Reversible cerebral vasoconstriction syndrome presenting as thunderclap headache following high-altitude exposure and coca leaf tea consumption

Background: Reversible cerebral vasoconstriction syndrome (RCVS) is a rare cause of thunderclap headache, often triggered by environmental or pharmacologic stressors. Methods: A 56-year-old women presented with thunderclap headache and focal neurological signs following high-altitude exposure and coca leaf tea consumption Results: Neuroimaging demonstrated acute ischemic lesions in different arterial territories and severe narrowing of all medium-diameter intracranial arteries. She was started on dual antiplatelet therapy, intravenous fluids, and was instructed to remain in bed in a strictly flat position. Repeated MRI showed marked improvement of both ischemic lesions and the arterial vasospasm. Conclusion: High-altitude hypoxia and sympathomimetic alkaloids may synergistically precipitate RCVS. Awareness of traditional remedies and environmental exposures is essential in evaluating acute neurological syndromes in travelers.