脑梗死后锥体束增生性重塑的弥散张量研究及其意义

Autopsy experiments had determined that there were neural prolifrating reorgnization within the brain following an acute cerebral infarct. Speculation, during the course of movement function recovery in patients with cerebral infarction, neural prolifrating reorgnization of motor cortex and pyramidal fibers near to the cortex is likely to be the most active. Today, it is possible to evaluate the proliferating reorganization in a fiber tract after cerebral infarction with developing technique of diffusion tensor imaging (DTI). In this project, patients with internal capsule infarction would undergo four times DTI scans from the first week to the six months, and before every DTI scan their neurological function were evaluated with the Fugl-Meyer motor scale (FMS). The changes of DTI parameters, such as FA, FA⊥, FA‖ and MD, of affected hemisphere pyramidal fibers near to motor cortex were analysed and were correrated to the changes of patients' FMS. When the project finished, it would be observe that the increment of the FA‖ value of affected hemisphere pyramidal fibers near to motor cortex correlate positively with the accretion of the value of patients' FMS. Which would indicate that the proliferating reorganization of affected hemisphere pyramidal fibers near to motor cortex may be the structural base through which patients' motor function recover. As a result, the mechanism of motor functional recovery after stroke would be partially elucidated. This finding would promote forward the development of stroke academic theory and clinical treatment.

尸体解剖的实验证实，脑梗死后脑内存在神经组织增生。推测，当脑梗死患者运动功能逐渐恢复的时候，脑内运动皮质及近皮质神经纤维的增生很可能是最活跃的。目前的DTI分析技术已经可以检测到锥体束内微小的纤维增生。本研究中，局灶性内囊梗死患者在发病的第1周至第6个月进行4次DTI检测，同时用简式Fugl-Meyer运动功能评分（FM）评估肢体运动功能状态；应用新的分析纤维束本征值的DTI研究方法，观察锥体束在梗死灶上方、运动皮质内、近皮质部纤维（包括与梗死灶相联系或没有联系的纤维）的FA、FA⊥、FA‖、MD等弥散参数的变化；及其与患者FM变化的相关关系。完成本项目，将可能发现锥体束在近皮质部的FA‖逐渐增大，与患者逐渐增大的FM呈正相关，揭示锥体束在近皮质部发生增生性重塑是患者肢体运动功能重建的结构基础，部分阐明脑梗死患者运动功能重建在神经结构上的发生机制，促进脑卒学术理与临床治疗向前发展。

目的 本研究应用弥散张量成像（DTI）技术前瞻性分析内囊梗死后，与梗死灶不相联系的锥体束纤维的弥散变化，探讨脑梗死后锥体束增生性重塑及意义。.方法 选择15例单侧内囊梗死的患者作为实验组，选取15例健康志愿者作为对照组。患者分别在发病第1周、第1个月、第3个月进行DTI检测，测量梗死灶周围、对侧内囊、双侧放射冠区、双侧半卵圆的部分弥散异向（FA）和平均弥散量（MD），对照组在相同的时间间隔进行同样的DTI检测，同时采用美国国立卫生研究院卒中评分表 （NIHSS）、简式Fugl-Meyer运动功能评分表（FM）和Barthel生活指数表(BI)对患者进行评分，P < 0.05具有统计学意义。.结果 在观察期内（1）患者NIHSS评分（12.07±1.75 vs 7.13±1.19 vs 3.47±1.41, P < 0.05）逐渐降低，FM评分（43.93±6.55 vs 71.00±4.12 vs 86.40±3.04, P < 0.05）和BI评分（46.00±6.33 vs 67.00±5.28 vs 83.33±5.56, P < 0.05）逐渐升高。（2）患者梗死灶周围区域的FA值（0.58±0.02 vs 0.61±0.01 vs 0.67±0.01, P < 0.05）；梗死灶同侧放射冠区的FA值（0.47±0.02 vs 0.49±0.02 vs 0.52±0.01, P < 0.05）和半卵圆区域的FA值（0.38±0.02 vs 0.39±0.02 vs 0.43±0.01, P < 0.05）逐渐升高，同时梗死灶对侧内囊区域的FA值（0.58±0.02 vs 0.62±0.02 vs 0.66±0.01, P < 0.05）；放射冠区的FA值（0.48±0.02 vs 0.52±0.02 vs 0.54±0.01, P < 0.05）和半卵圆区的FA值（0.38±0.01 vs 0.41±0.01 vs 0.43±0.01，P < 0.05）逐渐升高。然而，对照组在上述相应部位的FA值始终没有变化。（3）患者上述部位FA值变化的百分数与NIHSS评分变化百分数呈负相关（P < 0.05），与FM评分以及BI评分变化百分数呈正相关（P < 0.05）。.结论 一侧内囊梗死后，双侧锥体束纤维会发生增生性重塑，而且这种增生性重塑促进患者神经功能的恢复。