A complex pathology involving the brain, muscles and peripheral nerves, fibromyalgia affects 680,000 people in France, with an incidence four times higher in women. © Inserm / P. Delapierre
Collective scientific expertise sheds new light on the pathological mechanisms of fibromyalgia. Of unknown origin, the localization of these chronic pains now targets certain regions of the brain as well as the muscles. With the impact, the incidence of stress and a genetic track.
Insufficiently diagnosed, seriously impacting the quality of life and, above all without effective treatment because not medically explained. This is how fibromyalgia is characterized today , a disease that is far from being confidential.
Indeed, this source of generalized chronic pain affects 680,000 people in France, with an incidence four times higher in women.
A pathology in its own right, not imaginary
This observation is in the process of changing thanks to the results of a collective expertise conducted by Inserm . It is based on the analysis of 1,600 studies on fibromyalgia, conducted over the past ten years. First lesson: this syndrome is not, as sometimes implied, an imaginary or psychosomatic disease. This is a ” full-fledged pathology, potentially linked to biological abnormalities “, underlines neurologist Didier Bouhassira, one of the Inserm experts.
Amplification of pain by the brain
Thanks to advances in brain imaging, expertise has been able to demonstrate that patients suffering from fibromyalgia amplify the pain sensation. How? ‘Or’ What ? By over-activating the region of the brain measuring the intensity of pain, while under-activating, this time, the regions controlling it.
Brain prostheses: the new generation goes through synchronization
” This hypersensitivity means, for example, that a painless stimulus, such as a little pressure on the hand, will be perceived as painful ,” explains Gisèle Pickering, another expert.
A syndrome of great complexity
However, the brain is not the only one involved. Research shows that, in some cases, the muscle weakness often associated with chronic pain is caused by dysfunctions in the electrical and / or energy activity of the muscles. The absence of small nerve fibers, responsible for driving the painful influx to the spinal cord, would also be suspected.
In the end, fibromyalgia presents itself as a complex pathology because it involves the brain, muscles and peripheral nerves. It remains to be determined for each of these three actors whether it is indeed the cause of the pathology or just a consequence.
Stress and a genetic factor involved?
The collective expertise also suggests the existence of psychological factors (certain personality traits, a traumatic experience, etc.). By promoting significant stress, they are the ones that would cause the brain pain pathways to change as observed. Relevant conclusions when we know, remarks Didier Bouhassira, ” the strong interconnection at the cerebral level of the systems of stress and pain regulation “.
Finally, the analysis of the DNA of people suffering from fibromyalgia made it possible to identify a genetic variant. A large-scale study (700 patients) is underway to confirm the role of this gene. First results expected in 2022.