An Exercise in Hope Program aims to help spinal cord injury patients improve cardiovascular health, regain some sensation and movement - October 9, 2006
Dr. Lisa Griffin
Lisa Griffin watched CNN’s coverage of “the first bionic woman” a couple of weeks ago with more interest than most. She’s a neuroscientist who spends her days studying communication between the brain and body in people who are paralyzed from spinal cord injuries. She knows that what we don’t know about the brain’s power and adaptability is a lot.
Griffin, who is an assistant professor in the Department of Kinesiology and Health Education at The University of Texas at Austin’s College of Education, is in the third year of a study to determine if paralyzed individuals can regain muscle control and feeling, as well as achieve optimum cardiovascular health.
“Participants in our study go to a lab at The Brain & Spine Center at Brackenridge Hospital here in Austin for 10 weeks,” says Griffin, “and spend time cycling on one of the computer-programmed recumbent bikes. We hook electrodes up to their glutes, hamstrings and quadriceps and fire specific patterns of electrical stimulation into their muscles. The appropriate patterns of stimulation cause muscles to contract and pedaling to occur.
“While they’re pedaling we’re collecting data that will help us to determine how the central nervous system adapts to fatigue and the optimal patterns of electrical stimulation for reducing fatigue. Two days a week they train on the bikes with the electrodes and functional electrical stimulation (FES) and then one day a week we have them try to achieve some voluntary muscle contractions without any artificial assistance or stimulation.”
As the study participant rides the bike, she is able to view digital indicators of her performance to determine if unassisted pedaling can be achieved or changed. Even using a high electrical dose of around 140 milliamps (a non-paralyzed person would be made uncomfortable by as little as 20 milliamps) it takes most study participants about five weeks to reach the point at which they can ride the bike for at least 30 minutes. If the cyclists get stronger, or contribute more of their own muscle power and pedal longer, the bike’s computer chip can be reprogrammed and wider parameters can be set, allowing them room to work at their own pace.
“With the improvements in biomedical technology and pharmaceutical intervention,” says Griffin, “we’re seeing more patients who are only partially paralyzed or who are completely paralyzed but graduate to partial paralysis. The use of functional electrical stimulation attempts to get the muscles working and the brain ‘talking’ to the body, which can be beneficial for some individuals.
“We’re also working with biofeedback therapy. On the weekday when participants try to achieve voluntary muscle contractions there may actually be some activity occurring in their muscles, but you’re not seeing the leg, for example, move and they cannot actually feel the muscle contractions. We have them view a readout of what’s going on electrically in the muscle and they can see if something is happening and use that feedback as a target.”
Although most people who have spinal cord injuries are wheelchair-bound, around 95 percent of them have incomplete damage and can experience partial movement. No one knows exactly how intact the nerve pathways are between the brain and the body. Sometimes the brain is injured and cannot communicate with the spinal cord or the spinal cord is injured and cannot carry the communication, but the impairment can fall within a very broad range.
Research like Griffin’s represents largely unexplored territory and for medical professionals who work with the injured, it can be like first witnessing someone break the four-minute mile.
Dr. John Ivy
“There’s nothing wrong with these folks’ legs and arms,” says Kristin Kitchen, an occupational therapist who works with patients in Griffin’s study at Brackenridge’s Brain & Spine Center. “There’s simply been a wreck on the highway between their brain and their body.”
“We try to help the brain relearn how to communicate with the body, and in this line of work, what you don’t know gives you a lot of hope! Even when two individuals have had the exact same injury, the ‘presentation’ of it in their bodies can be completely different—we have to investigate every single person’s potential. I tell my patients that we should try everything and not to give up until there are proven reasons for quitting.”
In the Brackenridge study the participants are split almost evenly between male and female and range from teenagers to septuagenarians, but national statistics show that spinal cord injury victims are overwhelmingly male and young—around 80 percent being between 16 and 30 years of age. Finding a way to keep injured individuals in good overall health and improve quality of life becomes doubly important, Griffin asserts, when the person in the wheelchair is a formerly very active 17- or 18-year old who may have decades of living left to do.
