Stroke and migraine both happen in the brain, and sometimes the symptoms of a migraine can mimic a stroke. However, the causes of the symptoms are different. A stroke is due to damage to the blood supply inside the brain, but migraine is thought to be due to problems with the way brain cells work. In a stroke, the blood supply to part of the brain is cut off, killing brain cells. This causes permanent damage to the brain, and can have long-lasting physical, cognitive and emotional effects. A migraine causes pain and sensory disturbances, but the changes inside the brain are usually temporary. The relationship between migraine and stroke is complex. The symptoms can sometimes seem similar (see How do I tell the difference between migraine and stroke later in this guide), and they may share some underlying risk factors.
Migrainous infarction: Occasionally migraine and stroke can occur at the same time, but there is no evidence to suggest that one causes the other. Migrainous infarction is the term given to an ischemic stroke (clot) that happens during a migraine. This tends to happen alongside prolonged aura symptoms, but is extremely rare. Stroke risk and migraine If you have migraine with aura, you are about twice as likely to have an ischemic stroke in your lifetime compared to those without migraine. However, the overall risk linked to migraine is still very low, and you are far more likely to have a stroke because of other risk factors like smoking and high blood pressure. If you have migraine, your GP or nurse can give advice on reducing your risk of a stroke from any other health conditions you may have, like high blood pressure, diabetes, atrial fibrillation or high cholesterol. They can also support you with making lifestyle changes such as stopping smoking, losing weight, healthy eating and exercise.
Women and migraine: Taking the combined oral contraceptive pill (combi pill) increases the risk of a stroke in women who have migraine with aura. Because of this, women who have migraine with aura are not usually given the combi pill. If you have migraine without aura you should be able to take the combi pill, unless you have other risk factors like smoking or being overweight.
When an ischemic stroke occurs along with a migraine headache, it is known as a migrainous stroke or migrainous infarction. In migrainous strokes, the migraine must occur with aura. Aura is a set of symptoms preceding the migraine, such as flashes of light or tingling in the face or hands.
Migraine without aura: Between 70% and 90% of the population with migraine have this type, which is sometimes called common migraine it consists of a headache with other symptoms such as nausea and sensitivity to light, sound or smell. The other symptoms usually begin at the same time as the headache, and disappear once the headache goes. Many people feel irritable and need to rest in a dark room or sleep. Migraine with aura about 30% of people with migraine has migraine with aura (sometimes called classical migraine). Some people have both types. Attacks typically begin with an ‘aura’ consisting of one or more of the following symptoms which develop gradually over five to 30 minutes and last less than one hour. The headache can occur with or after the aura.
• Visual changes: This is the most common aura symptom, and the changes can include flashing lights, zig-zags, sparks or blank spots. These can appear on one side or centrally and commonly expand and move across your field of vision. Visual changes such as flashing lights can also be signs of acute eye disease, so if you get any of these symptoms and have not been diagnosed with migraine, visit your optician or GP urgently.
• Sensations such as pins and needles, tingling or numbness, weakness or a spinning sensation or vertigo.
• Less commonly, you may have difficulty speaking or hearing, and feel fear or confusion and even have paralysis.
Whether or not you have a migraine aura, you may experience some different symptoms hours or days before a migraine attack. These can include changes in mood and energy levels, aches and pains and sensitivity to light or sound. These are called prodromal or premonitory symptoms. Migraine aura without headache Also known as a silent migraine, this is an aura without the headache. Rare types of migraine there are some rare types of migraine, which are also classed as migraine with aura. Migraine with brainstem aura previously known as basilar-type migraine, people with this condition experience two or more of the following symptoms before a migraine:
• Visual disturbances, including double vision
• speaking difficulties hearing problems, including ringing in the ears
• tingling in the hands and feet
People may experience these symptoms either ahead of or alongside typical migraine symptoms.
Hemiplegic migraine: Hemiplegia means paralysis on one side of the body, and weakness or paralysis on one side is a key symptom of this type of migraine. Other symptoms might include numbness or pins and needles, visual problems, confusion and speech problems. These problems usually go away within 24 hours, but they may last a few days. A headache usually follows. If you have a parent with hemiplegic migraines then you have about a 50% chance of having this type of migraine yourself, known as familial hemiplegic migraine (FHM). In some families with FHM, problems have been found with particular genes which affect how the brain cells communicate with each other.
