Data_Sheet_1_Cortical activation of neuromuscular electrical stimulation synchronized mirror neuron rehabilitation strategies: an fNIRS study.docx

BackgroundThe mirror neuron system (MNS) plays a key role in the neural mechanism underlying motor learning and neural plasticity. Action observation (AO), action execution (AE), and a combination of both, known as action imitation (AI), are the most commonly used rehabilitation strategies based on MNS. It is possible to enhance the cortical activation area and amplitude by combining traditional neuromuscular electrical stimulation (NMES) with other top-down and active rehabilitation strategies based on the MNS theory.
ObjectiveThis study aimed to explore the cortical activation patterns induced by NMES synchronized with rehabilitation strategies based on MNS, namely NMES+AO, NMES+AE, and NMES+AI. In addition, the study aimed to assess the feasibility of these three novel rehabilitative treatments in order to provide insights and evidence for the design, implementation, and application of brain-computer interfaces.
MethodsA total of 70 healthy adults were recruited from July 2022 to February 2023, and 66 of them were finally included in the analysis. The cortical activation patterns during NMES+AO, NMES+AE, and NMES+AI were detected using the functional Near-Infrared Spectroscopy (fNIRS) technique. The action to be observed, executed, or imitated was right wrist and hand extension, and two square-shaped NMES electrodes were placed on the right extensor digitorum communis. A block design was adopted to evaluate the activation intensity of the left MNS brain regions.
ResultsGeneral linear model results showed that compared with the control condition, the number of channels significantly activated (PFDR < 0.05) in the NMES+AO, NMES+AE, and NMES+AI conditions were 3, 9, and 9, respectively. Region of interest (ROI) analysis showed that 2 ROIs were significantly activated (PFDR < 0.05) in the NMES+AO condition, including BA6 and BA44; 5 ROIs were significantly activated in the NMES+AE condition, including BA6, BA40, BA44, BA45, and BA46; and 6 ROIs were significantly activated in the NMES+AI condition, including BA6, BA7, BA40, BA44, BA45, and BA46.
ConclusionThe MNS was activated during neuromuscular electrical stimulation combined with an AO, AE, and AI intervention. The synchronous application of NMES and mirror neuron rehabilitation strategies is feasible in clinical rehabilitation. The fNIRS signal patterns observed in this study could be used to develop brain-computer interface and neurofeedback therapy rehabilitation devices.

背景 镜像神经元系统（mirror neuron system, MNS）在运动学习与神经可塑性的神经机制中发挥关键作用。基于MNS的常用康复策略主要包括动作观察（action observation, AO）、动作执行（action execution, AE）以及二者结合的动作模仿（action imitation, AI）。有研究表明，将传统神经肌肉电刺激（neuromuscular electrical stimulation, NMES）与其他基于MNS理论的自上而下主动康复策略相结合，可增强皮层激活区域与激活幅度。
目的 本研究旨在探究与基于MNS的康复策略同步应用的NMES所诱导的皮层激活模式，即NMES+AO、NMES+AE与NMES+AI三种组合模式。此外，本研究还旨在评估这三种新型康复治疗方案的可行性，以期为脑机接口的设计、实施与应用提供理论依据与实验证据。
方法 本研究于2022年7月至2023年2月期间共招募70名健康成年受试者，最终纳入66名受试者进行数据分析。采用功能性近红外光谱（functional Near-Infrared Spectroscopy, fNIRS）技术，检测NMES+AO、NMES+AE与NMES+AI三种状态下的皮层激活模式。本次实验的观察、执行或模仿动作均为右侧腕部与手部伸展，且将两枚方形NMES电极放置于右侧指总伸肌。本研究采用区组设计，以评估左侧MNS脑区的激活强度。
结果 广义线性模型分析结果显示，与对照条件相比，NMES+AO、NMES+AE与NMES+AI条件下显著激活的通道数（PFDR<0.05）分别为3、9与9。感兴趣区（region of interest, ROI）分析结果显示，NMES+AO条件下有2个感兴趣区显著激活（PFDR<0.05），包括BA6与BA44；NMES+AE条件下有5个感兴趣区显著激活，包括BA6、BA40、BA44、BA45与BA46；NMES+AI条件下有6个感兴趣区显著激活，包括BA6、BA7、BA40、BA44、BA45与BA46。
结论 当神经肌肉电刺激分别联合动作观察、动作执行与动作模仿干预时，镜像神经元系统均可被激活。将NMES与镜像神经元康复策略同步应用于临床康复具有可行性。本研究观测到的fNIRS信号模式可用于开发脑机接口与神经反馈治疗康复设备。