What is the Cause of FMS?
Possible Triggers and Sleep Disturbances

The cause and underlying background (aetiology) of fibromyalgia remain unknown. Fibromyalgia and sleep disturbance have been linked to certain neurochemicals or neurohormonal changes, since most people with fibromyalgia have disrupted sleep patterns. Disturbances of the non-REM sleep phase have often been observed among patients with FMS. There were also alpha-delta waves observed in IV phase of sleep in the EEG examination. According to Dr. R. Bennett, these changes may be related to the imbalance of neurochemicals or neurotransmitters in the central nervous system that controls much of the body's functioning. So in the case of fibromyalgia symptoms, any number of factors could lead to a chemical imbalance in the body: excessive fatigue, stress, sleep deprivation, depression, anxiety or pain are all responses that could trigger FMS symptoms in some people.

To examine this further, consider when a healthy individual is injured in an automobile accident. The event causes significant stress physically and emotionally. The pain from the injury offers additional stress to an already stressful situation. To further complicate the situation, sleeping becomes difficult due to the pain of the injuries. The lack of sleep causes fatigue, which leads to feelings of depression and anxiety, and additional stress, which in turn makes sleep much more difficult. This series of events can result in the snowballing of several vicious cycles, specifically the stress cycle and the fatigue cycle, which can trigger fibromyalgia symptoms in some individuals. It is unclear why events such as these will trigger fibromyalgia in some people, yet not in others.

Serotonin and Neurotransmitters Hypothesis

Scientists now focus their attention on examining neurochemicals found to be abnormal in persons with fibromyalgia. Several neurotransmitters are responsible for transmitting signals from the brain to the nerves and muscles and these are thought to be key to the disrupted functions in persons with fibromyalgia. For example, persons with fibromyalgia have been found to have very low levels of serotonin (4 times) and its precursor tryptophan and also low levels of norepinephrine, and dopamine. This finding is accompanied by the fact that many FMS patients have decreased expression of the gene for serotonin. Some scientists raise the issue that impaired serotonergic neurotransmission is related to the impaired function of hypothalamus - pituitary - adrenal axis. One the other hand, extremely high levels of substance P in the cerebrospinal fluid have been observed. Having four times the normal level of substance P, the main pain neurotransmitter, suggests that the pain levels experienced by persons with fibromyalgia is not imaginary. However, the reasons for these neurochemical abnormalities still remain unclear. Possible links between neurochemical abnormalities and serotonin (5-HT) deficit and different FMS symptoms are presented in the diagram.

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