Fibromyalgia and Associated Disorders: From Pain to Chronic Suffering, From Subjective Hypersensitivity to Hypersensitivity Syndrome

Abstract

The concept of fibromyalgia has progressed to achieve a certain consensus regarding the definition of the condition. We summarize what is known in 2020, be it in terms of diagnosis, with the criteria that have changed over the years, or at the level of the psychological profile, via the notions of "catastrophizing" and "coping" and post-traumatic syndrome. The importance of fatigue and sleep disorders is underlined, with the chronological sequence of post-traumatic syndrome, chronic fatigue, and then amplification of the pain and the onset of multiple associated symptoms. The etiopathogenic debate has been enriched thanks to neuro-imaging data to discover the start of the central neurological signature. The many associated symptoms are reanalyzed in the context of so-called sister conditions which form sometimes more or less separate entities, such as chronic fatigue syndrome or restless legs syndrome for example. What these conditions have in common is hypersensitivity, not just to pain, but also to all exteroceptive stimuli, from deep sensitivity in the neuro-vegetative system, the sense organs and certain functions of the central nervous system, to the psychological aspects and sleep control. In summary, it is possible to define fibromyalgia as a cognitive disorder of cortical integration of chronic pain, with amplification of painful and sensory nociception, decrease in the threshold for the perception of pain, and persistence of a stimulus that maintains the process in chronicity. Fibromyalgia is part of a group of chronic hypersensitivity syndromes of central origin, with a very wide range of means of expression.

Keywords: diagnosis; fatigue; fibromyalgia; hypersensitisation; neuro-imaging; pain; psyche.

Figure 1

Respective role played over time of the psyche, sleep disorders, fatigue, pain, and sensory functional disorders: kinetic analysis of the events occurring in the life of a fibromyalgia patient. The traumatic psychological events are old, or even dating back to childhood. The sleep disorders are secondary and quickly associated with a state of fatigue, which precede often by several years the chronic pain state and associated functional signs, in the sequence illustrated below.

Figure 2

The different paths to the origin of the stimuli responsible for the symptomatology in fibromyalgia are illustrated in the bubbles, with the associated signs in the boxes linked by arrows. The stimuli at the origin of the associated symptoms of fibromyalgia are either of exteroceptive origin, or profound, or related to the neuro-vegetative system, all with medullary relays, or in relation to sensoriality and its bulbar relays, or even central origin with regard to the psyche or fatigue. Each time, there is chronicization and amplification of the signal, which can thus only be done at the central level. The supposed mechanism is either abnormal amplification of the signal itself, or inhibition of the retrocontrol system, or a quantitative decrease in the perception threshold for the signal. A few entities (in bold in the boxes with rounded corners) are the subject of specific names in relation to the more specific predominant symptomatology, but with clear ties with fibromyalgia in the context of the hypersensitization which is common to all these syndromes.