Stroke
This essay aims to cover the causes, affects and symptoms of Stroke as well as the different risk factors involved. This particular field of study has been chosen because Stroke is recognized as the third biggest killer in Australia, USA and the UK and when it does occur, is treated as a medical emergency much like a heart attack. A stroke occurs when blood supply to the brain is disrupted or cut off and depending on which part of the brain this transpires, can affect the patient in many ways and in some cases can be fatal. This essay will illustrate the different affects the illness can have on the patient and the possible effects to the family, in conjunction with the impact it can have on the conventional anatomy and physiology of the area of the human body affected by stroke. This essay will also aim to cover the different types of stroke, along with the different symptoms that can be recognised.
There are two main types of stroke, the most common type is an Ischaemic stroke which is a blockage and this happens when an artery that carries blood to the brain clots therefore depriving the brain of blood. The second type is known as a haemorrhagic stroke, which is caused by the burst of a blood vessel inducing bleeding into the brain or the subarachnoid space, the space between the brain and the skull. Research suggests (Hachinski et al 2004) that you are never too young or old to be at risk of stroke and even an unborn baby can experience the harmful effects of a stroke.
stroke is usually considered to be an illness associated with the elderly, but this publication suggests this is not the case.
An estimated one hundred and fifty thousand people suffer from stroke each year in the UK, and sixty seven thousand of which will die from their symptoms. This evidence supports the claim that stroke can be a life threatening illness and these figures appear to show that it is a common condition for people in the UK. Inasmuch, the survivor’s of stroke and their families also have to deal with the subsequent effects the patient’s stroke has made in conjunction to their work and social life, which can depend on which part of the brain has been damaged. Dealing with depression, memory loss, slow thought process, speech and language difficulties and even paralysis is common in a stroke survivor.
If a patient has lost the use of or sustained a weakness to the right side of the body, it means they have suffered a stroke that has caused damage to the left side of their Cerebrum, and this is reversed in the case of a left sided attack which can result in right sided weakness.
The Cerebrum is the central system where the thought processes, memory and sense functions are stored. The right side of the Cerebrum, known as the right hemisphere, controls the left side of our body and the left Hemisphere controls the right side. Patients who have suffered from stroke may experience difficulty when eligible for discharge from hospital as it may be found to be problematic returning home with paralysis to one side of the body and other changes the body has undergone physically. In this case the relevant changes may need to be implemented to the home, alterations such as handlebars built in to the walls to help the patient with transferring and toileting, as well as suitable sized ramps for the patient if a wheelchair is required.
To gain an understanding of the pathological change that Stroke can have to the body, looking at the basic anatomy and physiology of the brain will highlight the effects stroke can have.
An important part of the brain where stroke can cause significant damage is known as the Cerebrum. Hachinski et al (2004) suggests the Cerebrum defines us as humans, it receives information from all parts of the body, analyses it, compares it with previously stored information and decides if any action needs to be taken; it then sends information to the muscles, causing them to perform the appropriate actions, all of this happens instantaneously.
This statement highlights the significance of the Cerebrum showing evidence for it as being at the centre of a lot of brain activity, and being able to process information at a fast pace so the body can respond to specific activities it is faced with on a daily basis.
The Cerebrum has two halves known as hemisphere’s, a left and a right. Each hemisphere has its own unique functions controlling the side of the body opposite to it, but both are able to work together and when both hemispheres’ are able to do so creating the right balance, the learning and thinking process is enhanced.
The left hemisphere controls the movement of the right side of the body as well as being regarded as the “logical” Hemisphere, as it is the side of the brain where the problem solving and speech functions are stored. It is also the side that controls exact calculation, numerical comparison, estimation and direct fact retrieval (Dehaene et al 1999).
The right Hemisphere controls movement on the left side of the body, it is the side of the brain responsible for imagination, creativity and is also important for one’s awareness of the space surrounding the body and the recognition of the body itself. The right hemisphere is not like the left in relation to processing information, it is more likely to develop an understanding of analogies, intuition, insight and visual images where the left Hemisphere mainly controls the logic and speech characteristics.
Both Hemispheres’ are divided into four Lobes. Each Lobe has its own functions and important factors that help define the different characteristics of the brain.
Firstly is the Occipital Lobe. Located at the very back of the brain, this is the centre for visual perception and interprets signals sent from the eyes, allowing the brain to recognize and make logical sense of what the eyes are seeing.
Secondly is the Temporal Lobe where features such as memory, hearing and comprehension of speech are dominant factors. It can be found beneath the Sylvian Fissure in both left and right Hemisphere’s.
Thirdly, found superior to the Occipital Lobe and posterior to the Frontal Lobes, are the Parietal Lobes. These help to give an understanding of the space around one’s body, as well as sensation and perception.
