By Pat Anson, Editor

Fibromylagia and urological pelvic pain would seem to have little in common. The former causes widespread body pain, while the latter is marked by chronic inflammatory pain in the bladder or prostate.

But researchers at the University of Michigan have stumbled upon something that both conditions share – besides being difficult to treat.

While examining MRI brain scans of over 1,000 participants enrolled in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network  -- also known as the MAPP study – they found that people with fibromyalgia or chronic urological pelvic pain both have increased “gray matter” in their brains. Gray matter is tissue in the brain that helps transfer signals between nerves.

"Interestingly, when we put these individuals into the brain imaging scanner, we found that those who had widespread pain had increased gray matter and brain connectivity within sensory and motor cortical areas, when compared to pain-free controls," says Richard Harris, PhD, an associate professor of anesthesiology and rheumatology at Michigan Medicine.

Harris and colleagues want to know if widespread pain, thought to be a marker of centralization in the nervous system, actually originates in the brain. So it was a bit of a surprise to find additional gray matter in the brains of people with urological pelvic pain, a condition that can be caused by interstitial cystitis or chronic prostatitis.

"What was surprising was these individuals with widespread pain, although they had the diagnosis of urological chronic pelvic pain, were actually identical to another chronic pain disorder: fibromyalgia," said Harris.

In addition to the MRI scans, study participants were also asked to draw on a body map where they were experiencing pain. Many of those with pelvic pain indicated they had widespread body pain.

"This study represents the fact that pelvic pain patients, a subset of them, have characteristics of fibromyalgia," Harris says. "Not only do they have widespread pain, but also they have brain markers indistinguishable from fibromyalgia patients."

Harris hopes the study will lead to new ways of treating chronic pain -- as there might be similarities across pain conditions if both show widespread pain.

"We think that this type of study will help treat these patients because if they have a central nerve biological component to their disorder, they're much more likely to benefit from targets that affect the central nervous system rather than from treatments that are aimed at the pelvic region," Harris said.