September 18, 2013
Structure Of The Brain May Predispose You To Chronic Pain
[ Watch the Video: Pain in the Brain with Dr. Vania Apkarian ]
Brett Smith for redOrbit.com - Your Universe Online
By using brain scans on chronic pain sufferers, neuroscientists based in Chicago have discovered a connection between the brain and experiencing chronic pain, according to a report in the journal Pain.
"We may have found an anatomical marker for chronic pain in the brain," said study author Vania Apkarian, a professor of physiology at Northwestern University Feinberg School of Medicine.
About 23 percent of individuals with low back pain are chronic, or long-term, sufferers. While some sources of pain can be seen at the site of injury, recent research indicates that the brain may be more involved with chronic pain than previously thought.
"Currently we know very little about why some patients suffer chronic low back pain," said Dr. Debra Babcock, a program director at the National Institute of Neurological Disorders and Stroke (NINDS). "The earlier we detect pain will become chronic, the better we may be able to treat patients."
The research team began by scanning the brains of 46 volunteers who reported low back pain for about three months before coming to a hospital for treatment, but who had not experienced any pain for at least a year before onset.
The researchers scanned the subjects' brains and evaluated their pain four times over the course of one year. About half of the subjects recovered at some point during the course of the study, while the other half reported persistent pain throughout.
A scanning technique used by the researchers called diffusion tensor imaging (DTI) measured the structure of participants’ white matter, or the nerve cells, which connect brain cells in different regions of the brain. The team was able to discover a marked difference in white matter between the subjects who recovered from chronic pain and those who felt pain throughout the year.
"Our results suggest that the structure of a person's brain may predispose one to chronic pain," Apkarian said.
The scientists also found that the white matter of subjects with persistent pain resembled a third group of subjects that reported chronic pain. Additionally, the white matter of participants who recovered resembled that of healthy control subjects.
To expand on their findings the researchers looked to see if the white matter differences predicted whether the subjects would recover from or continue to experience pain. They discovered that white matter brain images predicted more than 80 percent of the outcomes.
"We were surprised how robust the results were and amazed at how well the brain scans predicted persistence of low back pain," Apkarian said. "Prediction is the name of the game for treating chronic pain."
The researchers identified the nucleus accumbens and the medial prefrontal cortex as two brain structures most likely involved with pain. They added that the brain scans indicate structural differences in the white matter linking these brains regions between the subjects who recovered and those who reported persistent pain.
"Our results support the notion that certain brain networks are involved with chronic pain," Apkarian said. "Understanding these networks will help us diagnose chronic pain better and develop more precise treatments."