Alzheimer’s Disease –
The loss of brain cells in Alzheimer’s disease causes the brain to shrink. The area most affected is the cerebral cortex, this area of the brain is responsible for the processing of thoughts and memory.
It has been found that protein in the brain gather together causing clumps, and is associated with the death of brain cells. Cognitive impairment is due to the connections between the brain cells are lost, leading to a decrease in the neurotransmitters.
Vascular Dementia –
Vessels become narrower as people age, and can harden due to fatty deposits. The brain tissue is staved of oxygen as less blood can get through the vessels. Vascular dementia occurs when the cells become damaged, thus resulting in a lack of blood and oxygen.
People are at a higher risk of developing vascular dementia, if they have suffered from a transient ischaemic attack (TIA) or a stroke in the past.
Lewy bodies –
Lewy bodies are small lumps of protein which develop inside the nerve cells in the brain. To this day researchers still do not know why Lewy bodies appear, but what is known is that Lewy bodies affect the brain and the nervous system and will get worse over time.
As stated by Alzheimer’s Society, (2018) Lewy bodies have been linked to two factors:
“low levels of important chemicals (mainly acetylcholine and dopamine) that carry messages between nerve cells”
“a loss of connections between nerve cells, which then die.”
Due to Lewy bodies affecting the brain and nervous system it has close links to Parkinson’s disease. Lewy bodies can cause problems with movement, if they are at the base of the brain, which is also the main feature of Parkinson’s disease.
If Lewy bodies are in the outer layers of the brain, it can lead to problems with a person’s mental ability, a common feature of someone suffering from Dementia Lewy Bodies.
Frontotemporal dementia –
Frontotemporal dementia mainly affects the front and the sides of the brain. These areas of the brain become damaged by abnormal protein clumps forming inside of the brain cells, causing them to stop working properly and for the brain to shrink.
The areas of the brain affected are important for controlling a person’s behaviour, language and personality.
Frontotemporal is the most common form of dementia in those under the age of 65 years. Researchers do not fully understand why it happens but believe it may be linked to an inherited genetic mutation.