A new study from the U.K. shows that oscillations, or variations, in specific brain waves seem to correlate with fibromyalgia (FM) pain symptoms and fatigue in a small group of female patients.
Findings from the study, “Altered theta oscillations in resting EEG of fibromyalgia syndrome patients,” can be found in the European Journal of Pain.
Previous studies have shown that fibromyalgia as well other chronic pain conditions can affect brain activity. However, many of the experimental studies are unable to distinguish whether altered brain activity is a result of acute pain attacks or is more reflective of an ongoing state of sensitization.
The current study assessed the resting-state brain activity to better understand the relationship between fibromyalgia symptoms and brain oscillations.
Using electroencephalographic (EEG) recordings, the researchers looked at changes in recordings between 19 female fibromyalgia patients and 18 age-matched healthy controls. The average age of the participants was 40.
Oscillations in different wavelength were assessed. These included the delta, theta, alpha, beta, and gamma frequency bands.
To correlate the results with fibromyalgia-associated symptoms, the team also used the Manual Tender Point Scale (MTPS) to quantify pain and tenderness and other measurement tools to assess mood, arousal, and fatigue.
As expected, fibromyalgia patients reported higher levels of pain and decreased mood, and were significantly more tired compared to healthy participants.
Concerning brain activity, the fibromyalgia patients had higher levels of theta activity relative to healthy controls in the prefrontal cortex and anterior cingulate cortex regions.
Oscillations in both the medial prefrontal cortex and anterior cingulate cortex have been shown to relate to a reduction of pain inhibition.
Importantly, in this small cohort of female fibromyalgia patients, the increased theta brain activity correlated with measures of pain, tenderness, and tiredness on the day of testing. No correlations between these measures and brain activity were seen in healthy controls.
“The findings indicate that alterations to resting-state oscillatory activity may relate to ongoing tonic pain and fatigue in [fibromyalgia], and manifest in brain regions relevant for cognitive-attentional aspects of pain processing and endogenous pain inhibition,” the researchers wrote.
“Increased prefrontal theta activity may contribute to persistent pain in fibromyalgia or represent the outcome of prolonged symptoms,” they added.
The team suggests that therapeutic interventions aimed at normalizing neural oscillations could help ease the symptoms experienced by fibromyalgia patients.