COVID-19-Associated Reversible Cerebral Vasoconstriction Syndrome: A Rare Case of Secondary Thunderclap Headache.

Reversible cerebral vasoconstriction syndrome (RCVS) is a condition characterized by severe, sudden headaches, and transient cerebral artery constriction, often triggered by medications, physical activities, or comorbidities. Recent studies have linked RCVS to SARS-CoV-2 infection. This case report presents a novel instance of RCVS with nonaneurysmal subarachnoid hemorrhage (SAH) following COVID-19. A 44-year-old female with COVID-19 presented with a sudden, severe headache, confusion, dizziness, and photophobia. Imaging revealed extensive SAH and hydrocephalus. Despite the absence of classic RCVS triggers, a cerebral angiogram showed multifocal vasospasms in both anterior and posterior circulations which later resolved on repeat cerebral angiography. The patient's condition improved with external ventricular drainage followed by symptomatic treatment. She was diagnosed with RCVS after achieving an RCVS2 score of seven points. She had a final modified Rankin scale of zero at 40-month follow-up. This case highlights the potential association between COVID-19 and RCVS, even in the absence of common triggers. While causality cannot be definitively established, the temporal relationship and plausible biological mechanisms warrant further investigation. This report underscores the importance of considering RCVS in patients with neurological symptoms following COVID-19 and contributes to the understanding of the virus's impact on the vasculature.