正常人三种模式手指运动时脑激活区域的功能磁共振研究

A study of the cortical activation induced by hand movement in normal subjects by use of fMRI

目的 研究简单动作 (反复连续的手指对指动作 )、随意动作 (抓物体 )和假想动作三种运动模式时 ,脑功能区域的活动机制。方法 利用功能磁共振 (fMRI)影像技术分别摄取 1 0例正常人的利手和非利手在不同运动模式下的双侧脑激活区域 ,再进行机制分析。结果 随意动作时 ,脑同侧激活区的数目多于简单动作 (P <0 .0 5) ,而对侧无明显差异。在简单动作和随意动作中 ,无论利手或非利手 ,主要的激活区为对侧的初级感觉运动皮质 (SM1 ) ,但非利手也可激活同侧少量的SM1。另外 ,脑双侧辅助运动区 (SMA)、前运动区 (PMA) ,对侧顶上小叶 ,同侧小脑也有明显激活 ;偶见基底节激活。假想动作时主要激活额上回、额中回、顶上小叶 ,另见少量扣带回、小脑、脑干、中央旁小叶、基底节处激活。结论 利手的简单动作支配主要在对侧脑SM1 ,而双侧的SM1参与了非利手的简单动作。随意动作属于复杂动作 ,参与动作的区域多于简单动作 ,且双侧SMA均参与 ,可能与双手协调、记忆动作模式的选择、动作顺序的执行有关。假想动作时主要由SMA、PMA支配。

Objective To study the pattern of the brain activation induced by simple hand motor tasks (repetitive and sequential finger to thumb opposition movements, manipulation of different shapes of objects) and imaging motor task, respectively. Methods By using the technique of functional magnetic resonance imaging (fMRI), the activated areas of cerebral cortex were recorded and analyzed in 10 normal subjects during their finger movement at the dominant or non dominant side. Results During the finger to thumb opposition movement, more ipsilateral cortical areas were activated than those during manipulation of objects ( P <0.05), but the contralateral cortex activation was not significantly different with regard to the two types of movement. No matter it was the dominant or non dominant side, opposition and manipulation induced significant activation in the contralateral primary sensorimotor cortex (SM1). The non dominant hand opposition and manipulation caused mild ipsilateral SM1 activatin. In addition, remarkble activation can also be seen in the bilateral supplementary motor areas (SMA), premotor areas (PMA), ipsilateral cerebellum, and the contralateral superior lobulus parietal cortex. The basal ganglia was occasionally activated. When the subjects were asked to imagine the motor task of opposition, significant activation can be seen in the superior frontal gyrus, medial frontal gyrus, superior lobulus parietal cortex, and less activation in the cingulate gyrus, cerebellum, brainstem, lobulus paracentral as well as in the basal ganglia. Conclusion Finger opposition in the dominant side is controlled by contralateral SM1, and finger opposition in the non dominant side by bilateral SM1. During the more complicated manipulation movement, more areas will be activated than that of opposition, in which the bilateral SMA is involved. This may be correlated with the cooperation of both hand, the choice of motor pattern from memory and the execution of movement sequence. Imagined motion is controlled by SMA, and PMA.