Evidence for physiological response stereotypy in migraine headache.

Several biological theories of psychosomatic disorders predict that susceptible individuals will have stereotypic physiological responses to stress. This hypothesis was tested in a sample of 13 migraine headache subjects by observing their head and hand temperature, frontal electromyography (EMG), heart rate, skin conductance level, and finger pulse amplitude under the conditions of rest, orienting to a tone, time estimation, reaction time, and mental arithmetic. Thirteen nonheadache cohorts served as a control group. For the migraine group, analyses of variance revealed significantly warmer head and hand temperatures and lower frontal EMG. Range-corrected data, which allow comparisons among the physiological measures, showed the migraine group to have a more stereotypic response pattern across tasks. Discriminant analyses, using both untransformed and range-corrected data made excellent post-dictions of group membership.