Definition: Defining the Meaning of Stroke
Sometimes referred to as a cerebrovascular accident (CVA), cerebrovascular insult (CVI), or colloquially called a brain attack, is the loss of brain function due to a disturbance in the blood supply to the brain. This disturbance is due to either ischemia (lack of blood flow) or hemorrhage. As a result, the affected area of the brain cannot function normally, which might result in an inability to move one or more limbs on one side of the body, failure to understand or formulate speech, or a vision impairment of one side of the visual field.
What is a Stroke
A stroke is the rapidly developing loss of brain functions due to a disturbance in the blood vessels supplying blood to the brain. This can be due to ischemia (lack of blood supply) caused by thrombosis or embolism or due to a hemorrhage. As a result, the affected area of the brain is unable to function, leading to inability to move one or more limbs on one side of the body, inability to understand or formulate speech or inability to see one side of the visual field
A stroke occurs when the supply of blood to the brain is suddenly interrupted. There are two types of strokes. When the arteries carrying blood to the brain are abruptly blocked, it is called an ischemic stroke. When a blood vessel bursts and blood seeps into the brain tissue it is known as a hemorrhagic stroke.
Types of Strokes Include:
Ischemic stroke - In an ischemic stroke, blood supply to part of the brain is decreased, leading to dysfunction of the brain tissue in that area.
Hemorrhagic stroke - Intracranial hemorrhage is the accumulation of blood anywhere within the skull vault.
Thrombotic stroke - In thrombotic stroke, a thrombus (blood clot) usually forms around atherosclerotic plaques. Since blockage of the artery is gradual, onset of symptomatic thrombotic strokes is slower.
Embolic stroke - An embolic stroke refers to the blockage of an artery by an embolus, a traveling particle or debris in the arterial bloodstream originating from elsewhere.
According to neurologists, if a stroke can be immediately recognized and medical attention made available within three hours, it is normally possible to reverse the effects, often completely. The problem is that strokes are often unrecognized since most people are unaware of the symptoms.
A severe stroke, if not treated in time, can result in death. Even if the stroke is not fatal, it may cause neurological damage that will the leave patient incapacitated for life. The brain is one of the most complex organs in the body. Even if other organs fail, the brain may continue to keep functioning. But when the brain stops functioning completely - brain death - the other organs have nothing to control them and gradually die also.
The effects of a stroke depend on the location of the obstruction - which part of the brain is deprived of blood - and the amount of tissue damage.
One side of the brain controls the opposite side of the body and also specific organs, so a stroke occurring in the right side of the brain could result in, among others:
- Paralysis of the left side of the body
- Problem with vision
- A sudden change in behavior
- usually rapid erratic movement
- Loss of memory
A stroke in the left side of the brain may cause:
- Paralysis to the right side of the body
- Problem in speaking, incoherent speech
- Memory loss
- Slow uncertain body movements
Warning signs of a stroke are:
- Any sudden weakness or numbness of the face or the limbs, especially on one side of the body
- Sudden severe headaches with no discernible cause
- A sudden onset of confusion
- being unable to talk, speaking in an unclear or garbled manner, speaking illogically
- Inability to understand what is being said
- Trouble with seeing or focusing, with both or just one eye
- A sudden onset of dizziness, loss of balance, uncoordinated physical movements or trouble in walking.
Remember that these symptoms maybe transitory, as in the case of the lady at the party. Do not ignore any of these symptoms even if these seem to disappear in a few seconds or minutes and the person appears to be fine. If a stroke has occurred, brain damage need not be immediately apparent and signs may not surface for several hours, by which time it may be too late to help.
There is a simple and medically approved way to see if a person has suffered as stroke. It is called STR and is worth remembering.
STR stands for:
Smile - ask the person suspected of having had a stroke to smile.
Talk - ask the person to speak a simple sentence: describe what kind of car he owns or where he lives.
Raise - ask the person to raise his arms above his head.
Doctors suggest one other way to know if a person has suffered a stroke - ask the person to stick out his tongue. If his tongue is not straight or droops or slants to one side rather than coming straight out of his mouth, it is an indication of a stroke.
If the person has difficulty in performing any one of these tasks, it is more than likely he has suffered a stroke and medical help should be IMMEDIATELY called for.
Until help arrives, caring for a stroke victim is limited to offering support to the victim. But this is important and may prevent further deterioration of the condition while waiting for medical help - If there is someone available with CPR training, the victim's circulation, breathing and airway should be checked as per standard CPR procedure.
The paramedics should be briefed, when they arrive, on symptoms observed and action taken.
- Lay the victim down flat with the head and shoulder slightly raised to reduce the blood pressure in the brain
- If the victim is unconscious, gently roll him so he is lying on his left side and pull the chin forward. This will help to keep the airway open and allow any vomit to drain and not hamper the breathing.
- If the victim is conscious speak reassuringly and offer all the positive support you can. Keep saying that help is on the way.
- Never give a stroke victim any thing to eat or drink. The throat may be paralyzed and they may choke.
Strokes are the third largest killers in America, after heart disease and cancer.
There is a relationship between high blood pressure, snoring and strokes.
Various systems have been proposed to increase recognition of stroke by patients, relatives and emergency first responders. 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.
Hypertension (high blood pressure) accounts for 35 to 50% of stroke risk. Blood pressure reduction of 10 mmHg systolic or 5 mmHg diastolic reduces the risk of stroke by ~40%. Lowering blood pressure has been conclusively shown to prevent both ischemic and hemorrhagic strokes. It is equally important in secondary prevention. Even patients older than 80 years and those with isolated systolic hypertension benefit from antihypertensive therapy. The available evidence does not show large differences in stroke prevention between antihypertensive drugs - therefore, other factors such as protection against other forms of cardiovascular disease should be considered and cost. The routine use of beta-blockers following a stroke or TIA has not been shown to result in benefits.
- Dysfunctions correspond to areas in the brain that have been damaged.
- The results of stroke vary widely depending on size and location of the lesion.
- Stroke can affect peoples physically, mentally, emotionally, or a combination of the three.
- A stroke sufferer may be unaware of his or her own disabilities, a condition called anosognosia.
- If a stroke is severe enough, or in a certain location such as parts of the brainstem, coma or death can result.
- Post-stroke emotional difficulties include anxiety, panic attacks, flat affect (failure to express emotions), mania, apathy and psychosis.
- Cognitive and psychological outcome after a stroke can be affected by the age at which the stroke happened, pre-stroke baseline intellectual functioning, psychiatric history and whether there is pre-existing brain pathology.
- Overall two thirds of strokes occurred in those over 65 years old.
- Disability affects 75% of stroke survivors enough to decrease their employability.
- Stroke was the second most frequent cause of death worldwide in 2011, accounting for 6.2 million deaths (~11% of the total).
- Approximately 17 million people had a stroke in 2010 and 33 million people have previously had a stroke and were still alive.
- Between 1990 and 2010 the number of strokes decrease by approximately 10% in the developed world and increased by 10% in the developing world.
- 30 to 50% of stroke survivors suffer post-stroke depression, which is characterized by lethargy, irritability, sleep disturbances, lowered self-esteem and withdrawal.
- Up to 10% of people following a stroke develop seizures, most commonly in the week subsequent to the event; the severity of the stroke increases the likelihood of a seizure.