Two recent studies expand the body of knowledge on why people with fibromyalgia experience pain differently than other people.
Research just published in the journal Arthritis & Rheumatismidentifies possible mechanisms for an absence of what's calledpain inhibition, a problem liked to fibromyalgia by prior research. In pain inhibition, the brain compensates for pain that expected, thereby reducing it. It's why a shot hurts less when the nurse warns you that it's coming. (That is, if you don't have fibromyalgia.)
This new study looked at what's going on in the brain when pain is anticipated. Researchers found that a region called the ventral tegmental area (VTA) had substantially less activity in fibromyalgia participants than in healthy controls. The reduced activity was also present in the anticipation of pain relief, which researchers say may be why we tend to be less responsive to narcotic painkillers.
The other study, published in Neuroimage Clinical, revealed several structural abnormalities in brain regions that deal with pain.
People with fibromyalgia had a differently shaped portion of the brainstem, which links the brain with the spinal cord, and reduced volume of the entire brainstem. Researchers say the lower the brainstem volume, the higher the tender-point count.
MRI also revealed low gray-matter volumes in the brainstem and a region called the left precuneus, but increased gray matter in areas called bilateral primary somatosensory cortices.
They conclude that these shape and volume differences may contribute to our high sensitivity to pressure pain, such as that from a blood-pressure cuff or waistband.
These studies contribute to the growing body of literature showing that fibromyalgia pain processing involves abnormal activity throughout the brain.
Also see this recent research: Brainstem Involvement in Fibromyalgia.