Central and peripheral sensitization in tension-type headache.

Recent studies on tension-type headache indicate that the nociceptive input to the central nervous system may be increased as a result of activation or sensitization of peripheral sensory afferents. Moreover, pain perception studies and pharmacologic studies strongly suggest that the central nervous system is sensitized in patients with chronic tension-type headache. The barrage of nociceptive impulses from the periphery may be responsible for the sensitization of second- and third-order neurons in the central nervous system. In this way, sensitization may play a role in the initiation and maintenance of tension-type headache. Studies have demonstrated that treatment with drugs that counteract sensitization has an analgesic effect on tension-type headache. Targeting this mode of action seems to be a promising way of improving the treatment for this prevalent disorder.