Psychophysiologic response patterns in tension headache: effects of tricyclic antidepressants.

Tension headache (TH) and control subjects (n = 22, 11 in each group) were evaluated within a habituation experimental design, in which psychophysiologic responses to auditory stimulation were measured. Auditory stimuli were 20 80-dB, 1000-Hz tones, each lasting 2 sec and sounded at irregular intervals. Subjects were evaluated twice, with a 6-month interval. At the time of the first session TH subjects were being treated with tricyclic antidepressant, yielding a positive clinical effect. Medication was withdrawn 3 weeks before the second session. Phasic responses in heart rate and temporal artery pulse amplitudes and averaged EMG levels from the frontal muscles were measured. Significantly lower heart rate reactivity and significantly less pronounced left temporal artery pulse amplitude responses were found in non-medicated TH subjects than in controls. TH patients showed a pulse amplitude increase in response to stimulation, whereas control subjects showed a decrease. The pulse amplitude response pattern was normalized in medicated TH patients. EMG levels were similar in TH patients and controls when patients were receiving medication, whereas TH patients showed significantly higher frontal EMG levels than control when medication had been withdrawn.