Treatment for spinal cord injury leading to paralysis continues to stymie physicians but a clinical trial at the Indiana University School of Medicine reported in the January issue of the Journal of Neurosurgery – Spine may point researchers in a positive direction.
Ten patients with complete motor and sensory spinal cord injury were implanted with an experimental device designed to regenerate nerve fibers, promoting some degree of functional recovery. The device, an oscillating field stimulator or OFS, creates an electrical field in the area of injury.
All 10 trial participants implanted with the OFS showed some improvement in sensation at six months and the nine patients who remained in the trial also showed improvement one year post surgery, although the degree of improvement varied by patient.
Two of the patients recovered some lower extremity function, and one man had restored sexual function. All patients participating in the trial had sustained complete motor and sensory spinal cord injury within 18 days of the surgery.
“This isn’t a home run, but it warrants additional investigation,” said Scott Shapiro, M.D., professor of neurosurgery at the Indiana University School of Medicine. “The big question was whether the procedure, which is very invasive and requires two surgeries, is efficacious and the initial results indicate that it is.”
The cigarette lighter-sized oscillating field stimulator was developed at Purdue University and first tested in more than 100 dogs crippled by naturally occurring spinal cord injuries. The prognosis for severely injured paraplegic dogs, even with current treatment techniques, remains poor.
“The results of these various animal studies were positive and somewhat mirrored what was later observed in humans, including recovery of sensation and other important functions,” said Richard Borgens, Ph.D., professor of biomedical engineering in the Center for Paralysis Research at Purdue.
In the IU School of Medicine study, the OFS was surgically removed at 15 weeks and patients were followed for one year.
Three tests were used to evaluate sensory recovery: pinprick sensation, light touch sensation and motor function. Patients recorded a net improvement at one year of 20.4 points (maximum 112) pinprick sensation, 25.5 points (maximum 112) light touch sensation, and 6.3 points (maximum 100) for improved motor function.
The patients had no sensation below the level of their injury prior to the implantation of the OFS, said Dr. Shapiro. Afterwards, the patients’ sensation was almost back to normal in the immediate area affected by their injury where nerve regeneration occurred.
“This was a pilot device trial,” said Dr. Shapiro, the lead author of the journal article and chief of neurosurgery at Wishard Memorial Hospital. “Some patients did regain sensation and motor function in their lower extremities but not enough to stand unassisted. However, the improvement experienced by the patients is encouraging and deserves more study.”
The Food and Drug Administration has approved a second clinical trial involving 10 additional patients with severe spinal cord injuries. It is expected to begin at the IU Medical Center in early 2005. This trial will again explore the efficacy of the OFS device and could lead to a larger randomized trial for spinal cord injury patients.
The initial study was supported by a special appropriation by the Indiana General Assembly.
(Dr. Shapiro can be reached through the IUSM Office of Public and Media Relations at 317-274-7722. Dr. Borgens can be reached through the Center for Paralysis Research at Purdue at 765-494-7600.)