Migraine Headaches Introduction
Migraine headaches are a type of neurovascular headaches, a category that also includes cluster headaches. Doctors believe that neurovascular headaches are caused by an interaction between blood vessel and nerve abnormalities. Migraine headaches are the second most common type of primary headache after tension headaches. A primary headache is a headache that is not caused by another disease or condition. [For more information, see In-Depth Report #11: Headaches – tension and Report #99: Headaches - cluster.]
Migraine headaches are characterized by throbbing disabling pain on one side of the head, which sometimes spreads to affect the entire head. In fact, migraine comes from the Greek word hemikrania, meaning “half of the head”.
Migraines are classified as occurring either:
- With aura (previously called classic migraine) or
- Without aura (previously called common migraine).
Auras are sensory disturbances that occur before a migraine attack that can cause changes in vision, with or without other neurologic symptoms. [For more information on auras, see Symptoms section of this report.]
Episodic and Chronic Migraine
Migraines typically occur as isolated episodic attacks, which can happen once a year or several times within one week. In some cases, patients eventually experience on-going and chronic migraine (previously called transformed migraine). Chronic migraines typically begin as episodic headaches when patients are in their teens or 20s, and then increase in frequency over time. A headache is considered chronic when it occurs at least half of the days in a month, and often on a daily or near-daily basis.
The majority of chronic migraines are caused by overuse of analgesic migraine medications, both prescription pain reliever drugs and over-the-counter medications. Medication overuse headaches are also called rebound headaches. Obesity and caffeine overuse are other factors that may increase the risk of episodic migraine transforming to chronic migraine.
Chronic migraines can resemble tension headaches and it is sometimes difficult to differentiate between them. Both types of headaches can co-exist. In addition to throbbing pain on one side of the head, chronic migraine is marked by gastrointestinal symptoms such as nausea and vomiting. Many patients with chronic migraine also suffer from depression.
Other Types of Migraine
Menstrual Migraines. Migraines are often tied to a woman's menstrual cycle, typically in the first days preceding or beginning menstruation. Estrogen and progesterone fluctuations may play a role. About half of women with migraines report an association with menstruation. Compared to migraines that occur at other times of the month, menstrual migraines tend to be more severe, last longer, and not have auras. Triptan drugs can provide relief and may also help prevent these types of migraines.
Basilar Migraine. Considered a subtype of migraine with aura, this migraine starts in the basilar artery, which forms at the base of the skull. It occurs mainly in young people. Symptoms may include vertigo (a sensation of dizziness), ringing in the ears, slurred speech, unsteadiness, possibly loss of consciousness, and severe headaches.
Abdominal Migraine. This migraine tends to occur in children who have a family history of migraine. Periodic migraine attacks are accompanied by abdominal pain, and often nausea and vomiting.
Ophthalmoplegic Migraine. This very rare headache tends to occur in younger adults. The pain centers around one eye and is usually less intense than in a standard migraine. It may be accompanied by vomiting, double vision, a droopy eyelid, and paralysis of eye muscles. Attacks can last from hours to months. A computed tomography (CT) or magnetic resonance imaging (MRI) scan may be needed to rule out bleeding from an aneurysm (a weakened blood vessel) in the brain.
Retinal Migraine. Symptoms of retinal migraine are short-term blind spots or total blindness in one eye that lasts less than an hour. A headache may precede or occur with the eye symptoms. Sometimes retinal migraines develop without headache. Other eye and neurologic disorders must be ruled out.
Familial Hemiplegic Migraine. This is a very rare inherited genetic migraine disease. It can cause temporary paralysis on one side of the body, vision problems, and vertigo. These symptoms occur about 10 - 90 minutes before the headache.
Status Migrainosus. This is a serious and rare migraine. It is so severe and lasts so long that it requires hospitalization.