[A case of Sjögren-Larsson syndrome with peripheral nerve involvement]

A case of Sjögren-Larsson syndrome (SLS) with peripheral nerve involvement was described. A patient was a 37-year-old man with marked mental retardation who had ichthyosis since several months of age. He developed spastic gait at age 20 and noticed muscle weakness and atrophy in lower extremities at age 30. On examination, electromyogram showed neurogenic changes with polyphasic motor unit potentials of high amplitude and long duration, and motor and sensory conduction velocities were slightly decreased in lower extremities. Muscle biopsy specimens of the left quadriceps showed grouped atrophy and pyknotic nuclear clumps, suggestive of neurogenic changes. Left sural nerve biopsy showed decreased number of myelinated fibers. On electron microscopy, some myelinated fibers revealed proliferation of the organelles in axons with disruption of the myelin sheath, and glycogen granules in Schwann cell cytoplasm. Unmyelinated fibers showed no reduction in the density, but accompanied numerous collagen pockets and Schwann cell cytoplasmic processes arranged in many stacks, suggesting the presence of some degenerative changes. With the present findings at peripheral level and a review of the literature, we may assume that SLS has extensive disorders of the ectodermal tissues including the peripheral nerve as well as the skin and the central nervous system.