Migraine Aura

Credit: Migraine Matters 

WARNING: Some images in links to follow may affect you. They are of various types of visual aura, and some are pretty striking. They may cause upset to anyone prone to migraine or with sensitive vision. 

Phases of migraine 

Migraine attacks generally have four or five phases – Not everyone will experience all these phases and indeed many may never experience more than one or may not notice more than one. 

• Prodrome 
• Aura 
• Headache/Main attack 
• Resolution 
• Postdrome 

For more on these phases see the excellent video of Prof. David Dodick’s Recent presentation which he did with MAI in March of this year. https://youtu.be/jXkCNHI4G7I  

This article will concentrate on the second phase for some migraineurs, the Aura Phase.  

An estimated 20% of migraineurs experience this as part of their migraine.  It can manifest in different ways, but however it does manifest it can be very distracting, disconcerting, and sometimes disturbing. 

What is a Migraine Aura? 

In short, Aura is a series of sensory changes or disturbances that happen in the brain of some people with migraine. It can precede the headache phase, or it can occur with the headache phase, or indeed can be the most prominent symptom of migraine.  

The International Classification of Headache Disorders (ICHD) 3 Diagnostic Criteria1 for Migraine with Aura are

A. At least two attacks fulfilling criteria B and C

B. One or more of the following fully reversible aura symptoms:

• visual 
• sensory 
• speech and/or language 
• motor 
• brainstem 
• retinal

C. At least three of the following six characteristics:

• at least one aura symptom spreads gradually over ≥5 minutes 
• two or more aura symptoms occur in succession. 
• each individual aura symptom lasts 5-60 minutes. 
• at least one aura symptom is unilateral. 
• at least one aura symptom is positive. 
• the aura is accompanied, or followed within 60 minutes, by headache.

D. Not better accounted for by anotherICHD-3 diagnosis.

How does it manifest? 

Aura comes in many forms. The most commonly spoken about and therefore the one everyone assumes you mean when you mention the word is a visual aura, such as; – WARNING Some images may affect those prone to migraine or with sensitive vision 

• Scotoma, an area of decreased or lost vision. 
• Phosphenes, brief flashes of light that streak across the visual field. 
• Blurry vision. 
• Wavy lines, which some people describe as being similar to how things appear on a hot day when viewed through the heat rising off the footpath in the distance. 
• Other visual symptoms. 

However, there are many other aura forms and symptoms, including: 

• Aphasia - the loss or impairment of speech or understanding of words and numbers. 
• Allodynia - hypersensitivity to feel and touch. 
• Dizziness
• Confusion – the inability to think properly. 
• Yawning – Excessive yawning 
• Phantosmia – smelling smells that are not there.
• Alice in Wonderland Syndrome  - distortion of body image and perspective that can occur with a rare aura. 
• Other symptoms, including hiccups. 

Some of these symptoms can also be precursors to the aura and may occur separately in earlier phases of an attack. It can be difficult to tell if they are part of the aura or early warning signs. The Migraine diary or app can, over time, help to distinguish which they are. 

In extreme cases some people can experience temporary weakness or numbness on one side of their body as in Hemiplegic Migraine2, decrease levels of consciousness in Migraine with Brainstem Aura3 (formerly called Basilar Migraine) and temporary loss of sight as in Retinal Migraine4. 

A migraine aura will be temporary, usually occurring about 20 – 60 before the headache phase and lasting usually up to 30 minutes. 

What causes Aura? 

No one is absolutely sure about the answer to this question; however, it may be linked to something called Cortical Spreading Depression or CSD.  

 A simple explanation is as follows. 

• Cortical refers to the ‘Cortex’, the majority of the brain which is divided up into different areas each responsible for different functions (see diagram below) 

Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014“. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. This image is flipped, the back of the brain is on the left, the front on the right.

• Depression in this case refers to the reduction or lessening of the normal electrical waves so it is not a physical depression or squeezing of blood vessels.  Each nerve cell works by electricity.  
• Normally the substances in and around the cells are in balance.  
• When the nerves are activated by something such as a pinprick, the substances become unbalanced, sending signals through the nerves to the brain. 
• Sometimes cells become less stable under certain stimuli and have an uncontrolled reaction. 
• As it spreads through the brain the electrical activity becomes depressed, effectively sending some cells to sleep. 
• The wave generally begins near the visual centre at the back of the brain and the distortion it causes is what you see if you experience a visual aura – how it manifests is different for everyone (flashing lights, zig-zag patterns, floaters, blind spots, grids, etc) 
• Sometimes, the wave spreads to other centres of the brain causing pins and needles, temporary paralysis, speech problems, confusion. 

Tips for those with Migraine Aura 

If you experience aura as part of your migraine, then these tips may help you… 

• Use a migraine diary – any kind of diary will do, but we are happy to send you one. 
  • With time you may be able to spot the triggers, anticipate the aura and with medical/complementary techniques delay or even avoid the entire attack. 
• If taking medication, try to figure out which is the best time to take them. Talk to your GP about it.  
  • Try to take your medication as early in the attack as possible, Prof. Dodick says that if you treat your headache when it is mild you may keep it from developing further. If you do not get headache but get other symptoms such as nausea or vomiting, then you could take an anti-emetic if your doctor has okayed this. See here the Acute Treatment plan devised by the migraine clinics. 
• If you are driving or operating machinery when the aura begins… 
  • Pull over at the safest and nearest place possible or stop what you are doing if possible. 
  • Take your medication, and if it is safe to and possible, have a short nap.
  • Do not start driving or using heavy machine again unless you are completely sure that neither your migraine nor your medications will inhibit you in any way. See the Migraine Trust information on Driving Safely with Migraine and the PDF from the Irish National Driver Licence Service PDF on Your Health and Driving 
  • If you’re still affected, please don’t try to push through it. If you can, make other arrangements for someone to take over for you or to help get you home. 
• If your aura is debilitating 
  • Discuss preventative medication with your GP/Neurologist. 
  • Carry a migraine ID card that will explain to people what is going on and tell them how to help you – We can provide you with the card. 
• Try some complementary or relaxation techniques. 

With thanks to MAI’s medical advisors for reviewing this article.  

The information contained in this article is for information only and not intended to replace medical advice or diagnosis. 

[1] https://ichd-3.org/

[2] https://ichd-3.org/1-migraine/1-2-migraine-with-aura/1-2-3-hemiplegic-migraine/

[3] https://ichd-3.org/1-migraine/1-2-migraine-with-aura/1-2-2-migraine-with-brainstem-aura/

[4] https://ichd-3.org/1-migraine/1-2-migraine-with-aura/1-2-4-retinal-migraine/