Uozumi T, Tsuji S, Murai Y
Department of Neurology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu City, Japan.
Electroencephalogr Clin Neurophysiol. 1991 Aug;81(4):251-6. doi: 10.1016/0168-5597(91)90010-u.
Motor evoked potentials (MEPs) elicited by magnetic coil stimulation of motor cortex were studied at rest and during maximum voluntary muscle contraction in 20 normal subjects and 42 patients with motor disorders. MEP parameters employed in this study included: onset latency, amplitude, MEP/M wave amplitude ratio and background EMG/MEP area ratio. Maximum voluntary contraction increased the amplitude of MEPs compared to the size of M waves elicited by peripheral nerve stimulation. A reduced MEP/M wave amplitude ratio had a higher correlation with pyramidal tract involvement than did a prolonged MEP onset latency. Analysis of MEP parameters may help in the differential diagnosis of cerebral infarction, ALS and cervical spondylotic radiculomyelopathy. The inhibitory period which follows MEPs during voluntary contraction was observed in all subjects; the mean duration in normal subjects was 126.6 +/- 29.5 msec. The mean duration of the inhibitory period in patients with cerebral infarction, ALS and cervical spondylotic radiculomyelopathy was 73.9 +/- 41.7 msec, 79.5 +/- 54.5 msec and 85.1 +/- 36.5 msec, respectively. These values were significantly shorter than in normal subjects.
在20名正常受试者和42名运动障碍患者中，研究了在静息状态和最大自主肌肉收缩期间，磁刺激运动皮层所诱发的运动诱发电位（MEP）。本研究采用的MEP参数包括：起始潜伏期、波幅、MEP/M波幅比以及背景肌电图/MEP面积比。与外周神经刺激所诱发的M波大小相比，最大自主收缩增加了MEP的波幅。MEP/M波幅比降低与锥体束受累的相关性高于MEP起始潜伏期延长。MEP参数分析可能有助于脑梗死、肌萎缩侧索硬化症（ALS）和颈椎病性神经根脊髓病的鉴别诊断。在所有受试者中均观察到了自主收缩期间跟随MEP后的抑制期；正常受试者的平均持续时间为126.6±29.5毫秒。脑梗死、ALS和颈椎病性神经根脊髓病患者的抑制期平均持续时间分别为73.9±41.7毫秒、79.5±54.5毫秒和85.1±36.5毫秒。这些值明显短于正常受试者。
