Scientists Find a New Way to Measure Pain

When you tell a doctor you're having pain, he or she will typically ask you to rank it on a scale of one to ten. But if you say "five," does the doctor really know what you're feeling? Is your five the same as someone else's five? And what if you aren't able to verbally communicate? How will your physician know what you're feeling without your saying anything?

New research has uncovered a tool that lets doctors accurately assess your pain without needing your input.

A team of scientists from Stanford University tested 24 subjects who had an arm heated to the point of moderate pain. Rather than rely on the subjects' self-reported discomfort, the doctors gave the subjects functional magnetic resonance imaging (MRI) brain scans. The brain scans generated brain patterns in the pain-processing centers of the brain, which the doctors recorded. For comparison, the doctors also recorded the participants' brain patterns when they were not subjected to pain.

These patterns were then tested on 16 new subjects who had an arm heated and were found to be more than 80 percent accurate in portraying the amount of pain experienced. The research is groundbreaking because prior pain studies have focused on things like heart rate and skin response, not brain waves. The researchers note, however, that there are limitations to a study that only focuses on heat-based pain. Pain from fractures or systemic disorders could present differently. Still, the results offer hope that the medical community will soon have new ways to measure—and quickly treat—patients' discomfort.

The next time you go to the doctor and tell her that your arm/leg/throat hurts, you'll probably still be asked to rate your pain on a scale of one to ten. The new research does not mean everyone with an ache or pain will be sent for an MRI, of course. But consider the impact this could have for trauma patients who might be unable to talk but are experiencing considerable pain, or young children who are not yet verbal, or stroke patients who have difficulty speaking. Doctors could, with careful consideration, choose to assess that person's pain by examining brain waves.




Brown JE, Chatterjee N, Younger J, Mackey S. Towards a Physiology-Based Measure of Pain (September 13, 2011): Patterns of Human Brain Activity Distinguish Painful From Non-Painful Thermal Stimulation. PLoS One, 2011;6(9):e24124.