利手和非利手随意运动的全脑功能磁共振成像

Whole-brain functional magnetic resonance imaging of human brain during voluntary movements of dominant and subdominant hands

目的 利用全脑功能磁共振成像 (fMRI)技术 ,探讨参与利手和非利手简单随意运动的关键脑结构。方法 采用Siemens公司Sonata 1.5T磁共振成像系统 ,对 7名健康右利手志愿者的利手或非利手食指按键运动进行了全脑扫描。数据经头动矫正、空间标准化、空间平滑等预处理后 ,通过互相关分析分别获得利手和非利手运动的脑激活统计参数图。结果 利手运动主要激活对侧初级运动区 (MI)、双侧辅助运动区 (SMA)、双侧运动二区 (MII)和同侧小脑 ,而非利手运动除以上区域外还激活了对侧前运动区 (PMC) ,而且SMA和MII的激活体积大于利手运动。结论 全脑fMRI研究表明 ,随意运动依赖于大脑皮质和小脑等许多脑结构的参与。与利手运动相比 ,非利手运动更依赖于SMA和PMC等高级运动控制区。

Objective To identify the neural substrates of voluntary movements of dominant and subdominant hands by using the whole-brain functional magnetic resonance imaging. Methods Seven right-handed healthy volunteers were scanned at a Sonata 1.5 Tesla magnetic resonance imaging scanner (Siemens) while they were performing the visually instructive movement tasks with their right and left index fingers. Image data were co-registered to correct head motion, spatially normalized according to the standard coordinates, and spatially smoothed with isotopic Guassian Kernel. Statistical parametric maps (activation maps) for right and left hands were generated respectively by cross-correlation analysis. Results Voluntary movements of the right/dominant hand mainly activated contralateral primary motor cortex (MI), bilateral supplementary motor area (SMA), bilateral second motor area (MII), and ipsilateral cerebellum, whereas movements of the left/subdominant handadditionally elicited activation in contralateral premotor area (PMC). Moreover, activation volumes in SMA and MII during movements of the subdominant hand were significantly larger than those during movements of the dominant hand. Conclusion A large set of structures in the cerebral cortex and cerebellum is involved in voluntary movements, as revealed by whole brain-based fMRI. Movements of the subdominant hand are more dependent on higher control areas, such as SMA and PMC, comparing to movements of the dominant hand.