[Central nervous system mechanisms of pathological pain]

Unlike physiologic pain which has a signal, adaptive role, pathologic pain is a pathogenic factor causing disturbances in activity of organism systems. Current views on the nature of pathologic pain are mainly concerned with neurochemical and plastic processes occurring in nociceptive neurons but not with systemic mechanisms of pathological pain. This limitation has been overcome with elaboration of the pathophysiologic theory of generatory and systemic mechanisms of algesic syndromes. According to this theory, a pathogenetic basis for a pathologic pain are formation and functioning of new pathologic integrations within algesthesia system--an aggregate of changed nociceptive neurons acting as a generator of pathologically enhanced excitation and a new pathodynamic organization from changed parts of algesthesia system which represents a pathological algic system. This theory is competent to explain many peculiarities of pain syndromes without denying cell-mediated and neurochemical mechanisms of pathological pain.