Enxaqueca

Migraine (from the Greek words hemi, meaning half, and kranion, meaning skull^[1]) is a chronic neurological disorder characterized by moderate to severe headaches, and nausea. It is about three times more common in women than in men.^[2] The typical migraine headache is unilateral (affecting one half of the head) and pulsating in nature and lasting from four to 72 hours; symptoms include nausea, vomiting, photophobia (increased sensitivity to light) and phonophobia (increased sensitivity to sound); the symptoms are generally aggravated by routine activity.^[3][4] Approximately one-third of people who suffer from migraine headaches perceive an aura—transient visual, sensory, language, or motor disturbances signalling the migraine will soon occur.^[5][6]
Initial treatment is with analgesics for the headache, an antiemetic for the nausea, and the avoidance of triggers. The cause of migraine headache is unknown; the most supported theory is that it is related to hyperexcitability of the cerebral cortex and/or abnormal control of pain neurons in the trigeminal nucleus of the brainstem.^[7]
Studies of twins indicate a 60- to 65-percent genetic influence upon their propensity to develop migraine headaches.^[8][9] Moreover, fluctuating hormone levels indicate a migraine relation: 75 percent of adult patients are women, although migraine affects approximately equal numbers of prepubescent boys and girls. Propensity to migraine headache sometimes disappears during pregnancy, but in some women, migraines may become more frequent.^[10]

Migraines typically present with recurrent severe headache associated with autonomic symptoms.^[13] An aura only occurs in a small percentage of people.^[13] The severity of the pain, duration of the headache, and frequency of attacks is variable.^[13] A migraine lasting 72 hours is termed status migrainosus and can be treated with intravenous prochlorperazine. The four possible phases to a migraine attack^[3] are listed below — not all the phases are necessarily experienced. Additionally, the phases experienced and the symptoms experienced during them can vary from one migraine attack to another in the same person:

1. The prodrome, which occurs hours or days before the headache
2. The aura, which immediately precedes the headache
3. The pain phase, also known as headache phase
4. The postdrome