Movement disorders and neurodegenerative disease
Movement disorders and neurodegenerative disease
The exam tests recognition of parkinsonism, tremor, chorea, dystonia, ataxia, and atypical neurodegenerative syndromes. Parkinson disease typically has asymmetric resting tremor, bradykinesia, rigidity, and levodopa responsiveness. Red flags for atypical parkinsonism include early falls, vertical gaze palsy, prominent dysautonomia, and poor levodopa response; PSP, MSA, and DLB are key considerations. Huntington disease causes chorea, psychiatric changes, and caudate atrophy with autosomal dominant inheritance. Wilson disease should be excluded in young patients with movement disorder and liver disease. Drug-induced parkinsonism is common and often symmetric.
Worked example
A 62-year-old has a right-hand resting tremor, slowed movements, and rigidity that improves with levodopa. Reasoning: idiopathic Parkinson disease. If instead he had early vertical gaze palsy and repeated falls, PSP would be more likely.
Traps
Do not label essential tremor as Parkinson disease; do not overlook dopamine-blocking drugs; do not use typical antipsychotics in Parkinson disease; remember that levodopa responsiveness supports but does not prove Parkinson disease; check ceruloplasmin in young-onset movement disorder.