Congenital muscular dystrophy with leukoencephalopathy.

Two patients with 'benign' congenital muscular dystrophy (CMD) have been observed for several years. Symptoms and signs of central nervous system (CNS) disease occurred at the age of 7 and 16 years, respectively. CNS involvement in CMD may be more common than generally recognized, slowly progressive and delayed in onset. The combination of congenital hypotonia, contractures, 'dystrophic' muscle biopsy changes and diffuse subcortical hypodensity on computed-tomographic scans seems unique and specific for CMD and of differential diagnostic significance.