Migraines are generally broken down into two main classifications; migraine attack without aura (commonly referred to as common migraine) and migraine attack with aura (commonly referred to as classic migraine).
Basilar-type migraine and hemiplegic migraine have both been classified as sub-categories of migraine with aura.
Aura is a term for a warning sign that occurs before the headache part of a migraine attack begins. It generally occurs during the second phase of a migraine attack and is likely to precede the head pain, although this isn’t true for every migraine attack. It is possible to experience aura without any head pain following, this is known as a silent or acephalgic migraine.
Aura isn’t experienced by all sufferers of migraine, in fact, only 25-30 per cent of people who suffer from migraines are likely to have the head pain preceded by aura. People who do experience aura may find that aura doesn’t occur with every migraine.
Types of aura
There are lots of different types of aura symptoms that are experienced differently by every individual. The two most common types of aura are visual aura and sensory aura.
Visual aura would usually refer to a form of visual illusion or disturbance. It is possible for the migraine sufferer to experience a temporary loss of vision in one or both eyes, see shapes or light that isn’t present or experience other transformation in their vision. This is easily the most common aura, with up to 90 per cent of people who suffer from migraine with aura reporting a visual aura experience.
Sensory aura refers to a change in any other of your body’s senses that can last anywhere from a couple of minutes to a few hours. It is usually experienced as a numbness or tingling sensation, similar to pins and needles, and can occur in any body part. The majority of the time the sensation will begin in the hand, travel up the arm and into the face lips and tongue. This is the second most common aura, with approximately 11 per cent of people who suffer from migraine with aura reporting a sensory aura experience.
Other types of aura symptoms:
- Blurry/Cloudy vision
- Complete loss of vision
- Seeing flashes of light/flickering lights
- Seeing lines, zigzags, spots, halos, circles, waves or other shapes and illusions
- Having problems with speech
- Food cravings
- Odd smells/smelling things that aren’t there
- An overwhelming sense of wellbeing
- Sensation of spinning around
- Sensitivity to feel or touch
- Any other odd sensations
- Before suffering a migraine it is possible to feel one or more of the auras mentioned but all signs of the aura will disappear prior to the head pain beginning.
Causes of Aura
The cause of aura is currently not fully understood, however, there is a strong theory put forward that they are caused by slow moving changes in the brain. When sufferers of aura have undergone MRI scans while the aura is occurring it has been found that a wave of impulses are slowly moving across the brain which is disrupting normal brain activity. Although it is not fully understood how these impulses occur, it is widely recognized that the changes these impulses bring about in the brain are the cause of a wide range of migraine symptoms.