Alzheimer's disease

Alzheimer’s disease is a form of dementia  and is described as a physical disease that affects the brain.

Through the course of the disease, protein builds up in the brain causing the formation of structures called ‘plaques’ and ‘tangles’. This results in the loss of connections between nerve cells and eventually the death of those nerve cells and a loss of brain tissue.

Alzheimer’s disease is a progressive disease which means that gradually, more parts of the brain are affected and damaged. As this occurs, more symptoms develop.4

What causes Alzheimer’s disease?

The exact cause of Alzheimer’s disease is unknown, although a number of factors have been identified as increasing one’s risk of developing the disease. These include:5

  • increasing age
  • a family history of the condition
  • previous severe head injuries
  • lifestyle factors and conditions associated with cardiovascular disease

Impact of Alzheimer’s disease

Alzheimer’s disease can have a deep impact not only on those who are diagnosed, but also people who are closest to them. Family members may have to take on different responsibilities and may become the primary caregiver to a person with Alzheimer’s.6  

Symptoms of Alzheimer’s disease

Symptoms can vary across individuals. However, the most common symptom is the gradual worsening of the ability to remember new information. This occurs because neurons in the brain which malfunction and die are usually in brain regions involved in forming new memories.The resulting memory loss can interfere with daily life as the condition progresses. The person may:8

  • lose items around the house
  • struggle to find the right word in a conversation
  • get lost in a familiar place 
  • forget appointments or anniversaries.

People with Alzheimer’s disease may also go on to develop problems with other aspects of thinking, reasoning, perception or communication.They may display the following symptoms:10  

  • Challenges in planning or solving problems.
  • Confusion with time or place.
  • Trouble understanding visual images and spatial relationships.
  • Changes in mood and personality.

What treatments are available for Alzheimer’s disease?

Currently there is no cure for Alzheimer’s disease but drug treatments may help with both the cognitive and behavioural symptoms.11 There are two types of medication used to treat Alzheimer’s disease: acetylcholinesterase inhibitors and NMDA receptor antagonists.12

Generally, people with Alzheimer’s disease, have lower levels of acetylcholine and there is also a loss of nerve cells that use acetylcholine.13 Acetylcholine is a chemical substance that allows brain cells to communicate with one another.14 

Acetylcholinesterase inhibitors work by sending messages (in the form of electrical signals) between certain nerve cells.15 These inhibitors prevent acetylcholinesterase from breaking down acetylcholine in the brain, this supports increased the communication between nerve cells as a result of the increased levels of acetylcholine.16  

NMDA receptor antagonists, such as memantine, work quite differently from acetycholinerestrase inhibitors. In our brain we have another chemical called glutamate which also helps the communication between nerve cells. When the brain cells are damaged by Alzheimer’s disease, excessive amounts of glutamate is released, which causes further damage. NMDA receptor antagonists protect the brain cells by blocking the effect of excess glutamate.17