Two brothers, presented at ages 6 and 3, for evaluation of dystonia present from early infancy. Muscle strength was normal and the deep tendon reflexes brisk. Borderline intelligence, chorea, and abnormal electroencephalograms further documented the presence of cerebral disease. In the skeletal muscle, the A-fibers (dark reacting to adenosine triphosphatase pH 9.4) were abnormally small and contained ringbinden. These muscle findings are considered the result of an abnormal cerebral influence on the developing motor unit. Because of the unity of the neuromuscular system, abnormalities distant from the motor unit may be reflected in muscle fiber size and structure.
Fenichel GM, Olson WH, Kilroy AW. Hereditary Dystonia Associated With Unique Features in Skeletal Muscle. Arch Neurol. 1971;25(6):552–559. doi:10.1001/archneur.1971.00490060086009
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