Cortical Subarachnoid Hemorrhage and Reversible Cerebral Vasoconstriction After a Roller‐Coaster Ride

ABSTRACT Roller‐coaster headache is a rare condition, and its underlying mechanisms remain poorly understood. We report a case of cortical subarachnoid hemorrhage (SAH) with reversible cerebral vasoconstriction presenting as a thunderclap headache during a roller‐coaster ride. A 43‐year‐old woman with untreated hypertension developed a sudden severe headache during rapid descent, and brain imaging revealed non‐aneurysmal cortical SAH with multifocal cerebral arterial narrowing. Follow‐up magnetic resonance angiography demonstrated resolution of vasoconstriction, supporting the diagnosis of reversible cerebral vasoconstriction syndrome (RCVS). The temporal relationship between SAH and vasoconstriction could not be definitively established, as neuroimaging was performed 4 days after symptom onset. Two mechanisms were considered: RCVS triggered by an abrupt blood pressure surge and SAH followed by secondary post‐traumatic vasospasm. Although both are plausible, the distribution of vasoconstriction favors RCVS. Clinicians should consider both RCVS and post‐traumatic vasospasm in patients presenting with persistent severe headache, and repeat neuroimaging may be warranted.