Department of Bioengineering, Stanford University, Stanford, California, United States of America.
Department of Neurology and Neurological Sciences, Stanford University, Stanford, California, United States of America.
PLoS One. 2020 Apr 29;15(4):e0231984. doi: 10.1371/journal.pone.0231984. eCollection 2020.
Freezing of gait (FOG) is a devastating motor symptom of Parkinson's disease that leads to falls, reduced mobility, and decreased quality of life. Reliably eliciting FOG has been difficult in the clinical setting, which has limited discovery of pathophysiology and/or documentation of the efficacy of treatments, such as different frequencies of subthalamic deep brain stimulation (STN DBS). In this study we validated an instrumented gait task, the turning and barrier course (TBC), with the international standard FOG questionnaire question 3 (FOG-Q3, r = 0.74, p < 0.001). The TBC is easily assembled and mimics real-life environments that elicit FOG. People with Parkinson's disease who experience FOG (freezers) spent more time freezing during the TBC compared to during forward walking (p = 0.007). Freezers also exhibited greater arrhythmicity during non-freezing gait when performing the TBC compared to forward walking (p = 0.006); this difference in gait arrhythmicity between tasks was not detected in non-freezers or controls. Freezers' non-freezing gait was more arrhythmic than that of non-freezers or controls during all walking tasks (p < 0.05). A logistic regression model determined that a combination of gait arrhythmicity, stride time, shank angular range, and asymmetry had the greatest probability of classifying a step as FOG (area under receiver operating characteristic curve = 0.754). Freezers' percent time freezing and non-freezing gait arrhythmicity decreased, and their shank angular velocity increased in the TBC during both 60 Hz and 140 Hz STN DBS (p < 0.05) to non-freezer values. The TBC is a standardized tool for eliciting FOG and demonstrating the efficacy of 60 Hz and 140 Hz STN DBS for gait impairment and FOG. The TBC revealed gait parameters that differentiated freezers from non-freezers and best predicted FOG; these may serve as relevant control variables for closed loop neurostimulation for FOG in Parkinson's disease.
冻结步态（FOG）是帕金森病的一种严重运动症状，可导致跌倒、活动能力下降和生活质量降低。在临床环境中可靠地引出 FOG 一直具有挑战性，这限制了对其病理生理学的发现和/或对治疗效果的记录，例如不同频率的丘脑底核深部脑刺激（STN DBS）。在这项研究中，我们使用国际标准的 FOG 问卷问题 3（FOG-Q3，r = 0.74，p < 0.001）验证了一种仪器化步态任务，即转弯和障碍课程（TBC）。患有帕金森病并出现 FOG 的人（冻结者）在 TBC 中比在向前行走时冻结的时间更多（p = 0.007）。与向前行走相比，冻结者在 TBC 中进行非冻结步态时表现出更大的非节律性（p = 0.006）；在非冻结者或对照组中未检测到任务之间这种步态非节律性的差异。与非冻结者或对照组相比，冻结者的非冻结步态在所有步行任务中都更不规律（p < 0.05）。逻辑回归模型确定，步态非节律性、步幅时间、小腿角度范围和不对称性的组合具有最大的可能性将一步分类为 FOG（受试者工作特征曲线下面积 = 0.754）。冻结者在 TBC 中的冻结时间百分比和非冻结步态非节律性降低，小腿角速度增加，在 60 Hz 和 140 Hz STN DBS 期间（p < 0.05）达到非冻结者的值。TBC 是一种诱发 FOG 的标准化工具，并证明了 60 Hz 和 140 Hz STN DBS 对步态障碍和 FOG 的疗效。TBC 揭示了区分冻结者和非冻结者的步态参数，并能最好地预测 FOG；这些可能作为帕金森病中针对 FOG 的闭环神经刺激的相关控制变量。
