Basic information about dementia

What is dementia?

Dementia occurs as a result of a disease process. It is a term used to describe different brain disorders that have in common loss of brain function which is usually progressive and eventually severe. Dementia affects memory, thinking, behaviour and emotion. Dementia affects all groups in society and is not linked with social class, gender, ethnic group or geographical location. Although dementia is more common among older people, younger people can also be affected.

What causes dementia?

Dementia is caused by a number of diseases which produce changes in the brain resulting in the ultimate loss of nerve cells (neurons). These diseases include

Alzheimer’s disease

This is the most common cause of dementia and accounts for 50% – 80% of all cases of dementia. It destroys brain cells and nerves disrupting the transmitters which carry messages in the brain, particularly those responsible for storing memories.

Vascular dementia

The brain relies on a network of vessels to bring it oxygen-bearing blood. If the oxygen supply to the brain fails, brain cells are likely to die and this can cause the symptoms of vascular dementia.These symptoms can occur either suddenly, following a stroke, or over time through a series of small strokes.

Dementia with Lewy bodies

This form of dementia gets its name from tiny spherical structures that develop inside nerve cells. Their presence in the brain leads to the degeneration of brain tissue. Memory, concentration and language skills are affected.

Frontotemporal dementia (including Pick’s disease)

In frontotemporal dementia (FTD), damage is usually focused in the front part of the brain. Personality and behaviour are initially more affected than memory.

Posterior Cortical Atrophy (PCA)

In PCA, damage is caused to the visual cortex in the back of the brain, or posterior region. People have difficulty with vision and interpreting what they see which is more apparent than memory symptoms when first diagnosed.

Rarer causes of dementia

There are many other rarer causes of dementia, including progressive supranuclear palsy, Korsakoff’s syndrome, Binswanger’s disease, HIV and Creutzfeldt-Jakob disease (CJD). People with multiple sclerosis, motor neurone disease, Parkinson’s disease and Huntington’s disease can also be at an increased risk of developing dementia,

What is Mild Cognitive Impairment (MCI)?

MCI refers to the beginnings of memory decline without other symptoms of dementia. Current research suggests about half of people with MCI will further develop dementia.

What are the symptoms of dementia?

Dementia is a progressive condition. This means that the structure and chemistry of the brain become increasingly damaged over time. The person’s ability to remember, understand, communicate and reason gradually declines. How quickly dementia progresses depends on the individual but the progression can take many years. Each person is unique and experiences dementia in their own way. The way people experience dementia depends on many factors, including physical make-up, emotional resilience, the environment they live in and the support available to them. Viewing dementia as a series of stages can be a useful way to understand the illness, but it is important to realise that this only provides a rough guide to the progress of the condition and not all people will display all of these symptoms. Some of these symptoms may appear in any of the stages, for example a behaviour listed in the late stage may occur in the middle stage. Also, care partners should be aware that in all stages, short, lucid periods can occur.

The following outlines the characteristics of early, middle, late and end stage Alzheimer’s disease, and briefly looks at other dementias.

Alzheimer’s disease

Early stage

The early stage is often overlooked and incorrectly labelled by professionals, relatives and friends as ‘old age’ or a normal part of the process of ageing. Because the onset of the disease is gradual, it is

difficult to identify the exact time it begins.

The person may:

• Have difficulty following conversation with more than one person at a time

• May forget specific words for objects

• Experience short-term memory loss such as not remembering having lunch yesterday with a friend

• Have trouble with appointments and schedules

• Have difficulty with numbers and money

• Become lost in familiar places

• Display difficulty in making decisions

• Lack initiative and motivation

• Show signs of depression and anger

• Show a loss of interest in hobbies and activities

Middle stage

As the disease progresses, problems become more evident and restricting. The person with dementia has difficulty with day-to-day living, and:

• May become very forgetful – especially of recent events and people’s names

• Has difficulty living alone

• Is unable to cook, clean or shop without support

• May need assistance with personal hygiene, i.e. toilet, washing, and dressing

• Needs cueing on how and when to eat

• Has increased difficulty understanding language

• May wander or show other challenging behaviours

• Can become lost at home and in the community

• May experience hallucinations


Late stage

This stage is one where constant support and supervision are needed. Memory disturbances are very serious and the physical side of the disease becomes more obvious. The person may:

• Need assistance to eat

• Not recognise relatives, friends, and familiar objects

• Have difficulty understanding and interpreting events

• Be unable to find their way around in the home

• Have difficulty walking

• Have bladder and bowel incontinence

• Display inappropriate behaviour such as yelling which may express an unmet need or physical pain

End stage

In the end stage of dementia, the person is in the active dying process. Very often a person with dementia will die of other diseases and conditions prior to dementia being the actual cause of death.

