Levy R, Lang A E, Hutchison W D, Lozano A M, Dostrovsky J O
Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
Exp Brain Res. 2002 Dec;147(3):322-31. doi: 10.1007/s00221-002-1257-8. Epub 2002 Oct 12.
Patients with Parkinson's disease (PD) commonly exhibit difficulties performing simultaneous tasks and levodopa has been shown to improve the performance of these movements to a greater extent than movements performed in isolation. The aim of this study was to compare the effects of acute unilateral pallidal lesions (nine patients) and bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) (eight patients) with levodopa therapy (ten patients) on the performance of isolated versus bilateral simultaneous repetitive movements. The STN group was assessed with and without DBS both on and off levodopa. The two tasks employed were maximally paced button tapping (Tap) and wrist pronation-supination (WPS) movements. During the off drug state (12-14 h after the last oral dose of levodopa), the performance of simultaneous Tap and WPS movements in all three groups was significantly slower and more irregular than when each movement was performed in isolation. For example, WPS velocity decreased by at least 37% (P<0.05) with concomitant Tap. Following levodopa, pallidotomy or STN DBS, WPS velocity was increased during the simultaneous task to a greater extent than in the isolated task. All treatments also improved WPS velocity and increased the regularity of movement during concomitant Tap (P<0.01). The findings indicate that, like levodopa, surgical therapies can improve the performance of simultaneous tasks more than isolated tasks. These observations suggest that the excessive neuronal activity and/or abnormal firing patterns in the globus pallidus internus that is found in parkinsonian patients contribute to difficulties in the execution of complex motor tasks.
帕金森病（PD）患者通常在执行同时进行的任务时表现出困难，并且已证明左旋多巴在改善这些运动的表现方面比单独进行的运动效果更显著。本研究的目的是比较急性单侧苍白球毁损术（9例患者）、双侧丘脑底核（STN）深部脑刺激（DBS）（8例患者）与左旋多巴治疗（10例患者）对孤立运动与双侧同时重复运动表现的影响。STN组在服用和未服用左旋多巴的情况下，分别在开启和关闭DBS时进行评估。所采用的两项任务是最大速度的按键敲击（Tap）和手腕旋前 - 旋后（WPS）运动。在停药状态（最后一次口服左旋多巴后12 - 14小时），所有三组同时进行Tap和WPS运动时的表现明显比单独进行每项运动时更慢且更不规律。例如，同时进行Tap时，WPS速度至少降低37%（P<0.05）。服用左旋多巴、进行苍白球毁损术或STN DBS后，同时任务期间WPS速度的增加幅度大于孤立任务。所有治疗方法还提高了WPS速度，并增加了同时进行Tap时运动的规律性（P<0.01）。研究结果表明，与左旋多巴一样，手术治疗对同时进行的任务表现的改善作用大于孤立任务。这些观察结果表明，帕金森病患者中发现的内侧苍白球过度神经元活动和/或异常放电模式导致了复杂运动任务执行困难。
