Fernandes Corina Aparecida, Coelho Daniel Boari, Martinelli Alessandra Rezende, Teixeira Luis Augusto
Human Motor Systems Laboratory, School of Physical Education and Sport, University of São Paulo, Brazil.
Human Motor Systems Laboratory, School of Physical Education and Sport, University of São Paulo, Brazil.
Hum Mov Sci. 2018 Feb;57:374-387. doi: 10.1016/j.humov.2017.09.015. Epub 2017 Oct 7.
Our aim in this investigation was to assess the relative importance of each cerebral hemisphere in quiet and perturbed balance, based on uni-hemispheric lesions by stroke. We tested the hypothesis of right cerebral hemisphere specialization for balance control. Groups of damage either to the right (RHD, n=9) or the left (LHD, n=7) cerebral hemisphere were compared across tasks requiring quiet balance or body balance recovery following a mechanical perturbation, comparing them to age-matched nondisabled individuals (controls, n=24). They were evaluated in conditions of full and occluded vision. In Experiment 1, the groups were compared in the task of quiet standing on (A) rigid and (B) malleable surfaces, having as outcome measures center of pressure (CoP) amplitude and velocity sway. In Experiment 2, we evaluated the recovery of body balance following a perturbation inducing forward body oscillation, having as outcome measures CoP displacement, peak hip and ankle rotations and muscular activation of both legs. Results from Experiment 1 showed higher values of CoP sway velocity for RHD in comparison to LHD and controls in the anteroposterior (rigid surface) and mediolateral (malleable surface) directions, while LHD had lower balance stability than the controls only in the mediolateral direction when supported on the rigid surface. In Experiment 2 results showed that RHD led to increased values in comparison to LHD and controls for anteroposterior CoP displacement and velocity, time to CoP direction reversion, hip rotation, and magnitude of muscular activation in the paretic leg, while LHD was found to differ in comparison to controls in magnitude of muscular activation of the paretic leg and amplitude of mediolateral sway only. These results suggest that damage to the right as compared to the left cerebral hemisphere by stroke leads to poorer postural responses both in quiet and perturbed balance. That effect was not altered by manipulation of sensory information. Our findings suggest that the right cerebral hemisphere plays a more prominent role in efferent processes responsible for balance control.
在本研究中，我们的目的是基于中风导致的单侧大脑半球损伤，评估每个大脑半球在安静和受干扰平衡中的相对重要性。我们检验了右大脑半球在平衡控制方面具有特异性的假设。比较了右侧（RHD，n = 9）或左侧（LHD，n = 7）大脑半球受损的两组患者在需要安静平衡或机械扰动后身体平衡恢复的任务中的表现，并将他们与年龄匹配的非残疾个体（对照组，n = 24）进行比较。在全视野和视野被遮挡的条件下对他们进行评估。在实验1中，比较了两组在（A）刚性和（B）可塑表面上安静站立任务中的表现，以压力中心（CoP）振幅和摆动速度作为结果指标。在实验2中，我们评估了在诱发身体向前摆动的扰动后身体平衡的恢复情况，以CoP位移、髋部和脚踝的峰值旋转以及双腿的肌肉激活作为结果指标。实验1的结果显示，与LHD组和对照组相比，RHD组在前后方向（刚性表面）和内外侧方向（可塑表面）上的CoP摆动速度更高，而LHD组仅在支撑于刚性表面时，在内外侧方向上的平衡稳定性低于对照组。实验2的结果显示，与LHD组和对照组相比，RHD组在前后方向的CoP位移和速度、CoP方向反转时间、髋部旋转以及患侧腿部肌肉激活幅度方面的值增加，而LHD组仅在患侧腿部肌肉激活幅度和内外侧摆动幅度方面与对照组存在差异。这些结果表明，与左侧大脑半球相比，中风导致的右侧大脑半球损伤会使安静和受干扰平衡中的姿势反应更差。这种影响不会因感觉信息的操控而改变。我们的研究结果表明，右大脑半球在负责平衡控制的传出过程中发挥着更突出的作用。
