The reaching movements of patients with Parkinson's disease under self-determined maximal speed and visually cued conditions
The reaching movements of patients with Parkinson's disease under self-determined maximal speed and visually cued conditions
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DOI：
10.1093/brain/121.4.755
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发表时间：
1998-04-01
期刊：
影响因子：
14.5
通讯作者：
Flanagan, JR
中科院分区：
文献类型：
--
作者：
Majsak, MJ;Kaminski, T;Flanagan, JR
对6名帕金森病患者和6名健康受试者在自行确定的最大速度和视觉线索条件下产生的伸展动作进行了二维运动学分析。受试者被要求以尽可能快的速度抓住一个球，该球(I)固定在倾斜坡道上指定接触区的中心(自行确定的最大速度条件)，或(Ii)从左向右快速滚下斜坡进入接触区(视觉提示条件)。帕金森氏症受试者在达到静止球的最大速度时表现出运动迟缓，但当他们达到移动的球时却没有。帕金森氏症受试者在移动球的外部驱动刺激下，表现出超过自我确定的最大伸展速度的能力，同时仍保持与健康受试者相当的运动精度。因此，帕金森氏病受试者的运动迟缓似乎并不是他们的力量生产能力基本不足的结果，也不是运动准确性差的一种补偿机制。相反，运动迟缓似乎是由于帕金森氏症患者在需要内部驱动运动输出时无法最大限度地提高运动速度所致。帕金森氏症受试者偶尔无法成功地抓住移动的球，这表明他们的预期错误和抓取能力上的障碍，而不是他们伸展的速度或准确性的限制。这些结果与基底节的运动回路在调节内部调节运动中起重要作用这一概念有关。
Two-dimensional kinematic analysis was performed of the reaching movements that six subjects with Parkinson's disease and six healthy subjects produced under self-determined maximal speed and visually cued conditions. Subjects were required to reach as fast as possible to grasp a ball (i) that was fixed stationary in the centre of a designated contact zone on an inclined ramp (self-determined maximal speed condition), or (ii) that rolled rapidly from left to right down the incline and into the contact Zone (visually cued condition). Parkinson's disease subjects displayed bradykinesia when performing maximal speed reaches to the stationary ball, but not when they reached for the moving ball. In response to the external driving stimulus of the moving ball, Parkinson's disease subjects showed the ability to exceed their self-determined maximal speed of reaching and still maintain a movement accuracy that was comparable to that of healthy subjects. Thus, the bradykinesia of Parkinson's disease subjects did not seem to he title result of a basic deficit in their force production capacity or to be a compensatory mechanism for poor movement accuracy. Instead, bradykinesia appeared to result from the inability of Parkinson's disease subjects to maximize their movement speed when required to internally drive their motor output. The occasional failure of Parkinson's disease subjects to successfully grasp the moving ball suggested errors of coincident anticipation and impairments in grasp performance rather than limitations in the speed or accuracy of their reaches. These results are discussed in relation to the notion that the motor circuits of the basal ganglia play an important role in the modulation of internally regulated movements.