Feb. 4, 2000 (Cleveland) -- On Sunday, Jan. 30, 2000, the largest television audience of the millennium watched as the actor Christopher Reeve, a quadriplegic since an accident in 1995, rose from his chair and walked to a podium to accept an award. The very same day that Reeve's computer-generated image shocked Super Bowl fans, seven spinal cord injury patients really were rising from their wheelchairs and standing on their own two feet.
Those seven patients, all with injuries at the base of the neck or lower, are participants in a study of functional electrical stimulation (FES) implants being developed at the Cleveland FES Center. The National Spinal Cord Statistical Center estimates there are between 7,600 and 10,000 new spinal cord injuries in the U.S. each year, a number that drives research efforts on all fronts.
Last month a team of British researchers reported that they had restored limb function and sensation in rats with nerve damage by administering proteins that promote nerve growth directly into the injured areas. These findings are very preliminary and as yet are only used in animal experiments, but may mean hope for the future for people paralyzed due to spinal cord injury.
At the University of Massachusetts Medical School, a team led by Charles A. Vacanti, MD, took immature spinal cells from adult rats, induced them to grow, and then implanted them in the gap of the severed spinal cords of paralyzed rats. The paralyzed animals began to move, although this movement was limited.
Meanwhile, a multinational team of researchers report they have identified the "nogo" gene, a gene scientists say may block regrowth of nerves and requires further study to determine if something can be developed to counteract it.
And all of that comes in just the first month of the new year. The scientists working at the Cleveland FES Center say it looks like a very good year.
The center, founded in 1998, is a joint endeavor of Case Western Reserve University School of Medicine, the Edison Biotechnology Center, MetroHealth of Cleveland, and the Cleveland VA Medical Center. Its work is funded by a number of National Institutes of Health (NIH) grants, as well as grants from the Whitaker Foundation, the Department of Veterans Affairs, the Paralyzed Veterans of America, and the State of Ohio.
P. Hunter Peckham, PhD, director of the FES Center, tells WebMD that he and his colleagues have been working for "about 30 years with functional electrical stimulation."
The nervous system operates by means of electrical impulses, which pass information from one nerve to the next. With this system, a stimulating device is used to pass electrical information along and amplify the impulse, even when the nerves are severed, thus bypassing the point of injury and using the nerves' natural electrical activity that is still in place.
Using this principle, Peckham's team worked out a way to deliver electrical stimulation in a way that could be tolerated by the patient. They decided to start by implanting the stimulator in tissues near the point of injury, rather than using external stimulation. The main drawback with external or surface stimulation, says John Chae, MD, MS, is that few patients can tolerate sufficient energy to get adequate deep muscle stimulation. Chae is an assistant professor at Case Western Reserve University School of Medicine and the director of stroke rehabilitation at MetroHealth. Peckham says that too much surface stimulation not only can cause burns, but can also result in uncontrolled leg movements.
Thus far, two implantable stimulators developed by Peckham's team are approved by the FDA. Vocare -- a device facilitating bladder and bowel control that has been implanted in more than 1,600 paralyzed patients -- and Freehand, a stimulator that permits patients with a neck spinal injury who have some shoulder control to open and close a hand for grasping and holding objects, are manufactured by NeuroControl of Cleveland.
While these may seem like impressive accomplishments, they are just the beginning of what may be a 'golden age' of spinal research. David Yu, MD, an assistant professor of medicine at Case Western Reserve, is principle investigator of an NIH- and VA-funded study that will, for the first time, look at whether it is feasible to help people with high neck injuries who have virtually entire body paralysis. "This is an injury like Christopher Reeve's injury," Yu tells WebMD. "Thus far we have [operated on] five limbs of three subjects," Yu says. "We've demonstrated that we are able to generate a response in one of the three subjects," he says.
Although this work is very preliminary, Yu says that he sees it as a necessary task to prepare the next big step in spinal cord research: a link-up between those working in functional restoration, such as the Cleveland FES Center, and biologic researchers who are concentrating on nerve regeneration. Yu says that nerve regeneration has just "really taken off in the last 10 years, because it's only in the last 10 years that it has been apparent that something can be done."
The studies now underway in Cleveland, such as Yu's study, will become especially useful in an era "when we have incomplete spinal cord injuries," says Yu. If nerve regeneration is successful in the future, it is likely to lead to only partial restoration, which will mean incomplete spinal cord injuries. In that case FES becomes even more important, as stimulation can be used not only to strengthen muscles but also to help nerve pathways begin working again, Yu says.
The Cleveland team is hoping to put this theory to the test in a joint project with nerve regeneration researchers. The first steps toward that goal are preliminary talks slated to begin later this spring with researchers from Washington University in St. Louis.
Ronald J. Triolo, PhD, professor of biomedical engineering at Case Western Reserve and senior research scientist at the Cleveland VA, is also eagerly awaiting collaboration with nerve regeneration researchers. Triolo specializes in movement restoration in the lower extremities at Cleveland FES. Working with E. Byron Marsolais, MD, PhD, Triolo is overseeing experimental work in stand-transfer, or helping patients to stand for a short period in order to change location (such as moving from bed to wheelchair) and to walk for a short distance. "Our goal is to provide power to lift the body weight, to maintain an upright position, and then to lower the body again," Triolo tells WebMD. The feasibility of their system has been tested in seven patients, but at this point numerous human studies will be necessary before it is available to spinal injury victims.
Although the stand-transfer system and the limited walking system are impressive, Triolo says the real excitement will come with collaboration with biologic researchers. Already, he says, "medicine has progressed [to the point that we can reduce the damage after injury] so that we are seeing less and less damage from trauma," thus the number of incomplete spinal injuries is growing. However, he adds, "it is really best to mix caution with optimism."
- Some investigators say science is entering a "golden age" of spinal injury research.
- These studies include implanting patients with electric stimulators, promoting nerve growth, and studying why damaged nerves don't usually heal on their own.
- The results are very preliminary.