Stroke is the second major cause of death worldwide and the leading cause of long-term disability in adults.
In the world, there are approximately 80 million people living with stroke aftermath at any one time with approximately 13 million new cases every year. In the United States alone:
- There are about 5.5 million stroke survivors
- Every 45 seconds someone has a stroke
- Every 3 minutes someone in the USA dies from a stroke
- About half of stroke survivors are left disabled.
- Approximately 46,000 more women than men have a stroke annually.
In American and UK Black people the risk of having a stroke is about 1.5 - 2 times greater compared with Caucasian people. In Maori and Pacific people the risk of having a stroke is also about 1.5 - 2 times greater compared with New Zealanders of European descent and most other ethnicities. The Framingham study recently showed that the lifetime risk of having a stroke after 55 years is 1 in 5 for women and 1 in 6 for men. It has been calculated that during the course of their lives, about four out of five families will have someone affected by a stroke. Although the number of people who experience a stroke greatly increases with age, up to 25% of all strokes happen in people younger than 65 years. Each year, stroke kills more than twice as many American women as breast cancer. In the USA, under age 45 stroke accounts for as many deaths as those from auto accidents for all ages combined.
Yes, stroke is one of the most preventable life-threatening diseases – over 90% of all strokes can be prevented by controlling a few major environmental risk factors (e.g. elevated blood pressure, smoking, abdominal obesity, poor diet, sedentary lifestyle).
What is a stroke or a transient ischemic attack (TIA)?
A stroke is called a vascular injury of the brain. Damage to the blood vessels could be due to a blood clot blocking the artery and therefore the flow of blood. This may result in ischemic stroke. Breaking/rupture of the blood vessel may cause a bleed with resulting hemorrhagic stroke. There are two major types of hemorrhagic stroke: intracerebral hemorrhage and subarchnoid hemorrhage. Intracerebral hemorrhage is the bleeding into the brain tissue.
Subarachnoid hemorrhage is the bleeding into the subarachnoid space, the narrow space between the brain surface and brain tissue. In White populations, about 85% of all strokes are ischemic strokes, 10% are intracerebral hemorrhages, and 5% are subarachnoid hemorrhages. Proportion of intracerebral hemorrhages in Blacks is greater compared with Whites.
A person has a stroke if their symptoms last more than 24 hours. Stroke symptoms that last less than 24 hours and the person fully recovers are an indicator of a TIA or transient ischemic attack or mini-stroke. If a person experiences a TIA it puts them at high risk of having a stroke, so they must see a doctor immediately.
What are the warning signs and symptoms of a stroke?
You should call an ambulance immediately if you or someone you know has any of the following signs :
- Sudden numbness or weakness of the face, arm, or leg, especially on one side of the body
- Sudden complete or partial loss of vision on one or both sides
- Sudden confusion or trouble speaking or understanding
- Sudden loss of balance, unsteadiness or an unexplained fall
- Sudden vertigo, dizziness, swallowing difficulties or memory disturbances
- Sudden, severe headache with no known cause
What is a risk factor for stroke?
A risk factor for stroke is anything that increases your chance of having a stroke. Risk factors may include medical (e.g. elevated blood pressure, heart disease, diabetes, elevated cholesterol in the blood, family history), behavioural and environmental factors (e.g. smoking, unhealthy diet, sedentary lifestyle).
Elevated blood pressure or hypertension
An adult’s blood pressure is considered to be normal if it is below 120/80. That is, less than 120 systolic blood pressure and less than 80 for diastolic blood pressure. Blood pressure above the normal value but below 140/90 is called a borderline hypertension, and blood pressure 140/90 or greater is called hypertension. High blood pressure over time damages the walls of the blood vessels, causing hardening of the arteries and promotes the forming of blood clots and aneurysms.
People with heart problems are at an increased risk of stroke. Possible heart problems are angina, atrial fibrillation (that is irregular heart beat rhythm), heart failure, valve disorders, artificial valves and congenital heart defects. Valve disorder, irregular heartbeat rhythms, and sometimes after a heart attack or myocardial infarction can result in blood clots being formed in the heart. These blood clots may get loose or break down into small particles which can travel to the brain and block blood vessels, and these loose blood clots or particles are called emboli. The blockage of the blood vessels can cause an ischemic stroke.
Atherosclerosis and high cholesterol levels
An artery is a blood vessel that carries blood. Hardening of the arteries is called atherosclerosis. When the arteries harden, it narrows the middle of the artery where the blood flows. About 20-30% of people who have an ischemic stroke have hardening of the arteries, especially narrowing of the carotid artery in the neck which carries blood to the brain. High cholesterol levels (low-density and very low-density cholesterols) increase your chance of having a stroke very substantially, and therefore should be carefully controlled.
Having a diabetes mellitus doubles the chance of having a stroke. Therefore people with diabetes should try to keep their blood sugar level under very tight control and make sure that all aspects of their health are carefully controlled.
