Stroke Mimic Caused by Acetazolamide

OBJECTIVES: To describe a case of a stroke mimic caused by iatrogenic ataxia due to acetazolamide. CASE DESCRIPTION: An 86-year-old man with a history of gout and glaucoma, presented to the emergency department with progressive confusion, dizziness, disequilibrium and slurred speech, 3 days after he had started acetazolamide following ocular surgery. Physical examination showed he was hypertensive and had dysarthria; it was not possible to observe his gait due to pain in the right foot presumed to be due to a gout crisis. A stroke was thought to be the cause of these neurological deficits so a head CT scan was performed but did not show any alterations. During a stay in the stroke unit the neurological deficits remained unchanged and so, after review of the history, neurological side effects due to acetazolamide were suspected and the drug was suspended. A head MRI was performed to rule out stroke and the patient gradually improved. In the meanwhile, the patient was observed by an ophthalmologist and repeat surgery was proposed because of increased intraocular pressure. CONCLUSIONS: Neurological deficits with a normal head CT scan in the emergency department pose many difficulties and require extensive knowledge of brain vascular anatomy and the differential diagnoses for stroke. LEARNING POINTS: Not all focal neurological deficits are strokes. The need to diagnose stroke very quickly in order that effective treatment can be started can obscure the actual diagnosis so the differential diagnoses should always be carefully considered. Even though the sudden onset of focal neurological deficits suggests a stroke, a careful history should indicate the correct diagnosis.