Fibromyalgia and Sensory Perception
Fibromyalgia is considered to be a stress-related disorder because of the frequent onset and exacerbation of pain symptoms.
Not a Brain Disorder
As is common with fibromyalgia, there is little that is consistent from patient to patient meaning that a regular pattern doesn't always emerge to fit most patients. Such is the case with hormonal, metabolic, and brain chemical activity described in many research studies of FMS patients. Since there is no established and clear cause-and-effect relationship between brain chemical activity (neurotransmitters) and pain or sensory perception, it could be that fibromyalgia results from the effects of pain and stress on the central nervous system, leading to changes in brain circuitry, rather than a brain disorder. This has been supported by brain imaging studies that have indicated central nervous system disturbances happening in response to pain stimulation.
Each neurotransmitter has the ability to perform a variety of functions, interacting with one another and with the neurons in the brain, often using one neurotransmitter to create another. This function is appropriate especially in cases of neurotransmitters with opposite functions, like GABA and glutamate (serotonin and melatonin).
Serotonin is a nervous system chemical messenger found in the brain and other parts of the body that plays an important role in promoting sleep, feelings of well-being, and adjusting pain levels. Low serotonin levels are associated with several disorders, and it has been discovered that people with fibromyalgia tend to have low levels of serotonin as well. Additionally, FMS sufferers have also been found to be low on the stress hormone system HAP (hypothalamus-pituitary-adrenal gland) axis. Lower levels of this stress axis leads to an impaired response to psychological or physical stresses.
Feeling the Pain
Studies have shown that people with fibromyalgia tend to perceive pain differently than people who are healthy. FMS may involve hyperactivity in the parts of the central nervous system that manage pain, known as the nociceptive system. Abnormalities in pain processing centers in the brains of fibromyalgia patients have been seen in brain scans, with as much as three times the normal level of substance P (a chemical messenger associated with increased pain perception) detected in the cerebrospinal fluid of FMS patients.
Abnormal increases in blood flow (brain perfusion) have also been found by brain scans to be in the areas of the brain that define the intensity of pain. A decreased blood flow has been found in areas associated with the emotional response to pain. The fact that the abnormalities are unrelated to depression and anxiety levels in the patient, gives added support to the concept that fibromyalgia is a real disorder as opposed to being a side effect of depression.
Oversensitivity to external stimulation and extreme anxiety about pain sensations, called generalized hyper-vigilance, occurs in FMS patients. Additionally, a conflict between sensory perception and the processing done by the nervous system may occur in people with FMS. People with FMS are more likely to be acutely aware of (or less tolerant of) movement problems (tremors and twitches) that don't match with the sensory response feedback. The mismatch in signals may enhance the perception of pain. The same process works for sound and eye pain. The heightened sensory perception of FMS is capable of producing pain in the eyes and sensitivity to light. In a study done in Michigan in 2008, fibromyalgia subjects perceived auditory stimuli to be of the same intensity as that felt by the subjects in the control group, even though the actual intensity levels were lower.
It is a great relief to sufferers of FMS that there is a physiological issue that is now traceable and recognized as the trigger for exaggerated pain response. Central nervous system disturbances are at the root of many symptoms experienced by fibromyalgia patients and the research helps medical professionals to understand the syndrome and treat it more effectively.
This section provides great information on the various aspects of fibromyalgia. Have a question? We probably have the answer.