What is a stroke?
A stroke can be caused by an obstruction in the blood flow, or the rupture of an artery that feeds the brain.
The patient may suddenly lose the ability to speak, there may be memory problems, or one side of the body can become paralyzed.1
This Medical News Today information article provides details on the two types of stroke, who are at risk, what its causes are, its symptoms, how a stroke is treated, and how strokes can be prevented.
The two main types of stroke
The two main types of stroke include ischemic stroke and hemorrhagic stroke.Ischemic stroke
Ischemic stroke accounts for about 87% of all strokes and occurs when a blood clot, or thrombus forms that blocks blood flow to part of the brain.If a blood clot forms somewhere in the body and breaks off to become free-floating, it is called an embolus. This wandering clot may be carried through the bloodstream to the brain where it can cause ischemic stroke.
Hemorrhagic stroke
A hemorrhagic stroke occurs when a blood vessel on the brain's surface ruptures and fills the space between the brain and skull with blood (subarachnoid hemorrhage) or when a defective artery in the brain bursts and fills the surrounding tissue with blood (cerebral hemorrhage).Both types of stroke result in a lack of blood flow to the brain and a buildup of blood that puts too much pressure on the brain.
The outcome of a stroke depends on where the stroke occurs and how much of the brain is affected. Smaller strokes may result in minor problems, such as weakness in an arm or leg. Major strokes may lead to paralysis or death. Many stroke patients are left with weakness on one side of the body, difficulty speaking, incontinence, and bladder problems.
Fast facts on stroke
Here are some key points about stroke. More detail and supporting information is in the main article.
Here are some key points about stroke. More detail and supporting information is in the main article.
- A stroke is a condition in which the brain cells suddenly die because of a lack of oxygen.
- A stroke can be caused by an obstruction in the blood flow, or the rupture of an artery that feeds the brain.
- The patient may suddenly lose the ability to speak, there may be memory problems, or one side of the body can become paralyzed.
- There are two main types of stroke; ischemic and hemorrhagic.
- Anyone can suffer from stroke. Although many risk factors are out of our control, several can be kept in line through proper nutrition and medical care.
- Ischemic strokes are ultimately caused by a thrombus or embolus that blocks blood flow to the brain.
- Hemorrhagic strokes can be caused by uncontrolled high blood pressure, a head injury, or aneurysms.
- Symptoms include loss of balance, speech problems, dizziness, paralysis, impaired vision, sudden severe headache, confusion.
- Smaller strokes (or silent strokes), however, may not cause any symptoms, but can still damage brain tissue.
- Stroke is treated by trying to restore blood flow to the brain using a blood clot-busting drug called tissue plasminogen activator (tPA). In addition, surgical procedures may be performed that can open up or widen arteries.
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| A stroke is a condition in which the brain cells suddenly die because of a lack of oxygen. |
Who gets stroke?
Anyone can suffer from stroke. Although many risk factors are out of our control, several can be kept in line through proper nutrition and medical care.
- Age - as you get older your risk increases
- Being male
- A family history of stroke
- High blood pressure
- High cholesterol
- Smoking cigarettes
- Diabetes5
- Obesity and overweight
- A previous stroke or transient ischemic attack (TIA)
- High levels of homocysteine (an amino acid in blood)
- Divorced men have a higher risk of stroke.
Heavy use of alcohol
Researchers from the University of Lille Nord de France, Lille, France, reported in the journal Neurology that heavy regular drinkers have a considerably higher risk of stroke early in life compared to others.Depression
Middle-aged women with clinical depression have a higher risk of stroke, researchers from the University of Queensland, Australia, reported in the journal Stroke.The authors gathered data on 10,547 Australian females aged from 47 to 52 years. They found that women with depression are more likely to have a stroke by a factor of 2.4, compared to women without depression.Even after taking into account known stroke risk factors, depressed middle-aged women were still 1.9 times more likely to have a stroke.
Caroline Jackson, Ph.D., said "When treating women, doctors need to recognize the serious nature of poor mental health and what effects it can have in the long-term. Current guidelines for stroke prevention tend to overlook the potential role of depression."
The researchers emphasized that although the risk was higher for women with depression, their total risk of stroke was still low.
What causes stroke?
Ischemic strokes are ultimately caused by a thrombus or embolus that blocks blood flow to the brain. Blood clots (thrombus clots) usually occur in areas of the arteries that have been damaged by atherosclerosis from a build-up of plaques.Embolus type blood clots are often caused by atrial fibrillation - an irregular pattern of heart beat that leads to blood clot formation and poor blood flow.
Hemorrhagic strokes can be caused by uncontrolled high blood pressure, a head injury, or aneurysms. High blood pressure is the most common cause of cerebral hemorrhage, as it causes small arteries inside the brain to burst. This deprives brain cells of blood and dangerously increases pressure on the brain.
Aneurysms - abnormal blood-filled pouches that balloon out from weak spots in the wall of an artery - are the most common cause of subarachnoid hemorrhage. If an aneurysm ruptures, blood spills into the space between the surfaces of the brain and skull, and blood vessels in the brain may spasm. Aneurysms are often caused or made worse by high blood pressure.
