Todisco Massimiliano, Cosentino Giuseppe, Alfonsi Enrico
Translational Neurophysiology Research Unit; Movement Disorders Research Center, IRCCS Mondino Foundation; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.
Translational Neurophysiology Research Unit, IRCCS Mondino Foundation; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.
Neural Regen Res. 2023 Sep;18(9):1903-1907. doi: 10.4103/1673-5374.367833.
Multiple system atrophy is a sporadic, progressive, adult-onset, neurodegenerative disorder characterized by autonomic dysfunction symptoms, parkinsonian features, and cerebellar signs in various combinations. An early diagnosis of multiple system atrophy is of utmost importance for the proper prevention and management of its potentially fatal complications leading to the poor prognosis of these patients. The current diagnostic criteria incorporate several clinical red flags and magnetic resonance imaging markers supporting diagnosis of multiple system atrophy. Nonetheless, especially in the early disease stage, it can be challenging to differentiate multiple system atrophy from mimic disorders, in particular Parkinson's disease. Electromyography of the external anal sphincter represents a useful neurophysiological tool for differential diagnosis since it can provide indirect evidence of Onuf's nucleus degeneration, which is a pathological hallmark of multiple system atrophy. However, the diagnostic value of external anal sphincter electromyography has been a matter of debate for three decades due to controversial reports in the literature. In this review, after a brief overview of the electrophysiological methodology, we first aimed to critically analyze the available knowledge on the diagnostic role of external anal sphincter electromyography. We discussed the conflicting evidence on the clinical correlations of neurogenic abnormalities found at external anal sphincter electromyography. Finally, we reported recent prognostic findings of a novel classification of electromyography patterns of the external anal sphincter that could pave the way toward the implementation of this neurophysiological technique for survival prediction in patients with multiple system atrophy.
多系统萎缩是一种散发性、进行性、成人起病的神经退行性疾病，其特征为自主神经功能障碍症状、帕金森样特征和小脑体征以各种组合形式出现。早期诊断多系统萎缩对于正确预防和管理其可能导致患者预后不良的致命并发症至关重要。目前的诊断标准纳入了多个支持多系统萎缩诊断的临床警示信号和磁共振成像标志物。尽管如此，尤其是在疾病早期阶段，将多系统萎缩与类似疾病（特别是帕金森病）区分开来可能具有挑战性。肛门外括约肌肌电图是一种有用的神经生理学鉴别诊断工具，因为它可以提供奥努夫核变性的间接证据，而奥努夫核变性是多系统萎缩的病理标志。然而，由于文献中有争议的报道，肛门外括约肌肌电图的诊断价值在三十年来一直存在争议。在本综述中，在简要概述电生理方法后，我们首先旨在批判性地分析关于肛门外括约肌肌电图诊断作用的现有知识。我们讨论了在肛门外括约肌肌电图中发现的神经源性异常与临床相关性的相互矛盾的证据。最后，我们报告了肛门外括约肌肌电图模式新分类的近期预后研究结果，这可能为将这种神经生理学技术用于多系统萎缩患者的生存预测铺平道路。
