正常人三种运动任务的血氧水平依赖性磁共振脑功能成像定量分析

目的 利用全脑血氧水平依赖性磁共振脑功能成像(BOLD-fMRI)技术,探讨参与对指、握拳、被动运动的关键脑功能区.方法对10例健康右利手志愿者右手(利手)或左手(非利手)的对指、握拳、被动运动进行全脑BOLD-fMRI扫描,记录激活体积、激活强度,应用配对t检验进行定量分析.结果三种运动模式下,左手运动激活对侧感觉运动皮层(SMC)体积、强度大于右手运动(P<0.05).被动、时指运动激活对侧SMC体积、强度差异无统计学意义(P>0.05).被动、对指运动激活对侧SMC体积大于握拳运动(P<0.05).被动运动激活对侧SMC强度大于握拳运动(P<0.05).对指与握拳运动激活对侧SMC强度差异无统计学意义(P>0.05).结论脑功能区的激活情况与手运动复杂程度有关,体积、强度等定量指标进一步证实利手、非利手激活脑功能区的不对称性.恒定的被动运动(五指依次被动曲伸)任务用于BOLD-fMRI研究具有实用性、可靠性.

BOLD-fMRI quantitive analysis of motor cortex by three hand motor tasks in normal subjects

Objective To identify the neural substrates of three motor tasks (repetitive and sequential fin-get-to-thumb opposition movements in turn, making fates, fingers passive flexion-extension movements in turn) of dominant and subdominant hands by using the whole-brain functional magnetic resonance imaging. Methods Ten right-handed healthy volunteers were scanned while they were performing the movement tasks with their right and left fingers. The motor cortex active volume and intensity was recorded. Quantitive analysis of motor cortex was conducted with paired t test. Results Under the three hand motor tasks, activation volumes in SMC during movements of the subdominant hand were significantly larger than those during movements of the dominant hand (P < 0. 05). Activation volumes during finger-to-thumb opposition movements and passive bendlng-extending fingers movements were significantly larger than those during movements of making fasts (P < 0.05). Activation intensity during passive ben-ding-extending fingers movements was significantly larger than those during movements of making fasts (P < 0.05). Conclusion The representation of the Motor Cortex is related to the complexity of the hand motor exercises. Quantitive criterion as volume and intensity approves the dissymmetry of cortex activation by dominant and subdominant fingers'movements. It is practicable and credible to adopt invariable fingers passive flexion-extension movements in turn in the study on BOLD-fMRI.