University of Arkansas Medical Sciences Neuroscientists Enable Injured Man to Walk Again

LITTLE ROCK, Ark., Mar 18, 2002 (ASCRIBE NEWS via COMTEX) -- President Bill Clinton recently told an audience at the University of Arkansas for Medical Sciences (UAMS), "I hope I live to see people like Christopher Reeve get up out of their wheelchairs and walk." At the university that day (February 19) to participate in a "topping out" ceremony for a new building that includes spine and neuroscience research facilities, he also learned that a UAMS research scientist has already helped a paralyzed man living in Arizona to accomplish this "miracle."

Edgar Garcia-Rill, Ph.D., of the Department of Anatomy and Neurobiology in the UAMS College of Medicine, led a research team whose work in the late 1980s has now made it possible for a spinal-cord-injured patient to perform a dramatic walk of 1000 feet on a national TV network news program (CBS - "The Early Show"). The patient suffered a spinal injury in a car accident and was wheelchair bound - unable to walk. Arizona surgeon, Richard Herman, M.D., surgically implanted into this patient a type of stimulation device patented a decade ago at UAMS and applied the technology developed by Dr. Garcia-Rill.

With the benefit of two forms of physical therapy - Partial Weight Bearing Therapy (PWBT) and Epidural Spinal Cord Stimulation (ESCS) - the patient is now able to walk up to 1,000 feet with the aid of only a walker. The results of this first clinical trial of its kind was published [February, 2002] in the journal, "Spinal Cord" and will be featured in a documentary TV program for the Discovery Channel later this year.

The pioneering research performed by Garcia-Rill and Robert Skinner, Ph.D., received a U.S. patent in 1991 for a "Method and Device for Inducing Locomotion by Electrical Stimulation of the Spinal Cord" (U.S. Patent #5,002,053).

These researchers found that long duration (0.2 msec to 2 msec) pulses delivered at low frequencies (0.5/sec to 10/sec) to the surface of the spinal cord could induce walking movements in the legs even after a complete lesion of the spinal cord. The authors suggested that such stimulation "has the potential for serving as a valuable adjunct to post spinal cord injury treadmill training and other therapeutic interventions."

The surgery performed by Dr. Herman at Good Samaritan Medical Center in Phoenix, Ariz., consisted of surgical implantation of stimulating electrodes in a Spinal Cord Injured (SCI) patient for the purpose of assisting locomotion. Herman secured approval from the hospital and the FDA to begin the therapy program with advice gleaned from Garcia-Rill and Skinner at UAMS.

PWBT consists of a device that supports the weight of the body while the legs are brought into contact with a moving treadmill. This helps the patient re-learn how to walk, although some motor function in the legs is required. This form of training allowed the patient to walk slowly but with poor endurance.

When Herman combined PWBT and ESCS, there was an immediate improvement in the speed, duration and endurance of walking. ESCS reduced the oxygen (energy) cost of walking by eight times and decreased the sense of effort for walking by three times. After four months of training, the patient could perform community and homebound walking for up to 1,000 feet with only moderate fatigue. Herman established that long-duration pulses were absolutely critical, but he did not test low frequencies of stimulation. Instead, he used higher frequencies (20/sec to 60/sec).

Garcia-Rill believes that such "low-tech" approaches to SCI, as he refers to these methods, are more likely to help patients now. The "high-tech" approaches involve controversial issues and unwanted effects. For example, using fetal spinal cord grafts creates ethical problems and may involve tissue rejection because of tissue incompatibility between donor and host. Also, using stem cells - which scientists have already found can produce tumors - will require additional research to resolve that problem.

Instead, intensive physical therapy in the form of PWBT and ESCS is more likely to bring immediate benefits for SCI patients. However, such intensive approaches require immense dedication on the part of the patient and investment in expensive devices.

According to Garcia-Rill, "Arkansas already has one of the most progressive Spinal Cord Commissions in the country, and their collaborative efforts could help create a positive environment for future progress in this state." He hopes that this approach to therapy could become an emerging focal point of neuroscience and neurosurgery programs at UAMS.

T. Glenn Pait, M.D., a neurosurgeon and leader in spinal cord surgery at UAMS, agrees. "This technology could be developed at the Jackson T. Stephens Spine and Neurosciences Institute at UAMS for the benefit of those who have suffered loss of locomotion because of a spinal cord injury," he said.