Adult metachromatic leukodystrophy. II. Ultrastructural findings in peripheral nerve and skeletal muscle.

Sural nerve biopsy in a 44-year-old woman with adult metachromatic leukodystrophy (MLD) confirmed by deficient arylsulfatase-A activity, showed a reduction in the number of large and small myelinated axons, and sparse metachromatic material. Ultrastructurally, the latter consisted of various types of residual bodies including the tufaceous and prismatic forms typical of MLD. In the striated muscle, large amounts of regular lipofuscin but no MLD-characteristic inclusions were encountered. Inclusion-bearing mitochondria in the muscle appeared to be an incidental finding.