Valkovic Peter, Krafczyk Siegbert, Saling Marian, Benetin Ján, Bötzel Kai
Department of Neurology, Ludwig-Maximilians University, Munich, Germany.
Mov Disord. 2006 Jan;21(1):59-65. doi: 10.1002/mds.20679.
To test the hypothesis that reduced reactions to proprioceptive input signals contribute to postural instability in Parkinson's disease (PD), pulses of mechanical vibration were applied to the neck muscles of PD patients and healthy controls. This stimulus elicits postural reactions in standing subjects. Participating were 13 moderately affected PD patients, 13 severely affected PD patients, and 13 age-matched healthy subjects. Patients were tested on and off medication. Three-second-long pulses of vibration were regularly (10 times) applied to the posterior neck muscles while subjects kept their eyes open or closed. Postural responses to the stimuli were measured by static posturography. No intergroup difference in the pattern and latencies of responses was found. However, the amplitudes of the postural reactions (shift of center of foot pressure) were significantly larger in advanced PD patients; those of moderately affected PD patients did not differ from those of control subjects. Moreover, the size of postural responses in both latter groups decreased across the trial contrary to that of advanced PD patients. Comparison of the measures during on and off testing revealed no significant differences. These results indicate that neither afferent proprioceptive deficits nor central integrative functions but rather scaling and habituation of erroneous proprioceptive information are disturbed in the postural control of advanced PD. Nondopaminergic structures seem to be responsible for this impairment.
为了验证帕金森病（PD）患者对本体感觉输入信号反应减弱导致姿势不稳这一假说，对PD患者和健康对照者的颈部肌肉施加机械振动脉冲。这种刺激会在站立受试者中引发姿势反应。参与研究的有13名中度受累的PD患者、13名重度受累的PD患者和13名年龄匹配的健康受试者。患者在服药和未服药状态下接受测试。在受试者睁眼或闭眼时，对后颈部肌肉定期（10次）施加持续3秒的振动脉冲。通过静态姿势描记法测量对刺激的姿势反应。未发现各实验组在反应模式和潜伏期方面存在差异。然而，晚期PD患者姿势反应的幅度（足底压力中心的偏移）显著更大；中度受累的PD患者与对照受试者的姿势反应幅度没有差异。此外，与晚期PD患者相反，后两组在整个试验过程中姿势反应的大小均下降。服药和未服药测试期间的测量结果比较显示无显著差异。这些结果表明，在晚期PD的姿势控制中，传入本体感觉缺陷和中枢整合功能均未受干扰，而是错误本体感觉信息的缩放和习惯化受到了干扰。非多巴胺能结构似乎是造成这种损害的原因。
