Migraine with aura: what happens in the brain during aura

“At first it was just a tiny spark, to the right of the letters on the screen. I thought I’d been staring at the light for too long. Then the spark grew into an arc that shimmered like broken glass, and halfway through a sentence I could no longer see the word I was reading.”

Almost anyone who knows aura could begin a description of it like this. Some describe it as a zigzag line slowly drifting across their field of vision, others as a haze through which they cannot see the face of the person they are talking to, others again as tingling that creeps from the fingers towards the elbow and then into the lip. What all these descriptions share is something people are often embarrassed to say out loud: I was frightened that something serious was happening in my brain.

That fear is understandable. Aura really is something happening in the brain. But in the vast majority of cases it is not what people are afraid of. In this post I will explain what goes on in the cortex during aura, how a typical aura differs from the signs where you must not wait, and what you can do with the fear that aura leaves behind. The medical part belongs with your doctor and neurologist. My part is what happens in the person who lives through it.

Migraine is a brain disease, not “just stress”

Before I get to aura, something I want to say clearly. Migraine is a neurological disease. It is not a psychosomatic symptom, not a sign of weak character and not something a person “brings on themselves” by worrying. It has recognisable mechanisms in the brain and nervous system, it has diagnostic criteria, and it has treatment that is led by a doctor. With an illness that is otherwise invisible, this matters, because people with migraine often get the feeling that those around them do not believe them.

Stress, anxiety and relationships do influence migraine — I write about this in other posts, and it is something we can talk about in therapy. But influence is not the same as cause. Anyone who says migraine is “all in your head” in the sense of imagination is wrong. Anyone who thinks the psychological side of migraine does not count is wrong too. The truth sits on both sides at once.

It is striking how heavy a burden this illness is. Researchers who track the global burden of disease wrote in 2018 that among people under fifty, migraine is the leading cause of years lived with disability of all diseases. If your colleague or partner has migraine, it is not a minor inconvenience.

What aura is and how common it is

Aura is a set of temporary neurological symptoms that, in some people with migraine, come before the headache, during it or even without it. According to commonly cited estimates, roughly a third of people with migraine experience it — so most people with migraine never have it, some have it with every attack, and many only now and then.

The international classification of headache disorders describes several features by which doctors recognise aura:

• It develops gradually. At least one symptom spreads over several minutes rather than arriving all at once like a blow.
• It lasts a limited time. Each symptom usually lasts from five minutes to an hour.
• It is fully reversible. When it passes, it leaves no lasting damage.
• Symptoms often follow one another rather than all arriving at once: first vision, then perhaps tingling, less often difficulty finding words.

By far the most common is visual aura: shimmering zigzag lines, which the specialist literature also calls a “fortification spectrum” because they resemble the ground plan of old fortress walls, and the blind spot that remains behind them. Sensory aura is also common — tingling or numbness that slowly travels along the arm and face. Speech disturbances are rarer, and very rare forms involving weakness must always be assessed by a neurologist.

A wave slowly travelling across the cortex

What happens during aura? People searched for the answer for almost a hundred years, and how it emerged is one of the loveliest stories in neurology.

In 1941 the American neuropsychologist Karl Lashley, who himself had migraine with aura, drew his blind spot during attacks and measured how fast it spread. From this he calculated that something must be travelling across the visual cortex at around three millimetres a minute. Three years later the Brazilian researcher Aristides Leão described in animals a phenomenon that came to be called cortical spreading depression: a wave of intense activation of nerve cells, followed by a wave of silencing, both moving across the cortex at just such a slow pace.

Only decades later did brain imaging confirm that Lashley had guessed correctly. In 2001 Nouchine Hadjikhani’s team used functional MRI in people with visual aura to record changes that slowly spread forward across the visual cortex — matching what the participants were describing in their field of vision at the same time.

This is why aura is such a strange experience. The sparkles are the part of the wave where cells are overactive. The blind spot is the part where they have temporarily gone quiet. And because the wave travels across a cortex that holds a “map” of the visual field, the disturbance in your vision also slowly moves and grows. Tingling works similarly: a wave that reaches the part of the cortex responsible for touch shows up as tingling that travels up from the fingers.

