Fibromyalgia Pain: Physiological Evidence

It's Not In the Mind, But In the Brain

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Fibromyalgia pain isn't caused by obvious sources. Our muscles and connective tissues show no signs of degeneration. Our bones and joints are as healthy as anyone's. Pain without damage is hard to understand and treat, and that's much of the reason that for decades fibromites were told the pain was all in their heads. But as researchers looked to the head -- the brain, more specifically -- they started uncovering more about our pain.

Instead of being in the mind (psychological), it's in the brain (neurological).

The highly respected website UpToDate, a resource trusted by physicians as well as patients who want in-depth information, delves into the neurological abnormalities of fibromyalgia (FM or FMS).

From UpToDate:

"Some differences in pain processing that may be important in pathogenesis include the following:
  • Upregulation of opioid receptors in the periphery, as well as reduced brain opioid receptors.
  • Elevated levels of substance P were found in the cerebrospinal fluid of FMS patients compared to controls.
  • Differences in activation of pain-sensitive areas of the brain, as determined by increased regional brain blood flow using magnetic resonance imaging (MRI), and functional MRI (fMRI), and MR spectroscopy have been noted in FMS."

Fibromyalgia Pain & Your Brain

So what do all those medical terms mean? Let's break it down:

  • "Upregulation of opioid receptors in the periphery, as well as reduced brain opioid receptors."

Opioid receptors are specialized parts of cells that bind to opiates -- pain killers contained in Vicodin (hydrocodone) and Percocet (oxycodone).

The periphery in this case is the parts of your nervous system outside the brain and spinal cord.

"Upregulation" means increased numbers of opioid receptors.

Upregulation of peripheral opioid receptors is common in damaged or inflamed tissues, neuropathy, or bone damage. In some cases, this upregulation is believed to help opiates work.

Reduced brain opioid receptors, however, make your brain less sensitive to opiate pain killers. This helps explain why opiates are generally ineffective at treating fibromyalgia pain.

  • "Elevated levels of substance P were found in the cerebrospinal fluid of FMS patients compared to controls."

Substance P is involved with the pain threshold -- the point at which sensation becomes painful. Elevated levels of substance P could help explain why the pain threshold is low in people with fibromyalgia.

  • "Differences in activation of pain-sensitive areas of the brain, as determined by increased regional brain blood flow using magnetic resonance imaging (MRI), and functional MRI (fMRI), and MR spectroscopy have been noted in FMS."

High blood flow to an area of the brain shows how much activity is going on there.

The 3 types of brain scans listed above have all demonstrated that, in fibromyalgia, activity is higher than normal in the areas of the brain that deal with pain. This suggests that pain signals are bombarding the brain or that the brain is abnormally processing pain signals from the body.

Basically, all of this is physiological evidence that those of us with fibromyalgia experience real, physical pain and that our bodies are highly sensitive to pain. We don't yet know if the pain comes from abnormal pain signals or abnormal brain processing of normal signals (or both) -- or how to stop it -- but ongoing research may hold the answers.

Want to learn more? See UpToDate’s topic, "Pathogenesis of fibromyalgia," for additional in-depth, current and unbiased medical information on fibromyalgia, including expert physician recommendations.

Source:

"Pathogenesis of fibromyalgia." UpToDate. Accessed: March 2009.

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