A transient ischaemic attack (TIA), or mini stroke, happens when there is a temporary disruption in the blood supply to part of the brain.
The disruption in blood supply results in a lack of oxygen to the brain. This can cause sudden symptoms like those of a stroke.
However, a TIA does not last as long as a stroke. The effects only last for a few minutes or hours and fully resolve within 24 hours.
Symptoms of a TIA
Like a stroke, the signs and symptoms of a TIA usually begin suddenly.
The main symptoms of stroke can be remembered with the word FAST.
FAST stands for:
- Face – the face might drop on one side, the person may not be able to smile or their mouth may have dropped, and their eyelid may droop
- Arms – the person may not be able to lift both arms and keep them there because of arm weakness or numbness in one arm
- Speech – they might slur their speech or it might be garbled, or the person may not be able to talk at all despite appearing to be awake
- Time – it’s time to phone 999 immediately if you see any of these signs or symptoms
It's important to be aware of the symptoms of a stroke or TIA, especially if you live with or care for somebody in a high-risk group, such as an elderly person or someone with diabetes or high blood pressure.
Symptoms in the FAST test identify most strokes and TIAs. TIAs sometimes cause different symptoms that appear suddenly (usually over a few seconds).
Other signs and symptoms may include:
- complete paralysis of one side of the body
- sudden loss or blurring of vision
- difficulty understanding what others are saying
- problems with balance and co-ordination
However, there may be other causes for these symptoms.
During a TIA, it's not possible to tell whether you're having a TIA or a full stroke, so it's important to phone 999 immediately. Even if the symptoms disappear, you should still have an assessment at hospital.
A TIA is a warning that you're at risk of having a full stroke. An assessment can help doctors decide the best way to reduce the chances of this happening.
Causes of a TIA
TIAs happen when there is a temporary disruption in the blood supply to part of the brain.
In TIAs, the blockage resolves before any significant damage. A full stroke disrupts the blood flow to your brain for much longer. This leads to more severe damage to the brain and longer-term problems.
The blockage responsible for most TIAs is usually caused by a blood clot that has travelled to the blood vessels supplying the brain.
A type of irregular heartbeat called atrial fibrillation can also cause TIAs. It can create blood clots that escape from the heart and become stuck in the blood vessels that supply the brain.
There are some things that can make you more likely to have a stroke or TIA:
Lifestyle changes can help control some of these risk factors. You may also need to take regular medication.
Taking anticoagulant medication if you have an irregular heartbeat due to atrial fibrillation will help reduce the risk of stroke.
If you've had a stroke or TIA, these measures are particularly important because you're more likely to have another stroke in future.
There are some risk factors you can't change like:
- age – people over 65 are most at risk of having strokes, although they can happen at any age – including in children
- family history - if a close relative (parent, grandparent, brother or sister) has had a stroke, your risk is likely to be higher
- ethnicity – if you're south Asian, African or Caribbean, your risk of stroke is higher, partly because rates of diabetes and high blood pressure are higher in these groups
- your medical history - if you’ve had a stroke, transient ischaemic attack (TIA) or heart attack, your risk of stroke is higher
You should have an assessment in hospital as soon as possible if you think you've had a TIA.
TIAs are often over very quickly, so you may not have any symptoms by the time you see a doctor.
You should tell the person assessing you about the symptoms you experienced and how long they lasted. This will help to rule out other conditions that may have caused your symptoms.
Even if you no longer have symptoms, you might still need a neurological examination. This involves simple tasks designed to check your strength, sensation and co-ordination skills.
Referral to a specialist
If a TIA is suspected, you'll see a specialist for further tests as soon as possible.
You'll normally take aspirin while you're waiting for specialist assessment. This can help to reduce your risk of having a stroke or another TIA in the meantime.
It's likely you'll see a doctor who specialises in strokes.
You might have some tests to rule out other causes of your symptoms and to help identify the underlying cause of your TIA.
You might need blood tests to determine whether you have high cholesterol, and to check if you have diabetes.
An electrocardiogram (ECG) measures your heart's electrical activity using electrodes (small, sticky patches) on your skin.
An ECG can detect abnormal heart rhythms, which may be a sign of conditions like atrial fibrillation (where your heart beats irregularly).
A carotid ultrasound scan can show if there's narrowing or blockages in the neck arteries leading to your brain.
A small probe (transducer) sends high-frequency sound waves into your body. When these sound waves bounce back, they create an image of the inside of your body.
Brain scans are not always necessary if you've had a TIA.
You might have a magnetic resonance imaging (MRI) scan. This scan uses a strong magnetic field and radio waves to create an image of your brain.
You might have a computerised tomography (CT) scan if an MRI scan is not suitable for you. This type of scan uses a series of X-rays to produce an image of the inside of brain.
Although the symptoms of a TIA stop on their own, you'll need treatment to help reduce the risk of another TIA or a full stroke.
Appropriate treatment following a TIA can help to reduce your risk of having one.
Your doctor will tell you about lifestyle changes you can make to reduce your stroke risk. Your doctor will prescribe medication to treat the underlying cause of your TIA. You might need surgery as part of your treatment.
There are lifestyle changes you can make that may help reduce your chances of having a stroke after a TIA like:
Most people who've had a TIA will take medication to reduce their chances of having a stroke or another TIA.
After a TIA, the aim is to reduce the risk of a stroke especially in the first few days. To do this a combination of treatments is usually recommended. Some of the treatments might include:
- antiplatelets like aspirin and clopidogrel
- anticoagulants like apixaban, edoxaban, rivaroxaban, dabigatran or warfarin
- medication to lower your blood pressure (antihypertensives)
- statins to lower your cholesterol
The antiplatelet medications need to be taken immediately. Others may only be started later and usually need to be taken long term.
A carotid endarterectomy is an operation to remove part of the lining of the carotid artery and any blockage in the artery.
By unblocking the carotid arteries, a carotid endarterectomy can reduce the risk of having a stroke or another TIA.