Haughton J F, Little J W, Powers R K, Robinson L R, Goldstein B
Department of Rehabilitation Medicine, University of Washington, Seattle.
Muscle Nerve. 1994 Aug;17(8):936-42. doi: 10.1002/mus.880170814.
A new method for quantifying upper motoneuron (UMN) weakness using standard EMG equipment is presented and compared to the twitch occlusion method. Control subjects and patients with stroke, spinal cord injury (SCI), and peripheral nerve injury (PNI) were evaluated. Force, EMG, and twitch force from nerve electrical stimulation were recorded during isometric contractions of the biceps and triceps. Ratios of the elicited CMAP amplitude (M)/voluntary-root-mean-square EMG activity (RMS) and of the voluntary contraction twitch force (Ti)/the resting twitch force (Tmax) were the two measures of UMN weakness studied. Both ratios are linearly correlated with force for controls, log M/RMS (r = 0.96) and Ti/Tmax (r = 0.86). Log M/RMS ratio was abnormally high (> mean + 2 SD; i.e., > 1.09) for weak muscles affected by stroke and incomplete SCI, but was normal in muscles weakened by PNI. An elevated M/RMS ratio, may aid in quantification of deficient supraspinal activation from UMN or functional weakness.
本文介绍了一种使用标准肌电图设备量化上运动神经元（UMN）无力的新方法，并将其与抽搐阻塞法进行比较。对对照组以及患有中风、脊髓损伤（SCI）和周围神经损伤（PNI）的患者进行了评估。在二头肌和三头肌等长收缩期间，记录了神经电刺激产生的力量、肌电图和抽搐力量。引出的复合肌肉动作电位（CMAP）幅度（M）/自愿性均方根肌电图活动（RMS）的比率以及自愿收缩抽搐力量（Ti）/静息抽搐力量（Tmax）的比率是研究UMN无力的两项指标。对于对照组，这两个比率与力量均呈线性相关，log M/RMS（r = 0.96）和Ti/Tmax（r = 0.86）。对于受中风和不完全SCI影响的无力肌肉，Log M/RMS比率异常高（>平均值 + 2标准差；即> 1.09），但在因PNI而减弱的肌肉中则正常。升高的M/RMS比率可能有助于量化UMN的脊髓上激活不足或功能性无力。
