According to the definition ofInternational Association for the Study of Pain, Pain is an unpleasant sensory and emotional experience associated with or described in terms of actual or potential tissue damage. We speak of chronic pain when this pain persists beyond three months. “It is then disconnected from the initial lesion and loses its purpose as an alarm signal. It becomes a disease in its own right, unrelated to the initial trauma.”, explains Dr Hayon-Sonsino. It is estimated that 20% of the population suffers from chronic pain.
The different types of pain: nociceptive, neuropathic and nociplastic
“There nociceptive pain is linked to direct stimulation of pain receptors, called nociceptors. They are the ones who will raise the alarm under the effect of an attack: infection, trauma, inflammation. explains the specialist.
Neuropathic pain is quite specific pain that meets very precise clinical criteria. “They are linked to damage to the nervous system, wherever it may be: the peripheral nervous system (nerve, nerve root) or the central nervous system: spinal cord, brain stem, brain,” explains Dr. Hayon-Sonsino.
These nociplastic pains are linked to an attack on the systems for interpreting and filtering sensations and pain. “We find filters of sensation in the brain which prevent permanent hyperstimulation. The brain carries out a sorting process. But in nociplastic pain, these filter mechanisms are annihilated or overwhelmed and the slightest perceptions of the body are perceived painfully.”, explains the anesthesiologist. The particularity of these pains is that they occur in the obvious absence of a clear lesion or disease, precisely because of this alteration of the pain perception system. One of the biggest examples is fibromyalgia.
The causes of chronic pain
It is estimated that 20% of the French population suffers from chronic pain, this represents more than 20 million people. Between 7 and 10% suffer from chronic neuropathic pain.When we ask a patient about their pain, we induce a fixation bias. We must therefore moderate these figures and the impact of this pain on the daily lives of patients. nuances the specialist. Of course, even if the patient mentions a simple irritative discomfort or describes pain at 3 on the VAS (Visual Analogue Scale), corresponding to moderate pain, this must be taken into consideration.
We find different causes of chronic pain. In the case of neuropathic pain, the primary cause is surgery. “20% of all interventions can be complicated by neuropathic pain, persisting for more than 3 months”, confirms Dr Hayon-Sonsino.
For chronic nociceptive pain, osteoarthritic and inflammatory rheumatic diseases are most often to blame. “Even if the disease is supervised and controlled, and no markers of inflammation are found, patients still have pain because the pain systems are disrupted. explains the doctor.
The third leading cause of chronic pain is diabetes, a disease that causes nerve damage. Of the 3,500,000 people who have diabetes in France, half suffer from neuropathic pain. Finally, neuropathic pain, when peripheral, is often post-zoster pain, while central neuropathic pain is usually following a stroke (stroke) or linked to an attack of multiple sclerosis.
Thanks to Dr. David Hayon-Sonsino, resuscitation anesthesiologist and pain doctor.