Background

Altered corticospinal excitability in Parkinson’s disease (PD) is related to many of the motor signs.

Objective

We examined whether the recruitment properties of the corticospinal pathway to hand muscles are changed after 8 weeks of specialized upper limbs exercise in PD.

Methods

Seven PD subjects were enrolled. Upper limb exercise was achieved by using a specially designed device. The input–output (I–O) curves were obtained by transcranial magnetic stimulation (TMS). The conduction of peripheral axons and H reflex was also recorded. UPDRS scale, part-III motor examination was used to assess the motor symptom. Clinical and neurophysiological data were obtained before and after 2-month exercise training.

Results

After 2-month exercise training, the UPDRS score was significantly improved. Threshold, slope, and V50 (i.e., the stimulus intensity required to obtain a response 50% of the maximum) of the I–O curve were unchanged, whereas the plateau value was significantly higher.

Conclusions

Exercise training affects the larger motoneurons, that is those activated at higher TMS stimulation intensity. These motoneurones are related to the large, type II motor units. Clinical improvement after exercise may depend upon restoration of the recruitment of the large motor unit, i.e., those necessary to perform rapid and strong movements, known to be deficient in PD.

中文翻译：

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帕金森病运动训练后皮质运动通路兴奋性的变化

背景

帕金森病 (PD) 中皮质脊髓兴奋性的改变与许多运动体征有关。

客观的

我们检查了在 PD 中进行 8 周专门的上肢运动后，皮质脊髓通路对手部肌肉的募集特性是否发生了变化。

方法

招募了 7 名 PD 受试者。上肢锻炼是通过使用专门设计的设备实现的。通过经颅磁刺激（TMS）获得输入-输出（I-O）曲线。还记录了外周轴突和 H 反射的传导。UPDRS 量表，第三部分运动检查用于评估运动症状。在 2 个月的运动训练前后获得临床和神经生理学数据。

结果

经过2个月的运动训练，UPDRS评分明显提高。I-O 曲线的阈值、斜率和 V50（即获得最大响应的 50% 所需的刺激强度）没有变化，而平台值明显更高。

结论

运动训练会影响较大的运动神经元，即在较高 TMS 刺激强度下激活的运动神经元。这些运动神经元与大的 II 型运动单位有关。运动后的临床改善可能取决于大运动单位的恢复，即执行快速和有力运动所必需的运动单位，已知在 PD 中是有缺陷的。