How aura is linked to the pain that often follows it is not yet fully understood. Animal research suggests the wave can release inflammatory substances that irritate nerve endings in the membranes around the brain, and this is one pathway to headache. But since most people with migraine have attacks without aura, the wave is clearly not a necessary condition for pain. More than a single mechanism, migraine is an altered way in which the brain processes sensory input — which also explains why light, sound and smell bother people during an attack.

Aura is just one phase of an attack. I describe in more detail how warning signs, aura, headache and the exhaustion afterwards follow one another in The phases of a migraine attack: what happens from the first signs to the end.

When it is not aura: signs you do not wait out

This section is the most important in the whole post, so I will write it plainly.

Call 112 (the emergency number in Slovenia) or go to A&E immediately if:

• weakness or paralysis on one side of the body appears — an arm or leg will not respond, the corner of the mouth droops;
• speech is disturbed — you cannot find words, your speech is slurred, or you cannot understand what people are saying to you;
• you have aura for the first time in your life, or it is different from the ones you know — it lasts longer, is stronger, has new symptoms;
• symptoms arrive suddenly, all at once, instead of spreading gradually;
• a headache strikes like lightning and is the worst of your life, or comes with fever, a stiff neck, confusion or a fall.

The reason is simple: a stroke or a transient ischaemic attack can begin in a way that resembles aura, and a layperson at home cannot tell them apart reliably. Even a doctor often distinguishes them only with tests. With a stroke, every minute counts. If it turns out to have been aura, you have not wasted anyone’s time — you have got an answer.

Even when none of the above applies and it is an aura you already know, it is right that a doctor has made the diagnosis at some point. In migraine with aura, the risk of ischaemic stroke is somewhat higher than in people without it. The absolute risk remains small, but smoking and some hormonal medicines affect it, so this is a topic for a conversation with your GP or neurologist — not for guesswork online.

The fear that stays when the aura has gone

For many people aura is more frightening than the pain that follows it. Pain you know; you know how you get through it. Aura, though, takes away something you take for granted for a few minutes — your sight, the feeling in your hand, the word you are looking for. And because it happens in the brain, a question quickly starts spinning: what if this time it is not migraine?

In some people this turns into constant watchfulness. Every flicker of light, every moment your eyes tire from the screen becomes a possible beginning. This attention to the body has a name — interoception — and in itself it is not a problem. The problem arises when it joins up with catastrophic interpretation: “this is a stroke”, “this time it won’t pass”, “I’m going to lose my sight”. Then the body responds with a stress reaction, the heart speeds up, palms sweat, and these bodily signs feel like fresh proof that something is wrong.

If you recognise this circle, you may find Health anxiety: when every symptom means the worst helpful. How the brain sets off the body’s alarm before we have even formed a thought I describe in What happens in the brain during anxiety.

There is one trap worth knowing about here: the answer to fear of aura is not to stop taking new signs seriously. The answer is to have a clear rule, shaped with your doctor’s help, and then not to let anxiety decide for you all over again every time.

How I hear it in conversation

A short example of how such fear can show up in conversation (composed, not a real person):

“I’ve had aura since I was twenty. My neurologist explained everything, they scanned me, everything was fine. And yet when it starts, I’m convinced this is it.”
“What happens inside you in those first minutes?”
“I start checking. I clench my fist to see if my hand works. I read signs to see if I still understand. I ask my partner whether my mouth is drooping.”
“And when the aura passes?”
“I’m so worn out by the fear that I almost don’t care about the headache.”

This person does not need another explanation of what aura is. They already know. What they need is a way to stay in their body when it begins, and a way to tell apart checking that makes sense from checking that only feeds anxiety. And there was someone else in that conversation — the partner being asked. They too have their own fear and their own role in that moment.

Aura in a relationship: when the other person is frightened too

Because I am training in relational family therapy, with aura I am always interested in what happens between people too. Aura often arrives in the middle of something — over dinner, in the car, while talking to a child. The person experiencing it suddenly needs darkness, quiet and perhaps help. And the people around them respond in different ways.

Some get frightened and start asking, checking, suggesting A&E with every aura. Others learn that “it’s just her migraine” and gradually stop noticing when action really might be needed. Both are understandable and both can be hard. The first reaction feeds fear; the second leaves the person alone.

It helps to talk about aura at home when it is not happening. What is a normal aura for you? What would be different? Who calls 112 if you cannot speak? How do the people around you help most — with silence, by darkening the room, by taking over with the children? When this is agreed in advance, you do not have to sort everything out in the moment when aura is taking away your sight and your words.

