Institute of Neurology, Università Cattolica del Sacro Cuore, Rome, Italy.
Gait Posture. 2011 Mar;33(3):436-41. doi: 10.1016/j.gaitpost.2010.12.020. Epub 2011 Jan 21.
Previous studies have reported that patients with Parkinson's disease (PD) show, in the "off medication" state, a reduced activation of tibialis anterior (TA) in the late swing-early stance phase of the gait cycle. In PD patients the pathophysiological picture may cause differences among the stride cycles. Our aims were to evaluate how frequently TA activity is reduced in the late swing-early stance phase and if there is a relationship between the TA pattern and the clinical picture. Thirty PD patients were studied 2 h after Levodopa administration ("on-med") and 12 h after Levodopa wash-out ("off-med"). They were evaluated by the Unified Parkinson's Disease Rating Scale (UPDRS III) and surface electromyography of TA and gastrocnemius medialis (GM). The root mean square (RMS) of the TA activity in late swing-early stance phase (RMS-A) was normalized as a percent of the RMS of the TA activity in late stance-early swing (RMS-B). RMS-A was reduced in 30% of patients in the "off-med" condition. Within these patients, the percentage of stride cycles with reduced RMS-A, ranged between 28% and 83%. After Levodopa intake, no stride cycle showed reduced RMS-A. Patients with reduced RMS-A had a lower UPDRS III total score in the "on-med" rather than in the "off-med" condition (p=0.02). Our data confirm and extend previous observations indicating that, in "off-med" the function of TA is impaired in those patients clinically more responsive to Levodopa. TA activation is reduced in a relatively high percent of gait cycles in the "off-med" state. Since the variability of TA activation disappears after Levodopa administration, this phenomenon could be the expression of an abnormal dopaminergic drive.
先前的研究报告表明，帕金森病（PD）患者在步态周期的“停药”状态下，胫骨前肌（TA）在晚期摆动早期支撑阶段的激活减少。在 PD 患者中，病理生理图像可能会导致步幅周期之间的差异。我们的目的是评估 TA 活动在晚期摆动早期支撑阶段减少的频率，以及 TA 模式与临床情况之间是否存在关系。30 例 PD 患者在左旋多巴给药后 2 小时（“开”）和左旋多巴洗脱后 12 小时（“关”）进行研究。他们通过统一帕金森病评定量表（UPDRS III）和 TA 和内侧腓肠肌（GM）的表面肌电图进行评估。晚期摆动-早期支撑阶段 TA 活动的均方根（RMS）（RMS-A）作为晚期支撑-早期摆动阶段 TA 活动的 RMS（RMS-B）的百分比进行归一化。在“停药”状态下，30%的患者 RMS-A 减少。在这些患者中，RMS-A 减少的步幅周期百分比在 28%到 83%之间。在服用左旋多巴后，没有一个步幅周期显示 RMS-A 减少。与“停药”相比，RMS-A 减少的患者在“开”时的 UPDRS III 总分较低（p=0.02）。我们的数据证实并扩展了先前的观察结果，表明在“停药”状态下，那些对左旋多巴反应更敏感的患者，TA 的功能受损。在“停药”状态下，TA 激活在相对较高比例的步态周期中减少。由于 TA 激活的可变性在服用左旋多巴后消失，这种现象可能是异常多巴胺能驱动的表现。
