Cortical Preparation for Postural Responses in Parkinson's Disease

描述（由申请人提供）：帕金森病（PD）是一种慢性进行性疾病，通常影响65岁以上的人群，这一人群在美国人口中正在迅速扩大。本研究的总体目标是了解健康个体对姿势扰动反应的预备皮层机制，以及PD成人患者的这种预备活动如何受损。更具体地说，脑电图（EEG）将用于测量偶然负变化（CNV），即在提示自主运动之前发生的脑电图振幅的缓慢负移。CNV测量预备皮层活动，反映反应的“中枢集”和预期准备。先前的研究表明，帕金森病影响“中枢集”和姿势反应，但没有测量相应的皮层活动。这一提议的假设是，预备性皮层活动代表姿势反应预期尺度的“中心集”，PD影响这一“中心集”。第一个目的是比较健康个体在可预测和不可预测的姿势扰动量级之前的预备皮质电位，验证预期皮质活动的作用是衡量预期扰动量级的姿势反应的假设。健康成人受试者在可预测量级扰动前的脑电图中显示出比不可预测量级扰动更大的幅度cnv。还假设，在大的、可预测的扰动之前，比需要较小姿态响应的小的、可预测的扰动之前，会有更大的幅度cnv。第二个目的是比较成年PD患者与年龄匹配的健康个体在可预测和不可预测的姿势扰动量级之前的预备皮质电位。与健康成人相比，PD患者表现出预期缩放行为受损。假设是，与健康对照相比，患有PD的成年人将表现出较小幅度的CNV。第三个目的是比较“胸怀大志”（一种注意力提示策略）如何影响大脑皮层预备电位和可预测姿势反应的大小。据推测，指导成年PD患者在接受姿势扰动之前“想大”会增加CNV的振幅和姿势反应的大小。这些研究将支持重点康复方法，通过更好地了解1)皮质准备与姿势控制的“中枢集”相关，2)PD影响“中枢集”和CNV功能，3)提示改变PD的CNV功能和姿势反应，从而改善成人帕金森病患者的姿势控制和减少跌倒。

DESCRIPTION (provided by applicant): Parkinson's disease (PD) is a chronic, progressive disease usually affecting people over the age of 65, a segment of the United States population that is rapidly expanding. The broad goal of this proposal is to understand the preparatory cortical mechanisms that underlie response to postural perturbation in healthy individuals and how this preparatory activity is impaired in adults with PD. More specifically, electroencephalography (EEG) will be used to measure contingent negative variation (CNV), a slow, negative shift in EEG amplitude that occurs prior to cued voluntary movements. The CNV measures preparatory cortical activity and reflects 'central set' and anticipatory preparation of responses. Previous studies have shown that PD affects 'central set' and postural responses, but have not measured corresponding cortical activity. The hypothesis of this proposal is that preparatory cortical activity represents 'central set' for anticipatory scaling of postural responses and that PD affects this 'central set'. The first aim is to compare preparatory cortical potentials prior to predictable and unpredictable magnitudes of postural perturbations in healthy individuals, testing the hypothesis that the role of anticipatory cortical activity is to scale postural responses for the anticipated magnitude of perturbations. It is proposed that healthy adult participants will show larger amplitude CNVs in their EEG prior to predictable magnitude perturbations than to unpredictable perturbations. It is also hypothesized that there will be larger amplitude CNVs before large, predictable perturbations than before small, predictable perturbations requiring a smaller postural response. The second aim is to compare preparatory cortical potentials prior to predictable and unpredictable magnitudes of postural perturbations in adults with PD to age-matched, healthy individuals. Adults with PD show impaired anticipatory scaling behaviorally, as compared to healthy adults. The hypothesis is that adults with PD will show smaller amplitude CNV as compared to healthy controls. The third aim is to compare how "Think Big", an attentional cuing strategy, affects preparatory cortical potentials and the size of predictable postural responses. It is hypothesized that instructing adults with PD to "think big" prior to receiving a postural perturbation will increase both the amplitude of the CNV and the size of the postural response. These studies will support focused rehabilitation approaches to improve postural control and decrease falls in adults with Parkinson's disease by providing a better understanding of how 1) cortical preparation is related to 'central set' for postural control, 2) PD affects 'central set' and CNV function and 3) cuing alters CNV function and postural responses in PD. PUBLIC HEALTH RELEVANCE: In the United States, it is estimated that 60,000 new cases of Parkinson's disease (PD) are diagnosed each year, joining the 1 million Americans who currently have PD. Although medications help with many symptoms of PD, they do not stop disease progression and are not beneficial for posture, balance and gait problems associated with PD. A better understanding of how PD affects the ability to prepare responses for anticipated postural perturbations is needed before effective rehabilitation interventions can be developed for adults with PD.