A stroke causes an immediate medical emergency. Seconds count and delays can cause permanent brain damage, complications and death.
In simple terms, a stroke is a disturbance in the blood supply to the brain and stroke causes are differentiated in two categories.
The first is labeled an ischemic stroke which means that a blood vessel has become clogged by a clot or plaque buildup. The medical term is a thrombosis or embolism. What it means is that the blood supply to some part of the brain has been cut off.
The second of the stroke causes is the hemorrhagic, meaning that a blood vessel has burst.
In either case the result is the same; the affected area in the brain can no longer function...no blood supply, no brain function.
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It would be a good reference book for anyone interested in knowing more about the subject.
Whether the stroke causes are ischemic or hemorrhagic, visible symptoms of a brain attack are the loss of control over one or more limbs, the inability to understand or speak, or possibly the inability to see one side of the visual field.
Stroke symptoms typically start suddenly, over seconds to minutes, and in most cases don't progress further.
The symptoms depend on the area of the brain affected and the more extensive the area of brain affected, the more functions that are likely to be lost.
Some forms of stroke can cause additional symptoms: in intracranial hemorrhage, the affected area may compress other structures.
Most forms of stroke are not associated with headache, apart from subarachnoid hemorrhage and cerebral venous thrombosis and occasionally intracerebral hemorrhage.
Early recognition of a brain attack is critical and various systems have been proposed to increase recognition of stroke by patients, relatives and emergency first responders. The easiest to remember is FAST.
FAST stands for face, arm, speech and time. Sudden-onset face weakness, arm drift, and abnormal speech are the findings most
likely to lead to the correct identification of a case of stroke.
For people referred to the emergency room, understanding stroke causes and early recognition of stroke by ER personnel is vital as this can expedite diagnostic tests and treatments. In addition to FAST, emergency room personnel are trained to recognize stroke based on medical history and physical examination.
In 2010 strokes were the number four cause of death in the U.S. behind heart disease (No. 1), Cancer (No. 2) and chronic lower respiratory diseases (No. 3). The number four spot accounted for 129,476 deaths or 5.25% of all deaths.
In 2010 there was a bit of good news on the incidence of strokes. There was actually a decrease of 14,103 deaths from 2005 to 129,476 stroke deaths.
It appears that Americans are starting to do something right in terms of stroke prevention in that by 2009, the incidence of stroke deaths was down considerably, moving stroke to the number 4 cause of death in the U.S. where it sits today.
Stroke deaths have actually been declining for the last 100 years and dropped 30% over the last eleven years although the Southeastern U.S. is still a hot bed of stroke activity.
From the Centers for Disease Control, we get the following sound bites:
Worldwide, brain attack, or stroke, is the number two cause of death and may rise to number one due to improving survival rates in cancer and cardiovascular diseases.
80% of stroke causes are related to ischemia; the remainder are due to hemorrhage. Some hemorrhages develop inside areas of ischemia ("hemorrhagic transformation") but it is unknown how many hemorrhages actually start off as ischemic stroke.
If a heart attack is a myocardial infarction, then a brain attack (stroke) is a cerebral Infarction.
In an ischemic stroke, blood supply to part of the brain is decreased, leading to dysfunction or death of the brain tissue in the affected area.
Four typical stroke causes in an ischemic incident are:
Sometimes stroke causes are not readily apparent. They occur without any obvious explanation, in which case they are referred to as a "cryptogenic" (of unknown origin) event. This is a fairly usual situation accounting for between 30 and 40% of all ischemic strokes.
There are various classification systems for an acute ischemic strokes based on the initial symptoms, the extent of the symptoms, site and area of tissue death from the circulation blockage.
Other systems are based on whether a thrombosis or embolism is suspected due to atherosclerosis of one of the large arteries, an embolism of cardiac origin, obstruction of a small vessel, or some undetermined cause.
The hemorrhagic stroke results from a ruptured vessel in the brain. An Intracranial hemorrhage refers to the accumulation of blood anywhere within the skull while intracerebral hemorrhage is inside the brain.</p>
Other terms are intra-axial and extra-axial hemorrhages meaning blood accumulating inside the brain or between the skull and brain.
Photo: CT scan showing an intracerebral hemorrhage
In intracerebral hemorrhage, bleeding occurs directly into the functional parts of the brain, called the parenchyma.
The usual mechanism is leakage from small arteries in the brain that sustain damage from long term high blood pressure.
Other stroke causes may include spontaneous bleeding from a defective clotting mechanism or structural defect in the blood
vessel, prescribed blood thinning medications (iatrogenic anticoagulation), abnormal protein buildup in the brain, and, occasionally, cocaine abuse.
