Observation of a paradoxical temperature increase during cognitive stress in some chronic pain patients

A total of 224 chronic pain somatoform disorder patients without obvious pa thophysiology or psychopathology were found to have colder hands than nonpa tients. A paradoxical temperature increase (PTI) in response to a cognitive stressor (mental arithmetic) was noted in a subset of these chronic pain p atients. Patients were defined as "PTI" responders if during cognitive stre ss, an increase in digital temperature occurred over a prior eyes closed re sting condition. It was found that 49.4% of males and 42.6% of females in a total sample of 224 patients demonstrated PTI. The PTI patients had signif icantly colder hands than non-PTI patients prior to stress. A concurrent SC L measure of sympathetic activation found no difference between the PTI and non-PTI groups either at baseline or during cognitive stress. It appears f rom this data that PTI is specific to the peripheral vascular system of the se patients and may be a marker of psychophysiological dissociation or trau ma blocked from consciousness.