Coelho Daniel Boari, Fernandes Corina Aparecida, Martinelli Alessandra Rezende, Teixeira Luis Augusto
Human Motor Systems Laboratory, School of Physical Education and Sport, University of São Paulo, SP, Brazil; Biomedical Engineering, Federal University of ABC, São Bernardo do Campo, SP, Brazil.
Human Motor Systems Laboratory, School of Physical Education and Sport, University of São Paulo, SP, Brazil.
J Stroke Cerebrovasc Dis. 2019 Apr;28(4):954-962. doi: 10.1016/j.jstrokecerebrovasdis.2018.12.021. Epub 2019 Jan 8.
Fast and scaled muscular activation is required to recover body balance following an external perturbation. An issue open to investigation is the extent to which the cerebral hemisphere lesioned by stroke leads to asymmetric deficits in postural reactive responses. In this experiment, we aimed to compare muscular responses to unanticipated stance perturbations between individuals who suffered unilateral stroke either to the right or to the left cerebral hemisphere.
Stance perturbations were produced by releasing a load attached to the participant's trunk, inducing fast forward body oscillation. Electromyography was recorded from the gastrocnemius medialis and biceps femoris muscles. Muscular activation from age-matched healthy individuals was taken as reference.
Analysis indicated that damage to the right hemisphere induced delayed activation onset, and lower rate and magnitude of activation of the proximal and distal muscles of the paretic leg. Those deficits were associated with stronger activation of the nonparetic leg. Comparisons between left hemisphere damage and controls showed deficits limited to activation of the biceps femoris of the paretic leg. Manipulation of visual information led to no significant effects on muscular responses.
These results suggest that right cerebral hemisphere damage by stroke leads to more severe deficits in the generation of reactive muscular responses to stance perturbation than damage to the left cerebral hemisphere regardless of visual information.
在受到外部干扰后，需要快速且成比例的肌肉激活来恢复身体平衡。一个有待研究的问题是，中风导致病变的大脑半球在多大程度上会引起姿势反应性反应的不对称缺陷。在本实验中，我们旨在比较右侧或左侧大脑半球发生单侧中风的个体对意外姿势干扰的肌肉反应。
通过释放连接在参与者躯干上的负载来产生姿势干扰，从而引发身体快速向前摆动。记录腓肠肌内侧头和股二头肌的肌电图。以年龄匹配的健康个体的肌肉激活情况作为参考。
分析表明，右侧半球损伤会导致激活起始延迟，以及患侧腿近端和远端肌肉的激活速率和幅度降低。这些缺陷与非患侧腿更强的激活有关。左侧半球损伤与对照组之间的比较显示，缺陷仅限于患侧腿股二头肌的激活。视觉信息的操控对肌肉反应没有显著影响。
这些结果表明，中风导致的右侧大脑半球损伤比左侧大脑半球损伤在对姿势干扰产生反应性肌肉反应方面会导致更严重的缺陷，且不受视觉信息影响。
