[Evaluation of a chronic pain syndrome]

Chronic pain, the pain which persists or appears after the initial lesions are healed, has recently been recognized as a medical entity called the "chronic pain syndrome". This condition may be differentiated from acute pain on the basis of biological finality, pathogenic mechanisms, autonomic reactions, affective and behavioural components but most of all of the therapeutic goals. It is important to remind that the experience of pain is the result of at least three interactive neuro-psychological determinants viz. the sensory-discriminative, the affective-motivational and the cognitive-evaluative systems. For this reason, when pain becomes treatment resistant, it is important to complete the usual diagnostic approach by an evaluation of pain as a phenomenon and to abandon a strictly "peripheral" model. Such evaluation is necessarily interdisciplinary.