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Blood contains oxygen and important nutrients for proper functioning. If brain cells do not get enough of this supply, they die.

Early treatment for stroke is critical – the longer a stroke remains untreated, the greater the chance that stressed brain cells will die, leaving behind permanent stroke-related brain damage.

Stroke can leave people with debilitating effects, such as weakness on one side of the body, difficulty controlling movements, personality or behaviour changes, or problems speaking and understanding.

The most common symptoms of stroke are:

  • weakness, numbness or paralysis of the face, arm, or leg on either or both sides of the body
  • slurred speech, difficulty speaking or understanding
  • loss of vision in one or both eyes
  • sudden, severe headache with no known cause
  • loss of balance, dizziness.

There are two major types of stroke: ischaemic and haemorrhagic. An ischaemic stroke is when blood flow is interrupted to the brain, due to a blood clot blocking the flow of blood through blood vessels that deliver oxygen and nutrients to the brain. A haemorrhagic stroke is when a blood vessel or artery in the brain bursts, and there is a leakage of blood into the brain. Both types of stroke share the same possible symptoms and effects.

The impact

Every day, about 24 New Zealanders experience a stroke.1

Stroke is a leading cause of disability in New Zealand.

Survivors are likely to suffer a decreased quality of life for many months, if not years, post-stroke. They may need long-term rehabilitation as well as the support of family, loved ones and other carers and healthcare professionals.

An estimated 60,000 New Zealanders live with the effects of stroke.1 Sadly, around one in five people will die within 28 days of a stroke.2

Over 90 per cent of people who have a stroke remain without effective treatment and must suffer the debilitating consequences, as the only clinically approved drug to treat ischaemic stroke can be used in only a small percentage of patients due to its severe side effects.

The risk

Up to 50 per cent of all strokes are preventable, and there are several factors that increase your risk of stroke that can be controlled or treated. The most important ones are:

  • high blood pressure – as the leading risk factor for stroke, the higher the blood pressure, the greater the stroke risk.
  • atrial fibrillation (AF) – one in every three strokes is linked to AF, a condition where the heart beats irregularly or rapidly. AF-linked strokes are more severe than other strokes.

Other risk factors that can be controlled include:

  • high cholesterol
  • smoking
  • excessive alcohol intake
  • poor nutrition
  • inactivity
  • diabetes
  • obesity or being overweight.

Risk factors for stroke that cannot be controlled include age (being over 65 years of age), gender (men have more strokes, though women have higher risk of fatal stroke), family history of stroke and previous stroke.

Recognising stroke

An easy way to recognise and remember the signs of stroke is to use the FAST test. If someone is showing these symptoms, then time is critical.

  • Face drooping
  • Arm weakness
  • Speech difficulty
  • Time to call 000

What is HRI doing?

HRI is tackling the devastating impact of stroke from a broad range of research angles. Our Heart Rhythm and Stroke Prevention Group is investigating how best to conduct large-scale screening for atrial fibrillation (AF), which is linked to one-third of strokes. If screening for AF could be implemented widely in those aged 65 or older, and this could be coupled with greater prescription of anticoagulant therapy as advised in guidelines, then many strokes could be avoided, not only in Australia but globally.

Our Thrombosis Research Group is investigating new ways to improve upon the limited current in-patient stroke treatment. Studies by HRI scientists have already discovered a novel drug class that can safely reduce dangerous blood clotting. They will test this novel drug in combination with thrombolysis to improve the dissolution of damaging blood clots that block blood flow to the brain. The ultimate aim of these studies is to reduce brain damage and improve outcomes post stroke-recovery.


  1. Stroke Foundation NZ; Facts and FAQs.
  2. Thrift AG et al; Stroke Incidence on the East Coast of Australia: The North East Melbourne Stroke Incidence Study (NEMESIS), 2000 Stroke, 31: 2087-2092.


Collaboration with researchers in Hanoi, Vietnam to screen in hospital to detect atrial fibrillation after cardio-thoracic surgery

Collaboration with researchers in Oklahoma (USA) to screen for atrial fibrillation in tribal Indian Clinics

Collaboration with researchers in Toyama (Japan) to investigate the incremental yield of annual screening

Collaboration with researchers in Shanghai to screen for atrial fibrillation

Collaboration with researchers in Frankfurt Germany about epidemiology of atrial fibrillation

Collaboration with Hamburg and Gutenberg Heart studies (Germany) on screening for atrial fibrillation


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