Abstract: ObjectiveTo explore the feasibility and potential benefit of olfactory ensheathing cell (OEC) intraspinal transplantation in the treatment of intractable chronic neuropathic pain after spinal cord injury (SCI).Methods17 patients, 15 male and 2 female, with intractable chronic neuropathic pain after spinal cord injury was treated by OEC implant from November, 2004 to November, 2007. The age ranged from 18 to 68 (mean 40.4) years. The etiology of cord impairment included car accidents, falls, radiation damage, machine extrusion, gun-shot, and diving. The patients suffered severe persistent pain for 6 to 309 (mean 102.2) months, and the time points when cell therapy were administrated in the patients ranged from 6 to 312 (mean 105.9 months) after their injuries. Olfactory bulbs were harvested and trypsinized down to single fetal OECs. They were cultured for 12～14 days before implant. The fetal OECs were transplanted by injection into spinal cord at opposing ends of the injury site. The degree of pain was assessed and compared before operation and long-term follow-up according to the International Association of Neurorestoratology Spinal Cord Injury Functional Rating Scale (IANR-SCIFRS), i.e., 0 point means extreme pain, uncontrolled; 1 point, severe pain, narcotics required; 2 points, mild pain, ordinary pain killer effective; 3 points, no pain.ResultsThe follow-up and pain reevaluation were performed at 0.5 to 88 months with an average of 17.5 months after cell transplantation. The mean score of pain amelioration is 1.2 points.ConclusionThe OEC intraspinal transplantation appears to have a promising role in treatment of intractable chronic neuropathic pain after SCI.

Key words: olfactory ensheathing cell, neuropathic pain, central pain, spinal cord injury, intraspinal transplantation, neurorestoration