Fortunately, most migraineurs are sensitive only to one or two of these triggers. But cold can be a trigger for one migraineur in three. These people experience a sharp pain in the, forehead or temple after swallowing ice cream or an iced drink. Often called the “ice cream headache” it is believed to be caused by irritation to nerve endings in the mouth or face. Pain impulses are referred by the trigeminal nerve to the forehead area where they set off blood vessel dilation and create a vascular headache. Exposure to icy winds or to any kind of cold on the face, or to diving into cold water, can also excite nerves that set off a migrainelike pain in the forehead or temple.
Yet another vascular variant is the hangover headache, caused by overindulgence in alcohol, a powerful stimulant dilates arteries inside the skull so that bending forward increases the pain. In this same class are rebound headaches, due to withdrawal from vasoconstrictors such as caffeine, nicotine or ergotamine.
Cluster Headache. While emotional stress is often the underlying cause of cluster headaches. Stage 2 occurs without any sensations. Research has yet to uncover all the mechanisms involved in the cluster process. But several experts have suggested that stress hormones released in Stage 1 cause calcium to flow into the muscular walls of blood vessels in the brain and scalp.
The presence of calcium causes blood vessels to go into spasm and constrict. When cerebral blood vessels spasm, the biochemical histamine is released. Studies have shown that levels of histamine are sharply higher at the onset of a
cluster headache while levels of other biochemicais, such as serotonin, remain constant.