Migraine

Migraine definition

A migraine headache is a form of vascular headache. Migraine headache is caused by a combination of vasodilatation (enlargement of blood vessels) and the release of chemicals from nerve fibers that coil around the blood vessels. During a migraine attack, the temporal artery enlarges. (The temporal artery is an artery that lies on the outside of the skull just under the skin of the temple.) Enlargement of the temporal artery stretches the nerves that coil around the artery and causes the nerves to release chemicals. The chemicals cause inflammation, pain, and further enlargement of the artery. The increasing enlargement of the artery magnifies the pain.

Migraine attacks commonly activate the sympathetic nervous system in the body.The increased sympathetic nervous activity in the intestine causes nausea, vomiting, and diarrhea. Sympathetic activity also delays emptying of the stomach into the small intestine and thereby prevents oral medications from entering the intestine and being absorbed. The impaired absorption of oral medications is a common reason for the ineffectiveness of medications taken to treat migraine headaches.

Signs and Symptoms

A typical migraine headache attack produces some or all of these signs and symptoms:

• Moderate to severe pain — many migraine headache sufferers feel pain on only one side of their head, while some experience pain on both sides
  
• Head pain with a pulsating or throbbing quality
  
• Pain that worsens with physical activity
  
• Pain that hinders your regular daily activities
  
• Nausea with or without vomiting
  
• Sensitivity to light and sound
  

When left untreated, a migraine headache typically lasts from four to 72 hours, but the frequency with which they occur can vary from person to person. You may have migraines several times a month or just once or twice a year.
Not all migraine headaches are the same. Most people suffer from migraines without auras, which were previously called common migraines. Some have migraines with auras, which were previously called classic migraines. If you're in the second group, you'll likely have auras about 15 to 30 minutes before your headache begins. They may continue after your headache starts or even occur after your headache begins. These may include:

• Sparkling flashes of light
  
• Dazzling zigzag lines in your field of vision
  
• Slowly spreading blind spots in your vision
  
• Tingling, pins-and-needles sensations in one arm or leg
  
• Rarely, weakness or language and speech problems
  

Whether or not you have auras, you may have one or more sensations of premonition (prodrome) several hours or a day or so before your headache actually strikes, including:

• Feelings of elation or intense energy
  
• Cravings for sweets
  
• Thirst
  
• Drowsiness
  
• Irritability or depression

Migraine headache symptoms in children
Migraines typically begin in childhood, adolescence or early adulthood and may become less frequent and intense as you grow older. Children as young as age 1 can have these headaches. In addition to physical suffering, severe headaches often mean missed school days and trips to the emergency room, as well as lost work time for anxious parents.
Children's migraines tend to last for a shorter time. But the pain can be disabling and can be accompanied by nausea, vomiting, lightheadedness and increased sensitivity to light. A migraine headache tends to occur on both sides of the head in children, and visual auras are rare. However, children often have premonition signs and symptoms, such as:

• Yawning
  
• Sleepiness or listlessness
  
• A craving for foods such as chocolate, hot dogs, sugary snacks, yogurt and bananas
  

Children may also have all of the signs and symptoms of a migraine headache — nausea, vomiting, increased sensitivity to light and sound — but no head pain. These "abdominal migraines" can be especially difficult to diagnose.
The good news is that some of the same medications that are effective for adults also work for children. Your child doesn't have to suffer the pain and disruption of migraines. If your child has headaches, talk to your pediatrician. He or she may want to refer your child to a pediatric neurologist.

Causes

Although much about headaches still isn't understood, some researchers think migraines may be caused by functional changes in the trigeminal nerve system, a major pain pathway in your nervous system, and by imbalances in brain chemicals, including serotonin, which regulates pain messages going through this pathway.
During a headache, serotonin levels drop. Researchers believe this causes the trigeminal nerve to release substances called neuropeptides, which travel to your brain's outer covering. There they cause blood vessels to become dilated and inflamed. The result is headache pain.
Because levels of magnesium, a mineral involved in nerve cell function, also drop right before or during a migraine headache, it's possible that low amounts of magnesium may cause nerve cells in the brain to misfire.

Migraine headache triggers
Whatever the exact mechanism of headaches, a number of things may trigger them. Common migraine headache triggers include:
Hormonal changes. Although the exact relationship between hormones and headaches isn't clear, fluctuations in estrogen and progesterone seem to trigger headaches in many women with migraine headaches. Women with a history of migraines often have reported headaches immediately before or during their periods. Others report more migraines during pregnancy or menopause. Hormonal medications, such as contraceptives and hormone replacement therapy, also may worsen migraines.
Foods. Certain foods appear to trigger headaches in some people. Common offenders include alcohol, especially beer and red wine; aged cheeses; chocolate; fermented, pickled or marinated foods; aspartame; caffeine; monosodium glutamate — a key ingredient in some Asian foods; certain seasonings; and many canned and processed foods. Skipping meals or fasting also can trigger migraines.
Stress. A period of hard work followed by relaxation may lead to a weekend migraine headache. Stress at work or home also can instigate migraines.
Sensory stimulus. Bright lights and sun glare can produce head pain. So can unusual smells — including pleasant scents, such as perfume and flowers, and unpleasant odors, such as paint thinner and secondhand smoke.
Physical factors. Intense physical exertion, including sexual activity, may provoke migraines. Changes in sleep patterns — including too much or too little sleep — also can initiate a migraine headache.
Changes in the environment. A change of weather, season, altitude level, barometric pressure or time zone can prompt a migraine headache.
Medications. Certain medications can aggravate migraines

Risk Factors

• Women are more likely to get migraines than men
• Having other family members with migraine headaches
• Use of birth control pills, especially if you also smoke or have high blood pressure
• Being under age 40; after that point, the likelihood of migraine declines for both men and women
• Exposure and sensitivity to any of the potential triggers listed above
  

Diagnosis

• Physical exam
• Blood tests
• Vision tests
• X-rays
• Computerized tomography (CT)
• Magnetic resonance imaging (MRI)
• Lumbar puncture  - to exclude from  meningitis or subarachnoid hemorrhage

Treatment Approach

At one time, aspirin was almost the only available treatment for headaches. Now there are drugs specifically designed to treat migraines. Several drugs commonly used to treat other conditions also may help relieve migraines in some people. All of these medications fall into two classes:

• Pain-relieving medications. These stop pain once it has started.
• Preventive medications. These reduce or prevent a migraine headache.

Choosing a preventive strategy or a pain-relieving strategy depends on the frequency and severity of your headaches, the degree of disability your headaches cause and other medical conditions you may have. You may be a candidate for preventive therapy if you have two or more debilitating attacks a month, if you use pain-relieving medications more than twice a week, if pain-relieving medications aren't helping or if you have uncommon migraines.

Some medications aren't recommended if you're pregnant or breast-feeding. Some aren't used for children. Your doctor can help find the right medication for you.

Pain-relieving medications
For best results, take pain-relieving drugs as soon as you experience signs or symptoms of a migraine headache. It may help if you rest or sleep in a dark room after taking them:

• Nonsteroidal anti-inflammatory drugs (NSAIDs).
• Triptans
• Ergots.
• Medications for nausea

Pregnancy

Many of the medications, herbs, and supplements used to prevent or treat migraines should not be used during pregnancy. Talk to your doctor before using any substance available over the counter or that you received by prescription prior to becoming pregnant.