What is dementia?

Understanding Dementia

The word ‘Dementia’ describes a set of symptoms that may include memory loss and difficulties with thinking, problem-solving or language.

These changes are often small to start with but for someone living with dementia they have become severe enough to affect daily life. A person with symptoms of Dementia may also experience changes in their mood or behaviour.

Dementia is caused when the brain is damaged by diseases, such as Alzheimer’s disease or a series of strokes. Alzheimer’s disease is the most common cause of Dementia, but not the only one. The specific symptoms that someone with Dementia experiences will depend on the parts of the brain that are affected.

What are the most common forms of Dementia?

The different types of Dementia tend to affect people differently, especially in the early stages. Other factors that will affect how well someone can live with Dementia include how other people respond to them and the environment they live in.

Dementia is progressive, which means the Dementia symptoms gradually get worse over time. How quickly this happens varies greatly from person to person. As Dementia progresses, the person may develop behaviours that seem unusual or out of character. These behaviours may include asking the same question over and over, pacing, restlessness or agitation. They can be distressing or challenging for the person and those close to them.

A person living with Dementia will have cognitive symptoms (to do with thinking or memory). They will often have problems with some of the following:

Day-to-day memory – difficulty recalling events that happened recently.

Concentrating, planning or organising – difficulties making decisions, solving problems or carrying out a sequence of tasks (such as cooking a meal)

Language – difficulties following a conversation or finding the right word for something

Visuospatial skills – problems judging distances (such as on stairs) and seeing objects in three dimensions

Orientation – losing track of the day or date or becoming confused about where they are.

A person living with Dementia will also often have changes in their mood. For example, they may become frustrated or irritable, apathetic or withdrawn, anxious, easily upset or unusually sad. With some types of Dementia, the person may see things that are not really there (visual hallucinations) or strongly believe things that are not true (delusions).

A person living with Dementia, especially in the later stages, may have physical symptoms such as muscle weakness affecting their mobility or weight loss. Changes in sleep pattern and appetite are also common.

Causes of Dementia

Alzheimer’s Disease – This is the most common cause of Dementia. In Alzheimer’s disease, an abnormal build-up of proteins surrounds brain cells and damages their internal structure. In time, chemical connections between brain cells are lost and cells begin to die. Problems with day-to-day memory are often the first thing to be noticed, but other symptoms may include difficulties finding the right words, solving problems, making decisions, or perceiving things in three dimensions.

Vascular Dementia – If the oxygen supply to the brain is reduced because of narrowing or blockage of blood vessels, some brain cells become damaged or die. The symptoms can occur suddenly especially following a stroke. They can also develop over time due to a series of small strokes.
Vascular dementia can also be caused by disease affecting the small blood vessels deep in the brain, known as Subcortical Vascular Dementia. The symptoms of Vascular Dementia vary and may overlap with those of Alzheimer’s Disease. Many people have difficulties with problem-solving or planning and concentrating.

They may also have short periods when they get very confused. 

Mixed Dementia – This is when someone is living with more than one type of Dementia and usually has a mixture of symptoms. It is common for someone to have both Alzheimer’s Disease and Vascular Dementia together.

Dementia with Lewy bodies – This type of Dementia involves tiny abnormal structures (Lewy bodies) forming inside brain cells. They disrupt the chemistry of the brain and lead to the death of brain cells. Early symptoms can include not being able to stay alert, hallucinations, and difficulties judging distances.

A person’s day-to-day memory is usually affected less than in the early stages of Alzheimer’s Disease. Dementia with Lewy bodies is closely related to Parkinson’s Disease and often has some of the same symptoms, including difficulty with movement, hallucinations, cognitive issues and sleep difficulty. 

 Frontotemporal Dementia (including Pick’s Disease) – In frontotemporal Dementia, the front and side parts of the brain are damaged. Clumps of abnormal proteins form inside brain cells, causing them to die. At first, changes in personality and behaviour may be the most obvious signs. Depending on which areas of the brain are damaged, the person may have difficulties with fluent speech or forget the meaning of words. Other common symptoms would include poor judgment, loss of empathy, lack of inhibition, mood changes and inability to concentrate.

Dementia and its progression

Care and support for someone living with an early, middle or late stage of dementia should always be ‘person-centred.’ This means it should be focused on that person and their current needs and preferences.  

Stan’s Story

Watch the 15-minute video of Stan and his family’s story