Migraine Auras

Migraines come with and without auras. Neither can be said to be less painful than the other, though the aura-less may be less stressful and frightening.

Although migraines are often associated with auras, in fact only about 20% of migraine sufferers actually experience any of the symptoms of aura. The aura stage is part of the complex migraine, following the prodome stage. The aura stage usually lasts less than half an hour and its symptoms and effects can vary tremendously from one migraine sufferer to the next.

Depending upon how extreme these symptoms get, the aura stage can be quite frightening, like a bad dream or, worse, a movie sequence of a bad dream.

Migraine Aura Symptoms

The aura is all about distortions in perception. A related type of migraine is the occular migraine, which consists only of the aura with no other symptoms. However, despite the connotation of aura as a visual component, symptoms associated with auras not limited to specifically visual distortions. Characteristics associated with auras can include:

  • flashing lights
  • wavy or zigzagging lines
  • spots or other shapes
  • blind spots or partial loss of sight
  • blurry vision
  • olfactory hallucinations, or the smelling of aromas that aren’t really there
  • tingling feeling or numbness about the face or extremities on the side where the headache develops
  • difficult speaking or forming words
  • confusion
  • vertigo
  • partial and temporary paralysis
  • decrease in or loss of hearing
  • reduced sensation
  • hypersensitivity to feel and touch

The aura is caused by changes taking place within the outermost layer of the brain, the cortex.

With the depression of activity in the nerve cells, there is a resulting impairment in the function of the body part that is controlled by those cells. A slow spread in the depression of nerve cell activity is theorized to be the cause of the development of aura. The symptoms gradually build up and slowly make their way from one visual region or one body part to another.

For the migraine patient, this means the appearances of a black spot arising in his field of vision. The black spot may also be encompassed by either flashing lights or bright lines that zig and zag back and forth.

The black spot will slowly, over a period of a few minutes, grow slightly larger. It is this unusual and often disturbing combination of a vision loss with accompanying flashing lights or zigzagging lines that distinguishes the typical migraine auras so-called positive symptoms.

It is this combination of so-called “negative symptoms” such as the loss of vision with the “positive symptoms” such as zigzagging lines that make up the typically distinctive features of a migraine aura.

The vision blackouts, the negative symptoms, are caused by a depression of nerve activity. On the other hand, the zigzagging lines are caused by hyperactivity in the nerve cells. The origin of this sequence of neurological events leading to auras and headaches is still unknown.

What is known, however, is that those suffering from migraines have been found to have an ingrained susceptibility to factors that generally are not headache triggers. In people with migraine, changes in body chemistry, such as menstruation, certain foods, and dozens of environmental influences, such as a change in weather, may trigger an attack.

In order to be officially designated as a migraine with aura, the headache sufferer is required to have had at least two headaches with three out of four of the following:

  • One or more aura symptom that originated in the cerebral cortex or brain stem.
  • At least one aura symptom that developed gradually over more than four minutes. Or, at least two or more aura symptoms occurring in succession.

No single aura symptom that lasts for more than an hour. (However, it is perfectly acceptable should there be successive symptoms of which extend that time, but each individual symptom should last no more than an hour).

The headache itself may begin before, at the same time, or at an interval of no more than an hour after the hour.

Image: Thomas Hawk/Flickr

Share
Tweet
+1