Richard L. Bruno is chairperson of the International Post-Polio Task Force and director of The Post-Polio Institute at Englewood Hospital and Medical Center. Please e-mail questions directly to him at ppseng@aol.com.

Note: This column is for information purposes only and is not intended as a substitute for professional medical advice.

Q: I heard that a study found that magnets do not help people who have back pain. But I read on the Internet that magnets cure back pain in polio survivors. What's the real story?

A study in the March 8, 2000, issue of the Journal of the American Medical Association found that wearing a magnet or an identical-looking nonmagnetic pad produced no significant relief in patients who had experienced low back pain for at least six months. In 1997 Carlos Vallbona of Baylor College of Medicine examined the effect of magnets in polio survivors. First, he identified places anywhere on polio survivors' bodies that hurt. He then caused pain "by firm application of a blunt object" to the area, asking subjects to rate the pain from zero to 10. Pain was rated as "nine" on average. Then either a magnet or a nonmagnetic pad was placed over the painful area for 45 minutes, and the blunt object was again pressed into the skin. Subjects wearing the magnet rated their pain as "four" on average while those wearing the nonmagnetic pad rated their pain "eight."

Unfortunately, the magnet companies immediately claimed magnets "cured post-polio pain." But pushing a blunt object into the skin does not produce the typical back, muscle or joint pain experienced by polio survivors. Without further study, we can't know if magnets decrease, let alone "cure," post-polio pain. It is unclear how magnets would decrease even experimentally-induced pain in polio. Vallbona refers to the Post-Polio Institute's finding that polio survivors have double the pain sensitivity of those who have not had polio. This heightened pain sensitivity may be related to the 50-year-old finding that the poliovirus kills brain neurons that produce endorphins and enkephalins, the body's own morphine. But regardless of how magnets might have decreased pain in Vallbona's study, polio survivors shouldn't think they can run themselves ragged, apply magnets, and "cure" their pain. Pain in polio survivors is an indication that damage is being done. Masking discomfort--with magnets or morphine--is not a "cure" for polio survivor's pain or for PPS. [New Mobility will have more to say about magnet therapy in our April issue].

Q: With cadaver stem cells being used to grow new neurons in the laboratory in hopes of curing spinal cord injury, could new nerves be implanted into spinal cords of polio survivors to reduce prior nerve damage or even cure PPS?

The hope with spinal cord injury is that stem cells might "bridge the gap" in severed spinal cord axons, which are like long telephone wires that connect brain motor neurons to spinal cord motor neurons, and once again allow the brain to "tell" muscles to move. This would require intact motor neurons below the injury level. In contrast, the poliovirus killed off at least 60 percent of motor neurons in the spinal cord. Stem cells injected into the spinal cord would have to become new motor neurons, not bridge a gap. Those new neurons would then have to send out axons to activate muscles paralyzed when the original axons disappeared 40-plus years ago at the time poliovirus-infected neurons died. These axons would have to find the appropriate muscles to activate by burrowing inches, and in the case of foot muscles, three feet through the tissues in the leg. Finally, the brain's motor neurons would have to send out new axons as well, since their axons also deteriorated after the spinal cord motor neurons died. These axons would have to burrow through the lower part of the brain, down through the spinal cord to newly-implanted motor neurons--a daunting task!

In summary, while reconnecting a spinal cord damaged by injury would require the physiological "home run" of bridging a gap between cut axons, the idea of rebuilding a polio-damaged spinal cord would be the equivalent of a "hat trick": creating new spinal motor neurons, new axons from brain to spinal cord, and yet more new axons growing from spinal cord to muscles.