Stroke is a form of cardiovascular disease affecting the blood supply to the brain. Also referred to as cerebrovascular disease or apoplexy, strokes actually represent a group of diseases that affect about one out of five people in the United States.
In the US, approximately 40% of stroke deaths are in males, with 60% in females. According to the American Heart Association (AHA), in 2006, the stroke death rates per 100,00 population could be split into specific social groups at 41.7% for white males, 41.1% for white females, 67.7% for black males and 57.0% for black females.
Blood carries essential nutrients and oxygen to your brain. Without blood, your brain cells can be damaged or destroyed and they won’t be able to do their job.
Because your brain controls everything your body does, a stroke will affect the way your body functions. For example, if a stroke damages the part of your brain that controls your right leg, then you may have weakness or numbness in that leg. Your brain also controls how you think, learn, feel and communicate. A stroke is sudden and the effects on your body are immediate.
How does Stroke happen?
There are two main types of stroke. The most common type of stroke (about 85% of cases) is caused by a blockage. This is called an Ischaemic stroke and may be caused when –
- Cerebral Thrombosis – A blood clot forms in a main artery to the brain.
- Cerebral Embolism – A blockage, usually a blood clot from the heart, is carried in the bloodstream to one of the arteries supplying the brain.
- Lacunar Stroke – A blockage forms in the tiny blood vessels deep within the brain.
Ischemic strokes may also be caused by a sticky substance called plaque that can clog arteries.
Some strokes are caused by bleeding in or around the brain. This type of stroke is called a Haemorrhagic stroke. It may be caused when –
- A blood vessel bursts within the brain (an intracerebral haemorrhage), or
- A blood vessel on the surface of the brain bursts, causing bleeding into the area between the brain and the skull (called a subarachnoid haemorrhage).
Hemorrhagic strokes may also occur when someone is taking blood thinners, such as warfarin (Coumadin). Very high blood pressure may cause blood vessels to burst, leading to hemorrhagic stroke.
An ischemic stroke can develop bleeding and become a hemorrhagic stroke.
Other Causes
High blood pressure is the main risk factor for strokes. The other major risk factors are:
- Atrial fibrillation
- Diabetes
- Family history of stroke
- High cholesterol
- Increasing age, especially after age 55
- Race (black people are more likely to die of a stroke)
- Stroke risk is also higher in:
- People who have heart disease or poor blood flow in their legs caused by narrowed arteries
- People who have unhealthy lifestyle habits such as smoking, a high fat diet, and lack of exercise
- Women who take birth control pills (especially those who smoke and are older than 35)
A transient ischaemic attack (also called a TIA or mini-stroke) happens when there is a temporary blockage in the blood supply to the brain. A TIA doesn’t cause permanent damage to your brain and the symptoms usually pass within 24 hours.
It’s often hard to tell the difference between a stroke or TIA, so if you think someone is having a TIA you should still call 999. A TIA can be an important warning that there is a problem with the blood supply to your brain.
Risk Factors
Age – The older a person gets, the greater the risk of stroke.
Sex – Men are 30% more likely to have a stroke than women. But after menopause, a woman’s risk of stroke rises significantly.
Family history – Having a parent, grandparent, or sibling who has had a stroke, puts you at greater risk yourself.
Race – African-Americans have a greater risk of stroke than Caucasians. This is related to an increased risk of high blood pressure, obesity, and diabetes in African-Americans.
Heart attack – If you have had a heart attack in the past, you are more likely to have a stroke than someone who has not had a heart attack.
A history of migraine headaches – Recent studies indicate that people with migraines may be at higher risk for ischemic stroke.
A prior stroke – If you have had a stroke, you are at increased risk for another.
Sickle cell anemia – People with this condition are at risk for stroke at a younger age.
Berry aneurysms – Some people are born with small, sac-like areas within the wall of an artery in the brain. They occur most often at the junctures of vessels at the base of the brain. Berry aneurysms may rupture without warning, causing bleeding within the brain.
Symptoms
The symptoms of stroke depend on which part of the brain is damaged. In some cases, a person may not know that a stroke has occurred.
Most of the time, symptoms develop suddenly and without warning. However, symptoms may occur on and off for the first day or two. Symptoms are usually most severe when the stroke first happens, but they may slowly get worse.
- A headache may occur if the stroke is caused by bleeding in the brain. The headache:
- Starts suddenly and may be severe
- May be worse when you are lying flat
- Wakes you up from sleep
- Gets worse when you change positions or when you bend, strain, or cough
Other symptoms depend on how severe the stroke is and what part of the brain is affected. Symptoms may include –
- Change in alertness (including sleepiness, unconsciousness, and coma)
- Changes in hearing
- Changes in taste
- Changes that affect touch and the ability to feel pain, pressure, or different temperatures
- Clumsiness
- Confusion or loss of memory
- Difficulty swallowing
- Difficulty writing or reading
- Dizziness or abnormal feeling of movement (vertigo)
- Eyesight problems, such as decreased vision, double vision, or total loss of vision
- Lack of control over the bladder or bowels
- Loss of balance
- Loss of coordination
- Muscle weakness in the face, arm, or leg (usually just on one side)
- Numbness or tingling on one side of the body
- Personality, mood, or emotional changes
- Trouble speaking or understanding others who are speaking
- Trouble walking
Treatment
People who are having stroke symptoms need to get to a hospital as quickly as possible.
If the stroke is caused by a blood clot, a clot-busting drug may be given to dissolve the clot.
To be effective, this treatment must be started within 3 to 4 1/2 hours of when the symptoms first started. The sooner this treatment is started, the better chances of a good outcome.
