Migraine aura is part of the total headache phase but occurs in only about 15% of people with migraines. It can vary from blurry vision to buzzing in the ears.
Auras are typically physical changes in the senses that herald a migraine.
Most people are familiar with visual auras. People will have changes to their vision that ranges from blurry vision and distorted vision all the way to full blindness. Sparkling lights, dancing dots and zig zags are common. Migraine aura also appears in a wide variety of colors.
Most visual disturbances last from 5-20 minutes and then the headache always follows. Now why did I say this?
Simple: A migraine aura that lasts over one hour or a span between the aura and a headache of 24 hrs or more may be
an emergency headache.
Other types of migraine auras exist. Many of my patients tell me of a buzzing sound in their ears just before a headache.
Auras are thought to be electrical events in the brain, not unlike similar phases seen in seizures. Now if you really want to get fancy, the official term is 'a wave of spreading cortical depression'.
Not the emotional depression, but a slowing or depression of nerve cells in the cortex or outer part of the brain. When this wave hits the back of the brain, or occiput, visual symptoms result.
As mentioned above,a migraine aura is an electrical event. Ocular migraine is the result of narrowing of the artery behind the eye..the retinal artery.
Ocular migraine also occurs only in one eye and the headache may or may not follow. Confusing isn't it?
Well, if this is a new symptom for you, it is best if you contact your doctor to discuss this as other conditions, such as a clot in the artery can cause the same symptoms.
Unlike "regular" migraines, ocular migraine should NOT be treated with a triptan like Imitrex. This could cause more constriction of the retinal artery and generally create more problems that it is worth!
Apparently, Alice also had migraine and would describe things 'getting large and getting small'. The clinical term for this phenomenon is "metamorphopsia". This form of ocular migraine has been described in children, and they may or may not grow out of it.
As seen in the picture to the left, these 'visions' that young Alice was having would be consistent with visual distortions in ocular migraine. Remember, this is not migraine aura which is seen in BOTH eyes and a headache always follows.