Stroke

A stroke is a disruption of blood flow to a part of the brain, which causes brains cells to be damaged or die because of a lack of oxygen.

A stroke is a medical emergency that requires immediate treatment. By learning to recognise common symptoms of stroke you could save a life - think “FAST”:

• Face - Is their face drooping on one side? Can they smile?

• Arm - Is one arm weak? Can they raise both arms?

• Speech - Is their speech jumbled or slurred? Can they speak at all?

• Take action - Call 111 immediately.

Approximately 9,000 New Zealanders have a stroke each year — it is the second biggest killer (approximately 2,500 deaths per year) and a major cause of disability in New Zealand.

The best way to prevent a stroke is to manage related medical conditions (notably high blood pressure) and live a healthier lifestyle.

Types of stroke

Ischaemic strokes:

Ischaemic strokes occur when a blood clot completely blocks an artery in or to the brain. They are the most common type of stroke, occurring in about 85% of cases.

Haemorrhagic Strokes:

Haemorrhagic strokes occur when an artery within the brain ruptures (bursts) and leaks blood into the brain. The presence of this extra blood causes pressure to build within the area of the brain where the bleed has occurred, causing damage to the brain tissue. Haemorrhagic strokes are less common than ischaemic strokes but their effects are generally more severe.

Transient ischaemic attack (‘mini-stroke’):

A transient ischaemic attack (TIA), commonly known as a ‘mini-stroke, occurs when there is a temporary disruption in the blood flow to the brain. Symptoms may last for only a few minutes or up to a few hours and resolve within 24 hours. If symptoms last longer than 24 hours the condition is diagnosed as a stroke.

Suffering a TIA increases the risk of having a full-blown stroke. Having a TIA should be a clear warning that a more severe stroke might follow. Immediate medical attention should be sought if a TIA is suspected as they can be a warning sign that a more severe stroke might follow.

The Stroke Foundation recommends a person with a suspected TIA should go directly to hospital for medical assessment.

Stroke risk

People of all ages and genders can suffer a stroke. In New Zealand, approximately 24 people have a stroke each day.

• Seventy-five percent of strokes occur in people over 65 years of age

• Māori and Pacific Island New Zealanders are more likely to suffer a stroke than European New Zealanders

• Men are more likely to suffer a stroke than women

• People who have previously had a TIA, or who have a family history of stroke, are at greater risk.

Getting on top of existing health conditions and living a healthier lifestyle can greatly reduce the possibility of stroke. This includes:

• High blood pressure

• Heart disease

• Heart rhythm disorders eg: atrial fibrillation

• Smoking or exposure to second-hand smoke

• Diabetes

• High blood cholesterol

• Oral contraceptives

• Being physically inactive

• Excessive alcohol intake

• Obesity.

The more risk factors a person has, the greater the chance of a stroke. High blood pressure (hypertension) is the main risk factor for stroke.

Signs and symptoms

Signs and symptoms of a stroke usually occur suddenly. The type of symptoms experienced will depend on what area of the brain is affected.

Common initial symptoms of a stroke include:

• Sudden numbness, paralysis, or weakness of an arm, leg, or side of the face

• Slurred or abnormal speech

• Severe headache

• Impairment or loss of vision

• Memory loss

• Confusion

• Poor balance and dizziness

• Loss of consciousness

• Incontinence.

If a stroke causes damage to the brain, long-term effects can include:

• Impaired vision

• Difficulty understanding or forming speech

• Severe weakness or paralysis of the affected side (hemiplegia)

• Numbness, strange sensations, or pain — sometimes made worse by movement or temperature change

• Swallowing difficulties

• Depression

• Emotional problems, such as difficulty controlling emotions or expressing inappropriate emotions.

Stoke may also cause problems with thinking, awareness, attention, learning, judgement, and memory.

Diagnosis and treatment

Stroke is a medical emergency requiring immediate treatment. Prompt diagnosis and treatment improves increases the chances of survival and increases the degree of recovery that might be expected.

To confirm a stroke diagnosis a doctor may make an assessment using several of the following:

• Assessment of current signs and symptoms

• Review of medical history (including current medications being taken, and head injuries)

• Review of personal and family history of heart disease, stroke, and TIA

• Electrocardiogram (ECG) — measures electrical activity in the heart

• Echocardiogram — to assess for any abnormalities in heart function and structure

• Electroencephalogram (EEG) — measures electrical activity in the brain

• Cerebral angiogram — provides a detailed view of the arteries in the brain

• Ultrasound scanning of the neck arteries (carotids)

• Computerised tomography (CT) scan — specialised x-rays that can provide detailed cross-sectional images of the brain

• Magnetic resonance imaging (MRI) — a specialised scan that produces a detailed image of the brain

• Blood tests

• Chest x-rays.

The treatment given depends on the type of stroke suffered.

