Fibromyalgia, or Fibromyalgia Syndrome, is a disease involving diffuse muscular and joint pain, fatigue, sleep disorders, minor cognitive impairment and mood disorders of varying intensity and chronic course. Diagnosis is based on clinical examination, usually normal outside sensitivity to soft tissue pressure, and simple bioassays, all of which rule out other diagnoses.
Pain is usually the main symptom. Present in the long term (at least 3 months) and insidious beginning, it is felt in the muscles and joints, and can vary from one day to another in terms of location and intensity. It can be influenced by weather conditions and stress. Most often, the pain is caused by pressure.
- Other pain may be present, related to irritable bowel syndrome, migraine, premenstrual syndrome in women, myofascial syndrome or algo-dysfunctional syndrome of the manducatory system.
This common, potentially debilitating disease most often affects middle-aged women. The cause is unknown, and an abnormal functioning of the central nervous system is assumed. There would be an excessive sensitization of the receptors involved in the perception of pain. Treatment, which is only symptomatic, is usually based on the combination of drugs and non-drug measures.
An average (worldwide) of 2 to 10% (depending on the country) of the population of “industrialized countries” is affected by this disease (2% of the American population with a clear female predominance). In France, a 2007 government report gives a French prevalence estimated at 3.4% for women and 0.5% for men. It affects about 900,000 people in Canada (in 2008), about 2% to 3% of adults.
Fibromyalgia constitutes 10 to 20% of the reasons for consultation in some rheumatology departments. Specialists prefer to use the term “multi-fibromyalgia,” with some biological research reporting subcategories.
Fibromyalgia can affect people of all ages and both sexes. However, it is more common among women between 30 and 60 years old. Smoking is associated with the forms with the most severe symptoms.
This disease usually occurs in the early to middle adulthood, but can occur in childhood. It causes a significant work-related disability in 10% to 30% of those affected.
Starting in 2000-2004, scientists are increasingly looking into neuronal, immuno-chemical or environmental disorders, given the surprising resurgence of cases. Central nervous system involvement and neuronal dysregulation have been widely reported in fibromyalgia patients. There seems to be a different perception of pain in fibromyalgia, with, in particular, a lower perception threshold. The mechanism of this fact is still debated, but heavily assumed to be related to the neurotransmitters responsible for the treatment of pain.
- Genetic predisposition
In addition to the fact that this disease affects many more women than men, there is ample evidence that a genetic factor can play an important role in the development of fibromyalgia. For example, there are many families with multiple sufferers. The mode of transmission is still unknown but is probably genetic. Research has shown that fibromyalgia is associated with variations (or polymorphism) in the genes producing serotonin, dopamine and catecholamine. However these polymorphisms are not specific to fibromyalgia, and are associated with a variety of other diseases (such as chronic fatigue syndrome, irritable bowel syndrome) and some forms of depression.
Finally, many teams are on the trail of potentially deficient genes:
-. A Turkish study has demonstrated a link between genetic polymorphisms linked to the synthesis of catechol-O-methyltranferase (COMT), and a predisposition to fibromyalgia.
-. A study by Professor Vargas-Alarcón’s team (on healthy women with Spanish and Mexican fibromyalgia) tends to prove links between fibromyalgia and a polymorphism of genes coding for both alpha-AR and beta-AR adrenergic receptors . The study of too few cases, and populations not sufficiently varied, must be confirmed. In addition, these polymorphisms are not found at 100% in the populations concerned. All these studies support the link with the deficient synthesis of certain neurotransmitters.
We are therefore moving towards the possibility that A group of deficient genes disrupt the synthesis of pain-related neurotransmitters, predisposing to fibromyalgia. The number and importance of the affected genes would thus determine the severity of the disease
- Immunological disorders
Other studies attempt to demonstrate that cytokines involved in the immune system have a disrupted action in people with fibromyalgia. There is therefore a cause of occurrence of fibromyalgia involving an immunological phenomenon closely related to a neurological phenomenon. These studies, which remain to be confirmed because they concern a small number of patients, prove that these people suffering from fibromyalgia have a cytokine excess, which can cause an excess in substance P. The level of cytokine observed would increase with the duration of the disease.
High levels of cytokine are also seen in people who are sleep deprived. It is therefore currently impossible to determine whether fibromyalgia’s lack of sleep is at the origin of this level of cytokine, or whether the cytokine level is able to cause the evils, and therefore the absence of sleep.
- Irrigation of the brain
At the end of 2008, a team of researchers from the University Hospital of La Timone in Marseille, led by Professor Eric Guedj, identified a blood circulation anomaly in the brains of fibromyalgia patients, thanks to an emission tomography of photons (SPECT). The study found that in patients with fibromyalgia, some areas of the brain are too much irrigated, while others are insufficiently so. This irregularity changes the way the patient feels and treats the pain. Researchers have also identified links between blood flow in certain areas of the brain and anxiety, untimely pain, disability and nervous breakdown. Researchers have identified an increase in blood flow in some areas of the brain that are used to feel the pain, while a decrease in blood flow has been identified in another area that is responsible for the emotional response to pain
- Other assumptions
Other hypotheses have been put forward, such as:
-. Some toxins in the patient’s environment.
-. A viral cause like the Epstein-Barr virus.
-. An abnormal immune reaction to an intestinal bacteria.
-. An erosion of the chemical sheath around the sensory nerves.
-. Deregulation of vasomotility resulting in muscle ischemia or abnormal blood circulation.
-. A deterioration of the posture caused by the dysfunction of the temporomandibular joint, itself due to a defective dental occlusion. The exhaustion generated by muscle contractures resulting from a twisted posture would contribute to chronic fatigue syndrome making any muscular effort painful or impossible.
ASIA syndrome refers to it. These diseases all have a common vector of the presence of a foreign body or vaccine adjuvant in contact in the tissues over a prolonged period.