Pain! It's not all in your head (click here for article)

In your old comic books, it’s simple. A few punches. Sharp, fleeting pain. Then it’s over.

That type of pain happens in real life too. But more often, the pain that puts us in the examining room isn’t colorful, and it isn’t quick — it lasts for weeks, months, even years. LaDonna Lindstedt, for instance, visited an ear, nose, and throat (ENT) specialist because of earaches and trouble hearing as well as daily “droning, constant” headaches. Occasionally she’d have a headache so bad she couldn’t open her eyes.

Before the headaches started, Lindstedt had experienced episodes of jaw pain and tension. She’d know it was coming on because “the first bite of anything I ate was excruciating,” she says. “It actually felt like an electric shock running through my jaw and my head.” Over a week, the pain and tightness would get so severe that she could open her mouth only wide enough to drink through a straw.

The ENT specialist diagnosed Lindstedt with Temporomandibular joint disorder (TMD), a chronic pain condition that affects 5 to 15 percent of the population. Like many chronic pain disorders, TMD has no apparent cause. The patient hurts all the time, but often x-rays and other tests don’t show tissue damage or inflammation.

In the three hundreds B.C., Aristotle suggested that pain was not a physical sense but an emotion. Today, most scientists would agree that pain is physical — the stuff of nerve fibers and receptors and chemicals. But for some chronic pain disorders, we wonder. Often these types of pain get labeled as possibly psychogenic — psychological in origin with no biological cause.

A study from Carolina shows that the pain is real. But the source won’t show up on an x-ray; it is in the genes, and in the firing of brain cells. This research is the first study to link a genetic variation with a chronic pain disorder.

This discovery took seven years of work from a team of thirteen scientists. One of those researchers is William Maixner, a pharmacologist, neuroscientist, and dentist. Maixner is a genial man with blue eyes, ruddy skin, and wavy hair turned mostly gray. In Carolina’s Oral and Maxillofacial Pain Clinic, he sees patients with TMD, including LaDonna Lindstedt. Her treatment includes twice-a-week physical therapy, nightly muscle relaxants, and a mouth guard to wear when she feels her jaws are beginning to clench. Such treatments help, but scientists still don’t know exactly what causes pain disorders such as TMD. Maixner says, “Patients will come to me and say, ‘I don’t see any reason why I should be having this pain. Do I have a brain tumor? Am I crazy?’”

Scientists know that, in general, people who suffer from chronic pain disorders are more sensitive to pain and often struggle with mild depression and anxiety. But which comes first: the pain disorder, or these other symptoms? And what makes some people, especially women, more likely to get chronic pain disorders?