Migraines are usually broken into two classifications: migraines with aura – which used to be called classic migraine – and migraines without aura – which were once called common migraines. The International Headache Society has identified basilar-type migraine and hemiplegic migraine as subtypes of migraine with aura.
Aura typically occurs before the head pain during the second phase of a migraine attack. Aura does not occur in all people with migraines. Approximately 25-30% of migraine sufferers experience migraine accompanied by aura. Those who do experience aura, don’t necessary experience aura with each migraine. There are also some people who experience migraine aura without head pain. This is referred to as a silent, or acephalgic migraine.
Aura usually describes a visual disturbance, or an illusion. The migraine sufferer may see light or a shape that isn’t there, experience temporary loss in vision, or experience other changes in vision. Somewhere between 82 percent and 90 percent of those who have migraines with aura experience a visual aura.
Sensory aura refers to changes in other senses that can last a few minutes or up to a few hours and strikes about 11 percent of migraine sufferers. It is usually described as tingling or numbness, the feeling of pins and needles or an odd sensation a body part, including the face, tongue, hand, arm, foot, leg or throughout the body. Common sensory aura complaints include numb fingers, numbness in the head or on one side of the body.
There are different types of aura symptoms, including:
Seeing flashes or flickering light
Seeing zigzag lines or waves, also called fortification illusions
Seeing spots, stars, halos, circles, lines, other shapes or colors
Aphasia (difficulty finding words and/or speaking)
Vertigo (sensation of spinning or whirling)
One sided weakness or paralysis (in hemiplegic migraine)
Olfactory hallucinations (smelling odors that are not present)
Auditory hallucinations (hearing sounds that are not present)
Alice in Wonderland Syndrome (distortion of body image/perspective)
Visit the migraine phases page to learn more about the phases of a migraine attack, including common symptoms experienced during aura.
What causes aura?
When migraine sufferers undergo MRI (magnetic resonance imaging) during aura, in certain patients, the changes in the brain (officially called a cortical spreading depression) can be seen slowly moving across part of the brain. It is thought that auras are caused by a wave of nerve signals or impulses that move across the brain, causing a disruption in normal activity in those parts of the brain. These changes are thought to cause a wide range of migraine symptoms.
Written by: Otesa Miles | Last review date: November 2010
International Headache Society, Slide Library: Migraine is a neuronal disorder & the cortex plays a pivotal