[A case of X-linked recessive bulbospinal muscular atrophy with demyelinating neuropathy and hypertrophy of the calves].

We report a 53-year-old man of X-BSMA with neuropathy. The patient developed slowly progressive muscular weakness and wasting over a 2-year period with an accompanying numbness in the finger tip. He can run normally but not so fast. When he was aged 52-year old, difficulty in running progressed. General physical examination revealed nothing particular except for hypertension and gynecomastia. He showed muscular weakness and atrophy in the tongue, shoulder girdle, and upper and lower limbs. Calf muscle hypertrophies were prominent on both sides. The tendon reflexes were absent. Slight sensory impairment for vibration and pin-prick was present distally in all limbs. Autonomic nerve dysfunction was not observed. Hyperglycemia, elevated HbA1c and elevated serum CK (1,242 IU/l) were seen. The computed tomographic analyses on skeletal muscle showed hypertrophic changes in the calf muscles with a few fatty infiltrations. Electromyography showed a systemic neurogenic pattern. Motor nerve conduction velocities were slightly delayed in the lower limits. Sensory nerve action potentials were not elicited in all nerves tested. Sural nerve biopsy disclosed marked reduction of myelinated fibres for that of large diameter with thin myelin. Teased fibre studies showed a definite increase in the incidence of fibres with segmental demyelination and remyelination. In electron microscopic examination, typical or atypical onion bulb formation was observed on individual fibres. Axonal changes were minimum. We believe that segmental demyelination observed in this patient is not secondary to axonal damage. We, also, investigated AR gene abnormality by polymerase chain reaction (PCR) in this patient.(ABSTRACT TRUNCATED AT 250 WORDS)