DIRECT STUDY OF MUSCLE CONDITION AND ITS CLINICAL APPLICATION IN HEALTH AND DISEASE

• Published in: Rihabiritēshon igaku Vol. 24; no. 3; pp. 153 - 162
• Main Author: NODA, Yukio
• Format: Journal Article
• Language: English
• Published: The Japanese Association of Rehabilitation Medicine 1987
• ISSN: 0034-351X; 1880-778X; 1880-778X
• DOI: 10.2490/jjrm1963.24.153

Directly stimulated muscle conduction studies were conducted in 80 normal, 8 myopathic, 11 neuropathic and 15 hemiplegic subjects. Two monopolar Teflon-coated needle electrodes with tips exposed 4mm were placed in the distal end of the brachial biceps muscles as the stimulating electrodes. A recording monopolar needle electrode was then placed 4cm proximal to the stimulation electrode along the same muscle with the surface reference electrode. After the maximal evoked response was detected using the supramaximal stimulation of 0.2msec square wave pulse, the latency, peak latency, amplitude and duration were measured. The maximum muscle fiber conduction velosity (CVmax) and peak muscle fiber conduction velocity (CVpeak) were calculated dividing the distance by each latency. The results showed that the age and sex in healthy subjects related to the muscle fiber conductivities. The amplitudes of the evoked responses increased as the age advanced. Also male subjects indicated faster CVmax and CVpeak and larger amplitudes compared with female subjects. Healthy subjects did not show the difference in conductivity between right and left arm and between the first and second examination. The patients of polymyositis showed decreased amplitudes and long durations compared to normal age-matched subjects. The neuropathic patients with branchial plexus neuropathy, revealed remarkable changes in muscle conductivities. They showed the decreased CVmax and CVpeak, accompanied with smaller amplitude and prolonged duration. As for the hemiplegic patients, there existed only slightly delayed CVpeak and small amplitude. Directly stimulated muscle conduction study might be useful for diagnosing and evaluating muscles themselves, without interference from neuronal transmission.