Around 50 million people suffer from dementia worldwide and there are nearly another 10 million new cases every year, according to the World health organisation (WHO). Furthermore It is estimated that 1 in 6 people over the age of 80 in the UK are diagnosed with dementia and that number is sure to increase due to the UK’s aging population. These statistics are evidence enough that dementia is a growing concern for the NHS.
Contrary to popular belief, dementia isn’t just memory loss. The word itself is an umbrella term used to describe various neurological disorders that essentially result in a loss of brain function. Memory, cognitive ability, communication, mood and behaviour are all affected by dementia. These conditions are often degenerative and become worse with time. It may begin slowly, and the decline can happen over a number of years. Gradually, normal everyday tasks can become more and more difficult and those suffering from dementia are often stripped of their independence and the ability to care for oneself.
Dementia is caused by damage to or loss of nerve cells and their connections in the brain, thus disrupting normal communication between neurons. The brain is made up of many neurons that interact and communicate with each other by sending messages. When these are damaged, messages are no longer sent effectively, preventing the brain from functioning normally. Depending on the area of the brain that’s damaged, dementia can affect individuals differently and show different symptoms. Therefore dementias are often grouped by what they have in common, such as the proteins deposited in the brain or the part of the brain that’s affected. Interestingly, there are over 200 subtypes and causes of dementia, the most common being: Alzheimer’s disease, vascular dementia, frontotemporal dementia and dementia with Lewy bodies. It is possible to have not just one but two types of dementia. The most common combination being Alzheimer’s disease and vascular dementia, normally referred to as mixed dementia.
The most common type of dementia is Alzheimer’s disease. This type of dementia is known to be progressive and irreversible. It is believed to be caused by the abnormal build-up of two proteins called amyloid and tau. These deposits of proteins build up around brain cells: amyloid forms deposits called plaques, and tau forms tangles. Plaques are clumps of a protein called beta-amyloid, and tangles are fibrous tangles made up of tau protein. However, there are still a few gaps in knowledge within this field: researchers do not yet know how amyloid and tau cause the loss of brain cells. It is thought that these clumps damage healthy neurons and the fibres connecting them, though more research needs to be done. As brain cells become affected in Alzheimer’s, there is a decrease in neurotransmitters, which are involved in sending messages, or signals, between brain cells. The neurotransmitter acetylcholine is particularly low in those suffering Alzheimer’s. The hippocampus (where all the new memories are stored) is often affected early on, which is why a common earlier symptom is memory loss.
Vascular Dementia, another common type, is caused by reduced blood flow to the brain, which damages and eventually kills brain cells. Typically this can happen as a result of the blockage (or damage) of small blood vessels supplying blood to the brain, a single stroke where blood supply to the brain is cut off, or a series of mini strokes which causes widespread damage to the brain. When people have mixed dementia, it is hard to determine what proportion of each dementia is causing damage to a patient’s brain.
The exact cause of dementia remains unknown, so there is no certain way to guarantee prevention. Keeping a healthy lifestyle can help to reduce its risk though. General things such as smoking, alcohol, lack of exercise, diabetes and an unhealthy diet can increase the risk of dementia, alongside hearing difficulties, depression, loneliness and a sedentary lifestyle. There is some evidence to suggest that rates of dementia are lower in people who remain mentally and socially active throughout their lives. Links to faulty or “risk” genes have been established and at the time of writing scientists have found possibly over 20 different genes associated with an altered risk of developing Alzheimer’s disease. However as discussed above, a number of risk factors play into the development of dementia, not just genes alone.
General risk factors that increase the risk of one developing Dementia:
Researchers are only beginning to understand the effects and causes of dementia. More work needs to be done before a proper cure is discovered, since there are so many gaps in knowledge as to what happens to the human body. Dementia is something which impacts many elderly people – we may not be aware of it, but it affects their living greatly. This is why it is important to be patient with the elderly as we don’t know what issues they are facing. The NHS is also encouraging people to help contribute towards the research for dementia, or at least promote it to others so they can be aware and help as much as they can. The more people contributing towards research gives hope that one day dementia will be a thing of the past and the future generations don’t need to endure the mental imprisonment that is dementia.
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References of pictures used are as follows:
Lack of Exercise: https://www.dreamstime.com/illustration/exercise-lack.html
Hearing Loss: https://en.wikipedia.org/wiki/Hearing_loss
Statistics of Dementia Report by Alzheimer’s Society.