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Migraines
 
 

A migraine is a throbbing or pulsating headache that is often one sided and associated with nausea; vomiting; sensitivity to light, sound, and smells; sleep disruption; and depression. Attacks are often recurrent and tend to become less severe as the migraine sufferer ages.

Types
Migraines are classified according to the symptoms they produce. The two most common types are migraine with aura and migraine without aura. Less common types include the following (more information about the different types of migraine headaches is below):

  • Basilar artery migraine
  • Carotidynia
  • Headache-free migraine
  • Ophthalmoplegic migraine
  • Status migraine

Some women experience migraine headaches just prior to or during menstruation. These headaches, which are called menstrual migraines, may be related to hormonal changes and often do not occur during pregnancy. Other women develop migraines for the first time during pregnancy or after menopause.

Incidence and prevalence
Migraines afflict about 30 million people in the United States. They may occur at any age, but usually begin between the ages of 10 and 40 and diminish after age 50. Some people experience several migraines a month, while others have only a few migraines throughout their lifetime. Approximately 75% of migraine sufferers are women.

Causes
The cause of migraine is unknown. The condition may result from a series of reactions in the central nervous system caused by changes in the body or in the environment. There is often a family history of the disorder, suggesting that migraine sufferers may inherit sensitivity to triggers that produce inflammation in the blood vessels and nerves around the brain, causing pain.

Triggers
A trigger is
any stimulus that initiates a process or reaction. Commonly identified migraine triggers include:

  • Alcohol (e.g., red wine)
  • Environmental factors (e.g., weather, altitude, time zone changes)
  • Foods that contain caffeine (e.g., coffee, chocolate), monosodium glutamate (MSG; found in Chinese food), and nitrates (e.g., processed foods, hot dogs)
  • Glare
  • Hormonal changes in women
  • Hunger
  • Lack of sleep
  • Medications (over-the-counter and prescription)
  • Perfume
  • Stress

Signs and symptoms
Migraine pain is often described as throbbing or pulsating pain that is intensified by routine physical activity, coughing, straining, or lowering the head. The headache is often so severe that it interferes with daily activity and may awaken the person. The attack is debilitating, and migraine sufferers are often left feeling tired and weak once the headache has passed.

A migraine typically begins in a specific area on one side of the head, then spreads and builds in intensity over 1 to 2 hours and then gradually subsides. It can last up to 24 hours, and in some cases, several days.

There may be accompanying symptoms such as nausea, vomiting, sensitivity to light (photophobia), or sensitivity to sound (phonophobia). Hands and feet may feel cold and sweaty and unusual odors may be intolerable.

Migraine with aura is characterized by a neurological phenomenon (aura) that is experienced 10 to 30 minutes before the headache. Most auras are visual and are described as bright shimmering lights around objects or at the edges of the field of vision (called scintillating scotomas) or zigzag lines, wavy images, or hallucinations. Others experience temporary vision loss.

Nonvisual auras include motor weakness, speech or language abnormalities, dizziness, vertigo, and tingling or numbness (parasthesia) of the face, tongue, or extremities.

Migraine without aura is the most prevalent type and may occur on one or both sides of the head. Tiredness or mood changes may be experienced the day before the headache. Nausea, vomiting, and sensitivity to light (photophobia) often accompany migraine without aura.

Basilar artery migraine involves a disturbance of the basilar artery in the brainstem. Symptoms include severe headache, vertigo, double vision, slurred speech, and poor muscle coordination. This type occurs primarily in young people.

Carotidynia, also called lower-half headache or facial migraine, produces deep, dull, aching, and sometimes piercing pain in the jaw or neck. There is usually tenderness and swelling over the carotid artery in the neck. Episodes can occur several times weekly and last a few minutes to hours. This type occurs more commonly in older people.

Headache-free migraine is characterized by the presence of aura without headache. This occurs in patients with a history of migraine with aura.

Ophthalmoplegic migraine begins with a headache felt in the eye and is accompanied by vomiting. As the headache progresses, the eyelid droops (ptosis) and nerves responsible for eye movement become paralyzed. Ptosis may persist for days or weeks.

Status migraine is a rare type involving intense pain that usually lasts longer than 72 hours. The patient may require hospitalization.

Diagnosis
Diagnosis of migraine is based on the history of symptoms, physical examination, and neurological tests. The tests are performed to rule out other neurological and cerebrovascular conditions, including:

  • Bleeding within the skull (intracranial hemorrhage)
  • Blood clot within the membrane that covers the brain (cerebral venous sinus thrombosis)
  • Cerebral stroke (infarct)
  • Dilated blood vessel in the brain (cerebral aneurysm)
  • Excess cerebrospinal fluid in the brain (hydrocephalus)
  • Inflammation of the membranes of the brain or spinal cord (meningitis)
  • Low level of cerebral spinal fluid (CSF)
  • Nasal sinus blockage
  • Postictal headache, which occurs after a stroke or seizure
  • Tumor

Laboratory and diagnostic tests

  • Computed tomography (CT scan) is performed to rule out an underlying brain abnormality when migraines are new or when there is a change in their character or frequency. CT scan involves injecting contrast dye and then taking a series of x-rays.
  • Electroencephalography (EEG) records electrical signal within the brain using electrodes placed on the scalp. This test is used to detect malfunctions in brain activity (e.g., seizures).
  • Spinal tap (lumbar puncture) is performed to detect infection and determine levels of white blood cells, glucose, and protein in the cerebrospinal fluid. This test involves withdrawing a small amount of fluid and examining it under a microscope.
  • Magnetic resonance imaging (MRI scan) and magnetic resonance angiography (MRA) may be performed for a more complete evaluation. MRI produces clear images of the brain using electromagnetic energy. MRA produces images of blood vessels in the brain and is used to detect aneurysms and other vascular abnormalities.

Treatment
The physician analyzes the patient's migraine history to devise an appropriate treatment program. The goals of treatment are to prevent or reduce the number of migraines (called prophylactic treatment) and to alleviate symptoms and shorten the duration of the migraine (called abortive treatment).

Preventative medication may be prescribed for patients who have frequent headaches (3 or more a month) that do not respond to abortive treatment. Studies have shown that as many as 40% of these patients may benefit from preventative treatment.

Using one medication (monotherapy) is tried first, but a combination of medicines may be necessary. Many of these medications have adverse side effects. If migraines become controlled, the dosage is often reduced or the drug discontinued.

Prevention
Avoiding triggers, managing stress, and taking prophylactic medications can help prevent migraines. Keeping a migraine journal can help identify triggers and gauge the effectiveness of preventive measures. Patients should monitor the following:

  • Activities
  • Emotional factors (e.g. stressful situations)
  • Environmental factors (e.g., weather, altitude changes)
  • Foods and beverages
  • Medications (over-the-counter and prescription)
  • Migraine characteristics (e.g., severity, length)
  • Physical factors (e.g., illness, fatigue)
  • Sleep patterns

Stress management techniques (e.g., biofeedback, hypnosis) and stress-reducing activities (e.g., meditation, yoga, exercise) may help prevent migraines.

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