Migraine and stroke

What is a stroke?

Stroke is a serious medical condition. It happens when the blood supply to part of the brain is cut off and brain cells die. There are two main causes of stroke:

• ischaemic – caused by the blood supply being stopped due to a blood clot, it’s responsible for most cases of stroke.
• haemorrhagic – where weakened blood vessels that supply the brain burst.

There is also another condition known as a transient ischaemic attack (TIA). This is where the blood supply to the brain is temporarily interrupted. It may also be called a ‘mini-stroke’ and can last a few minutes or go on for up to 24 hours. Some types of migraine attack may be mistaken for a TIA (see ‘Migraine or stroke’ below).

Stroke risk and migraine

If you have migraine you may be worried about stroke – whether migraine causes stroke or makes it more likely you’ll have a stroke.

As far as we know migraine doesn’t cause stroke. However, for some people migraine may increase their risk of stroke. This doesn’t mean they will have a stroke because they have migraine, but the chances of them having one is higher than if they didn’t have migraine.

Studies have shown that there is an increased risk of ischaemic stroke in people with migraine with aura, compared to people without migraine. The risk of ischaemic stroke is increased in women with migraine aura under 45, women who use oral contraceptives, women who smoke and people who get migraine with aura for the first time after the age of 50. We don’t fully know why this is.

In older people with migraine the evidence doesn’t show that migraine is a risk factor for stroke. The exceptions to this are if older people are smokers or if migraine started later in life.

For haemorrhagic stroke the relationship with migraine is unclear.

Although there is an increased risk, this doesn’t mean that people with migraine with aura will definitely experience a stroke. Overall, the risk of stroke is considered low in migraine. People with migraine are (generally) younger and this group tends to have a lower risk of stroke. If you are younger your risk of stroke is lower even if you have migraine. As you get older your risk of stroke increases due to your age and a range of other factors, such as high blood pressure, and migraine is considered an insignificant risk factor.

Managing risk of stroke in migraine

As a risk factor you can’t help having migraine with aura. However, there are some things that can help to manage other risk factors for stroke. Managing any vascular risk factors such as high blood pressure and high cholesterol can help. As can managing any other conditions that may increase your risk, such as arterial hypertension or Diabetes.

There are certain risk factors for stroke that can affect anyone at any age. These include:

• smoking
• high blood pressure
• being overweight

These are likely to have more of an impact on your risk of stroke than migraine. If you’re worried about your risk of stroke you should speak to your GP about your individual risk of stroke.

Oral contraception

Women with migraine with aura should discuss oral contraceptive options carefully with their GP or specialist. For most women, modern oral contraceptives are safe and highly effective. There are some groups of women who may be at higher risk of stroke from oral contraceptives including:

• women with migraine with aura
• women over 35
• women who smoke
• women who have other stroke risk factors

Can migraine and stroke happen at the same time?

You may be worried your migraine attack is a symptom of a stroke. Or that you are more at risk of a stroke during a migraine attack. In some people migraine and an ischaemic stroke occur together, but it’s not clear why this is. When this happens, it is known as ‘migrainous infarction’. It is considered rare, and is usually diagnosed by ruling out everything else.

Migrainous infarction features prolonged aura symptoms (lasting longer than 60 minutes), aura symptoms that are typical for you and a brain scan showing signs of damage, with no other cause.

It is possible to have a headache during a stroke which is similar to migraine. It is also possible for people to have a stroke which is mistaken for a migraine attack. Migraine aura symptoms can be similar to the symptoms of TIAs.

Migraine or stroke?

Sometimes migraine symptoms can be mistaken for stroke or vice versa. It can be difficult to tell the difference between migraine and stroke, especially a TIA as the symptoms can be similar. In migraine with aura people may experience:

• visual disturbances such as blind spots or zig zags
• numbness or tingling, like pins and needles in parts of your body
• dizziness
• speech difficulties

The symptoms of hemiplegic migraine – temporary weakness on one side of the body can often be mistaken for a stroke or TIA. Symptoms of migraine with brainstem aura, such as tingling in the hands and feet, dizziness, speech problems and visual disturbances in both eyes can also be mistaken for stroke or TIA.

Even doctors can find it challenging to tell the difference. Generally, migraine tends to come on gradually and feature ‘positive’ symptoms (this means added sensations) such as flashes in vision or tingling. Stroke or a TIA tend to come on suddenly and feature ‘negative’ symptoms (loss of sensation) such as loss of vision in one eye or loss of feeling in one of your hands.

If you are unsure if you’re having a stroke, TIA or migraine attack you should seek medical help as soon as possible. If it is stroke or a TIA it’s important to be reviewed and treated as soon as possible. If your symptoms have changed or you’re experiencing aura for the first time later in life it’s also very important to be reviewed by a doctor.

Useful organisations

The Stroke Association

Provide information and support to help people who have been affected by stroke.

Helpline: 0303 3033 100 or helpline@stroke.org.uk

Website: www.stroke.org.uk