Cruz Caio F, Genoves Giovanna G, Doná Flávia, Ferraz Henrique B, Barela José A
School of Arts, Sciences and Humanities, Universidade de São Paulo, São Paulo, SP, Brazil.
Institute of Physical Activity and Sport Sciences, Universidade Cruzeiro do Sul, São Paulo, SP, Brazil.
PeerJ. 2020 Feb 12;8:e8552. doi: 10.7717/peerj.8552. eCollection 2020.
Parkinson's disease (PD) leads to several changes in motor control, many of them related to informational or cognitive overload. The aim of this study was to investigate the influence of knowledge and intention on the postural control performance and on the coupling between visual information and body sway in people with and without PD standing upright.
Participants were 21 people with PD (62.1 ± 7.2 years), stages 1 and 2 (Hoehn & Yahr scale), under dopaminergic medication, and 21 people in the control group (62.3 ± 7.1 years). Participants stood upright inside a moving room, performing seven trials of 60 s. In the first trial, the room remained motionless. In the others, the room oscillated at 0.2 Hz in the anterior-posterior direction: in the first block of three trials, the participants were not informed about the visual manipulation; in the second block of three trials, participants were informed about the room movement and asked to resist the visual influence. An OPTOTRAK system recorded the moving room displacement and the participants' sway. The variables mean sway amplitude (MSA), coherence and gain were calculated.
With no visual manipulation, no difference occurred between groups for MSA. Under visual manipulation conditions, people with PD presented higher MSA than control, and both groups reduced the sway magnitude in the resisting condition. Control group reduced sway magnitude by 6.1%, while PD group reduced by 11.5%. No difference was found between groups and between conditions for the coupling strength (coherence). For the coupling structure (gain), there was no group difference, but both groups showed reduced gain in the resisting condition. Control group reduced gain by 12.0%, while PD group reduced by 9.3%.
People with PD, under visual manipulation, were more influenced than controls, but they presented the same coupling structure between visual information and body sway as controls. People in early stages of PD are able to intentionally alter the influence of visual information.
帕金森病（PD）会导致运动控制出现多种变化，其中许多与信息或认知过载有关。本研究的目的是调查有无帕金森病的人在直立站立时，知识和意图对姿势控制表现以及视觉信息与身体摆动之间耦合的影响。
参与者包括21名帕金森病患者（年龄62.1±7.2岁），处于1期和2期（霍恩和雅尔分级量表），正在接受多巴胺能药物治疗，以及21名对照组人员（年龄62.3±7.1岁）。参与者在一个移动的房间内直立站立，进行7次每次60秒的试验。在第一次试验中，房间保持静止。在其他试验中，房间在前后方向以0.2赫兹的频率振荡：在三个试验的第一个组块中，参与者未被告知视觉操纵情况；在三个试验的第二个组块中，参与者被告知房间的运动情况，并被要求抵抗视觉影响。一个OPTOTRAK系统记录房间的移动位移和参与者的摆动情况。计算平均摆动幅度（MSA）、相干性和增益等变量。
在没有视觉操纵的情况下，两组的MSA没有差异。在视觉操纵条件下，帕金森病患者的MSA高于对照组，并且两组在抵抗条件下都降低了摆动幅度。对照组的摆动幅度降低了6.1%，而帕金森病组降低了11.5%。在耦合强度（相干性）方面，组间和条件间均未发现差异。对于耦合结构（增益），组间没有差异，但两组在抵抗条件下均显示增益降低。对照组的增益降低了12.（此处原文可能有误，推测应为12.0%），而帕金森病组降低了9.3%。
在视觉操纵下，帕金森病患者比对照组更容易受到影响，但他们在视觉信息与身体摆动之间呈现出与对照组相同的耦合结构。帕金森病早期患者能够有意改变视觉信息的影响。
