Lupin Intoxication Presenting as a Stroke Mimic in an Elderly Patient: A Case Report

Bitter lupin beans are traditionally consumed in the Eastern Mediterranean region and contain quinolizidine alkaloids (QAs), including lupanine and sparteine.Inadequate processing may result in clinically significant exposure to these alkaloids, which interfere with cholinergic neurotransmission and can produce neurological and autonomic manifestations.Although lupin intoxication is classically associated with features such as mydriasis, xerostomia, tachycardia, visual disturbances, and urinary retention, the clinical presentation may be variable.We report the case of a 78-year-old man with multiple vascular risk factors and a history of bioprosthetic aortic valve replacement who presented to the emergency department (ED) with acute dysarthria, severe dizziness, gait instability, and urinary retention shortly after consuming approximately one cup of home-prepared bitter lupin beans.Because of the abrupt neurological presentation, an acute stroke protocol was initiated.Brain magnetic resonance imaging (MRI), including diffusion-weighted sequences, showed no definite evidence of acute ischemic injury.Following neurological assessment and consideration of the exposure history and clinical course, lupin-induced neurotoxicity was considered the most likely clinical diagnosis.The patient received supportive care, with complete resolution of urinary and neurological symptoms within approximately 24 hours.This case highlights an uncommon presentation of lupin intoxication in which neurological manifestations closely mimicked an acute cerebrovascular event.Recognition of dietary exposures may be particularly important in emergency settings when evaluating patients with acute neurological symptoms while maintaining appropriate consideration of cerebrovascular disease.