Congenital peripheral neuropathy with optic atrophy and symmetric white matter lesions

Objective: Peripheral neuropathy with optic atrophy is a clinically and genetically heterogeneous group of disorders classified as hereditary motor and sensory neuropathy (HMSN) Type VI. We report on a case which shows not only peripheral but also central myelinisation defects.

Case report: We describe a five-year-old patient with no familial history of neuropathy or visual dysfunction. He presented with onset of nystagmus and poor visual fixation in the first year of life. Ophthalmologic examination showed an optic atrophy with an extensivly reduced visual acuity. Muscular hypotonia was also recognized early, and because of severe sensory ataxia he never learned to stand or walk freely. Muscle tendon reflexes were absent, and nerve conduction velocity was diminished. Biopsy of peripheral nerve and muscle tissue revealed reduction in the number of myelinated fibers as well as signs of de- and remyelinisation with degenerativ changes in the skeletal muscle. Magnetic resonance imaging showed circumscribed symmetric lesions with deficient myelin in the corpus callosum and the cerebellum.

Conclusion: This patient demonstrates again the heterogeneity of disorders classified as HMSN VI and adds on a new picture with symmetrical white matter lesions to the spectrum of these diseases.

Keywords: peripheral neuropathy, myelin defects, corpus callosum, cerebellum