[A case of hereditary motor and sensory neuropathy type I with optic atrophy, neural deafness and pyramidal tract signs].

A case of hereditary motor and sensory neuropathy (HMSN) type I with optic atrophy, neural deafness and pyramidal tract signs was described. The patient was a 53-year-old man who had suffered from difficulty in walking, decreased visual acuity since age 16 years. These symptoms were slowly progressive. At the age of 37, he was pointed out optic atrophy, positive pyramidal tract signs. Distal muscle weakness with atrophy of four limbs was prominent at the age of 50. Since then, he noticed progressive hearing loss with blindness. His elder sister was diagnosed Charcot-Marie-Tooth disease. On neurological examination, he showed to have optic atrophy without retinitis pigmentosa and neural deafness. Also he showed mild degree of muscle weakness and atrophy in four limbs, severe in the distal part of lower limbs. Deep tendon reflexes were absent in all limbs with right Babinski sign. Superficial sensation was decreased slightly in the distal parts of four limbs. Deep sensation was markedly decreased in the leg. There were no cerebellar signs. Audiometric examination revealed bilateral neural hearing loss. There were no findings of spinal cord compression on spinal MRI. On the nerve conduction studies, sensory nerve action potential was not elicited in all nerves tested. Motor nerve conduction velocity of the right median was 41.1 M/sec, also ulnar nerve 44.7 M/sec, but M-wave was not elicited with the electrical stimulation of other tested nerves. On sural nerve biopsy, the density of myelinated fibers was severely decreased. Well-myelinated axon surrounded by onion bulb formation was observed in electron microscopic examination.(ABSTRACT TRUNCATED AT 250 WORDS)