Broeder S, Nackaerts E, Nieuwboer A, Smits-Engelsman B C M, Swinnen S P, Heremans E
Neuromotor Rehabilitation Research Group, Department of Rehabilitation Sciences, KU Leuven, Tervuursevest 101, bus 1501, B-3001 Heverlee, Belgium.
Movement Control and Neuroplasticity Research Group, Department of Kinesiology, KU Leuven, Tervuursevest 101, bus 1501, B-3001 Heverlee, Belgium.
Neuroscience. 2014 Mar 28;263:193-202. doi: 10.1016/j.neuroscience.2014.01.019. Epub 2014 Jan 19.
Previous studies have shown that patients with Parkinson's disease (PD) experience extensive problems during dual tasking. Up to now, dual-task interference in PD has mainly been investigated in the context of gait research. However, the simultaneous performance of two different tasks is also a prerequisite to efficiently perform many other tasks in daily life, including upper limb tasks. To address this issue, this study investigated the effect of a secondary cognitive task on the performance of handwriting in patients with PD. Eighteen PD patients and 11 age-matched controls performed a writing task involving the production of repetitive loops under single- and dual-task conditions. The secondary task consisted of counting high and low tones during writing. The writing tests were performed with two amplitudes (0.6 and 1.0cm) using a writing tablet. Results showed that dual-task performance was affected in PD patients versus controls. Dual tasking reduced writing amplitude in PD patients, but not in healthy controls (p=0.046). Patients' writing size was mainly reduced during the small-amplitude condition (small amplitude p=0.017; large amplitude p=0.310). This suggests that the control of writing at small amplitudes requires more compensational brain-processing recourses in PD and is as such less automatic than writing at large amplitudes. In addition, there was a larger dual-task effect on the secondary task in PD patients than controls (p=0.025). The writing tests on the writing tablet proved highly correlated to daily life writing as measured by the 'Systematic Screening of Handwriting Difficulties' test (SOS-test) and other manual dexterity tasks, particularly during dual-task conditions. Taken together, these results provide additional insights into the motor control of handwriting and the effects of dual tasking during upper limb movements in patients with PD.
以往研究表明，帕金森病（PD）患者在执行双重任务时会遇到诸多问题。到目前为止，PD患者的双重任务干扰主要是在步态研究的背景下进行调查的。然而，同时执行两项不同任务也是高效完成日常生活中许多其他任务的前提条件，包括上肢任务。为解决这一问题，本研究调查了次要认知任务对PD患者书写表现的影响。18名PD患者和11名年龄匹配的对照者在单任务和双任务条件下执行了一项涉及书写重复圆圈的书写任务。次要任务包括在书写过程中对高音和低音进行计数。使用书写板以两种幅度（0.6厘米和1.0厘米）进行书写测试。结果显示，与对照组相比，PD患者的双重任务表现受到影响。双重任务使PD患者的书写幅度减小，但健康对照组则未出现这种情况（p = 0.046）。患者的书写大小主要在小幅度条件下减小（小幅度p = 0.017；大幅度p = 0.310）。这表明，在PD患者中，控制小幅度书写需要更多的补偿性大脑处理资源，因此不如大幅度书写那样自动。此外，与对照组相比，PD患者在次要任务上的双重任务效应更大（p = 0.025）。书写板上的书写测试与通过“手写困难系统筛查”测试（SOS测试）及其他手动灵巧性任务所测量的日常生活书写高度相关，尤其是在双重任务条件下。综上所述，这些结果为PD患者手写的运动控制以及上肢运动过程中双重任务的影响提供了更多见解。
