不同时间电针刺激对大鼠脊髓损伤后磁共振弥散张量纤维束成像部分各向异性值均值的影响

目的探讨不同时间电针刺激对大鼠脊髓损伤后磁共振弥散张量纤维束成像(DTT)部分各向异性值(FA)均值的影响。方法将48 只清洁级Sprague-Dawley 大鼠用NYU打击器制成T10-11段脊髓损伤模型。造模成功后随机分为对照组(n=16)和实验组(n=32)。对照组不进行电针刺激。实验组采用运动区头皮表面投影区电刺激，并结合局部电刺激。实验组又分为实验1 组和实验2组。实验1 组3 d 时开始电针刺激，实验2 组2 周时开始电针刺激。各组分别于造模后1 周、2 周和4 周进行Basso-Beattie-Bresnahan(BBB)评分。于造模后2~4 h、3 d 及治疗后4 周进行磁共振弥散张量成像(DTI)检测，测量脊髓损伤区域及正常区域的FA均值，分析比较电针治疗不同时间间BBB评分及FA均值的变化。并通过DTT观察不同时间电针刺激后纤维束的形态变化。结果实验组和对照组在第1 周各组间BBB评分无显著性差异(P>0.05)，在第4 周实验组BBB评分显著高于对照组(P<0.001)。在第2 周和第4周，实验1 组显著高于实验2 组(P<0.001)。实验组与对照组在2~4 h 和3 d 各组间FA均值无显著性差异(P>0.05)，造模后4 周有非常高度显著性差异(P<0.001)。实验1 组优于实验2 组(P<0.05)。各组在伤后2~4 h 和治疗后4 周的DTT清晰显示，实验组纤维束修复程度均好于对照组。结论脊髓损伤后电针刺激介入的时间越早，治疗效果越好。

Effects of Electroacupuncture in Different Time on Variations of Fractional Anisotropy Mean Value of Diffusion Tensor Tractography in Spinal Cord Injured Rats

Objective To explore the effects of electroacupuncture in different time on the variations of fractional anisotropy (FA) mean value in diffusion tensor tractography (DTT) in spinal cord injured (SCI) rats. Methods 48 Sprague-Dawley rats were performed with Allen's method by NYU blow device, resulting in T10-11 SCI. They were divided into groups according to random table. Control group (n=16) received no treatment. Experimental group (Group A, n=32) received electric stimulation in the scalp surface projection area of motor area and local electric stimulation at damaged site. Group A was divided into Group A1 (n=16) and Group A2 (n=16) again. Group A1 received electric stimulation 3 days after SCI, while Group A2 received electric stimulation 2 weeks after SCI. They were assessed with Basso-Beattie-Bresnahan (BBB) scores and routine MRI and diffusion tensor imaging (DTI). Results There was no significant difference in BBB score among all the groups at the first week (P>0.05). BBB scores of the Groups A1 and A2 were significantly different from the control group at the second and fourth week (P<0.001), and the Groups A1 from A2 (P<0.001). 2~4 hours and 3 days after modeling, there was no significant difference in the FA value among the groups (P>0.05). There was significant difference among the Groups A1, A2 and the control group at the fourth week (P<0.001). Group A1 was better than Group A2 (P<0.001). DTT images of all the groups were successful reconstructed, the Groups A1 and A2 repaired better than the control group. Conclusion The earlier electroacupuncture is taken after spinal cord injury, the better the outcome is.