An ischaemic stroke is the most common form of stroke, occurring in 80% of all cases. It happens when a blood clot forms to block the flow of blood and oxygen to the brain. This occurs often because the arteries have become narrower or blocked, a process called atherosclerosis, which can occur with age. Time is of the essence in diagnosing a stroke as the sooner the treatment can begin, the better the likely outcome for the patient.
In this guide to Ischaemic strokes you will find information about causes, symptoms to look out for, tests and diagnosis and treatments.
What causes an Ischaemic Stroke?
Whilst narrowed or blocked arteries are the main cause of an ischaemic stroke, there are contributory health and lifestyle issues which include:
- High blood pressure
- High cholesterol
- Smoking and/or excessive alcohol consumption
Regular check ups and a healthy lifestyle can certainly have a positive impact on the likelihood of having a stroke.
Diagnosis of an Ischaemic Stroke
If you are in doubt, the key signs of an ischaemic stroke are:
F Face: numbness in the face (one side may drop, one eye or one side of the mouth)
A Arms: ability to raise both arms above the head
S Speech: maybe confused or garbled
T Time: to call 999
There are other signs, possibly less obvious, which include:
- Difficulty swallowing (dysphagia)
- Sudden loss or blurring vision
- Being or feeling sick
- Complete paralysis of 1 side of the body
- Difficulty understanding what others are saying
- Problems with balance and co-ordination
- Sudden and severe headache/blinding pain
- Loss of consciousness
Whilst some of these may not appear to be serious, or an obvious pointer to a possible stroke, don’t delay. Dial 999 if you are concerned as the sooner a diagnosis can be made, the faster treatment can begin.
Tests to confirm diagnosis of a stroke
A CT scan to confirm a stroke, is usually able to show whether it is an ischaemic stroke or a haemorrhagic stroke.
An MRI scan is usually used for people who have recovered from a TIA (mini-stroke) or who have complex symptoms where the extent or location of the damage is unknown. An MRI scan shows brain tissue in greater detail which allows smaller or more unusual areas affected to be identified.
An ultrasound may be carried out to see if there has been a narrowing or blockage of the arteries in the neck.
Echocardiogram and Transoesophageal echocardiography (TOE)
If there are concerns about a heart problem that may have contributed to the stroke, a different type of ultrasound, called a transthoracic echocardiogram may be used across the chest. To find blood clots or abnormalities behind the heart, a trans-oesophageal echocardiography (TOE) may be carried out, usually under sedation.
Treating Ischaemic Strokes
A combination of medication will be given to treat the condition and to prevent its re-occurrence.
Some medication will be taken immediately and for a short amount of time, while others will start once the stroke has been treated.
Thrombolysis (blood clot medicine)
Thrombolysis is a clot buster that will dissolve blood clots and restore blood flow to the brain. A drug called Altophase is the most effective if started as soon as possible, within hours after tests and a brain scan to confirm diagnosis.
Thrombectomy – this procedure is effective at treating ischmaeic strokes caused by a blood clot in a large artery in the brain. A catheter is inserted often into an artery in the groin to pass a small device into the artery in the brain to remove the blood clot.
Aspirin – for blood clots (anti-platelets)
Aspirin is prescribed to most ischaemic stroke patients to reduce the chances of another blood clot. Aspirin works to block an enzyme which produces hormones to cause platelets to stick together (blood clots).Other similar medication is called Clopidogral or Dipyridamole.
Anticoagulant medication for blood clots
Anti-coagulants change the chemical composition of the blood to prevent blood clots from forming. Some patients will be offered these to help reduce their risk of developing new blood clots in the future. Well known medication includes Warfarin, but also apixaban, dabigatran, deoxaban and rivaroxaban. Heparins are a type of anticoagulant that is only given by injection and used short term. Patients may be offered anticoagulents if they have:
- A history of blood clots
- Developed a deep vein thrombosis in the leg (DVT) because they are no longer able to move the leg
- An irregular heartbeat – called atrial fibrillation
Statins to prevent Strokes
Statins reduce the level of cholesterol in the body which are produced by an enzyme in the liver. Bad cholesterol gathers in the arteries and can break off to form a blood clot. As high cholesterol levels are one of the main causes of a stroke, many patients are prescribed statins. There is some wider concern over the prevalence and use of long-term use of statins, so do take medical advice if you are anxious about a prescription.
Physical impact of an Ischaemic Stroke
A stroke typically only affects one side of the brain. When a stroke damages the part of the brain that controls muscle movement, the signals between the brain and the muscles can be weakened, leading to muscle weakness or paralysis.
Because each side of the brain controls movement on the opposite side of the body paralysis/weakness also typically occurs on one side of the body, opposite to where the stroke occurred.
Weakness on one side of the body is often referred to as hemiparesis, and paralysis on one side of the body is called hemiplegia. The range can extend from mild weakness in one limb, such as an arm, which might impact the ability to use your fingers, to much more severe weakness with no movement in the limbs at all (paralysis). Another form of muscle weakness is called Drop Foot and occurs when muscle weakness in the foot means toes catch on the ground as the foot is lifted to step forwards.
Ischaemic Stroke Recovery
Some people recover quickly and well from an ischaemic stroke. For others it can be a life-changing event leading to years, maybe a lifetime of physical changes. Physiotherapy and rehabilitation particularly in the initial days, weeks and months of a stroke can have a positive impact on recovery. We have a guide to recovery from a stroke here.
Reducing the chances of an Ischaemic Stroke
100,000 people every year have a stroke in the UK, the majority of them suffering an ischaemic stroke. Largely due to blood clots which prevent blood flowing to the brain, there are lifestyle and health-related ways to reduce the chances of having a stroke.