How To Understand The Different Types Of Stroke.
What is a stroke?
Experiencing a stroke or having a loved one who has had a stroke can be devastating - sometimes fatal! The people who survive may have their lives altered from being an independent, vigorous person to someone who depends on others for their well-being.
The level of disability and recovery depends on where the stroke has happened and what type of stroke it is.
What is a stroke?
A stroke occurs when a part of the brain has the blood supply cut off to it by a blockage in a vessel or another type of trauma such as bleeding. The brain like any other organ in the body needs oxygen to survive. When it loses its supply the individual brain cells become damaged or die.
The brain has four main arteries that are responsible for supplying blood to it:
- Two carotid arteries - right and left
- Two vertebral arteries - right and left
These arteries split up and then divide multiple times into smaller and smaller blood vessels. These eventually take the blood supply to individual cells of the brain.
When someone has a stroke the severity will depend on, if an artery is affected - which would mean a large part of the brain would lose it's supply of oxygen. If it's one of the smaller vessels than less damage will occur.
Types of stroke
When a person has had a stroke it is not only important for doctors to confirm this by scanning the brain and completing a few tests. It's also important to determine what type of stroke the patient has developed.
There are two main types of stroke:
When a person suffers from an ischaemic stroke this means that a part of the brain has been damaged due to the blood supply being cut off by a blockage in a blood vessel. The most common type of blockage is a blood clot (thrombosis). Blockages can occur either in the neck or in the region of the brain itself.
Main causes of ischaemic stroke:
- A blood clot can form in the blood vessel due to a substance called - atheroma. Atheroma is basically fatty deposits that have built up inside an artery or blood vessel - commonly called hardening of the arteries. This fatty substance continues to build up over a number of years, leading to continual narrowing of the vessel. When this occurs the blood flow not only becomes more restricted, but it can slow down to such an extent that blood clots begin to form over the fatty deposit. Eventually the whole vessel becomes blocked, leading to a stroke.
- Arterialsclerosis or atherosclerosis are directly related to the cause above - both being contributory factors leading to a stroke. Sclerosis of an artery means the hardening or stiffening of the artery which in health is elastic and pliable. When the artery becomes immovable it not only slows blood flow down, but makes it much easier for deposits to stick to their walls so risking the vessel to block.
- Other less commn reasons for ischaemic strokes are - blood clotting disorder, illegal drugs, injury to the head, brain or neck.
There are two main types of ischaemic stroke:
- Thrombotic stroke - due to the blockage of a vessel when a blood clot forms
- Embolic stroke - this type of stroke is also caused by a clot - an emboli is a piece of a clot or other debris that has broken off from a main clot elsewhere in the body. This has gone through the bloodstream and lodged in one of the blood vessels of the brain.
Let's now look at a haemorrhagic stroke.
Shocking Stroke Facts!
Did you know?
1. Because of obesity children as young as 5 are showing signs of high blood pressure and raised cholesterol that increase their chances of having a stroke or heart attack by 40%!
2. People frequently ignore the warning signs and symptoms that a stroke is developing until it's too late!
3. A survey carried out in the UK discoverd that 3 out of 4 people would not attend a hospital or doctor if they experienced facial weakness.
What is a haemorrhagic stroke?
The second kind of stroke we're going to look at is called a haemorrhagic stroke. Instead of a blockage in a blood vessel, in this type of stroke the vessel ruptures, causing bleeding into the brain. This usually happens because of disease, weakness or trauma in the blood vessel.
There are two main types of stroke in the haemorrhagic category. One form of stroke bleeds inside the brain the other bleeds just outside.
- Intracerebral stroke - 'intra' means within and 'cerebral' the brain so it just means a stroke happening within the brain.
- Subarachnoid haemorrhage - this is a from of stroke that occurs just outside the brain within the subarachnoid space. This is a narrow area between the skull and the brain that is usually filled with cerebrospinal fluid. Strokes of all kinds are much more common in people who are older or sometimes even middle-aged. However, subarachnoid haemorrhage can also occur in the young - teenagers as well as young adults.
