The trigeminal nerve can be stimulated by both electrical and chemical activators including prostaglandins, serotonin, and histamines. Migraine triggers work either to directly alter these chemical mediators or through neural mediators. When stimulated, the trigeminal nerve releases tachykinins that result in mast cell histamine release, vasodilation and attraction of leukocytes and lymphocytes resulting in sterile arteritis. The resulting neurogenic inflammation causes both distention of cranial arteries and headache pain. Under the new classification, headaches are classified as primary vs. secondary cause of headache.
Duration is typically four to seventy-two hours.
Accurate diagnosis of migraine without aura requires at least two of the following four characteristics. Unilateral Position 2. Pulsating Quality 3. Moderate to Severe Quality 4. Nausea or Vomiting 2.