Effects of visual stimuli and a stressor on head pain.

This study sought to experimentally validate two reported precipitants of chronic headaches, namely, negative affect (anxiety, anger, depression) and visual disturbance (flicker, glare, eyestrain), and to investigate whether they triggered common or different physiological mechanisms. Twenty-two male and 68 female subjects (46 with migraine, 29 with tension-type headache, and 15 controls) were submitted to antecedent challenges in the laboratory which induced negative affect or visual disturbance and to a control challenge. The results demonstrated that negative affect and visual disturbance can indeed precipitate headaches, and that the physiological responses associated with these antecedents differ, but the findings were not conclusive as to whether one or more physiological mechanisms are operative. Follow-up revealed that the antecedent challenges had significant effects on headache activity 48 to 72 hours after termination.