Department of Rehabilitation and Movement Science, University of Vermont, Burlington, VT, USA.
Department of Neurology, Oregon Health & Science University, Portland, OR, USA; Parkinson's Disease Research Education and Clinical Center, Portland Veterans Affairs Medical Center, Portland, OR, USA.
Parkinsonism Relat Disord. 2014 Jul;20(7):779-81. doi: 10.1016/j.parkreldis.2014.04.001. Epub 2014 Apr 14.
Although falls in people with Parkinson's disease (PD) associate with dual tasking and freezing of gait (FoG), it is not known whether falls during dual tasking are due to FoG. This study investigated the effects of a cognitive task on the occurrence of falls and FoG when subjects with PD step in response to a postural perturbation.
Ten subjects with PD and a history of FoG as well as 10 age-matched subjects without PD stepped in response to large, backward displacements of the support surface, with and without performing a fluency task of listing items in a category. Subjects with PD performed the task in the "off" and "on" dopaminergic medication states. We recorded the percentage of trials with FoG (a lack of step in response to the perturbation), foot-lift latencies, and trials with falls into a safety harness.
Dual tasking significantly increased the incidence of falls in people with PD, but subjects without PD did not fall in any condition. Dual tasking did not significantly increase trials without steps or foot-lift latencies. Falls were often coincident with a lack of step (FoG) in the single-task condition, but the increased falls with dual tasking occurred on trials with steps. Levodopa tended to decrease FoG and falls with or without dual tasking. However, medication did not significantly alter the effects of dual tasking on FoG or falls.
For people with PD and FoG, forward falls may not always be caused by FoG, particularly under attention-distracting conditions.
尽管帕金森病（PD）患者的跌倒与双重任务和步态冻结（FoG）有关，但尚不清楚双重任务中的跌倒是否是由于 FoG 引起的。本研究调查了认知任务对 PD 患者在响应姿势扰动时跌倒和 FoG 发生的影响。
10 名有 FoG 病史的 PD 患者和 10 名年龄匹配的无 PD 患者在执行流畅性任务（列出类别中的项目）和不执行该任务的情况下，响应支撑面的大向后位移进行了跨步。PD 患者在“关”和“开”多巴胺能药物状态下执行任务。我们记录了 FoG （对扰动无反应）试验的百分比、抬脚潜伏期和跌倒到安全带上的试验次数。
双重任务显著增加了 PD 患者跌倒的发生率，但无 PD 的患者在任何情况下都不会跌倒。双重任务并未显著增加无跨步试验或抬脚潜伏期。在单任务条件下，跌倒常常与缺乏跨步（FoG）同时发生，但在双重任务条件下，跌倒增加是由于跨步试验。左旋多巴倾向于减少双重任务和无双重任务时的 FoG 和跌倒。然而，药物治疗并没有显著改变双重任务对 FoG 或跌倒的影响。
对于有 FoG 的 PD 患者，向前跌倒不一定总是由 FoG 引起的，特别是在注意力分散的情况下。
