强制性使用运动疗法治疗卒中上肢偏瘫患者的脑功能MRI研究

A functional MRI study of the brain in stroke patients with upper-limb paralysis treated with constraint-induced movement therapy

目的探讨脑卒中上肢偏瘫患者强制性使用运动疗法（constraint-induced movement therapy，CIMT）治疗后康复的机制。方法选取6例伴有右侧上肢运动功能障碍的慢性期脑卒中患者及9名正常志愿者。患者在CIMT治疗前和治疗后2周各行1次fMRI数据采集，并进行上肢动作研究量表（ARAT）评分。志愿者仅行1次fMRI数据采集。数据采集时受试者完成拇指与食指对指运动。患者治疗前后运动功能评分数据使用配对t检验。fMRI数据使用AFNI软件包进行处理，将正常志愿者BOLD信号变化百分比行单样本f检验以确定激活脑区，将患者治疗前后脑区的BOLD信号变化百分比数据分别与正常志愿者组的数据行独立样本t检验，并将患者CIMT治疗前后脑区的BOLD信号变化百分比数据行配对t检验。结果fMRI显示与志愿者相比CIMT治疗前患者左手运动时脑部相关区域激活与志愿者一致，但激活程度普遍低于志愿者水平；右手运动时相应区域激活程度明显低于志愿者水平，双侧大脑半球有广泛的低水平的代偿激活。CIMT治疗前患者右侧上肢运动功能评分为（27±4）分，治疗后运动功能评分为（40±3）分，差异有统计学意义（t=14．626，P〈0．05）。CIMT治疗后右手运动时左侧中央前回手部支配区激活强度明显增加，双侧纹状体、丘脑及小脑半球激活增加，右侧大脑半球顶叶可见激活。结论CIMT可以有效改善患者上肢的运动功能障碍，患肢的强制使用诱导出了大脑皮层功能区的重组和代偿，fMRI可以检测到这种变化，提供CIMT治疗后神经元重组与代偿的证据。

Objective To investigate and compare the activation patterns of stroke patients with upper-limb paralysis using functional MRI before and after treatment with constraint-induced movement therapy （CIMT） so as to explore the mechanism of CIMT. Methods Six patients in chronic stage of brain infarction who have functional disturbance in right upper-limb and 9 normal controls were entered into the study. All of the patients were asked to perform the thumb-to-index finger tapping task and underwent functional MRI before and two weeks after CIMT. The controls underwent fMRI of same protocol once. The patients＇ upper-limb function scores before and after CIMT were analyzed with SPSS 11.5 by paired t test. The fMRI data were analyzed with analysis of functional neuroImages （AFNI） software. The percentage of blood oxygenation level dependent （BOLD） signal change for the normal control was analyzed by one-sample t test to indentify the activated brain regions. The percentage change of BOLD signal for the patients before and after CIMT was compared to control＇s data by independent-samples t test. The percentage change of BOLD signal for the patients before and after CIMT was analyzed by paired-samples t test. The significant difference level was set P 〈 0. 05. Results The fMRI showed the patients＇ activated brain regions before CIMT were similar to that of the controls＇, while the activation level was lower. There were wide areas activated to compensate the impaired function especially for the right upper-limb. Before CIMT, the patients＇ score for right upper-limb on the action research arm test was 27 ±4. After CIMT, the patients＇ score was 40 ± 3, and the difference was significant （t = 14. 626, P 〈 0.05）, which indicated the improved function. These subjects also displayed cortical reorganization after CIMT on fMRI. The areas responsible for the right hand movement showed increased activation and the activation level at bilateral corpora striata thalami, and cerebella increased. There were also activated regions in the eontralateral parietal lobe. Conclusions CIMT can improve the patients＇ upper-limb function effectively. The constraint-induced movement of the affected arm during CIMT appears to induce cortical reorganization and compensation as measured by fMRI.