If you have a known, diagnosed aura, a simple plan can help — one you make now, while you are calm, and use when it begins. Go through it with your doctor first, so that it fits their guidance on medication and on when to come in.

Exercise: a plan for the first ten minutes of aura

This is not a substitute for medical advice. It is a way of making space between aura and panic.

1. Stop and look at the clock. Write down or remember the start time. It is useful information for your doctor and, at the same time, a small task that gives your brain something concrete instead of guessing.
2. Check the red flags once — only once. Can you lift both arms? Can you say a simple sentence? Is this like the auras you know? If any of these is “no”, call 112. If all are “yes”, do not repeat the check every minute.
3. Get safe and get dark. If you are driving, pull over. Move to a quieter, darker room. Tell someone nearby that you are having an aura and let them handle what needs handling.
4. Breathe slowly, with a longer out-breath. For a few minutes, breathe in through your nose and breathe out a little longer than you breathe in. Not to stop the aura — breathing does not do that — but to calm the stress response that joins it. You will find a precise description in the exercise breathing with a longer out-breath.
5. Name what is happening. Quietly tell yourself: “This is a wave travelling across the cortex. It knows its route and it will pass.” Describing it is not denial — it is what your doctor has already confirmed, said at the moment you need it most.

When the aura has passed, write down how long it lasted and what happened. Not to analyse it to exhaustion, but so that you have an accurate picture at your next doctor’s appointment, and so you can see for yourself that your auras are — fortunately — mostly similar to one another.

Where this view ends

Everything I have written about fear holds under one condition: that this really is a known, diagnosed aura. A psychological approach to fear of aura is not a way to avoid seeing a doctor. If you have not yet shown your aura to a doctor, that is the first step, not therapy.

Nor is it true that aura can be “thought away” or prevented by breathing. The wave across the cortex does not listen to our thoughts. What we can change is what happens around it: how much fear, how much checking, how much loneliness. That is not nothing, but it is not treatment for migraine. Treatment — both for attacks and for prevention — is a matter for your doctor.

I am also careful not to present anxiety as the cause of aura. In some people under heavy pressure, attacks really are more frequent. But people with aura are not more anxious people who have somehow “earned” their aura. In migraine, genes, hormones and the workings of the nervous system are a very important part of the story, one we cannot change through conversation. And finally: if your fear grows into panic attacks or starts to restrict your daily life, it is not something you should have to solve alone with an exercise from a blog. That is the time to seek help — from a doctor and from a psychotherapist.

Where psychotherapy can help

Psychotherapy does not treat migraine. It can, however, help with the part that medication does not reach. Research on behavioural approaches to migraine — relaxation techniques, biofeedback and cognitive behavioural therapy — suggests that, alongside doctor-led treatment, they can reduce the burden of attacks. You will find a short explanation of cognitive behavioural therapy in the knowledge base.

In conversation we often look at how fear of aura affects someone’s life. Do they avoid driving, travel, events? Do they not tell their partner when it starts, because they do not want to be a burden? Did they watch a parent suffer from migraine as a child, and now carry that same image inside them? In relational family therapy we also look at how the experience of illness is passed down through generations — how a family held that pain is not talked about, or the opposite, that every pain is a catastrophe.

It also matters to have a place where you can say what it is like to live with something others cannot see. With psychosomatic and neurological problems, people often feel they have to prove that it really hurts. I write about this in “The tests are normal, but it still hurts”. If fear of the next aura stays with you between attacks too, you will probably find Fear of the next migraine attack: when anticipation becomes a burden worth reading. I also see English-speaking clients in person in Ljubljana.

What to remember

• Migraine is a neurological disease. Aura is a wave of activation and silencing that slowly travels across the cortex — which is why the disturbance in your vision or sensation moves and grows.
• A typical aura develops gradually, lasts up to about an hour and passes completely. A doctor makes the diagnosis, not the internet.
• A new or different aura, weakness on one side of the body or speech disturbances mean call 112 straight away. Better one call too many.
• Fear of aura is understandable. What helps is a clear rule agreed with your doctor and a plan you use when it begins.
• Psychotherapy does not treat migraine, but it can reduce the fear, avoidance and loneliness that aura leaves behind — in relationships too.