Understanding the relationship between pain and emotion in idiopathic headaches.

The aim of this paper is to review hypotheses regarding pain mechanisms in headache and relationships between headache pain and the brain's emotional network. There is evidence that chronic pain in idiopathic headaches is, in part, an emotional response induced by alterations in the homeostasis of the interoceptive system--a system that integrates nociceptive information with the emotional network (mediating emotional awareness). These findings suggest that idiopathic headaches are probably due to both an altered pain matrix on the one hand, and an altered affective-cognitive state on the other.