What causes a migraine?
Migraine often runs in families, and if one or more close relatives experience migraine, it is more likely that you will too. Migraine triggers there are various triggers that can lead to a migraine attack, including:
• Emotional: such as stress, anxiety or depression
• Physical: such as tiredness or tension, particularly in the neck and shoulders
• Hormonal: some women experience migraine around the time of their period
• Dietary: missing a meal, drinking alcohol or caffeinated drinks, and eating certain foods such chocolate or cheese
• Environmental: such as bright lights or a stuffy atmosphere
• medicines: including some sleeping tablets, and the combined contraceptive pill Often it takes more than one trigger to lead to an attack, for example being under emotional stress and missing a meal
This information is a guide to some of the stroke-like symptoms of migraine, but it is not intended as a way of diagnosing migraine or stroke. You should get individual advice from a medical professional if you have migraine symptoms. If you have any stroke symptoms you must call 999. The symptoms of some types of migraine can mimic stroke, such as hemiplegic migraine, which can cause weakness down one side. Migraine auras can be confused with transient ischemic attack (TIA), where someone has stroke symptoms that pass in a short time. For instance, a migraine with only a visual aura but no headache may be mistaken for TIA. Like a stroke, a migraine can be sudden and can lead to mild confusion. However, migraine aura symptoms tend to develop relatively slowly and then spread and intensify, while the symptoms of a TIA or stroke are sudden. Migraine can sometimes be mistaken for a stroke caused by bleeding on the brain, called a subarachnoid haemorrhage (SAH), which is often characterized by a sudden, very severe headache. Unlike SAH, migraine headache is usually one-sided and throbbing, slow to come on and lasts for a shorter period of time. Vomiting usually starts after a migraine headache starts, but is likely to happen at the same time as headache during a SAH. Patients with a SAH also develop neck stiffness, which is uncommon during a migraine attack.
Migraine diagnosis and treatment:
Diagnosing migraine: Migraine is diagnosed by piecing together information about your symptoms and identifying patterns over time. Your GP will do a number of tests checking your vision, reflexes, coordination and sensations. They will ask you to keep a diary of your migraine symptoms and factors such as what you ate and how you slept leading up to them. This may help you identify and avoid your triggers. You should also record any medicines you are already taking. Painkiller over-use makes migraines difficult to treat. Managing migraine some people are able to avoid their triggers and so eliminate migraine that way. Many people find that ordinary painkillers such as paracetamol, ibuprofen and aspirin reduce the pain of their migraine headache. Do not take painkillers every day for a migraine, as painkiller over-use can cause headaches. You’re GP or a specialist can prescribe other treatments such as a migraine medication for headache and nausea. Botulinum toxin type A treatment (often known as Botox) is available for some cases of chronic migraine. For more information about managing migraine, visit www.migrainetrust.org or NHS Choices (see other sources of help and information)
Spotting the signs of a stroke:
The FAST test helps to spot the three most common symptoms of stroke. But there are other signs that you should always take seriously. These include:
• Sudden weakness or numbness on one side of the body, including legs, hands or feet
• Difficulty finding words or speaking in clear sentences
• Sudden blurred vision or loss of sight in one or both eyes
• Sudden memory loss or confusion, and dizziness or a sudden fall
• A sudden, severe headache. Stroke can happen to anyone, at any age. Every second counts. If you spot any of these signs of a stroke, don’t wait. Call 999 straight away.
A stroke occurs when part of your brain is deprived of its blood supply. There are two main types of stroke, one of which is suggested to have a link with certain types of migraine.
Migraine affects three times the number of women than men. The incidence of stroke in men is twice that of women. Several studies have shown that the risk of ischemic stroke was increased in women aged 35 to 45 years old who had migraine with or without aura and was exacerbated by oral contraceptive use, smoking and high blood pressure. Ischemic means a reduced blood and oxygen supply sometimes due to a clot. The other type of stroke is a hemorrhagic stroke, which is where a damaged or weakened artery bleeds into nearby tissue. The link of migraine to this type of stroke is small.
