Abstract: 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.

Key words: spinal cord injury, acupuncture, electroacupuncture, diffusion tensor tractography, rats