The symptoms include:

• Very little, if any, speech

• Very little movement and be confined to a bed

• Sleeps most of the time

• Needs total assistance with personal care

• Has swallowing problems

Starting in the late stage into the end stage, people with dementia should have access to any comforting measures to maintain the best quality of life possible. It is best to know ahead of time the wishes of the person with dementia in regards to dying peacefully or using life sustaining measures such as artificial hydration and nutrition when the individual is no longer able to eat or swallow his or her food properly. Using life-sustaining measures is a personal decision. Comfort can be provided either in addition to life- sustaining measures or in place of them to ensure the person with dementia maintains dignity and is pain free. Although these stages and symptoms are listed for Alzheimer’s disease, other types of dementia follow a similar progression, especially after the early stage.

Vascular dementia

Some people with vascular dementia find that symptoms remain steady for a time and then suddenly decline as the result of another stroke. This contrasts with the gradual decline many people with Alzheimer’s disease experience. It is sometimes difficult to determine whether people have Alzheimer’s or vascular dementia. It is also possible to be affected by both.

Dementia with Lewy bodies

Half or more of those affected also develop signs and symptoms of Parkinson’s disease such as slowness or movement, stiffness and tremor. They may also have difficulty in judging distances and are more prone to falls. People with this dementia also commonly experience visual hallucinations. One feature of this dementia which often puzzles care partners is that the abilities of the affected person often fluctuate.

Frontotemporal dementia (including Pick’s disease)

During the early stages the memory may be unaffected. However, there may be other changes. For example, the person may seem more selfish and unfeeling. They may behave rudely, or may seem more easily distracted. Other symptoms may include loss of inhibition, ritualised behaviour and a liking for sweet foods. In later stages the symptoms are more similar to those experienced in Alzheimer’s disease.

Posterior Cortical Atrophy (PCA)

During the early stages, memory may be less affected. Visual impairment is the most common experience for people with this type of dementia. Difficulty interpreting the environment, trouble reading and being overwhelmed by fast moving objects such as cars on a road are common. Falls can also be common as the person has difficulty judging distances.

Why is diagnosis important?

It is important to get a proper diagnosis of dementia. A diagnosis is essential to:

• Rule out other conditions that may have symptoms similar to dementia and that may be treatable. These include depression, chest and urinary infections, severe constipation, vitamin and thyroid deficiencies and brain tumours.

• Access advice, information and support to help manage each stage.

• Allow the person with dementia and care partner to prepare and plan Nfor the future.

• Benefit from services that have been developed to maintain a good quality of life.

• Give the person an opportunity to take part in research on future treatments or best practices for care.

There is no simple test to make a diagnosis. Making a diagnosis of dementia is often difficult, particularly in the early stages. A diagnosis is made by taking a careful history of the person’s problem from the person and a close relative or friend, together with an examination of the person’s physical and mental status. Blood tests, brain scans and an interview of the person and their care partner are common steps prior to a diagnosis.

Are there treatments for dementia?

At the moment there is no curative treatment for dementia. There are some drugs available for people with mild to moderate Alzheimer’s disease. These drugs are not a cure but may temporarily slow down the progression of symptoms of Alzheimer’s disease in some people. Contact your nearest Alzheimer association or physician for more information. There are other, non-medical therapies that have shown effectiveness for people with dementia, for instance Cognitive Stimulation Therapy, physical exercise and musical therapy. These types of therapies plus social interventions such as support groups and day programmes will help the person with dementia maintain abilities as long as possible. Programmes are also available for the care partner to learn to manage everyday life in a positive and supportive way while reducing their own stress. In addition to treatments, it is important to be aware that other medical conditions may co-exist with dementia and get those treated accordingly. Often, when new symptoms occur, those symptoms are blamed on the dementia rather than seriously investigated for cause and possible treatments that would help the person live a more comfortable life.


Help for care partners of people with dementia WHO & ADI .