Dietz V
Department of Clinical Neurology and Neurophysiology, University of Freiburg, Germany.
Adv Neurol. 1993;60:375-80.
Several aspects of characteristically impaired postural adjustments indicate a defective central programming of the respective EMG patterns in PD. This may be due to deficits in the supraspinal control of spinal interneuronal circuits. This impairment obviously contributes to the difficulty of these patients in performing two motor acts simultaneously. In addition, parkinsonian patients exhibit a reduced sensitivity of polysynaptic reflexes in the leg extensor muscles which correlates with their postural instability. The activity of monosynaptic reflexes is negligible, as in healthy subjects. The impairment of proprioceptive reflex function may be partially compensated for by changes of intrinsic muscle stiffness. Discrepancies in the literature about the behavior of the polysynaptic EMG responses in parkinsonian patients may in part arise from the fact that it depends on both the particular muscle under study and the actual motor task investigated.
典型的姿势调整受损的几个方面表明帕金森病中相应肌电图模式的中枢编程存在缺陷。这可能是由于脊髓上神经元回路的脊髓上控制存在缺陷。这种损伤显然导致了这些患者同时执行两种运动行为的困难。此外，帕金森病患者腿部伸肌的多突触反射敏感性降低，这与他们的姿势不稳相关。与健康受试者一样，单突触反射的活动可以忽略不计。本体感觉反射功能的损伤可能会通过内在肌肉僵硬度的变化得到部分补偿。关于帕金森病患者多突触肌电图反应行为的文献差异可能部分源于这样一个事实，即它取决于所研究的特定肌肉和所调查的实际运动任务。
