[Correlation between somatosensory evoked potentials and long loop reflexes--basic investigation and its application for multiple sclerosis].
Somatosensory evoked potentials (SEPs) and long loop reflexes (LLRs) to the median nerve stimulation were investigated on 25 normal controls and 25 patients with multiple sclerosis (MS). Fifteen normal controls were also subjected to LLR study by the common peroneal nerve stimulation. The mean height were 159 +/- 8.2 cm in normal controls and 160 +/- 8.9 cm in MS, respectively. LLRs were obtained with 100% reproducibility in all cases. Upper limb LLRs were recorded from m. abductor pollicis brevis by trigger stimulation during isotonic contraction of the thumb, while lower limb LLRs were recorded from m. peroneus longus by trigger stimulation during isotonic eversion of the foot. The threshold of LLR was lower than that of short latency reflex (H-wave) with the mean latency of 40.4 +/- 1.5 ms. The height of subjects revealed an obvious positive correlation not only with the latency of LLR but also with N 20 of SEP, whereas central conduction time was not. Furthermore, a significant correlation was present between the latencies of LLR and N 20, showing a twofold gradient of LLR against N20. There was a significantly prolonged latency difference between H-wave and LLR of lower limb as compared with that of upper limb. When the stimulation site was changed from the wrist to the elbow, the latency difference between M-wave and H-wave shortened. This fact, therefore, appears to be against "resonance hypothesis" that LLR is set off according to the intrinsic mechanical oscillation given to the muscle concerned.(ABSTRACT TRUNCATED AT 250 WORDS)
Kaneshige
Y
Y
Department of Rehabilitation and Neurology, Sapporo Medical College, Japan.
Matsumoto
H
H
Chiba
S
S
Hashimoto
S
S
Noro
H
H
Yanada
Y
Y
D000328:Adult; D001132:Arm; D001827:Body Height; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D007866:Leg; D008297:Male; D008475:Median Nerve / Q000502:physiology; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology*; D009119:Muscle Contraction; D010543:Peroneal Nerve / Q000502:physiology; D011237:Predictive Value of Tests; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012018:Reflex / Q000502:physiology*