By Pat Anson, Editor
A new method of analyzing brain scans using advanced computer algorithms can often predict whether a patient suffers from back pain. Researchers at the Stanford University School of Medicine say it could lead to a more accurate way to diagnose chronic pain in patients – as opposed to current methods that are often subjective.
The Stanford study, which will be published online in Cerebral Cortex, found that using computer algorithms to read brain scans accurately predicted lower back pain 76 percent of the time.
“People have been looking for an objective pain detector — a ‘pain scanner’ — for a long time,” said Sean Mackey, MD, PhD, chief of the Stanford Division of Pain Medicine and professor of anesthesiology, pain and perioperative medicine. “We’re still a long way from that, but this method may someday augment self-reporting as the primary way of determining whether a patient is in chronic pain.”
Chronic pain is notoriously challenging for doctors to diagnose and treat, because patients tolerate and describe their pain differently. Very young and very old patients may also have difficulty communicating.
The National Institutes of Health uses six different pain scales to measure pain, ranging from the smiley faces of the Wong-Baker Pain Scale to monitoring a patient’s grunts and grimaces. All six scales are highly subjective.
In a study published last year in PLoS ONE, Mackey and his colleagues used computer algorithms to analyze magnetic resonance imaging (MRI) brain scans to accurately measure thermal pain in patients 81% of the time.
The goal of the new study was to use brain scans to accurately identify patients with lower back pain and to investigate possible pathological differences in their brains.
Researchers conducted MRI scans of 47 subjects who had lower back pain and 47 participants who had no back pain. Both groups were screened for medication use and mood disorders.
A computer algorithm invented in 1995 was then used to analyze the brain scans of both groups.
It successfully predicted which patients had lower back pain 76% of the time.
“Lower back pain is the most common chronic condition we deal with. In many cases, we don’t understand the cause,” said Mackey. “What we have learned is that the problem may not be in the back, but in the amplification coming from the back to the brain and nervous system. In this study, we did identify brain regions we think are playing a role in this phenomena.”
According to 2011 report by the Institute of Medicine, an estimated 100 million Americans suffer from chronic pain. Lower back pain is the most common type of chronic pain for people under 45. The prevalence of lower back pain among Americans has risen significantly, from nearly 4% in 1992 to over 10% in 2006.
Previous studies suggest that lower back pain is characterized by structural changes in the gray matter, or nervous tissue of the brain, a possible sign of disease.
“There are functional changes in the brain of a chronic pain patient, and we show that structural changes may be used to differentiate between those with chronic lower back pain and those without,” said former research assistant Hoameng Ung, the author of the first study who is now a student at the University of Pennsylvania School of Medicine. “This observation also suggests a role of the central nervous system in chronic pain, and that some types of chronic low back pain may reflect pathology not within the back, but instead within the brain.”