GAIT ANALYSIS OF ADULT PARAPLEGIC RATS AFTER SPINAL-CORD REPAIR

This study presents a novel detailed method of analysis of rat gait an d uses this method to demonstrate recovery of forward locomotion patte rns in adult rats made paraplegic by surgical spinal cord transection slid subjected to a novel strategy for spinal cord repair, Six normal rats were compared to five animals in which the cord was transected at T8-T9, and a 5-mm segment of the spinal cord removed, and to seven an imals in which, following spinal cord transection and removal of a spi nal cord segment, multiple intercostal peripheral nerve bridges were i mplanted, rerouting pathways from white to gray matter in both directi ons. The implanted area was filled with fibrin glue containing acidic fibroblast growth factor Details of the repair strategy have been publ ished (H. Cheng, Y. Cao, and L. Olson, 1996, Science 273: 510-513), Ga it analysis was carried out 3 and 4 months after surgery and once in t he normal animals, Animals were allowed to walk across a runway with a transparent floor. Each test consisted of five trials, and each trial was videorecorded from underneath. Using frame-by-frame play-back, in dividual footprints were then recorded regarding location and order of limb use, as well as step quality (degree of weight bearing, etc.). T hese data allowed measuring runway transit time, five different measur es of step numbers, all possible temporal patterns of limb use, stride length, and base of support. Transected controls remained paralyzed i n the hindlimbs with only occasional reflex hindlimb movements without weight bearing. Animals subjected to the full repair procedure were s ignificantly faster than the controls, used their hindlimbs for 25-30% of the movements, and regained several of the specific limb recruitme nt patterns used by normal rats. Taken together the gait analysis data demonstrate remarkable recovery of coordinated gait in the repaired a nimals, which was significantly better than controls for all relevant parameters, while at the same time clearly inferior to normal rats for most of the examined parameters. We conclude that normal rats use a m ultitude of interchangeable step sequence patterns, and that our spina l cord repair strategy leads to recovery of some of these patterns fol lowing complete spinal cord transection, These data suggest functional ly relevant neuronal communication across the lesion. (C) 1997 Academi c Press.