Wu Tao, Hallett Mark, Chan Piu
Department of Neurobiology, Key Laboratory on Neurodegenerative Disorders of Ministry of Education, Beijing Institute of Geriatrics, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory on Parkinson's Disease, Parkinson Disease Center of Beijing Institute for Brain Disorders, Beijing, China.
Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
Neurobiol Dis. 2015 Oct;82:226-234. doi: 10.1016/j.nbd.2015.06.014. Epub 2015 Jun 21.
Bradykinesia is the most important feature contributing to motor difficulties in Parkinson's disease (PD). However, the pathophysiology underlying bradykinesia is not fully understood. One important aspect is that PD patients have difficulty in performing learned motor skills automatically, but this problem has been generally overlooked. Here we review motor automaticity associated motor deficits in PD, such as reduced arm swing, decreased stride length, freezing of gait, micrographia and reduced facial expression. Recent neuroimaging studies have revealed some neural mechanisms underlying impaired motor automaticity in PD, including less efficient neural coding of movement, failure to shift automated motor skills to the sensorimotor striatum, instability of the automatic mode within the striatum, and use of attentional control and/or compensatory efforts to execute movements usually performed automatically in healthy people. PD patients lose previously acquired automatic skills due to their impaired sensorimotor striatum, and have difficulty in acquiring new automatic skills or restoring lost motor skills. More investigations on the pathophysiology of motor automaticity, the effect of L-dopa or surgical treatments on automaticity, and the potential role of using measures of automaticity in early diagnosis of PD would be valuable.
运动迟缓是导致帕金森病（PD）运动障碍的最重要特征。然而，运动迟缓背后的病理生理学尚未完全明确。一个重要方面是，PD患者在自动执行已学运动技能方面存在困难，但这个问题通常被忽视了。在此，我们综述了与PD运动自动性相关的运动缺陷，如摆臂减少、步幅缩短、步态冻结、小写症和面部表情减少。最近的神经影像学研究揭示了PD中运动自动性受损的一些神经机制，包括运动的神经编码效率较低、无法将自动化运动技能转移至感觉运动纹状体、纹状体内自动模式不稳定，以及使用注意力控制和/或代偿性努力来执行健康人通常自动进行的运动。由于感觉运动纹状体受损，PD患者失去了先前获得的自动技能，并且在获得新的自动技能或恢复失去的运动技能方面存在困难。对运动自动性的病理生理学、左旋多巴或手术治疗对自动性的影响以及使用自动性测量方法在PD早期诊断中的潜在作用进行更多研究将很有价值。
