上肢辅助站立状态下姿态扰动诱发的脑电响应特征

Characteristics of EEG Response Evoked by Postural Perturbation During Standing with Upper Limb Support

探究上肢辅助站立状态下姿态扰动诱发的脑电响应特征,从而为下肢运动功能障碍患者失稳态的识别提供新的思路和方法。设计实验装置使人体随机侧的上肢支撑力发生快速变化,从而模拟人体在上肢辅助站立状态下的姿态扰动。实验同步采集20名被试64通道脑电、双侧支撑力和双侧前臂腕伸肌的表面肌电信号,分析姿态扰动事件发生时脑电诱发电位的神经响应特征,以及力学信号和表面肌电的行为学响应特征。在姿态扰动施加后,姿态扰动侧的支撑力在(200.5±15.4)ms的时间内快速减小。与此同时,双侧前臂腕伸肌的表面肌电值均增大,并且姿态扰动侧的表面肌电值更大。姿态扰动施加后诱发出了N1电位,其在FCz导联处幅值最大,其潜伏期为(62.3±5.5)ms,幅值为(15.6±6.1)μV;P2电位的潜伏期为(167.4±12.4)ms,幅值为(5.2±4.5)μV。该研究为通过神经响应过程识别人体的失稳态提供可行性。

This study investigated the characteristics of EEG response evoked by postural perturbation during standing with upper limb support, aiming to provide a new idea for detecting the instability of patients with lower extremity motor dysfunction. The experimental equipment was designed to apply rapid and sudden change of upper limb supporting force on random side of human body to simulate the perturbation during upper limb assisted standing. The EEG of 64 channels, two sides of supporting force and surface electromyogram(sEMG) of smaller forearm extensors on both sides of 20 subjects were recorded synchronously. We analyzed the neural response characteristics of EEG evoked potential, and the behavioral response characteristics of mechanical signal and sEMG. Results: After the postural perturbation was applied, the supporting force on the perturbed side suddenly decreased in the time of(200.5±15.4) ms. Meanwhile, sEMG of smaller forearm extensors on both sides increased, and the sEMG of perturbed side was higher than the other side. Following postural perturbation onset, N1 potentials were observed with a peak latency of(62.3±5.5) ms and the peak activity was located at FCz electrode with a peak amplitude of(15.6±6.1) μV. The peak latency of P2 potentials were(167.4±12.4) ms and peak amplitude were(5.2±4.5) μV. The findings of this study provided a feasibility of detecting human unsteady state through neural response process.