Transient ischaemic attack

What is a transient ischaemic attack?

A transient ischaemic attack, commonly called a TIA or a ‘mini stroke’, is when the blood flow to part of your brain is disrupted temporarily and then recovers quickly. 

This means that any symptoms from the TIA are short-lived (from a few minutes up to 24 hours). If they last longer then it would be classed as a stroke. In a TIA, there’s no permanent damage.

What are the symptoms of a TIA?

Symptoms of a TIA stroke vary depending on which part of the brain isn’t receiving good blood flow, and so not getting oxygen to be able to work properly. 

The symptoms are very similar to a stroke and follow the same acronym, FAST:

• Face – one-sided drooping – you might not be able to smile, swallow or tightly close your eyes or mouth.

• Arms – you may have weakness or numbness and not be able to raise one or both arms up and keep them there.

• Speech – your speech may be slurred or you may struggle to talk or make sense at all.

• Time – call 999 straight away if you notice any of these symptoms.

There are also some rarer symptoms of TIA:

• Visual changes or blindness

• Abnormal behaviour or memory loss

• Difficulty swallowing

• Vertigo (a feeling like the room is spinning) 

• Ataxia (unsteadiness and loss of balance)

What causes a TIA?

A TIA is caused by a temporary blockage of blood flow to a part of your brain. The most common cause of this is thrombotic. A thrombus is a blood clot that forms in a vein. This can block blood flow from moving on or can dislodge and block other arteries in the body.

There are three key types of blockages:

• Thrombotic – a thrombus is a blood clot that forms in a vein. This can block blood flow from moving on or can dislodge and block other arteries in the body.

• Embolic – emboli are things that block blood vessels and can come from elsewhere in the body. This can be fat, amniotic fluid in pregnancy or air bubbles

• Haemorrhagic – a haemorrhage is a bleed. If an artery supplying the brain begins to bleed it will not properly pass blood through. This is very rare, but they can cause swelling or damage to the brain.  

How common is a TIA?

50 out of 100,000 have their first TIA each year in the UK. This can be a precursor for stroke – 15% of people who’ve had a stroke have had a TIA first. It’s more common in older people and is very very uncommon before the age of 55. 

Who’s at risk of a TIA?

Due to how TIA’s happen, lots of things that increase the chance of clots or affect blood vessels can increase your risk of a TIA. All of the following conditions can be linked to TIA:

• High blood pressure (hypertension)

• Diabetes

• Heart disease

• Peripheral arterial disease

• Hyperlipidaemia (high fats and cholesterol in the blood)

• Clotting disorders

• Carotid artery stenosis 

• Irregular heart rhythms like atrial fibrillation

• Sickle cell or polycythemia 

The following factors can also increase your risk:

• Having or recently had Covid-19 

• Medications like the combined oral contraceptive pill

• Race – Black people are more at risk

• Smoking, drinking alcohol, being obese or having a family history

How is a TIA diagnosed?

A TIA diagnosis is based on the symptoms you have. The diagnosis can only happen after the symptoms stop to ensure it’s a TIA and not a stroke. If the symptoms resolve within 24 hours then a TIA can be diagnosed. 

After a TIA happens, a doctor will perform other tests, like measuring your blood sugar and blood pressure to help rule out other causes. You may have scans of your head and brain taken, particularly if you’re at risk of complications, like if you’re on blood thinners.

What happens after a TIA?

If a doctors think you have had a TIA, you’ll be referred to a specialist for an assessment within 24 hours. It’s important that you don’t drive until you’ve been seen by a specialist. 

How is a TIA treated?

You will be advised to start on medication immediately to help reduce any sudden risk of stroke or another TIA. You’ll be started on aspirin unless there’s a reason you shouldn’t take it.

You will be referred to a specialist team at the hospital. This might be called a TIA or stroke clinic.

The specialist team will see you within 24 hours. They might organise extra tests such as:

• Doppler – is a scan of your carotid arteries, the big blood vessels that supply your head and brain. This test will detect any blockages that might be disrupting your blood flow.

• MRI – a type of scan without radiation that will look at your brain to see which areas were affected and to check for any other issues.

How can I prevent a TIA?

If you’ve already had a TIA, doctors will recommend you take certain medications to help reduce your risk of having another TIA or stroke. These could include blood thinners, statins or changing other medications to lower your risk of stroke, like changing the type of contraception you take.

To prevent TIA in the future, adopting as many healthy habits as you can will help, like eating a healthy balanced diet, stopping smoking, reducing alcohol and exercising regularly.

When should I seek help?

Seek urgent medical help if you’re experiencing a sudden onset of the FAST symptoms by calling 999. If you’re unsure, call 111 or book an emergency GP appointment.