In situ measurements of muscle fiber conduction velocity in Duchenne muscular dystrophy

OBJECTIVE: To measure the muscle fiber conduction velocity in Duchenne muscular dystrophy patients.

METHODS: The muscle fiber conduction velocity of the biceps brachii and tibialis anterior was measured with the needle electrode. Eighteen controls and 32 Duchenne muscular dystrophy patients were studied. Clinical neurological examination, serum cretin kinase level estimation, conventional electromyogram were carried out for every individual and 17 of the Duchene muscular dystrophy patients were biopsied for further histological and histochemical examination.

RESULTS: The muscle fiber conduction velocity of the control group showed good reproducibility. The frequent distribution of the Duchenne muscular dystrophy data characterized by multi-peaks curve as compared to the control group. This is demonstrated as significant slowing (P<0.005) of the muscle fiber conduction velocity in the two muscle examined of the patients group.

CONCLUSION: The slowing of the muscle fiber conduction velocity is proposed to be due to the small size of the regenerating and splitting fibers. The multi-peaks frequency distribution curve indicates a great variability in the muscle fiber diameter. The muscle fiber conduction velocity is a useful tool for diagnosing myopathies.