兔坐骨神经挤压伤后FA值与神经功能变化的相关性研究

摘要

目的:探讨兔坐骨神经挤压伤后FA值与神经功能变化的相关性.方法:对32只兔建立坐骨神经挤压伤模型,将其随机分为8组,每组4只,分别于损伤后24h、4d、8d、2周、4周、6周、8周和10周共8个时间点行DTI扫描,另外4只无坐骨神经损伤兔作为对照组.测量并比较各时间点损伤远端及对照组坐骨神经FA值,扫描前定量评价各时间点兔坐骨神经的趾张反射和改良Tarlov评分,两者之和作为神经功能评分.分析损伤后4天～10周兔坐骨神经FA值与神经功能评分的相关性.结果:损伤后24h兔坐骨神经FA值(0.537±0.018)较对照组(0.579±0.019)有所下降(P<0.01),损伤4d后FA值(0.403±0.015)显著降低(P<0.001),损伤6周后FA值(0.508±0.023)显著回升(P<0.001),损伤后10周FA值(0.537±0.023)仍未达损伤前水平(P<0.01).FA值的变化与神经功能指数变化的时间过程基本一致.损伤后4天～10周兔坐骨神经FA值与神经功能评分具有高度相关性(r=0.898,P<0.01).结论:FA值可用于监测周围神经挤压伤后神经功能的变化.%Objective:To probe the relationship between fractional anisotropy (FA) and functional changes of sciatic nerve in rabbit after crush injury. Methods:Sciatic nerve crush injury models of 32 New Zealand rabbits were established and randomly divided into 8 groups,4 rabbits in each group. DTI scans were performed 24h,4 days,8 days,2 weeks,4 weeks,6 weeks,8 weeks and 10 weeks after injury accordingly,and 4 normal rabbits were scaned as pre-injury group. FAs of sciatic nerve distal to the injury site were measured and compared. Quantitative assessments of functional recovery including toe spreading reflex and modified Tarlov score were performed before each MR scan,Sum of the two scores was calculated as the nerve function score. Results:FA of distal injured nerve dropped 24h after injury (P<0. 01) ;FA dropped significantly 4 days after injury (P =0. 000) ;6 weeks after injury,FA increased significantly (P=0. 000) ;FA remained lower than pre-injury group 10 weeks after injury (P<0. 01). FA changes after injury showed a similar time course as functional recovery. FA of the sciatic nerve distal to the injured site showed a positive correlation with the nerve function score (r=0. 898,P< 0. 01). Conclusion:FA value can be used to monitor functional recovery of peripheral nerves after crush injury.