Safety of intramedullary autologous peripheral nerve grafts for post-rehabilitated complete motor spinal cord injuries: a phase I study

Many experimental studies have reported behavioral improvement after transplantation of peripheral nerve tissue into the contused spinal cord, even in large animals. The safety of this treatment in human remains unknown. In this translational phase 1 study, safety of peripheral nerve grafting for chronic spinal cord injuries and possible outcomes are being reported. Twelve complete motor spinal cord injury patients, who had finished their rehabilitation program, were enrolled. There were 4 thoracic and 8 cervical cases. Patients underwent sural nerve preconditioning in the calf, followed 1 week later, by intramedullary transplantation of the harvested nerve fascicles. The patients were followed up for potential complications periodically, and final assessment by American Spinal Injury association (ASIA) and Spinal Cord Independence Measure (SCIM) III were reported after 2 years of follow-up. The median duration of the spinal cord injury was 31 months. At two years of follow up, out of 7 cases with ASIA Impairment Scale (AIS) A, 4(57.1%) cases improved to AIS B and 1 (14.3%) case became AIS C. There were 1 patient with transient increased spasm, one case of transient cystitis, 3 patients with transient increased neuropathic pain and 1 case with transient episode of autonomic dysreflexia, all being managed medically. There was no case of donor site infection. The above complications were transient as they responded to temporary medical treatment. It may be deduced that after two years follow-up of patients that the procedure may be safe, however further controlled studies are needed to prove its efficacy.