Vodusek D B
Institute of Clinical Neurophysiology, Division of Neurology, University Medical Center, Ljubljana, Slovenia.
Mov Disord. 2001 Jul;16(4):600-7. doi: 10.1002/mds.1121.
Multiple system atrophy (MSA) is a degenerative disease manifesting a combination of parkinsonism, cerebellar, pyramidal, and autonomic (including urinary, sexual, and anorectal) dysfunction. It is pathomorphologically defined, but lacks a definitive clinical diagnostic test. Sphincter electromyography (EMG), reflecting Onuf's nucleus degeneration, has been proposed as a helpful test; its value has been reevaluated by a critical review of the literature. In patients with probable MSA, abnormal sphincter EMG, as compared to control subjects, has been found in the majority of patients in all the different forms of the disease in most studies, including patients who, as yet, have no urological or anorectal problems. The prevalence of abnormalities in the early stages of MSA is as yet unclear. Patients with Parkinson's disease (PD) as a rule do not show severe sphincter EMG abnormalities in the early stage of the disease. Anal sphincter EMG abnormalities (abnormal spontaneous activity or motor unit potential changes three standard deviations above valid control data) distinguish MSA from PD in the first 5 years after the onset of symptoms and signs, and from pure autonomic failure, as well as from cerebellar ataxias, if other causes for sphincter denervation have been ruled out. With such criteria, the sensitivity of the method is, however, low. EMG does not distinguish MSA from progressive supranuclear palsy. Future studies should use standardized anal sphincter EMG to better compare results from different centers and precisely define the sensitivity and specificity of the method.
多系统萎缩（MSA）是一种退行性疾病，表现为帕金森综合征、小脑、锥体束及自主神经（包括泌尿、性及肛门直肠）功能障碍的组合。它在病理形态学上有明确界定，但缺乏确定性的临床诊断测试。反映奥努夫核变性的括约肌肌电图（EMG）已被提议作为一种有用的检测方法；通过对文献的批判性综述对其价值进行了重新评估。在大多数研究中，包括那些尚无泌尿或肛门直肠问题的患者，在所有不同形式的可能患有MSA的患者中，与对照受试者相比，大多数患者发现括约肌EMG异常。MSA早期异常的患病率尚不清楚。帕金森病（PD）患者在疾病早期通常不会出现严重的括约肌EMG异常。肛门括约肌EMG异常（异常自发电活动或运动单位电位变化超过有效对照数据三个标准差）可在症状和体征出现后的前5年内将MSA与PD区分开来，也可与单纯自主神经功能衰竭以及小脑共济失调区分开来，前提是已排除其他导致括约肌去神经支配的原因。然而，按照这样的标准，该方法的敏感性较低。EMG无法将MSA与进行性核上性麻痹区分开来。未来的研究应使用标准化的肛门括约肌EMG，以便更好地比较不同中心的结果，并精确界定该方法的敏感性和特异性。
