- What is Alzheimer's disease?
- What is the cause of Alzheimer’s?
- What are the symptoms of Alzheimer’s?
- How is Alzheimer’s diagnosed?
- How is Alzheimer’s treated?
- What are the risk factors associated with Alzheimer’s?
- The seven stages of Alzheimer’s and how to deal with them
- Alzheimer's - Some further questions you may have …
What is the cause of Alzheimer’s?
As Alzheimer’s disease develops, being a physical disease that affects the brain, protein structures build up in the brain that are referred to as ‘plaques’ and ‘tangles’ – these are types of abnormalities. These cause the nerve cells to lose connection to one another, hampering the transmission of signals around the brain, eventually leading to the death of the nerve cells and brain tissue being lost, as a result, the brain shrinks.
The exact cause of the disease is still unclear, however there are genetic, lifestyle and environmental factors that may contribute.
It is known, as stated above, that the basis of the disease is the destruction of the nerve cells in the brain leading to brain damage. The two types of abnormalities responsible for cell destruction in Alzheimer’s are explained below:
- Plaques, called amyloid plaques, are groups of protein that disrupt the communication between the nerve cells of the brain. This disruption can lead to damage and eventually death of the brain cells.
- Neurofibrillary tangles are abnormal threads of tau proteins that have collected in the brain cells of someone with Alzheimer’s. Tau proteins help to make up the structure of a microtubule within nerve cells, which transports various nutrients and chemicals from one part of the cell to another. In Alzheimer’s the abnormal tau proteins cause the microtubules to collapse, preventing these essential nutrients and chemicals from being carried through the brain.
Genetics is also known to play a role in the cause of Alzheimer’s. The apolipoprotein E gene (APOE), is known for playing a part in the late-onset of the disease. If you have the gene, it does not mean you will definitely develop Alzheimer’s, it is merely a factor that may increase your risk of doing so.
Another cause can be changes in certain genes, for example, people with Down Syndrome have an increased risk of developing Alzheimer’s in later life, which is thought to be the result of their extra copy of chromosome 21.
Health, environmental and lifestyle causes
This is another entity that is thought to play a role in the development of Alzheimer’s disease. This is seen in the cognitive deterioration of patients with vascular conditions such as strokes, heart disease, high blood pressure or metabolic conditions such as diabetes.