Wing-Beating Tremor in Creutzfeldt-Jakob Disease

A 67-year-old man with progressive ataxia and dysarthria was diagnosed with Creutzfeldt-Jakob disease based on genetic testing. This video illustrates notable physical examination findings of negative myoclonus and a severe, low-frequency, high-amplitude wing-beating tremor elicited by sustained left arm abduction with flexed elbows and palms facing downward. The tremor is classically attributed to Wilson disease. Click the Related Article for complete case details and discussion.