Spinal Cord Injuries

by Food and Drug Administration (FDA)

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 bedsores, 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 that 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.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.