CAUSES AND MECHANISMS OF PRIMARY HEADACHES - TOWARD A BIO-BEHAVIORAL MODEL

Pathophysiological mechanisms of primary headache remain obscure, desp ite of numerous hypotheses that have been postulated for either migrai ne and cluster headache, Human experimental models are not available, however observation of clinical features of migraine or cluster headac he attacks support animal studies documenting the development of neuro genic inflammation in tissues receiving trigeminal innervation. The la tter studies provided also the background for better understanding the mechanism of action of aborting drugs such as sumatriptan and dihydro ergotamine. The debate is whether the primary cause of migraine and ot her neurovascular headaches is central or peripheral in origin. Trigge r factors (stressful events) and personality traits in migraine patien ts suggest that activation of neurovascular systems is secondary to mo ve complex events taking place in the central nervous system.