“…Multisegmental vasoconstriction has been reported in patients with a history of migraines, as well as in the postpartum period, following sexual intercourse, following aneurysmal SAH, and after admin- istration of serotonergic or sympathomimetic drugs. 9 Similar angiographic findings can also be associated with cerebral vasculitis or primary angiitis of the CNS, but these patients present with gradually progressive neurologic symptoms, encephalopathy, and CSF abnormalities in 80%-90% of cases. 10 The clinical context of pseudoephedrine ingestion, acute thunderclap headache, the rapidly progressive clinical course, and the imaging findings combined led to a diagnosis of RCVS in our case.…”