Using Gastrocnemius sEMG and Plasma α-Synuclein for the Prediction of Freezing of Gait in Parkinson's Disease Patients

Freezing of gait (FOG) is a complicated gait disturbance in Parkinson's disease (PD) and a relevant subclinical predictor algorithm is lacking. The main purpose of this study is to explore the potential value of surface electromyograph (sEMG) and plasma α-synuclein levels as predictors of the FOG seen in PD. 21 PD patients and 15 normal controls were recruited. Motor function was evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS) and Freezing of gait questionnaire (FOG-Q). Simultaneously, gait analysis was also performed using VICON capture system in PD patients and sEMG data was recorded as well. Total plasma α-synuclein was quantitatively assessed by Luminex assay in all participants. Recruited PD patients were classified into two groups: PD patients with FOG (PD+FOG) and without FOG (PD-FOG), based on clinical manifestation, the results of the FOG-Q and VICON capture system. PD+FOG patients displayed higher FOG-Q scores, decreased walking speed, smaller step length, smaller stride length and prolonged double support time compared to the PD-FOG in the gait trial. sEMG data indicated that gastrocnemius activity in PD+FOG patients was significantly reduced compared to PD-FOG patients. In addition, plasma α-synuclein levels were significantly decreased in the PD+FOG group compared to control group; however, no significant difference was found between the PD+FOG and PD-FOG groups. Our study revealed that gastrocnemius sEMG could be used to evaluate freezing gait in PD patients, while plasma α-synuclein might discriminate freezing of gait in PD patients from normal control, though no difference was found between the PD+FOG and PD-FOG groups.

冻结步态（Freezing of gait, FOG）是帕金森病（Parkinson's disease, PD）中一类复杂的步态障碍，目前尚无成熟的亚临床预测算法。本研究旨在探究表面肌电图（surface electromyograph, sEMG）与血浆α-突触核蛋白水平作为帕金森病患者冻结步态预测指标的潜在价值。本研究共招募21例帕金森病患者与15名健康对照受试者。采用统一帕金森病评定量表（Unified Parkinson's Disease Rating Scale, UPDRS）与冻结步态问卷（Freezing of gait questionnaire, FOG-Q）对受试者的运动功能进行评估。同时，针对帕金森病患者，采用VICON捕捉系统开展步态分析，并同步记录表面肌电图数据。所有受试者的血浆总α-突触核蛋白水平均通过Luminex检测进行定量测定。根据临床表现、冻结步态问卷结果及VICON捕捉系统分析结果，将招募的帕金森病患者分为两组：伴冻结步态帕金森病组（PD+FOG）与无冻结步态帕金森病组（PD-FOG）。步态试验结果显示，与PD-FOG组相比，PD+FOG组患者的冻结步态问卷评分更高，步行速度更慢，步幅、跨步长度更短，双支撑相时间更长。表面肌电图数据显示，PD+FOG组患者的腓肠肌活动水平显著低于PD-FOG组。此外，与健康对照组相比，PD+FOG组患者的血浆α-突触核蛋白水平显著降低；但PD+FOG组与PD-FOG组之间未观察到显著差异。本研究结果表明，腓肠肌表面肌电图可用于评估帕金森病患者的冻结步态，而血浆α-突触核蛋白或可区分帕金森病伴冻结步态患者与健康对照人群，尽管其在PD+FOG组与PD-FOG组之间无显著差异。