| Several models have been proposed to explain the exacerbation of headache pain. Recent findings have identified deficits in proprioceptive awareness and elevations in anger-related variables among headache sufferers as contributing factors to the development and maintenance of chronic headaches. The present study examined the role of these variables within the context of a psychophysiological model hypothesized to account for the exacerbation of headaches. Data were analyzed for 27 female tension-type headache sufferers and 27 female pain-free controls who completed a questionnaire packet followed by a psychophysiological assessment consisting of 3 phases (adaptation, scheduled-viewing, recovery) with EMG activity recorded continuously at 3 sites (frontalis, corrugator, zygomatic). During the scheduled-viewing phase, participants were presented with pictures (positive, neutral, negative) that included a 30-second waiting period scheduled between each picture. As predicted, a general pattern of significant elevations in EMG activity, oral habits, and pain was found during the scheduled-viewing phase, indicating increased physiological, behavioral, and pain responses to the task. In addition, the headache group reported significantly more oral habits and pain relative to the control group throughout the assessment. Furthermore, the headache group reported significantly more pain during the scheduled-viewing phase relative to the other phases while the control group reported low-levels of pain across all phases. Contrary to expectations, the control group exhibited significantly higher frontalis EMG levels relative to the headache group throughout the assessment. Additional analyses revealed unexpected differences in ethnicity that may have accounted for the elevations in the control group. Also contrary to expectations, analyses during the scheduled-viewing phase revealed significantly higher EMG levels during the viewing period relative to the waiting period. The hypothesized deficits in proprioceptive awareness and elevations in anger-related variables were not found for the headache group. Although the hypothesized differences in EMG response to negative pictures were not supported, the headache group reported significantly higher arousal ratings across all pictures relative to the control group. The present findings provide further evidence that the perception of pain and the appraisal of stress play important roles in the complex relationship between pain and the psychophysiological mechanisms of headache. |
