Silveira Carolina R A, Ehgoetz Martens Kaylena A, Pieruccini-Faria Frederico, Bell-Boucher Danielle, Roy Eric A, Almeida Quincy J
Sun Life Financial Movement Disorders Research and Rehabilitation Centre, Wilfrid Laurier University, 75 University Avenue West, Waterloo, ON, N2L 3C5, Canada.
J Neurol. 2015 Jul;262(7):1629-36. doi: 10.1007/s00415-015-7759-7. Epub 2015 May 1.
Although the underlying mechanisms of freezing of gait in Parkinson's disease (PD) are not fully understood, impaired sensory-perceptual processing has been proposed as an important contributor to freezing episodes. The aims of this cross-sectional study were to disentangle how sensory-perceptual deficits involved in planning (prior to movement) and sensory-perceptual feedback processing (during movement execution) contribute to freezing of gait in narrow spaces. Thirteen PD participants with freezing (PD FOG), 14 PD participants without freezing (PD non-FOG), and 15 healthy individuals made a perceptual estimate of the width of the distal opening of a corridor in two conditions: parallel and narrowing walls. Gait characteristics and number of freezing episodes were then compared while participants walked in baseline (no corridor), and through parallel walls and narrowing walls corridors. Visuospatial abilities were also assessed using neuropsychological tests. PD FOG had lower scores in the copy of the pentagons (p = 0.044) and had greater error variability in the perceptual judgment task (p = 0.008) than healthy participants. Although a similar number of freezing episodes occurred in both corridor conditions, PD FOG had greater step length variability while walking through the parallel walls corridor compared to healthy (p < 0.001) and PD non-FOG (p = 0.017) participants. Regression analysis revealed that error variability in perceptual judgment predicted the percentage of time spent in double support (R (2) = 0.347) only in the narrowing walls condition for PD FOG. These results support the notion that sensory-perceptual deficits both prior to movement planning and during movement execution are important factors contributing to freezing of gait.
尽管帕金森病（PD）中步态冻结的潜在机制尚未完全明确，但感觉-知觉加工受损被认为是导致冻结发作的一个重要因素。这项横断面研究的目的是厘清在狭窄空间中，计划阶段（运动前）和感觉-知觉反馈加工阶段（运动执行过程中）涉及的感觉-知觉缺陷是如何导致步态冻结的。13名有步态冻结的PD患者（PD FOG组）、14名无步态冻结的PD患者（PD非FOG组）和15名健康个体在两种条件下对走廊远端开口的宽度进行了知觉估计：平行墙壁和逐渐变窄的墙壁。然后在参与者在基线状态（无走廊）、通过平行墙壁走廊和逐渐变窄的墙壁走廊行走时，比较他们的步态特征和冻结发作次数。还使用神经心理学测试评估了视觉空间能力。与健康参与者相比，PD FOG组在五边形临摹测试中的得分较低（p = 0.044），在知觉判断任务中的误差变异性更大（p = 0.008）。尽管在两种走廊条件下发生的冻结发作次数相似，但与健康参与者（p < 0.001）和PD非FOG组参与者（p = 0.017）相比，PD FOG组在通过平行墙壁走廊行走时步长变异性更大。回归分析显示，仅在逐渐变窄的墙壁条件下，PD FOG组知觉判断的误差变异性可预测双腿支撑时间的百分比（R (2) = 0.347）。这些结果支持了这样一种观点，即运动计划前和运动执行过程中的感觉-知觉缺陷都是导致步态冻结的重要因素。
