功能磁共振成像在脑梗死患者运动功能评价中的作用探讨

Evaluation of Motor Recovery in Patients with Stroke by BOLD-fMRI

目的利用功能磁共振成像(functional magnetic resonance imaging,fMRI)分析单侧放射冠梗死患者大脑半球的激活部位及偏侧化指数(laterality index,LI)与运动功能康复水平的关系。方法选取12例单侧放射冠梗死的患者为卒中组,5例正常志愿者为对照组。所有入选者均进行血氧水平依赖功能磁共振成像(blood oxygenation level dependent-functional magnetic resonance imaging,BOLD-fMRI)检查,扫描设备为德国西门子3.0T磁共振扫描系统。试验采用Block设计,采取患手顺序对指任务。扫描结果采用统计参数图(Statistical Parametric Mapping,SPM2)进行数据分析和脑功能区定位,计算不同感兴趣区激活体素数目及LI。扫描结束后记录患者上肢运动功能评分(Fugl-Meyer评分,F-M评分),分析LI与F-M评分之间的相关性。结果与对照组相比,卒中组脑部激活范围较广泛,表现为双侧运动传导通路的激活;双侧大脑半球、初级感觉运动区(sensory motor cortex,SMC)、第一躯体运动区(M1区)LI明显减少(P=0.004,0.008,0.027)。卒中组L(I半球、SMC、M1)与F-M评分之间的相关性无统计学意义(r=0.133,P=0.618;r=0.558,P=0.059;r=0.297,P=0.348);卒中组最强激活点位于中央前回(Precentral gyrus,PRE)患者F-M评分较高(52±22),最强激活点位于中央后回(postcentral gyrus,POS)患者F-M评分较低(36±27),以上两组F-M评分之间差异无统计学意义(P>0.05)。结论fMRI可以显示卒中患者运动康复过程中功能区的变化;单侧放射冠脑梗死后,与运动任务相关的脑区激活范围存在明显偏侧化现象;偏侧化程度与患者上肢运动功能之间可能无明显关系。

Objective To evaluate the relationship between motor-related activated cortices,Fugl-Meyer score and rehabilitation of motor function in patients with unilateral corona radiata infarction. Methods Five healthy volunteers and 12 patients (8 females and 4 males,38～71 years) with solitary lacunar infarction of unilateral corona radiata (5,right side; 7,left) were recruited in the study. Each of them underwent blood-oxygen level dependent functional MRI(BOLD-fMRI) examination by a 3.0 Tesla MRI scanner (Trio Siemens,Germany). The fMRI was designed as a block task of affected hand-movement. The data were analyzed by SPM2. The activated voxels and laterality index (LI) were calculated and compared between subjects and controls. Correlative analysis was performed between LI and the Fugl-Meyer score in patients. Results The activated cortices in patients were larger than that of controls. The LI of bilateral hemisphere,sensory motor cortex (SMC) and M1 were higher than controls (P=0.004; P=0.008; P=0.027). No statistical correlation was shown between LI (hemisphere,SMC,M1) and Fugl-Meyer score (r=0.133,P=0.618; r=0.558,P=0.059; r=0.297,P=0.348). The motor score in PRE group is higher than that of POS group,but there is no statistical significance between two groups. Conclusion BOLD-fMRI can show the changes of motor-related activation after stroke. Obvious lateralization related to motor task is revealed in patients with unilateral corona radiata infarction. However,the degree of lateralization is not close related to the functional status of affected upper extremities.