Unlocking Pain's Secrets

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when we need it. It immobilizes us when we are injured so that healing can occur. Pain has an evolutionary importance, says Anatomist Allan Basbaum, of the University of California, San Francisco. "Not to have pain at all is a disaster." But when the pain alarm fails to shut off, it ceases to serve a useful function. "Uncontrolled pain," Basbaum notes, "is also a disaster." In fact, it can do serious harm. The acute pain that follows surgery can, for example, sometimes interfere with a patient's ability to breathe, as well as contribute to nausea and add to the strain on the heart. Chronic pain often leads to an endless cycle of anxiety, depression, loss of appetite, profound fatigue and sleeplessness, all of which make the pain seem worse. Says Neurologist Kathleen Foley, president of the American Pain Society: "Chronic pain destroys lives."

Thelma Beauregard is a gray-haired, pleasant-faced woman of 67, who awoke one night four years ago at her home in Plymouth, Mass., with tingling and burning sensations running from her left elbow to her hand and down into her fingers. From then on, the slightest touch triggered sharp pain. Tests showed that Beauregard 's ulnar nerve had been damaged at her left elbow. Her right elbow showed the same damage, although for some unknown reason she felt pain only on the left side. She has had three operations on the recalcitrant nerve, but at most these provided only a few months of respite. She has tried acupuncture, hypnosis, narcotics, electrical stimulation, antidepressants, heat therapy, ice-water therapy, all to no avail. Four years of suffering have conditioned her to cradle the stinging limb against her body, as though an invisible sling were holding it in place. The left hand has been used so infrequently that the muscles have visibly wasted away. Although the nails are beautifully manicured, the skin on her hand is paper dry. Daubing on lotion simply hurts too much. She looks weary. It is hard to sleep, she says, when "you feel as if you have a knife slicing into you."

Pain like Beauregard's is still something of a mystery to doctors. What caused it? Why did it arrive one night without warning? Why will it not go away? According to Neurologist Howard Fields of U.C.S.F., there is intriguing evidence that in many cases when pain persists for several months, changes of a relatively permanent nature occur in the nervous system, so that even if the original cause of the pain is removed, the sensation of pain continues. "We don't have any idea how that comes about," he says. Trying to reverse the changes, he observes, "may be something like trying to purge memory."

In simpler times, suffering like Beauregard's would have been attributed to evil influences. While early man had no trouble comprehending acute pain caused by injury, chronic pain was relegated to the occult realm of medicine men, sorcerers and shamans. Ancient Egyptians believed that chronic pain was caused by spirits, gods and the dead, but by the 16th century B.C. they had discovered a corporeal way to treat it. Opium is recommended as an analgesic in the Ebers Papyrus, an early reference work listing nearly a thousand prescriptions used in the times of the Pharaoh Amenhotep. Egyptians and some Eastern cultures believed that the physical locus of pain was the heart. This was