A study published in the American Journal of Human Genetics found a single gene defect can lead to stroke and deadly diseases of the aorta and coronary arteries.11
A less common form of hemorrhage stroke is when an arteriovenous malformation (AVM) ruptures. AVM is an abnormal tangle of thin-walled blood vessels that is present at birth.
An article published in the BMJ Online reported that migraines increase stroke risk during pregnancy.
What are the symptoms of stroke?
Within a few minutes of having a stroke brain cells begin to die and symptoms emerge. It is important to recognize the symptoms, as prompt treatment is crucial to recovery.Common symptoms include:
- Trouble walking, loss of balance and coordination
- Speech problems
- Dizziness
- Numbness, weakness, or paralysis
- Blurred, blackened, or double vision
- Sudden severe headache
- Confusion.
A transient ischemic attack (TIA) may be a sign of an impending stroke - TIA is a temporary interruption in blood flow to part of the brain. Symptoms of TIA are similar to stroke but last for a shorter period and do not leave noticeable permanent damage.
How is stroke diagnosed?
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| Doctor assessing an MRI brain scan |
A stroke is a medical emergency, and anyone suspected of having one
should be taken to hospital immediately so that tests can be run and the
correct treatment can be provided as quickly as possible.
Physicians have several tools available to screen for stroke risk and
diagnose an active stroke. These include:- Physical assessment - blood pressure tests and blood tests to see cholesterol levels, blood sugar levels, and amino acid levels
- Ultrasound - a wand waved over the carotid arteries in the neck can provide a picture that shows whether there is any narrowing or clotting
- Arteriography - a catheter is inserted into the arteries to inject a dye that can be picked up by X-rays
- Computerized tomography (CT) scan - a scanning device that creates a 3D image that can show aneurysms, bleeding, or abnormal vessels within the brain
- Magnetic resonance imaging (MRI) - a magnetic field generates a 3D view of the brain to look at tissue damaged by stroke
- CT and MRI with angiography - scans that are aided by a dye that is injected into the blood vessels in order to provide clearer and more detailed images
- Echocardiography - an ultrasound that makes images of the heart to check for embolus
- Eye-movement analyzer may diagnose stroke - researchers from Johns Hopkins University School of Medicine in Baltimore created a device that can help diagnose stroke by expertly analyzing eye movements. They reported their findings in the journal Stroke. The electronic device is a small, portable, video-oculography machine. It detects eye movements that most doctors find hard to notice.23
Recent developments on
stroke diagnosis from MNT news
'Strokefinder' helmet makes rapid stroke diagnoses - A helmet that uses microwaves to examine brain tissue has been found to accurately diagnose the type of stroke that a patient has suffered. If developed, the device could lead to early and correct diagnosis of stroke and may improve treatment for what is currently the 4th highest cause of death in the US.
'Strokefinder' helmet makes rapid stroke diagnoses - A helmet that uses microwaves to examine brain tissue has been found to accurately diagnose the type of stroke that a patient has suffered. If developed, the device could lead to early and correct diagnosis of stroke and may improve treatment for what is currently the 4th highest cause of death in the US.
How is stroke treated?
The primary goal in treating ischemic stroke is to restore blood flow to the brain. This will be attempted using a blood clot-busting drug called tissue plasminogen activator (tPA). A doctor will inject tPA into the patient's arm. If for some reason the patient can't receive the tPA then an anti-platelet medicine will be used instead.24In addition, surgical procedures may be performed that can open up or widen arteries. These include carotid endarterectomy (removal of plaque and widening of the carotid artery) and angioplasty (a balloon that widens the carotid artery and is held open with a metallic mesh tube called a stent).
Hemorrhagic stroke is treated differently than ischmic stroke. Surgical methods used to treat this stroke variant include aneurysm clipping, aneurysm embolisation, and arteriovenous malformation (AVM) removal.
Aneurysm clipping consists of a small clamp placed at the base of the aneurysm that isolates it from the circulation of it's attached artery and keeps the aneurysm from bursting or re-bleeding.24
Aneurysm embolisation (coiling) uses a catheter inserted into the aneurysm to deposit a tiny coil that fills the aneurysm, causing clotting and sealing off the aneurysm off from arteries. AVM removal is a surgical procedure to remove usually smaller AVMs or AMVs that are in more accessible portions of the brain in order to eliminate the risk of rupture
Most stroke patients will require rehabilitation after the event. A person's condition is generally dependent on the area of the brain and the amount of tissue that was damaged. It is common for the rehabilitation process to include speech therapy, occupational therapy, physical therapy, and family education.
Investigators at Massachusetts General Hospital found that patients who had experienced strokes as long as six months earlier were able to regain brain function through the help of a novel robotic device that they squeezed with their hand.
Recent developments on
stroke treatment from MNT news
University of Oxford researchers discovered how the brain protects itself from damage caused by stroke. If researchers can identify the inbuilt biological mechanism that protects the brain researchers will be a step closer to developing effective treatments for stroke.
