Cunnington R, Iansek R, Bradshaw J L, Phillips J G
Department of Psychology, Monash University, Clayton, Victoria, Australia.
Brain. 1995 Aug;118 ( Pt 4):935-50. doi: 10.1093/brain/118.4.935.
Activity of the supplementary motor area may be inferred from movement-related potentials (MRPs) which are associated with the preparation and execution of voluntary, or internally determined movements. Supplementary motor area activity may be abnormal in Parkinson's disease since its major input from the basal ganglia is disrupted. Investigation of the abnormalities in supplementary motor area activity associated with movement deficits in Parkinson's disease may therefore reveal functions of the basal ganglia and the supplementary motor area. Movement-related potentials associated with sequential movements were investigated under various cueing conditions in Parkinson's disease subjects and age-matched controls. In controls, MRPs revealed involvement of the supplementary motor area in movements which can be internally determined (non-cued and externally cued, predictable movements, but not unpredictable movements). In Parkinson's disease, however, the supplementary motor area was only involved in movements which must be internally determined (non-cued movements, but not externally cued movements); therefore impaired internal control mechanisms, operating via the supplementary motor area, are bypassed when external cues are given. As a result, Parkinson's disease patients are more reliant on external cues and are unable to use predictive models to internally guide movement. Supplementary motor area involvement also relied on the predictability (in controls) or presence (in Parkinson's disease) of timing cues and not spatial cues, indicating a role of the supplementary motor area and basal ganglia in the temporal organizations of sequential movement rather than the programming of specific movements. For non-cued movements, abnormalities in MRPs for Parkinson's disease subjects consisted of delayed MRP onset and peak times, and prolonged cortical activity following movement. These observations led to a proposed model of the interaction between the basal ganglia and the supplementary motor area, involving the temporal organization of voluntary and internally determined sequential movements.
辅助运动区的活动可从与自主或内在决定的运动的准备和执行相关的运动相关电位（MRP）中推断出来。帕金森病中辅助运动区的活动可能异常，因为其来自基底神经节的主要输入被破坏。因此，研究帕金森病中与运动缺陷相关的辅助运动区活动异常，可能揭示基底神经节和辅助运动区的功能。在各种提示条件下，对帕金森病患者和年龄匹配的对照组中与连续运动相关的运动相关电位进行了研究。在对照组中，MRP显示辅助运动区参与了可以内在决定的运动（无提示和外部提示的可预测运动，但不包括不可预测运动）。然而，在帕金森病中，辅助运动区仅参与必须内在决定的运动（无提示运动，但不包括外部提示运动）；因此，当给予外部提示时，通过辅助运动区起作用的内部控制机制受损就被绕过了。结果，帕金森病患者更依赖外部提示，并且无法使用预测模型来内在地指导运动。辅助运动区的参与还依赖于时间提示的可预测性（在对照组中）或存在（在帕金森病中），而不是空间提示，这表明辅助运动区和基底神经节在连续运动的时间组织中起作用，而不是在特定运动的编程中起作用。对于无提示运动，帕金森病患者的MRP异常包括MRP起始和峰值时间延迟，以及运动后皮层活动延长。这些观察结果导致了一个关于基底神经节和辅助运动区之间相互作用的模型，该模型涉及自主和内在决定的连续运动的时间组织。
