Predegenerated peripheral nerve graft with and without methylprednisolone administration after traumatic spinal cord injury in adult rats

Traumatic spinal cord injury (TSCI) produces paralysis by destruction of axons and demyelination of surviving fibers. Using methylprednisolone (MP) as neuroprotector and a predegenerated peripheral nerve (PPN) graft as regenerative strategy, 83 rats with TSCI were divided into non-grafted, fresh peripheral nerve (FPN) and PPN grafted groups with and without MP administration. Myelination index (MI), number of axons, myelinated fibers, and axon collaterals were assessed 21 h, 7 days, 2, and 4 months after TSCI. Animals with PPN grafts showed more axons and myelinated fibers than animals with FPN grafts, while the latter showed the highest number of axon collaterals. When MP was used, collateral emission was decreased in all treated groups. However, PPN graft plus MP group had the best MI and highest number of axons and myelinated fibers. Combination of one neuroprotective with a regenerative strategy is a good therapeutic option, although new combinations should be further explored.