利用fMRI和双手交替运动模式研究脑肿瘤所致的运动功能重组

目的应用fMRI研究双手交替运动模式下中央沟附近脑肿瘤患者运动功能重组的方式及特征.方法6名正常受试者和14名脑肿瘤患者采用双手交替对指运动模式行fMRI扫描,比较正常受试者与脑肿瘤患者脑激活的异同.结果正常人单手对指运动主要激活运动手对侧的大脑半球和同侧小脑半球.脑肿瘤患者非受累手运动所致的激活与正常受试者基本相同;而当受累手运动时,则出现运动功能的重组,包括肿瘤对侧正常半球内M1区的代偿性激活、肿瘤侧半球MI活动的减弱、双侧SMA等次级运动中枢激活区的增大以及双侧小脑半球的激活.结论采取双手交替运动模式,fMRI不仅显示了受累侧运动区的变形与移位,而且揭示了一种新的功能重组模式,即运动功能重组可能涉及分布于全脑的整个神经网络.

Reorganization of motor function in patients with brain tumors as revealed by fMRI combined with an alternating movement task

Objective To characterize reorganization of motor function in patients with brain tumors adjacent to the central sulcus by using functional MRI (fMRI). Methods Fourteen patients with brain tumors nearby the central sulcus and 6 normal volunteers underwent fMRI while they performing alternating unilateral finger-to-thumb opposition movements. The activated map for each unilateral hand movement was generated by cross correlation analysis following routine fMRI data pre-processing. The location and number of the activated voxels in both sides of cerebral and cerebellar hemisphere were then compared between the normal group and the patient group. Results For healthy subjects, unilateral hand, either right or left, movement, elicited activations mainly in the contralateral hemisphere and ipsilateral cerebellum. For the patients, while activation for the unaffected hand was essentially identical to that in the healthy subjects, the activation pattern during movement of the affected hand significantly changed, which includes compensational activation of primary motor area (M1) in the tumor unaffected hemisphere along with decreased activation in M1 in the affected hemisphere, increased activation in supplemental motor area (SMA) and other secondary regions, and bilateral cerebella activation. Conclusion With an alternating hand movement task, the present fMRI study not only demonstrated the displacement and distortion of the M1 in the tumor affected hemisphere, but also revealed a new pattern of functional reorganization, which appears to involve a distributed network throughout the whole brain.