DTI在脑梗死患者康复治疗前后皮质脊髓束损伤与临床预后的相关性研究

Correlation study of DTI in corticospinal tract injury and clinical prognosis of cerebral infarction before and after rehabilitation treatment

目的:应用磁共振弥散张量成像(DTI)研究脑梗死患者康复治疗前后皮质脊髓束损伤与肢体运动功能变化之间的关系,探讨DTI在评估脑梗死患者临床预后中的应用价值.方法:对23例梗死时间为23～90 d的慢性脑梗死患者分别在康复治疗前后进行两次DTI扫描,对数据进行后处理获得各向异性分数(Farctional anisotropy,FA)伪彩图,并重建双侧皮质脊髓束.按病灶与皮质脊髓束的关系把患者分为A、B两组,然后分别测量梗死灶、梗死同侧大脑脚及对侧相应区域皮质脊髓束的FA值.每次磁共振检查之前进行Fugl-Meyer运动功能评分(FM)和Barthel生活指数(Barthel index,BI)评定,然后分析临床评分与FA值变化之间的相关性.结果:23例患者康复前病灶处FA值为0.221±0.085,对侧相应区域FA值为0.514±0.071,梗死灶同侧大脑脚皮质脊髓束FA值为0.550±0.081,健侧FA值为0.682±0.051,经配对t检验两侧脑组织的FA值差异有统计学意义(P＜0.001);A、B两组患者梗死灶同侧大脑脚皮质脊髓束FA值与对侧相应区域FA值的比值(rFA)的差异有统计学意义(t=4.066,P＜0.01)；康复治疗前后两组患者大脑脚皮质脊髓束FA值下降的百分数与Fugl-Meyer运动评分增加的百分数之间呈负相关(r=-0.624,P＜0.01),与BI变化的百分数没有相关性.结论:通过对梗死区远端皮质脊髓束FA值的测量,可以判断其变性程度,并预测患者的运动功能转归.FA值下降越明显则变性程度越重,神经运动功能恢复就越差.

Objective: To study the relationship between the corticospinal tract(CST) injury and limb motor function by diffusion tensor imaging(DTI) in patients with cerebral infarction before and after the rehabilitation treatment,and to evaluate the application value of DTI in the assessment of clinical prognosis in patients with cerebral infarction.Methods: Twenty-three cases of chronic cerebral infarction for 23~90 days had DTI inspections respectively before and after rehabilitation.For imaging processing,fractional anisotropy(FA) encoded color maps and 3D tractography of bilateral CST of all patients were performed.The patients were divided into two group(A,B) according to the relationship between the lesions and CST,then measured FA values of the infarctions,ipsilateral cerebral peduncle and corresponding contralateral regions.The Fugl-Meyer motor scale(FM) and the Barthel index(BI) were used to evaluate the neurological function prior to each MRI.Then,the correlation between clinical markers and the changes of FA value were analyzed.Results: Before rehabilitation,FA value of the lesions in 23 cases was 0.221±0.085,and in corresponding contralateral area,the FA value was 0.514±0.071,in ipsilateral cerebral peduncle the FA value was 0.550±0.081,contralateral the FA value was 0.682 ±0.051.By paired t test,the FA values between bilateral brain tissues were statistically significant(P<0.001).The ratio between the FA value of ipsilateral cerebral peduncle and corresponding contralateral area of the two groups was statistically significant(t=4.066,P<0.01).Before and after rehabilitation,the reduction percent of FA value of CST in the cerebral peduncle of the two groups correlated negatively with the increase percent of FM(r=-0.624,P<0.01),but not with the percent change of BI.Conclusion: The measurement of FA values in distal infarction of CST can estimate the degree of degeneration and evaluate the recovery of motor function.The more obvious reduced of FA value,the more serious the nerve degeneration,and the worse recovery of the motor function.