Stem cell discovery: Astrocytes could repair stroke brain damage. A collaborative study published in Nature Communications revealed that astrocytes may prove useful against stroke and other brain disorders.27
University of Oxford researchers discovered how the brain protects itself from damage caused by stroke. If researchers can identify the inbuilt biological mechanism that protects the brain researchers will be a step closer to developing effective treatments for stroke.
Stem cell discovery: Astrocytes could repair stroke brain damage. A collaborative study published in Nature Communications revealed that astrocytes may prove useful against stroke and other brain disorders.27
Most stroke patients have undiagnosed "attention" disorders
A study carried out by a team at Imperial College London found that many stroke patients have undiagnosed attention problems. Examples include difficulties filtering out distraction, reduction in alertness, and problems following instructions.The researchers tested 100 stroke patients and 62 controls (people who had not had a stroke). Five of the stroke patients had already been diagnosed with neglect - poor awareness and attention in one side of the body.
All the 162 participants were given an ANT (attention network test), a computer-based test which measures alertness, executive control and orientation. They also underwent an MRI brain scan.
The team found that more than half of the stroke patients had undiagnosed attention disorders.
Head investigator, Dr. Paul Bentley, said:
"We found that more than half of stroke patients have some form of attention problem, and these may be missed by routine bedside examinations."Dr. Bentley explained that MRI brain scans can help predict what type of attention problems stroke patients might have. Those with the front of the brain affected tended to have problems filtering out distraction, if the center of the brain was affected the patients were more likely to have poorer alertness, while lesions in the back of the brain were linked to difficulties following instructions.
How can stroke be prevented?
One way to prevent a stroke is to be aware of a transient ischemic attack (TIA) - or mini stroke - if one occurs, the symptoms are similar to stroke. Knowing the symptoms of stroke can lead to earlier treatment and better recovery.Much of stroke prevention is based on living a healthy lifestyle, which include:
- Identifying and controlling blood pressure
- Not smoking
- Lowering cholesterol, sodium, and fat intake
- Drinking alcohol only in moderation
- Treating diabetes properly
- Managing stress
- Being physically active.
If you eat plenty of tomatoes, your risk of developing stroke could be reduced significantly. Tomatoes are rich in lycopene, a powerful antioxidant. In a study published in Neurology, October 2012, researchers found that people with high blood concentrations of lycopene had a 59% lower risk of stroke compared to those with the lowest concentrations.
Mediterranean diet helps prevent a genetic risk of stroke - a mutation in the Transcription Factor 7-like 2 (TCF7L2) gene, which is linked to the development of type 2 diabetes, is also associated with stroke risk, especially if the person is a homozygous carrier (carries two copies of the gene variant).
Scientists from the CIBER Fisiopatología de la Obesidad y Nutriciόn, Spain, and Tufts University, USA, found that the Mediterranean diet may protect homozygous carriers of the gene variant.
The investigators explained in the journal Diabetes Care "Being on the Mediterranean diet reduced the number of strokes in people with two copies of the variant. The food they ate appeared to eliminate any increased stroke susceptibility, putting them on an even playing field with people with one or no copies of the variant."
Recent developments on
stroke prevention from MNT news
Vitamin B supplements may protect from stroke. A study carried out at Zhengzhou University in China found that vitamin B supplements could reduce people's risk of having a stroke. The research was published in the journal Neurology.
Walking for at least 210 minutes each week was found to reduce the risk of stroke in women. Women who walk for more than 210 minutes per week are at a lower risk of stroke compared to those who did not do much physical activity, researchers from the Murcia Regional Health Authority, Spain, reported in the journal Stroke (January 2013 issue). However, the same benefit was not found among men
Cholesterol-lowering drugs can prevent stroke recurrence. According to research published in the May 26, 2009, print issue of Neurology, people who take cholesterol-lowering drugs called statins after a stroke may be less likely to have another stroke later.34
Could a diet higher in protein reduce the risk of stroke? A new or recurrent stroke occurs in around 795,000 Americans every year and causes approximately 137,000 deaths. But research published in the journal Neurology suggests a diet higher in protein may reduce stroke risk.
click :Stroke:
or
stroke: risk and effect
Vitamin B supplements may protect from stroke. A study carried out at Zhengzhou University in China found that vitamin B supplements could reduce people's risk of having a stroke. The research was published in the journal Neurology.
Walking for at least 210 minutes each week was found to reduce the risk of stroke in women. Women who walk for more than 210 minutes per week are at a lower risk of stroke compared to those who did not do much physical activity, researchers from the Murcia Regional Health Authority, Spain, reported in the journal Stroke (January 2013 issue). However, the same benefit was not found among men
Cholesterol-lowering drugs can prevent stroke recurrence. According to research published in the May 26, 2009, print issue of Neurology, people who take cholesterol-lowering drugs called statins after a stroke may be less likely to have another stroke later.34
Could a diet higher in protein reduce the risk of stroke? A new or recurrent stroke occurs in around 795,000 Americans every year and causes approximately 137,000 deaths. But research published in the journal Neurology suggests a diet higher in protein may reduce stroke risk.
click :Stroke:
or
stroke: risk and effect
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