Demirtas-Tatlidede Asli, Alonso-Alonso Miguel, Shetty Ravi P, Ronen Itamar, Pascual-Leone Alvaro, Fregni Felipe
Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul University, Istanbul Medical Faculty, Istanbul, Turkey.
Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
NeuroRehabilitation. 2015;36(1):51-9. doi: 10.3233/NRE-141191.
Contralesional hemispheric repetitive transcranial magnetic stimulation (rTMS) may improve motor function in mild to moderate stroke and effects are considered to be mediated through transcallosal motor fibers.
This study aimed to investigate the safety of contralesional rTMS in a selected group of severe chronic stroke patients.
Ten sessions of 1 Hz rTMS were applied to contralesional primary motor cortex (M1) using neuronavigated stimulation and changes in motor impairment were evaluated before, during and after rTMS applications and at 4-weeks follow-up. Neurophysiological response to stimulation was assessed through cortical excitability evaluations. The relationship between functional and neurophysiological response to rTMS and microstructural integrity of transcallosal motor fibers were searched using diffusion tensor imaging (DTI) based fractional anisotropy (FA).
rTMS was well-tolerated with high compliance and no dropouts; no seizures or motor worsening occurred. Transcallosal FA values revealed a positive linear relationship with the mild motor improvement detected after rTMS while higher FA values were observed in subjects with better motor outcome. Cortical excitability showed a significant change in contralesional short-interval intracortical inhibition indicating altered plasticity following rTMS.
Our results suggest that noninvasive neuromodulation of the contralesional hemisphere may present a possibility to assist adaptive neuroplastic changes in severe chronic stroke. Implementation of DTI-derived measures of transcallosal microstructural integrity may allow for individually-tailored interventions to guide processes of interhemispheric neuroplasticity. Further research is warranted to establish the clinical value of these findings in neurorehabilitation settings for subjects with chronic severe stroke.
对侧半球重复经颅磁刺激（rTMS）可能改善轻至中度卒中患者的运动功能，其作用被认为是通过胼胝体运动纤维介导的。
本研究旨在调查在一组特定的严重慢性卒中患者中对侧rTMS的安全性。
使用神经导航刺激对10例患者的对侧初级运动皮层（M1）施加1 Hz的rTMS，共10次。在rTMS应用前、应用期间、应用后以及4周随访时评估运动功能障碍的变化。通过皮质兴奋性评估来评估对刺激的神经生理反应。使用基于扩散张量成像（DTI）的分数各向异性（FA）来研究rTMS的功能和神经生理反应与胼胝体运动纤维微观结构完整性之间的关系。
rTMS耐受性良好，依从性高，无患者退出；未发生癫痫发作或运动功能恶化。胼胝体FA值与rTMS后检测到的轻度运动改善呈正线性关系，运动结局较好的受试者FA值更高。皮质兴奋性显示对侧短间隔皮质内抑制有显著变化，表明rTMS后可塑性改变。
我们的结果表明，对侧半球的非侵入性神经调节可能为严重慢性卒中患者的适应性神经可塑性变化提供帮助。实施基于DTI的胼胝体微观结构完整性测量可能允许进行个性化干预，以指导半球间神经可塑性过程。有必要进一步研究以确定这些发现在慢性严重卒中患者神经康复环境中的临床价值。
