What is a Stroke?
A stroke occurs when the blood supply to the brain is interrupted, causing brain cells in the affected part of the brain to die.
The blood supply can be interrupted because an artery supplying the brain is blocked (ischaemic stroke) or bursts, causing bleeding into the brain (haemorrhagic stroke).
Stroke is a very common condition. It is Australia’s second biggest killer after coronary heart disease and a leading cause of disability. Over 15% of Australians will have a stroke.
Types of Stroke
There are three types of Stroke these are:
- Ischemic stroke - when the brain's blood vessels become narrowed or blocked, causing severely reduced blood flow (ischemia)
- Hemorrhagic stroke - when a blood vessel in the brain leaks or ruptures
- Transient ischemic attack (TIA) - when a temporary decrease in blood supply to part of the brain, for a few minutes
What Are The Causes of Stroke?
Various factors can contribute to one’s risk of developing stroke. Some risk factors cannot be controlled. These are:
- History of stroke
- Age – Stroke risk increases as you get older
- Gender – Stroke is more common in men
- Family history of stroke
Stroke Risk Factors
Common risk factors that can lead to a stroke are:
- High blood pressure – that is when it is consistently over 140/90.
- Atrial fibrillation (a type of irregular heartbeat)
- Diabetes
- High cholesterol levels
- Carotid artery stenosis (narrowing of the carotid arteries supplying blood to the brain)
- Overtreatment with blood thinners (anticoagulants)
- Bulges at weak spots in your blood vessel walls (aneurysms)
- Trauma (such as a car accident)
- Protein deposits in blood vessel walls that lead to weakness in the vessel wall (cerebral amyloid angiopathy)
- Ischemic stroke leading to hemorrhage
Lifestyle Risk Factors for Stroke
Common risk factors cause by lifestyle include
- Cigarette smoking
- Heavy alcohol intake (6 or more standard drinks per day)
- A diet high in fat (particularly saturated fat) and salt but low in fibre, fruit and vegetables
- Lack of regular exercise
- Obesity
Symptoms of Stroke
An easy way to recognise and remember the most common symptoms of stroke is the acronym ‘FAST’:
- F = Facial weakness – facial numbness or paralysis. Has their mouth drooped?
- A = Arm weakness – Can they lift both arms or walk?
- S = Speech difficulty – Is their speech slurred? Do they understand you?
- T = Time is critical. If you see any of these signs, call 000 immediately.
A stroke is a life-threatening emergency. Even if symptoms go away quickly or do not cause pain, it is important to get treatment as early as possible.
Call 000 to get to a hospital immediately.
The absence of the above symptoms does not necessarily exclude stroke. For example, certain strokes may cause short-term memory loss or loss of coordination and balance. If in doubt, seek medical attention immediately.
Diagnosis of Stroke
Stroke is suspected on clinical assessment by considering the history of the patient’s symptoms and the physical examination.
Imaging of the brain with CT and MRI is generally required for the evaluation of stroke.
Other investigations include:
- Blood tests,
- ECG (Echocardiography),
- Ultrasound of the neck arteries or cerebral angiography.
Immediate Stroke Treatment
The only treatment available for reversing the effects of a stroke is a drug that breaks down blood clots called Tissue Plasminogen Activator (tPA).
This drug can only be given within 4½ hours of the stroke onset. Hence it is very important to get to the hospital as soon as possible after stroke symptoms begin.
Not all patients are suitable for this treatment. It can only be given after an experienced neurologist has assessed the patient and after a CT scan is done.
After Stroke Treatment
The prognosis for stroke depends on factors such as the severity of the stroke, including:
- the patient’s age,
- comorbidities and
- type of stroke.
The death rate from a stroke at 30 days is about 20%. 40-50% of patients will have persistent neurological deficits after strokes at six months, such as weakness or cognitive deficits. 25% of stroke sufferers have to enter institutional care.
Stroke Rehabilitation
Post Stroke Rehabilitation and Supportive care programs can include:
- Antithrombotic medication to reduce the risk of recurrent stroke,
- Treatment for lowering blood pressure and cholesterol,
- Controlling glucose levels,
- Managing complications of a stroke,
- Specialised nursing care and
- Rehabilitation of the patient’s disabilities with physiotherapy, occupational therapy,
- Speech/ swallowing therapy.
Some patients may also benefit from carotid artery surgery or stenting to reduce the risk of future stroke.