Intracerebral hemorrhage has a preference for certain locations in the brain such as the thalamus, the putamen in the forebrain, the cerebellum, and brain stem.
In addition to the area of the brain injured by the hemorrhage, the surrounding brain can be damaged by pressure produced by the mass effect of the hematoma.
A general increase in intracranial pressure may occur.
In a nutshell, risk factors for strokes causes include advanced age, hypertension (high blood pressure), previous stroke or transient ischemic attack (TIA), diabetes, high cholesterol, cigarette smoking and atrial fibrillation.
Let's consider the most treatable risk factors.
High blood pressure, also called hypertension, is the most potent risk factor for stroke and also the easiest to control or reverse.
If your blood pressure is high, you and your doctor need to work out an individual strategy to bring it down to the normal range.
Common sense ways that have been successful in lowering blood pressure include the maintenance of proper weight and avoiding drugs known to raise blood pressure.
Dietary changes include reducing salt intake and eating more fruits and vegetables to increase potassium in the diet. Recent studies show that a deficiency in vitamin C and iron are risk factors for stroke in some people.
Finally, add a daily exercise routine to your schedule.
Most doctors will quickly prescribe statins such as Lipitor, Crestor, Zocor or others that help lower blood pressure.
Most of the statin drugs have side effects; especially lapses of cognitive abilities, so beware of changes in cognitive ability while on statins.
Take a look at Duane Graveline's book, "Lipitor, Thief of Memory" shown above. Dr. Graveline, more affectionately known as "SpaceDoc" is an M.D. who was a NASA flight controller for the Mercury and Gemini missions.
The book chronicles his own experiences while taking prescribed statin drugs for cholesterol buildup. Click on the book image for ordering information from Amazon.com.
As an added benefit, controlling blood pressure will also help avoid heart disease, diabetes, and kidney failure.
Conversely, factors that tend to increase blood pressure are:
Cigarette smoking has been linked to the buildup of fatty substances in the carotid artery, the main neck artery supplying blood to the brain. Blockage of this artery is the leading cause of a brain attack in Americans.
Also, nicotine raises blood pressure; carbon monoxide reduces the amount of oxygen your blood can carry to the brain; and cigarette smoke makes your blood thicker and more likely to clot.
Doctors can recommend programs and medications that may help you quit smoking. By quitting, at any age, you also reduce your risk of lung disease, heart disease, and a number of cancers including lung cancer.
Common heart disorders such as coronary artery disease, valve defects, irregular heartbeat, and enlargement of one of the heart's chambers can result in blood clots that may break loose and block vessels in or leading to the brain.
The most common blood vessel disease, caused by the buildup of fatty deposits in the arteries, is called atherosclerosis.
Doctors typically treat heart disease with blood thinners or even aspirin to help prevent the formation of clots.
In addition, the doctor may recommend surgery to clean out a clogged neck artery if you match a particular risk profile.
In lieu of surgery, a Merci retriever may be threaded through the blocked vessel to ensnare the clot and pull it out. In the photo to the right, it resembles a "plumbers snake" used to pull hair clogs out of a drain.
Photo: The Merci Retriever grabbing a clot in a blocked blood vessel
If you experience a TIA, get help at once. Many communities encourage those with stroke's warning signs to dial 911 for emergency medical assistance.
If you have had a stroke in the past, it's important to reduce your risk of a second stroke. Your brain helps you recover from a stroke by drawing on body systems that now do double duty. That means a second stroke can be twice as bad.
You may think this disorder affects only the body's ability to use sugar, or glucose. But it also causes destructive changes in the blood vessels throughout the body, including the brain.
Also, if blood glucose levels are high at the time of a stroke, then brain damage is usually more severe and extensive than when blood glucose is well-controlled.
Treating diabetes can delay the onset of complications that
increase the risk of stroke.
From the foregoing, we can conclude that the risk of stroke should be lowered significantly by following a short
list of guidelines.
Finally, observe a few practical tips for getting started on a healthier diet and lifestyle.
For example, don't try to change everything at once. Whatever lifestyle changes need to be made should be done gradually, maybe one or two changes per month.
Make eating an adventurous experience by broadening your horizons in tastes. Try a greater variety of foods; venture into ethnic dining.
If you have been a meat and potatoes person, venture into Indian cuisine, Thai, Greek, Cuban; you get the idea. Learn to enjoy all foods but moderation is the watchword; small portions and five small meals throughout the day.
We said it before but it bears repeating. Be flexible by balancing what you eat with physical activity over several days. Exercise is critical for health and wellness. Strokes or brain attacks aren't any fun, help yourself to avoid them.
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