCVS. Relapses are possible but rare and have not been reported yet in prospective series. It seems appropriate to advise the patients to avoid sympathomimetic and serotoninergic substances.