Simultaneously stimulating both brain hemispheres by rTMS in patients with unilateral brain lesions decreases interhemispheric asymmetry.

IF 1.9 4区医学 Q4 NEUROSCIENCES

Restorative neurology and neuroscience Pub Date : 2021-01-01 DOI:10.3233/RNN-211172

Yuhua Zhong, Jianzhong Fan, Huijuan Wang, Renhong He

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Abstract

Background: Interhemispheric asymmetry caused by brain lesions is an adverse factor in the recovery of patients with neurological deficits. Repetitive transcranial magnetic stimulation (rTMS) has been shown to modulate cortical oscillation and proposed as an approach to rebalance the symmetry, which has not been documented well.

Objective: In this study, we investigated the influence of repetitive transcranial magnetic stimulation (rTMS) on EEG power in patients with unilateral brain lesions by simultaneously stimulating both brain hemispheres and to elucidate asymmetrical changes in rTMS-induced neurophysiological activity.

Methods: Fourteen patients with unilateral brain lesions were treated with one active and one sham session of 10 Hz rTMS over the vertex (Cz position). Resting-state EEGs were recorded before and immediately after rTMS. The brain symmetry index (BSI), calculated from a fast Fourier transform, was employed to quantify the power asymmetry in both hemispheres and paired channels over the entire range and five frequency bands (delta, theta, alpha, beta and gamma bands).

Results: Comparison between active and sham sessions demonstrated rTMS-induced EEG after-effects. rTMS in the active session significantly reduced the BSI in patients with unilateral brain lesions over the entire frequency range (t = 2.767, P = 0.016). Among the five frequency bands, rTMS only induced a noticeable decrease in the BSI in the delta band (t = 2.254, P = 0.042). Furthermore, analysis of different brain regions showed that significant changes in the BSI of the alpha band were only demonstrated in the posterior parietal lobe. In addition, EEG topographic mapping showed a decreased power of delta oscillations in the ipsilesional hemisphere, whereas distinct cortical oscillations were observed in the alpha band around the parietal-occipital lobe in the contralesional hemisphere.

Conclusions: When both brain hemispheres were simultaneously activated, rTMS decreased interhemispheric asymmetry primarily via reducing the delta band in the lesioned hemisphere.

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通过rTMS同时刺激单侧脑病变患者的两个大脑半球可减少半球间不对称。

背景:脑损伤引起的半球间不对称是影响神经功能缺损患者恢复的一个不利因素。重复经颅磁刺激(rTMS)已被证明可以调节皮质振荡，并被认为是一种重新平衡对称性的方法，但尚未得到很好的证明。目的:研究反复经颅磁刺激(rTMS)同时刺激双脑半球对单侧脑病变患者脑电图功率的影响，并阐明rTMS诱导的神经生理活动的不对称变化。方法:对14例单侧脑病变患者分别采用10hz rTMS治疗(Cz位)。静息状态脑电图记录于rTMS前后。通过快速傅立叶变换计算得出的脑对称指数(BSI)用于量化两个半球和配对通道在整个范围和五个频段(δ， θ， α， β和γ波段)的功率不对称性。结果:活动组与假组的比较显示了rtms诱发的脑电后效。活动期rTMS在整个频率范围内显著降低单侧脑病变患者的BSI (t = 2.767, P = 0.016)。在5个频带中，rTMS仅在δ频带显著降低BSI (t = 2.254, P = 0.042)。此外，对大脑不同区域的分析表明，α带BSI的显著变化仅在后顶叶表现出来。此外，脑电图地形图显示，同侧半球的δ振荡功率降低，而在对侧半球的顶叶-枕叶周围的α带观察到明显的皮层振荡。结论:当两个大脑半球同时被激活时，rTMS主要通过减少受损半球的δ带来减少半球间的不对称性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Restorative neurology and neuroscience 医学-神经科学

CiteScore

5.40

自引率

3.60%

发文量

审稿时长

>12 weeks

期刊介绍： This interdisciplinary journal publishes papers relating to the plasticity and response of the nervous system to accidental or experimental injuries and their interventions, transplantation, neurodegenerative disorders and experimental strategies to improve regeneration or functional recovery and rehabilitation. Experimental and clinical research papers adopting fresh conceptual approaches are encouraged. The overriding criteria for publication are novelty, significant experimental or clinical relevance and interest to a multidisciplinary audience. Experiments on un-anesthetized animals should conform with the standards for the use of laboratory animals as established by the Institute of Laboratory Animal Resources, US National Academy of Sciences. Experiments in which paralytic agents are used must be justified. Patient identity should be concealed. All manuscripts are sent out for blind peer review to editorial board members or outside reviewers. Restorative Neurology and Neuroscience is a member of Neuroscience Peer Review Consortium.