Spinal cord injuries

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Science Meets Challenge

After days of cramming for college mid-term exams while holding down a full-time job as a security guard, Marc Miller needed a break. So Miller and two friends made the rounds of three Richmond, Va., nightspots before going their separate ways at evening's end.

"I was more tipsy than normal, but I felt fine. I drove out of the parking lot where we had left our cars, and reached over to roll down the passenger window. That's the last thing I remember," Miller recalls. "It was so quick. Suddenly my whole life was changed."

In that instant, his '84 Toyota pickup truck had crossed to the other side of the road, slamming into a telephone pole. On that April 1989 evening, Miller went from carefree college student to paraplegic, joining the 10,000 Americans paralyzed by spinal cord injury each year. After a two-month hospital stay, he returned to college, earning an associate degree in architectural engineering. Now 26, he works full-time as an engineering technician, and lives in Richmond with his wife, Kimberly, 24, whom he met on the job.

"I'm lucky. I have a good job, I play wheelchair basketball, I can still have sex, and I found someone I really love. I couldn't have made it without my friends and family. I wasn't very close to my mother before the accident; now we're really close. I also got very close to my faith in God. Being in a wheelchair gives you a different perspective," he says. "But life is harder. You battle bladder infections. If you get sick, it's harder. I get irritated more easily, and occasionally I get depressed. Life is more of a struggle. It's a struggle to get in and out of cars-just driving to Hardees for an iced tea is exhausting."

Comebacks like Miller's would have been unheard of as recently as the World War II era, when 90 percent of spinal cord-injured patients died. It wasn't until the late 1960s and early 1970s that survival rates began approaching 90 percent, primarily due to advances in handling bladder problems. Today, estimates of the number of people living with spinal cord injuries vary from 200,000 to 500,000.
Spinal Cord Complex

Spinal cord injury is devastating because of the complexity, delicacy and importance of the spinal cord itself. Containing more than 20 million nerve fibers, it is the major conduit for transmitting motor and sensory information between brain and body. It runs vertically within the spinal column, composed of 33 vertebrae separated by rubbery disks.

The nerve signals that travel the spinal cord help regulate sensation, movement, and bodily functions, such as bladder control. When the spinal cord's axons (long fibers that nerve cells send out) are damaged, paralysis can result. Axons transmit nerve signals from cell to cell, so when they're destroyed the cells can't communicate, causing loss of functions controlled by the affected cells.

Spinal cord injury affects a number of body functions. Bladder control is usually impaired, and sometimes completely destroyed. Some people retain involuntary reflexes that help empty the bladder, but others have completely flaccid bladder muscles. Urine left in the bladder breeds infection, which can become chronic and cause kidney damage. Bowel management is another challenge, since messages from brain to bowel to empty don't get through, and anal sphincter muscle control is lost. Then there are skin problems like bed-sores, common to wheelchair patients.

The location of a spinal cord injury helps determine the level of disability: The higher the injury on the spinal cord, the more extensive the paralysis. Injury above the C7 vertebra results in quadriplegia--impaired function in arms, trunk, legs, and pelvic organs. Paraplegia results from damage done to the thoracic, lumbar or sacral regions of the spinal cord. Although arm function is spared, the trunk, legs, and pelvic organs may be involved, depending on the level of injury.
Advances Bring Hope

For many years, medical experts considered extensive recovery of body function after spinal cord injury hopeless. This is because in most mammals, nerve cells of the central nervous system (brain and spinal cord) show little evidence of being able to regenerate when damaged. But today, researchers and clinicians alike share optimism about improvements for people with spinal cord injuries. Electrical stimulation of muscles, use of restorative devices, drug therapy advances, and advances in nerve regeneration research are bringing hope to an area long deemed hopeless.

"Since the Vietnam war, there have been significant clinical advances as research centers across the country learned how to care for severely debilitated quadriplegic patients," says Paul R. Beninger, M.D., M.S., acting director for the Food and Drug Administration's division for general and restorative devices. "For example, use of automated wheelchairs became commonplace after the Vietnam war, and the pulmonary care of patients improved."

FDA regulates devices like motorized wheelchairs, but does not regulate accessories like mechanized van lifts for wheelchairs. A stair-climbing motorized wheelchair FDA approved three years ago is a recent advance in devices for patients with spinal cord injuries. The sophisticated chair has sensors that monitor the steepness of stairs, altering both position and speed depending on incline. But the chair is expensive (about $20,000) and heavy; home stairways need inspection to verify their capability for handling the weight.
Muscle Stimulators

Muscle stimulators using electrical currents that stimulate muscles to contract, especially FES systems (functional electrical stimulation), have been the focus of much media attention. Some FES systems under development are enabling paralyzed people to walk again. Such systems operate as a kind of complex prosthetic device, meaning that although the stimulation can cause muscles to contract and legs to move, it is a kind of "artificial" walking, since no actual movement has been regained by the patient and there is no sensation of movement.

