Diagnostic testing in movement disorders.

The diagnosis of movement disorders is essentially clinical. Work-up depends on patient age, part of the body affected, drug response, and presence of other systemic or neurologic symptoms and signs. Typical Parkinson's disease, essential tremor, and tics need only minimal work-up if any. Brain magnetic resonance imaging/computed tomography, positron emission tomography and single photon emission computed tomography, and DNA studies are promising diagnostic tools. Exclusion of Wilson's disease and neuroacanthocytosis is emphasized in children and young adults with movement disorders.