Teaching Video NeuroImages: Wernicke encephalopathy without mental status changes.

Ryan J. MacDonald, MD Peter P. Stanich, MD Priya A. Monrad, MD Farrah J. Mateen, MD A 43-year-old man with chronic pancreatitis and 7-kg weight loss secondary to persistent nausea and reduced oral intake presented with double vision and gait unsteadiness. Neurologic examination revealed complete horizontal and partial vertical ophthalmoplegia with prominent gait ataxia (video 1 on the Neurology Web site at www.neurology.org). Treatment with thiamine (500 mg IV every 8 hours for 72 hours and then 100 mg daily) was initiated immediately. Examination 12 hours after treatment demonstrated remarkable improvement in his eye movements (see video 2). His gait steadily improved throughout his 5day hospitalization. MRI of the brain was normal. Wernicke encephalopathy is an underdiagnosed disorder of thiamine deficiency, marked by ophthalmoplegia and nystagmus, mental status changes, and gait unsteadiness. Our patient did not experience neurocognitive changes. Like the majority of patients (84%), he did not have the complete symptomatic triad.1 Symptoms of Wernicke encephalopathy improve rapidly with thiamine therapy, which should always be started empirically when the diagnosis is suspected. Ocular symptoms usually resolve within hours, gait disturbance within days, and mental status changes within weeks.1