Symmetric deep cerebellar lesions after smoking heroin.

BACKGROUND Acute symmetric deep cerebellar lesions suggest toxic exposure. OBJECTIVE To describe a patient with striking neurologic and magnetic resonance image features. DESIGN Case report. SETTING Emergency department and office. METHODS Personal observation. RESULTS A middle-aged man had a day of unsteadiness, followed by acute and pronounced cerebellar signs. The degree of disability was remarkable. Magnetic resonance imaging showed almost perfectly symmetric deep cerebellar damage that ultimately became cavitated. Serial querying of the patient revealed the use of heroin by inhalation just prior to the emergence of the ataxic syndrome. CONCLUSIONS An acute and purely ataxic syndrome with symmetric deep cerebellar lesions suggests toxic exposure, in this case, the smoking of heroin.