Dementia is described as a set of symptoms that affect memory, difficulties with thinking, problem solving and language. Dementia is generally caused by cells in the brain gradually degenerating and dying more rapidly than they would with the normal ageing process. This is generally caused by a build up of proteins in the brain. When the brain cells are damaged they interfere with the brain cells ability to communicate with each other, thus impairing a person’s communication, feelings, thinking, and behaviour to not present in a normal manner. Dementia can also lead to different functions to become debilitated I.E memory, judgement and movement and in turn becoming progressively worse over time.
Vascular dementia is caused by an interruption of the blood supply to the brain. The interruption is by atherosclerosis I.e debris, or deposits of fats form inside the arteries either by partially or completely stopping oxygenated blood flow to the brain. This type of dementia is most commonly found in people who suffer other conditions I.e high blood pressure, high cholesterol, heart disease and diabetes, however not everyone who suffers with these conditions will suffer with vascular dementia.
When a person a suffered a stroke and the blood flow to the brain is restricted by a clot, this can damage brain cells leading to vascular dementia. Vascular dementia is the second most common type of dementia affecting around 150,000 people in the UK. However not everyone who has a stroke will develop vascular dementia, around 20 per cent of people who have a stroke will develop vascular dementia post stroke. Generally when a person has suffered a stroke they are at higher risk of suffering further strokes, thus their risk does increase of developing vascular dementia in the future.
Single and Multi Infarct Dementia
These types of dementia is caused by one or more mini strokes. This happens when a large or medium sized clot has interrupted the blood flow to the brain. When a person has this type of stroke also known as a Transient Ischaemic Attack, a person may not notice any symptoms, however people who do notice the symptoms will only experience them temporarily, either a few minutes or up to 24 hours, as the blockage will clear it self within this time. However should the interruption damage to a small part of the brain, known as an infarct, if the infarct occurs in an important part of the brain, this can cause a single infarct dementia. Should a TIA occur several times over a period of weeks or months and causes several infarcts around the brain, this type of dementia is known as a multi infarct dementia.
Alzheimers disease is the most common cause of dementia. It is thought that more than 850,000 people in the UK suffer with the disease. Alzheimers is a neuro degenerative disease, as the disease progresses the proteins in the brain bulid upand forms plaques, because of these plaques the connections between the nerve cells become damaged, eventually leads to the death of nerve cells and brain tissue.
The cerebral cortex is specifically affected by shrinkage with alzhiemers disease. The cerebral cortex is the grey matter surrounding the brain. The grey matter processes our thoughts, and many other functions of the brain I.e storing and recalling memories, organising,and coordination, and judgement.The part of the brain called the hippocampus is responsible of learning and memory in the brain, and the brain cells in the hippocampus are usually the first that are damaged. This is why memory loss is often one of the earliest symptoms of Alzheimer’s.
Dementia with Lewy Bodies
Dementia with lewy bodies has symptoms in common with alzhiemers, and is often misdiagnosed as alzheimers. It is estimated to affect more than 100,000 people in the UK. lewy bodies are small circular masses of protein that develops inside the brain cells, it is thought the proteins affecting the brains normal functions by interrupting the neurotransmitters sending signals from one brain cell to another.
Lewys bodies dementia has no specific cause(s) however, it is linked to factors that appear to contribute to it. The low levels of chemical in the brain called acetylcholine and dopamine, these chemicals are responsible for regulating brain functions I.e memory, learning, mood and attention, and a loss of connections between nerve cells, which consequently die.
Frontotemporal dementia is thought to affect less than 5% of people in UK. The exact cause of frontotemporall is not known, however the death of nerve cells in the frontal and temporal lobes of the brain is linked to clumps of proteins called Tau and TPU-43. They usually form inside the brain cells and stop them from working effectively. When this occurs iyys stops the brain from functioning to its normal capacity by affecting language, behaviour, planning ability, and organising. It usually affects people between the ages of 45-65.
Frontotemporal dementia can be inherited by a parent. It is not fully known why there is a genetic link to the disease, however one in three people are affected by frontotemporal dementia have a family history.
Sporadic Creutzfeldt-Jakob Disease
Sporadic CJD is caused by an infectious abnormal protein in the in the brain called a prion. Sporadic CJD usually affects people over 40. It is thought to affect one in a million people in the UK. The prions misfold throughout the brain, this effectively causes a domino effect and causes the brain cells to die, releasing more prions to infect the brain cells. It is not known why the prions do this this, and what their normal role is, however it thought that they may transport messages between certain brain cells.
People who are affected by Sporadic CJD usually die within six months of initial symptoms developing.
Alcohol Related Brain Damage/ Korsakoffs Syndrome
ARBD/ Korsakoffs syndrome are actually not a form of however they do share similar symptoms with dementia.
The cause of these conditions is a deficiency of B1 vitamin Thiamine. However excess drinking can lead to conditions that increase a persons risk of developing common types of dementia, such as high blood pressure, strokes, high cholesterol, and heart attacks.
ARBD has been defined as a long term decline in memory caused by excessive alcohol abuse, coupled with the lack of vitamin B1 Thiamine. Thiamine provides the body with energy, this is essentially important for brain and nerve cells, as they require a lot of energy to function effectively.