Objective: To provide follow-up information and a corrected diagnosis on two brothers who were primarily described in the ARCHIVES in 1971 as having had a genetic dystonia with unusual muscle biopsy features.
Measures: Clinical observation of response to treatment and muscle histologic findings.
Results: These brothers are an unusual example of dopa-responsive dystonia that was present since birth. The muscle histopathologic features were caused by an abnormal cerebral influence on the developing motor unit and were not a primary abnormality. A repeated muscle biopsy performed 1 year after treatment continued to show the same pattern of fiber-type abnormalities.
Conclusions: Dopa-responsive dystonia can be present from birth or early infancy. The response to levodopa is excellent even after a delay in treatment of more than 20 years. Intrauterine dystonia can cause a predominance of small type 2 fibers. A trial of levodopa/carbidopa is indicated in all patients with a childhood-onset dystonia or gait disturbance.