The so-called thermode can administer heat stimuli, which the test persons could either end themselves or which the computer controlled. CREDIT © Benjamin Mosch

Fibromyalgia is a mysterious chronic pain disorder that is difficult to treat. Its causes are also still largely in the dark. A study conducted by the team at the Clinic for Psychosomatic Medicine and Psychotherapy at Ruhr University Bochum, Germany, provides evidence that certain brain areas involved in processing pain don’t function normally in fibromyalgia patients. In healthy people, they ensure that pain that we can control is easier to bear. The study found that these brain areas showed altered activity in patients with fibromyalgia.

Controlling the off switch for heat pain

The degree to which we experience pain and the restriction caused by it depend largely on how we perceive it. If we have the feeling that we can control the pain and shut it down ourselves, for example, we will tolerate it better than if we feel at its mercy. “For people with chronic pain, the inability to control repeated attacks of pain is one of the most significant causes of impaired quality of life,” explains Benjamin Mosch, lead author of the study. “And yet, the underlying neural mechanisms have so far mainly been studied in healthy controls.”

The team compared two female cohorts in the current study: 21 healthy participants and 23 fibromyalgia patients. Both groups were exposed to heat pain while their brain activities were monitored by functional magnetic resonance imaging. In one experimental run, the participants were able to stop the pain stimulus themselves. In another run, a computer controlled the start and end of the stimulus. “We kept the duration of the stimuli terminated by the computer the same on average as the stimuli terminated by the test subjects,” says Martin Diers.

Cognitive resources are impaired

When women in the healthy control group were able to terminate the pain stimulus themselves, a number of mainly frontal brain areas were activated that seem to play an important role in modulating pain. This observation is consistent with previous studies involving healthy subjects. “Interestingly, however, we didn’t detect any such activations in our patient group,” points out Martin Diers. “This can serve as evidence for impaired pain processing among patients with fibromyalgia. It indicates that the cognitive resources for dealing with acute pain are impaired in these patients.”

There is new evidence that fibromyalgia, and the chronic pain associated with it, could worsen opioid use disorder. Researchers at The Ohio State University Wexner Medical Center, College of Medicine and University of Michigan report their findings in PAIN, the official journal of the International Association for the Study of Pain.

Scientists have long suspected a connection between opioid use disorder (OUD) and chronic pain. Many people first use opioids to treat pain. Chronic pain has been tied to worsening of OUD and even relapse among those in recovery from opioid addiction. However, researchers didn’t know if all pain has the same effect on OUD, or if certain pain diagnoses might have a much larger impact. Different impacts might lead to more targeted treatments for people with pain and OUD.

Symptoms of fibromyalgia include widespread body pain, extreme tiredness and difficulty thinking and sleeping. This condition is thought to involve unusually strong pain signals in the brain.

“Many of the brain pathways and chemicals believed to be involved in fibromyalgia are also involved in opioid addiction. This overlap made us suspect fibromyalgia might worsen OUD. It’s sort of a double hit hypothesis,” said Dr. O. Trent Hall, lead author and an addiction medicine physician in Ohio State’s Department of Psychiatry and Behavioral Health.

The research team surveyed 125 people living with pain and OUD, 39 (31%) of whom met criteria for fibromyalgia. Although all participants had pain and OUD, those with fibromyalgia were much more likely to say pain had worsened their addiction.

Specifically, those with fibromyalgia more often agreed that pain caused them to continue and increase their opioid use, and that they put off seeking help out of fear their pain would be unbearable if they stopped using opioids.

“These are serious findings. Worries about pain may cause people with fibromyalgia and OUD to delay getting addiction treatment. In our current overdose crisis, every day a person puts off OUD treatment might be the last day of their life,” said Dr. Julie Teater, study co-author and medical director of addiction medicine at Ohio State Wexner Medical Center.

Researchers also found fibromyalgia was associated with greater odds of fearing that pain might cause relapse in the future.

“There are ways we can help people living with fibromyalgia. It’s possible that combining lessons learned from years of studying fibromyalgia might one day inform new treatments for chronic pain and OUD. More research is needed. This is just the beginning,” said senior author Dr. Daniel J. Clauw,

Dr. Max Gomez has the latest on a new test to help detect fibromyalgia.