Triggers And Risk Factors to Develop a Reversible Cerebral Vasoconstriction Syndrome

This study investigates the triggers and risk factors for reversible cerebral vasoconstriction syndrome (RCVS), a condition where brain arteries suddenly and severely narrow, causing intense "thunderclap" headaches and sometimes stroke-like symptoms. The narrowing usually resolves on its own within weeks, but doctors still don't fully understand what causes it or why some people are at risk. The study compares people who have been diagnosed with RCVS against healthy volunteers and patients with non-neurological acute conditions, looking for differences in genetics, medications, lifestyle factors, and hormonal profiles that might explain why RCVS occurs. You may be eligible if (patients): - You are a man or woman aged 18 or older - You are being treated at the CHU of Montpellier - You were diagnosed with RCVS within the past 14 days - You have provided written informed consent You may be eligible if (volunteers): - You are a man or woman aged 18 or older, matched to a case patient by sex and age - You have an acute non-neurological and non-vascular condition OR are a healthy subject You may NOT be eligible if: - You are in a coma, have severe cognitive impairment, a language barrier, or severe aphasia - Follow-up for 3 months is considered impossible due to another priority condition - You are under legal protection or refuse to participate Talk to your doctor to see if this trial is right for you.