Reversible cerebral vasoconstriction syndrome (RCVS) caused by over-the-counter calcium supplement ingestion.

A 59-year-old woman was found unresponsive at home. Initial neurologic examination revealed aphasia and right-sided weakness. Laboratory results demonstrated a serum calcium level of 17.3 mg/dL (corrected serum calcium for albumin concentration was 16.8 mg/dL). Extensive workup for intrinsic aetiology of hypercalcemia was unrevealing. Further discussion with family members and investigation of the patient's home for over-the-counter medications and herbal supplements revealed chronic ingestion of calcium carbonate tablets. CT angiogram of the brain revealed multifocal intracranial vascular segmental narrowing, which resolved on a follow-up cerebral angiogram done 2 days later. These findings were consistent with reversible cerebral vasoconstriction syndrome.Appropriate blood pressure control with parenteral agents, calcium channel blockade with nimodipine and supportive care therapies resulted in significant improvement in neurologic status. By discharge, patient had near-complete resolution of neurologic symptoms.