Whilst several studies have shown a relative increased risk of stroke in young women with migraine compared to people without migraine, in absolute terms this risk remains extremely small since stroke is rare in young people.
Understandably, some people are afraid that their migraine is a symptom of a stroke and others worry that they are more at risk of a stroke during a migraine attack. There is little evidence to suggest that a stroke is more likely to occur during a migraine attack than at another time. Migraine is common. In some people migraine and stroke appear together but the nature of the causal relationship, if any, is difficult to establish firmly. Migraines infarction is the term given to an ischemic stroke occurring during a migraine attack.
In this condition aura symptoms are prolonged, and ischemic stroke is confirmed by being shown in a brain scan. However, research suggests that such a stroke would be independent of the migraine attack. It is also possible for a person to have a stroke but for this to have been mistaken for a migraine attack. The migraine aura can mimic transient ischemic attacks (TIAs). Conversely, in stroke, headache similar to migraine may occur.
Evidence supporting migraine as an independent risk factor for ischemic stroke comes from a review in 2018 that included 25 studies.
In nine studies, relative risk (RR) for ischemic stroke among subjects with any type of migraine was 1.73 compared to those without migraine. The increased risk was largely driven by participants who had migraine with aura. In contrast, the increase in risk for those who had migraine without aura was not statistically significant.
The relationship of migraine with hemorrhagic stroke is supported by a review of eight studies which found that the overall effect estimate of hemorrhagic stroke for subjects with any migraine was 1.48.
A study in America in 2004, called the Women’s Health Study, looked at 39,754 female health professionals. During the 9 years of the study there were 309 ischemic strokes in the total population in the study, so there was a total incidence of 8 ischemic strokes per 100,000 women (0.008%). This includes women with and without migraine aura, so it can be seen that although the relative risk is seemingly high, the actual risk is extremely small. This study confirmed previous studies suggesting that the association between migraine aura and stroke risk was greater in younger than in older women (in this case meaning women under age 55). The higher risk with aura will also include those who have other medical conditions that increase the risk of stroke and which can be associated with aura symptoms rather than true migraine aura. These conditions include some blood clotting disorders and heart conditions. The diagnosis of migraine and migraine aura was self-reported so is subject to bias (that is, there was not an objective person to make the diagnosis).
The mechanism of the increased risk of ischemic stroke in young women with migraine remains unknown. It does not seem to be due to an increase in conventional risk factors such as diabetes, high blood pressure and raised cholesterol levels. There are frequent reports of discoveries of differences between people with and without migraine, for example, the recent attention given to patent foramen ovale (PFO) or hole in the heart in patients with migraine with aura. However, these characteristics are not consistently found in people with migraine compared with people without migraine and they show no sex difference, so that they cannot explain why the increased risk of ischemic stroke in migraine is statistically significant in young women. Some recent studies suggest that aura is associated with adverse cardiovascular risk profile and prothrombotic factors (tendency of blood to clot). Research is continuing to look into this area in the hope of discovering more about the complex relationship between migraine with aura and ischemic stroke, and any underlying vascular differences between people with and without migraine.
Whatever the underlying mechanism, the practical implications of the increased ischemic stroke risk in young women with migraine with aura are relatively clear: when the low absolute risk and its increase by cigarette smoking are taken into account, the first recommendation is not to smoke.
The Faculty of Family Planning and the Family Planning Association guidelines confirm that best practice is to contraindicate the combined contraceptive pill for use by women who have migraine with aura, which is also in line with World Health Organization recommendations. The risk for women with migraine without aura is lower and other risk factors like smoking are far more likely to increase stroke risk than migraine. However, in practice, given the very low absolute risk of stroke in young women, there is no systematic contraindication to oral contraceptive use but rather a firm recommendation for no smoking and for the use of low estrogen or progestogen only pills particularly for women with migraine with aura. It is important however that woman with migraine who is taking the pill do not decide to suddenly stop taking it without discussing this with their doctor.
Being ‘at risk’ of stroke does not mean dying from a stroke. Around 25% of people who have stroke recover, and another 50% will have a disability after a stroke.