Transcranial magnetic stimulation (TMS) is a non‐invasive method to assess neurophysiology of the primary motor cortex in humans. Dystonia is a poorly understood neurological movement disorder, often presenting in an idiopathic, isolated form across different parts of the body. The neurophysiological profile of isolated dystonia compared to healthy adults remains unclear. We conducted a systematic review with meta‐analysis of neurophysiologic TMS measures in people with isolated dystonia to provide a synthesized understanding of cortical neurophysiology associated with isolated dystonia. We performed a systematic database search and data were extracted independently by the two authors. Separate meta‐analyses were performed for TMS measures of: motor threshold, corticomotor excitability, short interval intracortical inhibition, cortical silent period, intracortical facilitation and afferent‐induced inhibition. Standardized mean differences were calculated using a random effects model to determine overall effect sizes and confidence intervals. Heterogeneity was explored using dystonia type subgroup analysis. The search resulted in 78 studies meeting inclusion criteria, of these 57 studies reported data in participants with focal hand dystonia, cervical dystonia, blepharospasm or spasmodic dysphonia, and were included in at least one meta‐analysis. The cortical silent period, short‐interval intracortical inhibition and afferent‐induced inhibition was found to be reduced in isolated dystonia compared to controls. Reduced GABAergic‐mediated inhibition in the primary motor cortex in idiopathic isolated dystonia's suggest interventions targeted to aberrant cortical disinhibition could provide a novel treatment. Future meta‐analyses require neurophysiology studies to use homogeneous cohorts of isolated dystonia participants, publish raw data values, and record electromyographic responses from dystonic musculature where possible.

中文翻译：

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原发性肌张力障碍和非肌张力障碍成年人的皮层神经生理学：一项荟萃分析

经颅磁刺激（TMS）是一种非侵入性方法，可评估人的原发性运动皮层的神经生理学。肌张力障碍是一种鲜为人知的神经系统运动障碍，通常以特发性，孤立的形式出现在身体的不同部位。与健康成年人相比，孤立性肌张力障碍的神经生理学特征仍不清楚。我们对孤立性肌张力障碍患者进行了神经生理学TMS措施的荟萃分析，从而进行了系统的综述，以提供与孤立性肌张力障碍相关的皮层神经生理学的综合理解。我们进行了系统的数据库搜索，两位作者独立提取了数据。对TMS测量进行单独的荟萃分析：运动阈值，皮质运动兴奋性，短时皮质内抑制，皮质沉默期，皮质内促进和传入诱导抑制。使用随机效应模型计算标准化平均差异，以确定总体效应大小和置信区间。使用肌张力障碍类型亚组分析探索异质性。搜索结果符合纳入标准的78项研究，其中57项研究报告了局部手部肌张力障碍，宫颈肌张力障碍，睑裂痉挛或痉挛性肌张力障碍的参与者的数据，并且至少纳入了一项荟萃分析。与对照相比，孤立性肌张力障碍的皮层静默期，短间隔皮层内抑制和传入诱导抑制被降低。减少特发性孤立性肌张力障碍中初级运动皮层的GABA能介导的抑制作用 提示针对异常皮质去抑制的干预措施可以提供一种新颖的治疗方法。未来的荟萃分析需要进行神经生理学研究，以使用孤立的肌张力障碍参与者的同类队列，发布原始数据值，并在可能的情况下记录肌张力障碍肌肉的肌电图反应。