Finally, recognized as the most highly developed parts of the brain (Hachinski et al 2004) are the Frontal Lobes. The frontal lobes are situated at the front of each hemisphere and are responsible for emotion, anticipation, memory, social and sexual behaviour.
The information presented shows the different functions of the main parts of the brain, and this essay will aim to cover the changes these parts can cause to the patient if damaged by stroke.
Following a stroke to the left hemisphere it is common that the patient can expect problems in communication, as this part of the brain is in control of speech, language and understanding. Along with the possibility of causing a right side paralysis, a left sided stroke can cause disruption to thought process, logicality, pronunciation of words and even swallowing can become difficult. Changes induced following an attack to the language of a patient is a condition known as aphasia, occurring more accurately in the temporal-frontal lobe regions. Patients with aphasia can find it difficult to understand what is being said, and can often interpret a word to have a different meaning to what it actually is.
There is another disorder subsequent to damage in these regions known as dysphasia. This is where the patient knows what to say, but has difficulty in doing so accurately. There are two types of dysphasia, they are known as Receptive and Expressive, and Patient UK (2009) describes the difference by explaining Receptive dysphasia as being when a patient is experiencing difficulty in comprehension, whilst expressive dysphasia is difficulty in putting words together to make a meaning.
If a stroke was to occur in the right hemisphere, emotion and awareness can be altered as well as causing a left sided paralysis. It can also (Hachinski et al 2004) cause a patient to no longer feel that their body is their own, people who are paralyzed on their left side may not recognize their own left hand.
As well as the difficulty’s stated above, it can be found (Kandel et al 1991) that lesions to the parietal-temporal-occipital association area can cause word blindness and writing impairments. Other pathological changes the lobes’ can encounter can be seemingly more extreme such as behavioural alterations inducing aggression, depression or leaving the patient with a shorter span of attention. These affects can be due to an attack in several places, but are mainly the cause of damage to the frontal lobes.
The symptoms for stroke can sometimes be very sudden, and difficult to recognize. The person having the stroke will usually experience a weak or numb sensation of the face, arm or leg. A side of the face can start to wilt, along with the feelings of loss of balance, vertigo or even a sudden, unusual headache. Loss or slurring of speech is a very common symptom, along with blurred or complete loss of vision.
Sometimes symptoms can go away, usually within ten to fifteen minutes. Temporary symptoms can indicate a Transient Ischaemic Attack, or TIA. TIA’s are warning symptoms of an increased risk of a full-blown stroke (Hachinski et al 2004).
Fig 2. Stroke Symptoms
As previously stated, stroke can happen to anyone at any age. However, there are risk factors to be taken into account as explained by (The Stroke Association 2010) that having a close relative who has had a Stroke can increase the risk possibly because conditions such as Diabetes and high blood pressure tend to run in families. This statement suggests that there are hereditary risks involved which can affect the risk of Stroke.
Ripley (2006) suggests that those who suffer with Angina, hardening of the arteries, abnormal heartbeats, Diabetes, those who are physically inactive and those who smoke are at greater risk of Stroke.
Factor’s such as diet, exercise and smoking, which is said to increase the risk of Stroke threefold, are also important factors that determine the risk of Stroke. However, these factors can be addressed unlike the hereditary risks as previously stated.
Recognising and diagnosing stroke is very important. The Stroke Association (2010) state that the quicker someone who has had a stroke is diagnosed and treated, the better chance they have of recovering. The medical team will be carrying out an Assessment to find out how and where the attack has happened, the severity and what type (bleed or haemorrhage) of stroke has occurred.
The patient’s blood pressure is checked before any other tests are undertaken as hypertension (high blood pressure) is the main cause of Stroke. Blood tests are taken to check the levels of cholesterol, blood sugar and for any evidence of clotting. This can also help to determine why the patient has suffered a Stroke, and also if any other parts of the body are unhealthy, or perhaps any side effects that could be induced following drug treatment.
An electrocardiogram (ECG) is used to detect any evidence of unusual heart rhythm, along with a Computerised Tomography (CT) scan of the brain. Computerised Axial Tomography (CAT) or a Magnetic Resonance Imaging (MRI) are also used if the medical team need help to confirm the cause of the attack or where the Stroke is.
Patients suspected of having a TIA should also be treated with prompt efficiency. They are started immediately on 300mg of Aspirin, along with a specialist assessment and investigation within twenty four hours of onset symptoms. As soon as the diagnosis is confirmed, measures for secondary prevention are introduced as well as a discussion of individual risk factors.
To conclude, this essay has covered the different causes and affects of stroke as well as identifying the normal anatomy and physiology of the brain prior to stroke. This essay has highlighted the medical and social affect this condition can have, in conjunction with identifying the different signs and symptoms that can occur. The risk factors involved appear to show evidence that patients can have a certain amount of control over their own risk of having a stroke, but also that it can be limited in the case of risks that can be hereditary.
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