Headache

The U.S. prevalence of headache (HA) is 78% for females and 68% for males (Taylor, 1985). 40% of Americans have severe, debilitating HA at least once in life (Ballantyne, 2002). The vast majority of patients will suffer from recurrent headaches.

Pain-sensitive structures include extracranial structures, meningeal arteries, 5th, 9th, 10th cranial nerves, venous sinuses, meninge, dura, and upper 3 cervical nerves. Pain-insensitive structures include the brain parenchyma, pia, and arachnoid. A primary headache is a headache with no clear underlying structural, infectious or systemic abnormality.

Migraine headache

Migraines are syndromes consisting of paroxysmal headaches associated with other signs and symptoms, typically lasting anywhere between 4 and 72 hours. There are 5 stages to the migraine: prodrome, aura, pain/headache, resolution, and postdrome. Common triggers include hormonal changes (e.g., menstrual cycle), foods (e.g., chocolate), weather changes, skipped meals, and stress. There is a 3:1 female:male ratio.

Pathophysiological theories include: 1) the vasogenic theory, where intracranial vasoconstriction is responsible for aura, with headache resulting from rebound dilation and vaso-active polypeptides; and 2) the neurogenic theory, where a lower cerebral threshold with acute cortical spreading depression (neuronal depolarization), believed to originate in the occipital lobe and spreading rostrally, results in an aura and subsequent vascular headache.

Some migraine subtypes include:

migraine without aura (formerly, common migraine)
migraine with aura (classic migraine)
basilar migraine
migraine with prolonged aura
familial hemiplegic migraine
migraine without headache
status migrainosus (lasting for >72 hrs despite treatment)

Migraine without aura (formerly, common migraine) is defined as follows (International Headache Society criteria):

At least 5 attacks fulfilling criteria B-D
Headache attacks lasting 4-72 hrs
Headache has at least two of the following:
- unilateral
- pulsating
- moderate or severe pain
- aggravated by routine physical activity
During headache at least one of the following:
- nausea and/or vomiting
- photophobia and phonophobia
Not attributed to another disorder