Causes of haemorrhagic stroke
In both cases the cause of the stroke is due to bleeding from a blood vessel that has ruptured. There are two main causes for this:
- High blood pressure that is untreated is the major cause of haemorrhagic strokes. When the blood pressure is abnormally high this can lead to what is known as an aneurysm. This is where the wall of a blood vessel develops irregular or balloon like swellings that finally lead to a rupture of the wall, causing a haemorrhage.
- Age can also be a cause. As we get older blood vessels tend to become weaker.
The most common symptoms of having a stroke
There are quite a few signs and symptoms that indicate when someone is having a stroke. In addition, it's often the case that strokes don't just happen out of the blue, there can be early signs that a person may be heading for a major stroke. We'll look at the signs and symptoms of both a stroke and early symptoms prior to one developing.
Major stroke - signs and symptoms:
With a major stroke there can be indications for days or even weeks before that something is going wrong but with some people the signs and symptoms start suddenly. These can vary from person to person and it will depend on what kind of stroke they are having and what area of the brain is affected. The NHS (National Health Service UK) have had an excellent awareness campaign going on for a while now which uses the acronym F.A.S.T.
F.A.S.T. stands for the 4 major things you should look out for - Face, Arms, Speech, Time
- Face – the face may have dropped on one side, the person may not be able to smile. You may also notice that the mouth and eye have also dropped to one side.
- Arms – the person with suspected stroke may not be able to lift one or both arms and keep them there because of arm weakness or numbness.
- Speech – their speech may be slurred or garbled, or the person may not be able to talk at all despite appearing to be awake.
- Time – it is time to dial 999 immediately if you see any of these signs or symptoms. Or whatever emergency number you use in your own country.
The NHS information site states that the four categories above will help to identify 9 out of 10 strokes that occur. In addition, there are other symptoms that might be present:
- There could be tingling, numbness or loss of feeling on one side of the body. This can also include problems with their balance and coordination of their body.
- Difficulty swallowing - if you suspect that someone is having a stroke and their swallowing seems to be impeded, don't give them anything to eat or drink. Often with a stroke the swallowing reflex is damaged - this could be temporary - but the person would probably inhale fluid or substances straight into the lungs if given anything by mouth.
- A severe headache that comes on suddenly. This might also include stiffness in the neck.
- Dizziness and even blacking out may occur.
- Sudden loss of vision - sometimes only one eye is affected.
- Problems with communication. This is not just speech but the person's ability to understand even simple questions may be severely impeded.
I mentioned earlier that some people may get warnings that a major stroke is imminent. These warnings are often referred to as 'mini strokes' and the medical term is 'Transient Ischaemic Attack' - 'TIA' for short.
A TIA has the same signs and symptoms as a major stroke. The difference is that these signs disappear either within a few minutes or a few hours and the person returns to normal. However, TIA's should never, ever be ignored. People experiencing them should seek medical help immediately - doing so could save their life.
To finish the hub we'll take a quick look at the factors that increases the risk of someone developing a stroke.
Have you or someone you know suffered from a stroke?
Factors that increases the chances of having a stroke
There are a number of reasons that may lead to someone having a stroke and can be divided into three main groups:
- Poor diet - a low fat, high fibre diet is good for preventing strokes. Whereas a diet high in saturated fats not only increases weight but causes fatty deposits to collect on the inside of blood vessels that could cause clots to form.
- Lack of exercise - if you exercise regularly this not only helps to keep your weight down - obesity is a contributing factor towards having a stroke - but exercise also keeps your cardiovascular system healthy and lowers cholesterol that leads to fatty deposits in the blood vessels.
- Smoking and heavy alcohol intake are both factors that increase the risk of stroke as they tend to cause narrowing of the blood vessels.
- High blood pressure is one of the main factors leading to stroke.
- Diabetes and some heart conditions among others increases the risk of having a stroke.
- Age - with most types of stroke the older you are the more the risk increases of having a stroke.
- Family history - if a close relative has suffered a stroke, then this increases your chances of having one.
- Medical history - people who've already had a stroke are much more likely to develop another one.
Stroke is for the most part a preventable condition. Even making small changes to your lifestyle can decrease the risk of a stroke quite significantly. In addition, acting on early warning signs and being able to recognise the main signs of a stroke (F.A.S.T.) - not only makes full recovery much more likely but it also saves lives.