What is dementia?

A brief summary of some of the causes and symptoms of dementia.

What is dementia?

Dementia is the collective term for a group of illnesses that damage the brain and affect what it can do: including remembering, thinking and communicating. There around 100 causes of dementia: the most common are Alzheimer’s disease, vascular dementia, Lewy Body dementia and frontotemporal dementia. 

An estimated 90,000 people in Scotland have dementia. That number is likely to rise steeply as the population ages. Yet dementia it is not a normal part of ageing: only one in six people over age 80 have dementia. Scientists have found that as people get older some change in brain function can be expected: for example, they may need a little bit more thinking time ^[1]. Dementia also affects younger people: 12 percent of people with dementia are under age 70.

Signs and symptoms

The signs and symptoms of dementia can vary hugely. Not only are there different kinds of dementia: everyone is an individual, and no two people will be affected by any type of dementia in exactly the same way.

There are however signs and symptoms that typically appear in certain kinds of dementia. This is because different parts of the brain tend to be damaged in the early stages of different types of dementia. As time goes by the damage will become more widespread, and different kinds of dementia may look more alike in their later stages.

Some causes of dementia

Alzheimer’s disease can start in a part of the brain vital for forming memories.  Damage to this brain area can result in someone struggling to find the right word in conversation, forgetting the names of people and things, repeating themselves without being aware of it, and forgetting familiar faces. 

Posterior Cortical Atrophy is a rare form of dementia caused by Alzheimer’s disease that, in its early stages, affects parts of the brain vital for judging depth and distance, and for making sense of what we see. Damage in these brain areas can make people clumsier, and they can increasingly struggle with things such as parking a car or getting dressed. Activities such as reading and using a computer can be more difficult for them. They might fail to spot things right under their nose, or be unable to tell coins and notes apart when handling money.

Frontotemporal dementia typically starts in the front of the brain.  In its early stages it can have some effect on memory and language: but often it’s changes in someone’s behaviour that are more noticeable.  They may be less motivated, less kind, less polite, or have less self-control.  Damage to the frontal lobe of the brain can also affect someone’s ability to learn, solve problems, set goals, follow step-by-step instructions, and focus on getting a task done.

Lewy-Body dementia is related to Parkinson’s disease and people living with it can have many of the same physical symptoms, such as slower movement and tremors.  Also common in its early stages are sudden swings in alertness, hallucinations (seeing and hearing things that aren’t there) and delusions (unshakeable beliefs that don’t match reality). 

Vascular dementia is caused by problems with the supply of blood to the brain, for example as a result of a stroke. The early symptoms will depend on the areas of the brain that have been damaged. Sometimes there is a slow narrowing of blood vessels in the brain which means symptoms get worse only gradually. However sometimes symptoms get worse very suddenly as a result of mini-strokes that the person experiencing them may not even be aware of. You can find out more about early signs of the different kinds of dementia online: www.alzheimers.org.uk/braintour