Department of Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy.
Sleep Research Center, Department of Neurology IC, Oasi Research Institute - IRCCS, Troina, Italy.
Sleep. 2020 Mar 12;43(3). doi: 10.1093/sleep/zsz242.
Previous studies found an early impairment of the short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) to transcranial magnetic stimulation (TMS) in Parkinson's disease. However, very little is known on the TMS correlates of rapid eye movement (REM) sleep behavior disorder (RBD), which can precede the onset of a α-synucleinopathy.
The following TMS measures were obtained from 14 de novo patients with isolated RBD and 14 age-matched healthy controls: resting motor threshold, cortical silent period, latency and amplitude of the motor evoked potentials, SICI, and ICF. A cognitive screening and a quantification of subjective sleepiness (Epworth Sleepiness Scale [ESS]) and depressive symptoms were also performed.
Neurological examination, global cognitive functioning, and mood status were normal in all participants. ESS score was higher in patients, although not suggestive of diurnal sleepiness. Compared to controls, patients exhibited a significant decrease of ICF (median 0.8, range 0.5-1.4 vs. 1.9, range 1.4-2.3; p < 0.01) and a clear trend, though not significant, towards a reduction of SICI (median 0.55, range 0.1-1.4 vs. 0.25, range 0.1-0.3), with a large effect size (Cohen's d: -0.848). REM Sleep Atonia Index significantly correlated with SICI.
In still asymptomatic patients for a parkinsonian syndrome or neurodegenerative disorder, changes of ICF and, to a lesser extent, SICI (which are largely mediated by glutamatergic and GABAergic transmission, respectively) might precede the onset of a future neurodegeneration. SICI was correlated with the muscle tone alteration, possibly supporting the proposed RBD model of retrograde influence on the cortex from the brainstem.
既往研究发现，帕金森病患者经颅磁刺激（TMS）的短程皮质内抑制（SICI）和皮质内易化（ICF）早期受损。然而，对于快速眼动（REM）睡眠行为障碍（RBD），即α-突触核蛋白病发病前的 TMS 相关性，知之甚少。
对 14 例新发孤立性 RBD 患者和 14 例年龄匹配的健康对照者进行以下 TMS 测量：静息运动阈值、皮质静息期、运动诱发电位的潜伏期和振幅、SICI 和 ICF。还进行了认知筛查和主观嗜睡程度（Epworth 嗜睡量表[ESS]）及抑郁症状的量化评估。
所有参与者的神经系统检查、整体认知功能和情绪状态均正常。患者的 ESS 评分较高，但不提示日间嗜睡。与对照组相比，患者的 ICF 明显降低（中位数 0.8，范围 0.5-1.4 与 1.9，范围 1.4-2.3；p<0.01），且 SICI 呈显著降低趋势（中位数 0.55，范围 0.1-1.4 与 0.25，范围 0.1-0.3；p=0.07），且效应量较大（Cohen's d：-0.848）。REM 睡眠去抑制指数与 SICI 显著相关。
在尚未出现帕金森综合征或神经退行性疾病症状的无症状患者中，ICF 变化（主要由谷氨酸能和 GABA 能传递介导），以及在较小程度上的 SICI 变化，可能先于未来神经退行性变的发生。SICI 与肌肉张力改变相关，可能支持从脑干向皮质逆行影响的 RBD 模型。
