Migraine. Stimulation of the facial nerves (yellow) can lead to a cascade of neurological and biochemical events that cause the blood vessels of the brain to become inflamed. One step in this cascade is the release of inflammatory chemicals by the trigeminal nerve (above the ear). The inflammation causes the pain associated with migraine. Migraines typically affect one half of the head.HD master is flattened onto a black background, as seen in this preview. The original file has a transparent alpha channel and is available as the HD master of clip K003 3736.