Dr. John Ivy, chair of the Department of Kinesiology and Health Education, has joined Griffin in examining how to improve the cardiovascular health of spinal cord injury patients. As Griffin and Ivy point out, ironically fewer and fewer people who have spinal cord injuries are dying from problems related to those injuries. They are living longer and dying from the same health maladies—heart disease, stroke, cancer, diabetes—as the general population.
“I teamed up with Dr. Griffin in the second year of her study,” says Ivy, “did some blood work and looked at the changes in body composition that happen when participants exercise. We’ve examined changes in glucose tolerance, insulin resistance, plasma lipid levels, triglycerides, bone density and low-grade inflammation and seen that health can improve when they can exercise.
“People with spinal cord injuries traditionally have had rather sedentary lifestyles, and the main cause of death is cardiovascular disease due to inactivity. By getting involved in exercise, reducing body fat and building muscle mass—particularly in the legs—they may be able to reduce those disease risk factors.”
Griffin has carved out a niche in the area of spinal cord studies that sets her apart and seems to offer endless avenues for research. Although plenty of bioengineers have labored over bike design and plenty of clinicians have studied how an injured body works, or doesn’t work, Griffin is a rare bird in that she’s bridged the gap between the clinicians and engineers. Mirroring the marriage of the two fields, Griffin has six kinesiology graduate students who work on the physiology end of her study and six biomedical engineering graduate students who deal with issues of design.
“Mine is the only research that I know of,” says Griffin, “that records natural single motor unit firing patterns of muscles in the legs and hands of able-bodied individuals and then stimulates paralyzed muscle with those patterns.”
Occupational therapist Kristin Kitchen helps a spinal cord injury patient monitor his progress with the digital readout on his bike.
Before coming to The University of Texas at Austin, Griffin did post-doctoral work at the Miami Project to Cure Paralysis and was impressed by the scope of the project’s operations—it had 26 labs, a mutually beneficial relationship between the University of Miami and Jackson Memorial Hospital, a large population of injured individuals and they spend around $46,000 a day on research.
Shortly after Griffin arrived in Austin, Brackenridge medical professionals heard about her experience in the area of spinal cord injuries, informed her that the Lone Star Paralysis Foundation had given them some money and invited her to come on board and perform research in their lab. What Griffin discovered as she investigated the national spinal cord injury database, Brackenridge Hospital’s resources and the College of Education’s kinesiology labs more closely gave her a little thrill. She spotted the ingredients for a human spinal cord injury research program that might eventually give the Miami Project a run for its money.
Where the Miami Project—touted as the only program of its kind in the nation—has only five labs for human research, the Department of Kinesiology has at least a dozen labs where research on humans is conducted. Because Brackenridge Hospital is the only Level 2 trauma center in Central Texas, it sees virtually all spinal cord injuries from Austin and the surrounding area—around 100 cases a year—providing a researcher like Griffin with an unusually large subject pool to study. And although Griffin has not reached the $46,000 a day mark yet, she has received enthusiastic support from the Lone Star Paralysis Foundation, and grants from the National Institutes of Health and the Christopher Reeves Foundation look promising.
“The study is still in its fledgling stage,” says Griffin, “but we’ve already had people from out of state visit and look at what we’re doing in the Brackenridge lab. We have other professors here on campus, like Dr. James Pennebaker, who have offered to consult with us if we examine the emotional and psychological rehabilitation of injured patients, and I see incredible potential at UT for a multidisciplinary approach to spinal cord injury research.
“When I worked with the Miami Project, every time we wrote a grant we would state it was the only place in the world where that level of spinal cord injury research could take place. Now, though, when I look at what we’re doing in Austin, I am convinced that we have the resources to create a premier institute for human research on recovery from paralysis. Even if we don’t find the cure, we’ll help patients be ready for it when it comes.”