THRESHOLD SENSITIVENESS AND INTENSITY OF CHRONIC PAIN

It is assumed that the intensity of pain in the pathological process d epends on the general sensitiveness to the stimuli of pain, and that i t co-operates significantly at the rise of chronic pain states. The th reshold of pain is an indicator of the sensitiveness to nociceptive st imulation and readiness to the creation of pain state. The opinions ab out the changes of thresholds in case of painful processes are not uni fied; the nociceptive mechanism, however, does not show a more conspic uous long-term adaptation. A longer-term (mal)adaptive changes can be explained mostly by non-specific mechanisms (a.o., by vegetative react ivity, emotions, cognitive and motivation processes and defense mechan isms). Measuring the threshold is still the best approximative test of the function of the specific pain mechanism. Measuring the relation b etween the threshold value and the intensity of pain will enable the e stimation of the influence of specific pain mechanism on the chronic p ain state. In 75 patients with chronic back pain, the intensity of pai n was measured by means of the VAS method, as well as the threshold of pain in the dorsal of both hands at lower and higher intensity of sti mulation by radiant heat (by the method of reaction time). A multiple regression explained the 9 % variance of the VAS value by four indicat ors of the threshold level that were used. Practically the same value can be explained by three indicators; one indicator explained to the m ost the 5,6 % variance of the VAS. Thresholds at lower level of stimul ation indicate a closer relation to the intensity of pain; this witnes s rather the threshold understood as a measure of general sensitivenes s than (economical) model of clinical pain. The results witness the si gnificant share of threshold sensitiveness on the intensity of chronic al pain; approximately one tenth of the explained VAS variance provide s theoretical space for the influence of other components.