Other treatments given in the hospital will depend on the cause of the stroke. These may include:
Blood thinners such as heparin, warfarin (Coumadin), aspirin, or clopidogrel (Plavix)
Medicine to control risk factors, such as high blood pressure, diabetes, and high cholesterol.
Physical therapy, occupational therapy, speech therapy, and swallowing therapy will all begin in the hospital. If the person has severe swallowing problems, a feeding tube in the stomach (gastrostomy tube) will likely be needed.
Medications –
Aspirin – Aspirin is an immediate treatment given in the emergency room to reduce the likelihood of having another stroke. Aspirin prevents blood clots from forming.
Intravenous injection of tissue plasminogen activator (TPA) – Some people can benefit from an injection of a recombinant tissue plasminogen activator (TPA), also called alteplase. An injection of TPA is usually given through a vein in the arm. This potent clot-busting drug needs to be given within 4.5 hours after stroke symptoms begin if it’s given in the vein.
Statins – If the level of cholesterol in the blood is too high, patient will be advised to take a medicine known as a statin. Statins reduce the level of cholesterol in the blood by blocking an enzyme (chemical) in the liver that produces cholesterol.
Antihypertensives – If the blood pressure is too high, patient may be offered medicines to lower it. Medicines that are commonly used include –
- thiazide diuretics
- angiotensin-converting enzyme (ACE) inhibitors
- calcium channel blockers
- beta-blockers
- alpha-blockers
Surgeries
- Carotid endarterectomy
- Angioplasty and stents
- Surgical clipping
- Coiling (endovascular embolization)
- Surgical AVM removal
- Intracranial bypass
- Stereotactic radiosurgery
Alternative treatment
Alpha-lipoic acid – Alpha-lipoic acid works together with other antioxidants, such as vitamins C and E. It is important for growth, helps to prevent cell damage, and helps the body rid itself of harmful substances. Because alpha-lipoic acid can pass easily into the brain, it has protective effects on brain and nerve tissue and shows promise as a treatment for stroke and other brain disorders involving free radical damage.
Calcium – In a population based study (one in which large groups of people are followed over time), women who take in more calcium, both through the diet and supplements, were less likely to have a stroke over a 14 year period.
Folic Acid, Vitamin B6, Vitamin B12, and Betaine – Many clinical studies indicate that patients with elevated levels of the amino acid homocysteine are as much as 2.5 times more likely to suffer from a stroke than those with normal levels. Homocysteine levels are strongly influenced by dietary factors, particularly vitamin B9 (folic acid), vitamin B6, vitamin B12, and betaine. These substances help break down homocysteine in the body.
Magnesium – Population based information suggests that people with low magnesium in their diet may be at greater risk for stroke.
Omega-3 Fatty Acids – Strong evidence from population-based studies suggests that omega-3 fatty acid intake (primarily from fish) helps protect against stroke caused by plaque buildup and blood clots in the arteries that lead to the brain.
Potassium – Although low levels of potassium in the blood may be associated with stroke, taking potassium supplements does not seem to reduce the risk of having a stroke.
Vitamin C – Having low levels of vitamin C contributes to the development of atherosclerosis and other damage to blood vessels and the consequences, such as stroke. Vitamin C supplements may also improve cognitive function if you have suffered from multiple strokes.
Vitamin E – Eating plenty of foods rich in vitamin E, along with other antioxidants like vitamin C, selenium, and carotenoids, reduces your risk for stroke. In addition, low levels of vitamin E in the blood may be associated with risk of dementia (memory impairment) following stroke.
Coenzyme Q10 – works as an antioxidant and may reduce damage following a stroke. CO Q10 may interfere with some blood-thinning medicines, such as warfarin (Coumadin) and others.
Selenium – low levels can worsen atherosclerosis and its consequences. However, it is not known if taking selenium supplements will help.
Bilberry – A close relative of the cranberry, bilberry fruits contain flavonoid compounds called anthocyanidins. Flavonoids are plant pigments that have excellent antioxidant properties.
Garlic – Clinical studies suggest that fresh garlic and garlic supplements may prevent blood clots and destroy plaque. Blood clots and plaque block blood flow and contribute to the development of heart attack and stroke. Garlic may also be beneficial for reducing risk factors for heart disease and stroke like high blood pressure, high cholesterol, and diabetes.
Ginkgo – Gingko may reduce the likelihood of dementia following multiple strokes (often called multi-infarct dementia). The protection from ginkgo may be related to the prevention of platelet adhesion which can help prevent blood clot formation. Most health care providers choose to use medications for this effect rather than herbs.
Ginseng – Asian ginseng may decrease endothelial cell dysfunction. Endothelial cells line the inside of blood vessels. When these cells are disturbed, referred to as dysfunction, it may lead to a heart attack or stroke.
Acupuncture – Many studies have been conducted on the effects of acupuncture during stroke rehabilitation. These studies show that acupuncture reduces hospital stays and improves recovery speed. Acupuncture has been shown to help stroke patients regain motor and cognitive skills and to improve their ability to manage daily functioning.
Chiropractors do not treat stroke, and high velocity manipulation of the upper spine is considered inappropriate in individuals who are taking blood-thinning medications or other medications used to reduce the risk of stroke.
Reference –
https://www.nice.org.uk/guidance/cg68/chapter/Introduction#drugs
http://www.nhs.uk/Conditions/Stroke/Pages/treatment.aspx
http://www.stroke.org.nz/preventing-stroke-translations
http://www.stroke.org.nz/preventing-stroke-translations
https://www.nlm.nih.gov/medlineplus/stroke.html
http://www.stroke.org/understand-stroke/what-stroke
http://www.emedicinehealth.com/stroke/article_em.htm
http://www.heartandstroke.com/site/c.ikIQLcMWJtE/b.3483935/k.736A/Stroke__What_is_Stroke.htm