CHANGE MECHANISMS ASSOCIATED WITH COMBINED RELAXATION EMG BIOFEEDBACKTRAINING FOR CHRONIC TENSION HEADACHE/

Therapeutic mechanisms hypothesized to underlie improvements in tensio n headache activity achieved with combined relaxation and electromyogr aphic (EMG) biofeedback therapy were examined. These therapeutic mecha nisms included (1) changes in EMG activity in frontal and trapezii mus cles, (2) changes in central pain modulation as indexed by the duratio n of the second exteroceptive silent period (ES2), and (3) changes in headache locus of control and self-efficacy. Forty-four young adults w ith chronic tension-type headaches were assigned either to six session s of relaxation and EMG biofeedback training (N = 30) or to an assessm ent only control group (N = 14) that required three assessment session s. Measures of self-efficacy and locus of control were collected at pr e-and posttreatment, and ES2 was evaluated at the beginning and end of the first, third, and last session. EMG was monitored before, during, and following training trials. Relaxation/EMG biofeedback training ef fectively reduced headache activity: 51.7% of subjects who received re laxation/biofeedback therapy recorded at least a 50% reduction in head ache activity following treatment, while controls failed to improve on any measure. Improvements in headache activity in treated subjects we re correlated with increases in self-efficacy induced by biofeedback t raining but not with changes in EMG activity or in ES2 durations. Thes e results provide additional support for the hypothesis that cognitive changes underlie the effectiveness of relaxation and biofeedback ther apies, at least in young adult tension-type headache sufferers.