WHAT IS A STROKE?
Stroke occurs when 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. In Australia, a stroke occurs every 10 minutes. 1 in 6 people will have a stroke in their lifetime.
What are the causes?
There are various factors which can contribute to one’s risk of developing stroke. Some risk factors cannot be controlled. These are:
- Past history of stroke
- Age – Stroke risk increases as you get older
- Gender – Stroke is more common in men
- Family history of stroke
However, many stroke risk factors are potentially treatable. These include:
- High blood pressure – This is the most significant risk factor for stroke. Blood pressure is considered high if it is consistently over 140/90.
- Atrial fibrillation (a type of irregular heartbeat)
- High cholesterol levels
- Carotid artery stenosis (narrowing of the carotid arteries supplying blood to the brain)
Lifestyle factors can also increase risk of stroke, for example:
- 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
What are the symptoms?
An easy way to recognize and remember the most common symptoms of stroke is the acronym ‘FAST’:
F = Facial weakness – Check their face. Has their mouth drooped?
A = Arm weakness – Can they lift both arms?
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.
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 just short-term memory loss, or loss of coordination and balance. If in doubt, seek medical attention immediately.
How is it diagnosed?
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/or MRI is generally required for evaluation of stroke. Other investigations such as blood tests, ECG, echocardiography, ultrasound of the neck arteries or cerebral angiography may also be done as part of the workup.
What are the treatment options?
The only treatment available for reversing the effects of a stroke is a drug that breaks down blood clots called tPA. This drug can only be given within 4½ hours of the stroke onset, hence it is very important to get to hospital as soon as possible after stroke symptoms begin. Not all patients are suitable for this treatment. It can only be given after the patient has been assessed by an experienced neurologist and after CT scan is done.
Patients with stroke are best cared for in dedicated stroke units in a hospital setting. Supportive care for stroke includes giving antithrombotic medication to reduce the risk of recurrent stroke, treatment for lowering blood pressure and cholesterol, controlling glucose levels, managing complications of stroke, specialised nursing care and rehabilitation of the patient’s disabilities with physiotherapy, occupational therapy, and speech/ swallowing therapy. Some patients may also benefit from carotid artery surgery or stenting to reduce the risk of future stroke.
What is the prognosis?
Prognosis for stroke depends on factors such as the severity of the stroke, the patient’s age, comorbidities and the type of stroke. The death rate from stroke at 30 days is about 20%. 40-50% of patients will have persistent neurological deficits after stroke at 6 months, such as weakness or cognitive deficits. 25% of stroke sufferers have to enter institutional care.