Migraine Headache: Definition, Statistics, and Pathophysiology

Definition

A migraine headache is a chronic (recurring) primary headache, which can persist for hours or even days. This headache pain is intense and of a throbbing and pounding nature and may be accompanied by symptoms like nausea, vomiting, and sensitivity to light and sound.

You usually feel it on one side of the head and any type of physical activity makes the headache worse.

It almost certainly has a genetic trait. If you are a migraine sufferer, you will find that one of your predecessors also had it.

A migraine can, at times, be preceded by warning symptoms called an aura, which tells you that your migraine is on the way. This is called migraine with aura. Its symptoms can include seeing flashes of light or blind spots or a feeling of tingling in your hands or legs. A migraine with aura is not so common and seen in only 20% of migraine sufferers.

Migraine can make life hell for the sufferer during an attack. Any form of activity becomes impossible and the only thing the sufferer yearns for is to lie down in a quiet and dark room.

Statistics and incidence

  • According to the American Migraine Association, about 36 million Americans suffer from migraine, which is about 12 percent of the population.
  • Before puberty, more boys are affected than girls. However, after puberty women are three times more affected by men.
  • You will find it in 6% of the men and 20% of the women.
  • In women, the onset is often seen around puberty.
  • 90% of migraine headaches usually start between the ages of 10 to 40 years and most commonly seen between the ages of 35 to 45 years.
  • It tends to run in families suggesting a hereditary trait.
  • During pregnancy, the frequency of attacks decreases.

Duration and frequency

A migraine attack can last anywhere from a few hours to a few days.  It can occur once a year or once a month (most common) or once a week.  In children, the attacks tend to be of a shorter duration and the accompanying abdominal symptoms like vomiting are more prominently seen.

Image showing a woman with a migraine headache

How do you get a migraine attack?

The theory behind the etiology of migraine is still not fully understood. However, some basic facts are being put forward.

Migraine is a vascular headache – meaning it occurs because of the dilation of the blood vessels in the brain. Due to this vasodilatation, the nerves, which supply the walls of the arteries get stretched. This causes the nerves to release chemicals, which further aggravates the pain due to inflammation and further dilation of the blood vessels caused by these chemicals.

Another explanation suggests that due to changes in the brain stem caused by migraine, the trigeminal nerve is affected and imbalances occur in the levels of the brain chemical, serotonin, which drop during a migraine attack.

The trigeminal nerve is a major pathway of pain and serotonin helps to regulate the pain. These changes trigger the trigeminal nerve to release neuropeptides, which travel to the meninges of the brain (membranes covering the brain) causing a migraine headache.

How do migraine symptoms occur?

During a migraine attack, the sympathetic nervous system is activated. This increased sympathetic activity in the G.I. tract results in symptoms like nausea, vomiting, and diarrhea.
The increased sympathetic nervous activity decreases blood supply to the skin, which results in pallor and cold hands and feet.
Sensitivity to light and sound and the visual symptoms of migraine such as blurred vision are also a result of the increased sympathetic activity.

Why oral medicines are ineffective during an acute attack of migraine?

This increased sympathetic nervous activity also slows down the emptying time of the stomach. This restricts the medicines taken, to enter the intestines and being absorbed.

For the oral medication to work, you must take it as soon as you feel that the attack will occur such as when the headache is just beginning to set in.

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