Other FES systems stimulate nerves to give hand movement so quadriplegic individuals without hand function can feed themselves. But FES systems are not without drawbacks: They aren't for everyone, they're costly and still largely experimental, and surgery to implant electrodes is required, which can pose possible complications.

Stimulators aren't just for walking or movement. For example, FDA-approved phrenic nerve stimulators allow people with high-level spinal cord injuries to breathe without respirators. (The phrenic nerve goes from the spinal cord to the diaphragm, and activating it causes the diaphragm to contract). But again, there are use limitations; the phrenic nerve has to be healthy. Robert F. Munzner, Ph.D., chief of FDA's neurological devices branch, estimates that only a few hundred people nationwide can use the device.

According to Marie A. Schroeder, a physical therapist and chief of FDA's restorative devices branch, many muscle stimulators have been cleared for marketing, but not specifically for functional purposes.

"For example, if some muscles are not totally paralyzed and doctors want to see how much improvement in movement or feeling someone will get, they may use a stimulator to maintain range of motion to help provide muscle reeducation, until they see how much voluntary control the patient gains," she explains. "But using stimulators for functional purposes gets into the investigational area. The only functional use of a muscle stimulator that has been cleared are those stimulators that might be used for a patient with a localized nerve injury-for example, a patient who can't lift his foot up. However, we consider the stimulation of muscles needed for the purpose of walking to be investigational."

Physicians surveyed say electrical stimulation is not being widely used on a routine basis because the technology is not yet "user-friendly." William O. McKinley, M.D., director of spinal cord injury and rehabilitative medical services at The Medical College of Virginia, notes that devices that assist paralyzed patients in coming to a standing position, for example, are "very expensive, very time-consuming to learn, and usefulness has to be determined on a patient-by-patient basis."

Many other uses of stimulators are not common or remain investigational. For example, although stimulators that offer pain prevention and electro-ejaculation to collect sperm to enable paralyzed men to become fathers are used clinically, their use is not widespread.

F. Terry Hambrecht, M.D., head of the neural prosthesis program at the National Institutes of Health's National Institute of Neurological Disorders and Stroke, says such systems are still technologically limited, but he is optimistic about the future.

"The problem now is that we're in the Model-T stage. We don't yet have the sophistication and reliability we need," he admits. "But there's no doubt in my mind that eventually functional stimulation devices will be developed for spinal cord-injured patients. We're funding quite a few projects for people who are paralyzed."

Hambrecht says one current project involves electrode implantation to restore bladder and sexual function to paralyzed men and women. He anticipates the first implants will be done within five years.
Drug Treatment

Muscle stimulators have provided drama, but the steroid methylprednisolone, experts say, has actually changed the face of clinical treatment for people with spinal cord injuries. A recent report of a 1985 to 1989 study of 487 patients, funded by the National Institute of Neurological Disorders and Stroke, showed that patients given high doses of this cortisone-like drug within eight hours of injury regained an average of 20 percent of lost motor and sensory function. Experts cite the study as the first evidence that a medication can improve the outcome of spinal cord injury, and today the drug is widely used for acute spinal cord injury.

Surgeons use the potent drug, which was approved some years ago by FDA as an anti-inflammatory agent and is also approved to treat swelling around the brain, to manage acute attacks of multiple sclerosis and for a variety of allergic conditions.

Wise Young, M.D., Ph.D., part of the methylprednisolone study team, is a professor of neurosurgery, physiology and biophysics and director of the neurosurgery research lab at New York University Medical Center. Young points out that the drug does not enable patients to immediately "leap out of bed." Beneficial effects are usually not apparent until at least six weeks after the drug is administered. Yet he believes the use of the drug is a landmark development.

"It has changed the attitude of doctors toward spinal cord injury. They no longer see it as a hopeless condition, and patients are rushed to hospitals earlier," he explains. "It also has tremendous implications for chronic spinal cord injury, since the finding that you only need a few axons to get function back means you don't have to regenerate as many axons."

"Currently there are over two dozen drugs reported to be neural-protective in animals," Young says. "The leap that was made in 1990 was between absolutely no hope to some hope. There is a real sense of optimism now; it's not a matter of if, but when, a drug will be available to aid regeneration of the spinal cord."
Treatments Under Study

Another drug under study is GM-1 ganglioside. Fred H. Geisler, M.D., Ph.D., a neurosurgeon at the Chicago Neurosurgical Center, headed a team at the University of Maryland Shock Trauma Center in Baltimore that studied 34 people with paralyzing spinal cord injuries in a placebo-controlled, double-blind, randomized study.