Family history and genetics
A person’s genetics that they inherit from their parents, is rarely on its own a direct cause of stroke. But genes do play a large role in some stroke risk factors such as hypertension, heart disease, diabetes, and malformed blood vessels.
Unruptured intracranial aneurysms
An aneurysm is caused by a weak point in the wall of an artery. As the wall of the artery is under pressure due to the blood pressure, the wall at the weak point may balloon out. This ballooning out of the blood vessel is called an aneurysm. If the aneurysm is inside the head, it is called an intracranial aneurysm. If the aneurysm bursts or ruptures, it will cause a bleed resulting in a subarachnoid or intracerebral haemorrhage. Whether an aneurysm ruptures is dependent on the size of the aneurysm, if the person smokes or has high blood pressure, and other mitigating factors.
The importance of stopping active smoking cannot be underestimated, no matter how long a person has smoked or the number of cigarettes smoked. It is a common misconception that if a long-term smoker stops smoking it will do them more harm than good. This is not true, the sooner a person stops smoking the more their health will benefit, and their risk of stroke is immediately lowered.
An unhealthy diet is a major risk factor for stroke. An unhealthy diet contains a lot of products that have high amounts of fat, cholesterol and salt, eg. fast food takeaways, red meat, dairy products like butter and cheese, pies and baked goods with high fat content like biscuits and pastries. These foods should be eaten in moderation. A healthy diet contains a mixture of vegetables, fruits, fish, nuts and cereals. A healthy diet lowers the risk of developing atherosclerosis and lowers blood pressure, both major risk factors for stroke.
Mild alcohol consumption of less than 2 standard drinks per day lowers the risk of stroke. However, drinking any more alcohol or binge drinking raises the risk of stroke.
People who do less than 30 minutes of exercise three times per week double their risk of stroke compared to people who exercise regularly. Lack of exercise can lead to being overweight and diabetes which are important risk factors for stroke, and can also lead to the development of atherosclerosis.
Why urgent hospitalisation is vitally important?
It is extremely important to ensure that a person who is experiencing the symptoms of a stroke, be taken to hospital urgently via ambulance. This is because ‘time is brain’, ie getting a person to hospital early will allow quick diagnosis and treatment which may not only save the person’s life, but may also improve their recovery. There are now effective medications and surgery that a doctor can provide if they feel the patient is suitable for the treatment.
What is the risk of death from a stroke?
Some strokes result in death whereas others cause permanent or temporary disability. About 2 out of 10 people who have a stroke die within the first month, 3 out of 10 die within the first year, and 5 out of 10 die within the first 5 years. The more time that passes after a stroke, the lesser is the risk of dying from it. People who have a subarachnoid or intracerebral hemorrhage as the cause of their stroke are more likely to die than people who have an ischemic stroke.
What are the possible medical complications after a stroke?
People who does survive a stroke may have permanent or temporary disability due to the damage to the brain caused by the stroke. Possible after-effects of a stroke are:
- Approximately two third of stroke survivors have partial or complete loss of movement and strength in a hand and/or leg on one side of the body. Partial loss of movement and strength is called paresis, complete loss is called paralysis.
- 80-90 per cent suffer from confusion, and problems with thinking and memory
- 30 percent have communication problems such as an inability to speak or understand spoken language
- 30 percent have difficulty swallowing called dysphagia
- 10 percent have vision problems such as complete or partial blindness, or double vision
- 10% have impaired coordination called ataxia
- 30% have problems in right-left orientation
- Up to 70% suffer from mood disorders, including depression
- 20 percent develop pain in the shoulder
- Less that 10% can develop seizures or epilepsy, especially after an intracerebral hemorrhage
- Without adequate prevention, 20 per cent develop a chest infection within one month of stroke and 10-20% develop bedsores and/or skin infection.
- Other possible complications are falls, joint deformities and contractures (where joints cannot fully bend or stretch), urinary tract infection, constipation, pulmonary embolism and heart attack (myocardial infarction)
What are the chances of having another stroke?
Whether a person will have another stroke depends on their age, the reason for the first stroke, and other medical conditions. The first 6-12 months is the time when a person who has experienced a stroke is at highest risk of another stroke. About 10% of stroke survivors have another stroke within a year, and 30% within the 5 years of their first stroke.
What are the chances of recovery?
Recovery from stroke is a long process that can continue over several years. Most of the recovery occurs in the first 2-3 years, and especially the first 6 months. Rehabilitation needs to continue in hospital, rehabilitation service, home and residential care.
- Approximately one third of stroke patients recover their lost functions fully or almost fully, and get back to their pre-stroke activities within a year.
- About 50% of stroke survivors under the age of 65 return to work.
- However at one-year after a stroke, about two third of stroke survivors will have some level of disability, ranging from light and moderate to very severe.