Chronic pain: a non-use disease.

One of the major problems in modern medicine is to find remedies for the group of people with chronic pain syndromes. Low back pain is one of the most frequent syndromes and perhaps the most invalidating of all of them. Chronic pain seems to develop through several pathways affecting the spinal cord and the brain: (1) neuro-anatomical reorganisation, (2) neuro-physiological changes, and (3) activation of glia cells (immune reaction in the central nervous system). Although all of these pathways seem to provide a (partial) plausible explanation for chronic pain, treatments influencing these pathways often fail to alleviate chronic pain patients. This could be because of the probability that chronic pain develops by all three mechanisms of disease. A treatment influencing just one of these mechanisms can only be partially successful. Other factors that seem to contribute to the development of chronic pain are psychosocial. Fear, attention and anxiety are part of the chronic pain syndrome being cause or consequence. The three pathways and the psycho-emotional factors constitute a psycho-neuro-immunological substrate for chronic pain syndromes; a substrate which resembles the substrate for phantom pain and functional invalidity after stroke. Both phantom pain and functional invalidity are considered non-use syndromes. The similarity of the substrate of both these two neurological disorders and chronic pain makes it reasonable to consider chronic pain a non-use disease (the hypothesis). To test this hypothesis, we developed a "paradoxal pain therapy". A therapy which combines the constraint induced movement therapy and strategies to dissociate pain from conditioning factors like fear, anxiety and attention. The aim of the therapy is to establish a behaviour perpendicular on the pathological pain-behaviour. Clinically, the treatment seems promising, although we just have preliminary results. Further clinical and laboratory studies are needed to measure eventual changes at neuro-anatomical and neuro-psychological level using modern neuro-imaging instruments (PET, SPECT, fMRI). Randomised clinical trials should be carried out to test our hypothesis for all-day use in clinical practice. The hypothesis: chronic pain is a non-use disease produced by psycho-emotional factors like fear, attention and anxiety. Optimal treatment should be based on physiological use, and dissociation of pain and the mentioned psycho-emotional factors. Paradoxal pain therapy could serve these treatment conditions.