Effort-induced mirror movements
Effort-induced mirror movements
复制标题
力引起的镜子运动
作者：
Z. Arányi;K. Rösler
在一只手的肌肉持续、疲劳的最大自愿收缩过程中，另一只手的肌肉也逐渐被激活。这种由努力引起的镜像运动表明中枢神经系统（CNS）选择性控制个体肌肉的能力下降。我们研究了改变的胼胝体抑制（TCI）是否导致了这种现象。通过测量由局灶单半球同侧经颅磁刺激引起的小指展肌持续收缩期间的同侧静默期 (iSP) 和对侧静默期 (cSP)，确定 10 名健康受试者的 TCI。作为对努力的反应，所有受试者都发生了镜子运动。双侧 cSP 增加，对侧工作肌肉 iSP 平行增加。相反，镜像肌中的 iSP 保持不变，这可以通过交叉锥体抑制 (cSP) 增加和胼胝体抑制减少的平衡来解释。在精细调整的单手动作中，对侧手的镜像活动受到源自工作半球的 TCI 的抑制。在持续、有力的收缩过程中，由于 TCI 减少，对侧半球的流出量增加。因此，努力引起的镜像收缩是对侧交叉投射去抑制的结果，而不是同侧非交叉路径去抑制的结果。
During sustained, fatiguing maximal voluntary contraction of muscles of one hand, muscles of the other hand gradually become activated also. Such effort-induced mirror movements indicate a decreased ability of the central nervous system (CNS) to selectively control individual muscles. We studied whether altered transcallosal inhibition (TCI) contributed to this phenomenon. TCI was determined in ten healthy subjects by measuring the ipsilateral silent period (iSP) and the contralateral silent period (cSP) during a sustained contraction of the abductor digiti minimi, induced by focal unihemispheric ipsilateral transcranial magnetic stimulation. Mirror movements occurred in all subjects in response to the effort. There was a bilateral increase in cSPs and a parallel increase in the iSP in the contralateral working muscle. In contrast, the iSP in the mirroring muscle remained unchanged, explained by a balance of increased crossed pyramidal inhibition (cSP) and decreased transcallosal inhibition. In finely tuned unimanual movements, mirroring activity of the contralateral hand is suppressed by TCI originating in the working hemisphere. During sustained, effortful contractions, the outflow of the contralateral hemisphere is increased due to reduced TCI. Effort-induced mirror contractions are thus the result of disinhibition of contralateral crossed projections rather than disinhibition of ipsilateral uncrossed pathways.
影响因子：
5.5
作者：
BIGLANDRITCHIE, BR;DAWSON, NJ;LIPPOLD, OCJ
通讯作者：
LIPPOLD, OCJ