Neuroscience and Motor Control Group (NEUROcom), Department of Medicine, INEF-Galicia and Institute of Biomedical Research of Coruña (INIBIC), University of A Coruña, 15006 A Coruña, Spain.
Parkinsonism Relat Disord. 2013 Dec;19(12):1123-9. doi: 10.1016/j.parkreldis.2013.08.005. Epub 2013 Aug 28.
Impaired temporal stability and poor motor unit recruitment are key impairments in Parkinsonian motor control during a whole spectrum of rhythmic movements, from simple finger tapping to gait. Therapies based on imitation can be designed for patients with motor impairments and virtual-reality (VR) offers a new perspective. Motor actions are known to depend upon the dopaminergic system, whose involvement in imitation is unknown. We sought to understand this role and the underlying possibilities for motor rehabilitation, by observing the execution of different motor-patterns during imitation in a VR environment in subjects with and without dopaminergic deficits.
10 OFF-dose idiopathic Parkinson's Disease patients (PD), 9 age-matched and 9 young-subjects participated. Subjects performed finger-tapping at their "comfort" and "slow-comfort" rates, while immersed in VR presenting their "avatar" in 1st person perspective. Imitation was evaluated by asking subjects to replicate finger-tapping patterns different to their natural one. The finger-pattern presented matched their comfort and comfort-slow rates, but without a pause on the table (continuously moving).
Patients were able to adapt their finger-tapping correctly, showing that in comparison with the control groups, the dopaminergic deficiency of PD did not impair imitation. During imitation the magnitude of EMG increased and the temporal variability of movement decreased.
PD-patients have unaltered ability to imitate instructed motor-patterns, suggesting that a fully-functional dopaminergic system is not essential for such imitation. It should be further investigated if imitation training over a period of time induces positive off-line motor adaptations with transfer to non-imitation tasks.
在整个节奏运动范围内，从简单的手指敲击到步态，帕金森病患者的运动控制存在时间稳定性受损和运动单位募集不良等关键缺陷。基于模仿的疗法可针对运动障碍患者设计，而虚拟现实（VR）提供了新的视角。众所周知，运动动作取决于多巴胺能系统，但其在模仿中的作用尚不清楚。我们试图通过观察在 VR 环境中进行模仿时不同运动模式的执行情况，来了解这种作用及其对运动康复的潜在可能性，研究对象包括有无多巴胺能缺陷的患者。
10 名未服用药物的特发性帕金森病患者（PD）、9 名年龄匹配的健康人和 9 名年轻受试者参与了研究。受试者在 VR 环境中以第一人称视角沉浸自己的“化身”，以“舒适”和“缓慢舒适”的速度进行手指敲击。通过要求受试者复制与其自然模式不同的手指敲击模式来评估模仿。呈现给受试者的手指模式与他们的舒适和舒适缓慢速度相匹配，但在桌子上没有停顿（连续移动）。
患者能够正确地调整他们的手指敲击，表明与对照组相比，PD 的多巴胺缺乏并没有损害模仿能力。在模仿过程中，肌电图的幅度增加，运动的时间可变性降低。
PD 患者具有不变的能力来模仿指令性运动模式，这表明完整功能的多巴胺系统对于这种模仿并非必需。如果模仿训练在一段时间内诱导出积极的离线运动适应，并转移到非模仿任务中，那么这需要进一步研究。
