扩散张量纤维束成像对脑桥梗死后运动功能恢复脑机制的研究

目的探讨脑桥梗死后皮质脊髓束损伤与运动功能转归的关系,并对其损伤后的功能重组情况进行初步研究。方法对17例脑桥梗死患者,分别于发病<7、15、30、90和180d进行扩散张量成像检查,应用扩散张量纤维束成像(diffusion tensor tractography,DTT)进行皮质脊髓束三维重建,观察梗死灶与纤维束的空间关系,分析皮质脊髓束受累程度与患者运动功能恢复的关系,并随访观察恢复过程中受损纤维束的变化情况。结果 17例患者中,皮质脊髓束损伤程度Ⅰ级4例,Ⅱ级3例和Ⅲ级10例。患者一侧肢体肌力明显减退或伴有头晕、言语不利等表现。皮质脊髓束损伤分级与患者发病90d时的运动功能评分呈负相关(r=-0.498,P<0.05)。其中7例皮质脊髓束严重受损的患者在梗死后90¹80d神经纤维发生不同方式的重组和修复。结论 DTT能够评价脑桥梗死皮质脊髓束的损伤程度及其与患者运动功能恢复的关系,并能够显示运动传导通路纤维束的重组和再生,为研究脑桥梗死后运动功能康复过程的脑机制提供可视化依据。

Mechanism of diffusion tensor tractography underlying motor function recovery after pontine infarction

Objective To study the relationship between corticospinal tract injury and motor function recovery after pontine infarction.Methods Seventeen pontine infarction patients underwent diffusion tensor imaging(DTI)on days 7,15,30,90 and 180after onset of pontine infarction.Three-dimensional corticospinal tract was constructed by diffusion tensor tractography(DTT).Relationship between the involved corticospinal tract and motor function recovery was analyzed.The patients were followed up,during which changes of the affected fibers were observed.Results GradeⅠ,gradeⅡ and gradeⅢof corticospinal tract injury were observed in 4,3and 10 patients,respectively.The grade of corticospinal tract injury was negatively related with the motor function score on day 90 after pontine infarction(r=-0.498,P<0.05).The nerve fibers were regenerated and repaired in 7patients with severe corticospinal tract injury on days 90-180 after pontine infarction.Conclusion DTT can assess the relationship between corticospinal tract injury and motor function recovery and show the regeneration and functional reorganization of nerve fibers in the motor pathway after pontine infarction,thus providing the visual evidence for the motor function recovery mechanism after pontine infarction.