Dystonia and unique muscle features. A 23-year follow-up and correction of diagnosis in two brothers

P. D. Charles, T. L. Davis, D. Robertson and G. M. Fenichel
Department of Neurology, Vanderbilt University School of Medicine, Nashville, Tenn., USA.

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.