腹直肌肌电图在肌萎缩侧索硬化诊断中的价值

The value of electromyography of rectus abdominis muscles in the diagnosis of amyotrophic lateral sclerosis

目的建立腹直肌肌电图运动单位动作电位(MUAP)各参数正常参考值,并探讨其在诊断肌萎缩侧索硬化(ALS)中的价值。方法对ALS组67例患者(其中有呼吸困难症状者19例)进行常规肌电图检测,包括上、下肢远近端肌肉、胸锁乳突肌、下胸段脊旁肌及腹直肌,测定自发电位、募集相、MUAP时限、波幅及多相波,其中脊旁肌只检测自发电位和募集相。对健康对照组109名健康志愿者进行腹直肌肌电图的检测。比较ALS组腹直肌肌电图与健康组的差异、ALS组中腹直肌肌电图与下胸段脊旁肌肌电图的差异以及腹直肌肌电图与呼吸障碍症状的关系。结果健康对照组腹直肌肌电图的MUAP参数分别为:波幅(373·78±56·46)μV,时限(9·95±1·13)ms,多相波(19·40±4·52)%;ALS组腹直肌肌电图的MUAP各参数分别为:波幅(537·19±159·04)μV,时限(13·02±1·30)ms,多相波(31·19±8·84)%,ALS组腹直肌肌电图各参数与健康对照组相比差异有统计学意义;ALS组腹直肌肌电图神经源性改变(63/67,94·0%)与下胸段脊旁肌肌电图(57/67,85·1%)的差异无统计学意义;有呼吸困难症状患者的腹直肌肌电图自发电位(18/19,94·7%)多于无呼吸困难症状患者(32/48,66·7%)。结论腹直肌肌电图各参数均能可靠、稳定地测出,可作为检测ALS患者胸段下运动神经元病变的辅助手段。

Objective To establish the normative value of motor unit action potentials （MUAP） of rectus abdominis muscles, and to assess the value of the electromyography （ EMG ） of rectus abdominis muscles in the diagnosis of amyotrophic lateral sclerosis （AKS）. Methods Standard EMG was recorded from at least three limbs, at sternocleidomastoid muscles, lower thoracic paraspinal muscles and rectus abdominis muscles in 67 patients with ALS including 19 cases with dyspnea. Parameters studied included spontaneous activity （fibrillation potentials （fib） and positive sharp waves （psw）） ; duration, amplitude and percentage of polyphasic wave of MUAP; pattern of recruitment. Only spontaneous activity and pattern of recruitment were studied in lower thoracic paraspinal muscle. EMGs of rectus abdominis muscles were also recorded from 109 healthy controls. EMG parameters of rectus abdominis muscles were compared between patients with ALS and the controls; the differences of EMG changes between rectus abdominis muscle and lower thoracic paraspinal muscle were analyzed in ALS patients ; the relationship of EMG of rectus abdominis muscle and dyspnea was also observed in ALS patients. Results The normative values of amplitude, duration and polyphasic wave of MUAP of rectus abdominis muscles in the controls were （373.78 ± 56.46）μV, （9.95 ± 1.13 ） ms, （ 19.40 ±4. 52） % , respectively, significantly different from those in ALS patients which were （537.19 ± 159. 04）μN, （ 13.02 ± 1.30） ms, （31.19 ± 8.84） %, respectively. There was no difference of EMG changes between rectus abdominis muscle （63/67, 94. 0% ） and lower thoracic paraspinal muscle （57/67, 85. 1% ） in patients with ALS. There were more spontaneous potentials in patients with dyspnea （ 18/19, 94.7% ） than those without （ 32/48, 66. 7% ）. Conclusion Neurogenic changes of EMG of rectus abdominis muscle might be regarded as an evidence of the lesion in lower motor neuron involved in thoracic region and is helpful in the diagnosis of ALS.