The study results were reported in the June 27, 1991, New England Journal of Medicine. Within three days of injury, 16 of Geisler's patients began daily injections of GM-1 for 18 to 32 days, while the rest received placebo injections. Patients given GM-1 had improved recovery of motor functions in the arms, and later in the legs. About half of the improvement occurred at the two-month mark. Most of the improvements happened within four months of patients' receiving GM-1 injections, but some improvements continued for up to one year after GM-1 treatment.

Researchers theorize that GM-1 ganglioside, naturally present in cell membranes of the spinal cord and brain, helps protect against additional nerve cell death after spinal cord injury and also stimulates nerve-fiber growth and repair.

"We saw some major improvements. ...In many cases, people were walking where they could not ambulate at all before," Geisler says. He is now heading a new study of this investigational drug, following 166 patients given GM-1 at 22 medical centers in North America. Geisler says the goal is to enroll 720 patients.

Neural grafting, or transplantation of tissue into the brain and spinal cord, is still highly experimental. Possible sources of grafting material include genetically engineered cells, human fetal tissue, and other tissues from a patient's own body. Neural grafts are being tested in animal models of brain and spinal cord injury to find out if they can induce growth or replace damaged areas.
Other Improvements

Other factors besides drug advances and technology are improving the outlook for people with spinal cord injuries. Car accidents by far remain the number one cause of spinal cord injuries (47.7 percent), followed by falls, gunshot wounds, and recreational sports, particularly diving accidents. Spinal cord injury happens mostly to young people, and mostly to males (82 percent).

MCV's McKinley says improvements in on-site emergency medical management, with better-trained technicians skilled in stabilizing the spine to prevent further injury, means doctors are seeing more patients with "non-complete" injuries, or injuries where some function and motor sensation is preserved.

"We are also doing a better job of educating people in how to protect against spinal cord injury, such as wearing seat belts, buying cars with air bags, and not diving into shallow water," he says.

In rehabilitation, the emphasis remains on regaining as much functional ability as possible.

"Chronic patients and rehabilitation are the real challenge. Research is exciting and potentially part of the future, but it still has a long way to go," McKinley says, pointing out that helping patients through the adjustment period after injury remains challenging. "They need to know how to self-catheterize, how to detect bladder infections," he says. "Are the doors at home wide enough for a wheelchair? Do they need a ramp?"

McKinley says the first thing newly injured patients ask about is their ability to walk, but questions about sexuality are not far behind.

"Paralysis can affect the ability to have an erection.... But with adaptations, sexual relations are very possible. So I tell patients yes, it's possible, but different. Loving and caring and other means of sexual gratification take on new priority for injured patients," he explains.

Hope and patience may be the most important factors regarding the future treatment of spinal cord-injured people. Hope comes from optimism about recent advances in treatment, but research complexity and funding issues make patience necessary as well.

"For at least the last decade, research papers have shown that spinal cord injuries can be improved, or that the amount of injury can be decreased," Geisler says. "My hope is that lab findings will be able to move to the clinical area."

Marc Miller, like many people with spinal cord injuries, is both optimistic and philosophical about the treatment advances.

"I think in the next 10 years they will find treatments that reduce the impact of spinal cord injuries. But I think it's important for people to remember that we're just normal folks who can't walk," he says. "I have a better grasp of who I am now; being in a wheelchair gives you a different perspective. I'm not disabled, I just can't walk. I play wheelchair basketball, I want to learn to water ski and to snow ski.... I just want to do all I can do now."
For More Information

The American Paralysis Association, an organization dedicated to eliminating paralysis, provides a 24-hour toll-free information and referral hot line, at (1-800) 526-3456. The hot line helps callers search for support and resources on everything from sexual concerns to selecting a rehabilitation facility.

The National Spinal Cord Injury Association also provides information and resource help at (1-800) 962-9629.

PHOTO: Marc Miller shoots baskets with friends at a gym in Richmond, Va. Miller became a paraplegic four years ago when his spinal cord was injured in an auto accident.

DIAGRAM: Paralysis Locations

The higher the injury on the spinal cord, the more extensive the paralysis. Injury above the C7 vertebra results in quadriplegia, impairing function in arms, trunk, pelvic organs, and legs. Damage to the thoracic, lumbar or sacral spinal cord regions results in paraplegia, in which arm function is retained while--depending on the level of injury-trunk, legs, or pelvic organs may be affected.

PHOTO: Susan Hoover, occupational therapist at the Kessler Institute for Rehabilitation, West Orange, N.J., shows Mignel Longo how to use devices that help a spinal cord-injured person activate household electrical appliances, lights, and electronic equipment. (Photo used by permission of Dalia Photo and Video, Morristown, N.J.)

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By Audrey T. Hingley

Audrey T. Hingley is a writer in Mechanicsville, Va.

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