INITIAL TREATMENT

Immediate treatment is aimed at limiting the size of the stroke and preventing further stroke.

Acute stroke therapies try to stop a stroke while it is happening by quickly dissolving the blood clot causing an ischaemic stroke or by stopping the bleeding of a haemorrhagic stroke. This will involve administering medications and may involve surgery in some cases.

Medications

• Thrombolytic therapy medications dissolve blood clots allowing blood flow to be re-established

• Anti-platelet drugs (eg: aspirin) and anticoagulants (eg: heparin) help to prevent blot clots getting bigger and prevent new blood clots from forming

• Antihypertensives may be used in cases of haemorrhagic stroke to help lower high blood pressure

• Medications to reduce swelling in the brain

• Medications to treat underlying causes for the stroke eg: heart rhythm disorders.

Surgery

Surgery may be needed to repair blocked or ruptured arteries. For a haemorrhagic stroke this may involve repairing a burst artery. Where an ischaemic stroke has been caused by a blockage in a neck artery, surgery to remove the blockage may be done.

Supportive treatment

Providing adequate fluid and nutrition intake after a stroke is vital, particularly if swallowing has been affected. This may require the insertion of an intravenous drip into a vein in the hand or arm. Or it may involve inserting a feeding tube via the nose into the stomach.

LONGER TERM TREATMENT

Brain cells do not generally regenerate (regrow). Following a stroke, surviving brain cells can take over the function of areas that are dead or damaged, but only to a certain degree. The adaptive ability of the brain requires the relearning of various skills.

As each person who suffers a stroke is affected differently, individual rehabilitation plans are developed in conjunction with the patient, family, and healthcare team. These aim to teach skills and maximise function so that the person can achieve maximum independence.

Rehabilitation may involve:

• Physiotherapy — to improve mobility

• Speech therapy — to improve communication

• Occupational therapy — to improve activities of daily living such as eating, cooking, toileting, and washing.

Recovery can take months and it may be several days or weeks after the stroke before doctors are able to give an accurate prediction for recovery.

Long-term treatment with medications to treat the underlying cause of the stroke and to minimise the risk of further stroke may be required. This includes ongoing use of medications to treat high blood pressure, heart rhythm disorders, high cholesterol, heart disease, and blood clotting disorders. Common long-term medications prescribed for people who have had a stroke include warfarin and aspirin — both of which aim to prevent the formation of blood clots.

Surgery to treat the underlying cause of the stroke may also be recommended. This can include surgery to repair or replace a damaged heart valve, rectify heart rhythm problems (which may involve the insertion of a pacemaker), or surgery to remove plaque from neck arteries.

Prevention

Reducing the number of controllable risk factors is the best way to prevent a stroke. This can include:

• Quit smoking

• Lose weight

• Eat a balanced diet low in sodium and saturated and trans fat

• Moderate alcohol intake (no more than two small drinks per day)

• Exercise regularly to stay physically fit

• Maintain good control of existing medical conditions such as diabetes, high blood pressure, and high cholesterol.

If discovered prior to a stroke, some medical conditions may be repaired surgically to prevent a stroke occurring in the first place eg: aneurysms, narrowed arteries, heart rhythm disorders, heart valve problems.

Medications (eg: aspirin or warfarin) may be recommended to help prevent another ischaemic stroke or TIA.

Further support

Stroke Foundation NZ offers information and support and can provide details for regional branches. Contact details are as follows:

Stroke Foundation NZ

Freephone: 0800 STROKE (0800 78 76 53)

E-mail: [email protected]

Website: www.stroke.org.nz

References

Mayo Clinic (2020). Stroke (Web Page). Rochester, MN: Mayo Foundation for Medical Education and Research. https://www.mayoclinic.org/diseases-conditions/stroke/symptoms-causes/syc-20350113 [Date accessed: 28/09/20]
Ministry of Health (2019). New Zealand Health Survey: Annual update of key results 2018/19 (Web Page). Wellington: Ministry of Health. https://www.health.govt.nz/nz-health-statistics/national-collections-and-surveys/surveys/new-zealand-health-survey#published [Accessed: 28/09/20]
O’Toole, M.T. (Ed.) (2017). Cerebrovascular accident (CVA). Mosby’s Dictionary of Medicine, Nursing & Health Professions (10th ed.). St Louis, MI: Elsevier.
Stroke Foundation NZ (Date Unknown). Facts about stroke in New Zealand (Web Page). Wellington: Stroke Foundation New Zealand. https://www.stroke.org.nz/facts-and-faqs [Accessed: 28/09/20]
Stroke Foundation NZ (Date Unknown). What is stroke (Web Page). Wellington: Stroke Foundation New Zealand. https://www.stroke.org.nz/what-stroke [Date accessed: 28/09/20]

Last Reviewed: September 2020

Go to our Medical Library Index Page to find information on other medical conditions.