Dementia is the ‘umbrella’ term for a large number of different diseases which affect the brain. These diseases can impact thinking processes, memory, language and communication, sensory abilities, daily function, mood and behaviour.
Each type of dementia has different patterns of changes in the brain, different symptoms and different treatments. Dementia can be complex and sometimes doctors can’t tell which types of dementia the person has.
There are some drug treatments suitable for some types of dementia but not others. However, there are also non-drug treatments and strategies that tend to work for all the different types of dementia; you can find these on this website in Section 3, Managing Changes.
Common types of dementia include:
Alzheimer’s disease
Alzheimer’s disease is the most common type of dementia. About 50-70% of all people with dementia have Alzheimer’s disease. People with this type of dementia typically have trouble with short-term memory and this is often affected more than their long-term memory of the past.
People with Alzheimer’s disease may find it harder to concentrate, solve complex problems, or find themselves thinking more slowly.
We don’t know what causes Alzheimer’s disease, however there are medications which can slow progression of symptoms. A healthy lifestyle, including exercise, diet and staying mentally active can also help. People with Alzheimer’s disease typically have deterioration in the areas of their brain involved in memory (i.e. the hippocampus and temporal lobes), as well as more general changes throughout the brain.
Read more about Alzheimer’s disease at Dementia Australia.
Vascular dementia
Vascular dementia is another common form of dementia. It’s caused by poor blood flow in the brain which can lead to brain cells dying, mini-strokes or larger strokes. People with vascular dementia experience problems with thinking depending on where the brain damage is.
People with vascular dementia usually have heart disease or risk factors for heart disease such as high cholesterol and high blood pressure. Managing these risk factors can help slow the progression of vascular dementia. Ask your doctor and for more information read 4.5 Attend to other health issues.
Read more about Vascular Dementia at Dementia Australia.
Lewy body dementia
Lewy body dementia is a less common type of dementia. People with Lewy body dementia have trouble with their visuo-spatial skills, concentration and attention. They have trouble with and movement and may be prone to falling. They frequently have abnormal movements during sleep. Their walking might become slow or stiff and their face less expressive. Their concentration and attention can fluctuate so that the person living with Lewy body dementia can be really clear-headed in the morning but muddled and confused later that same day. These fluctuations can also be experienced over a few days.
People with Lewy body dementia sometimes see things that aren’t there (visual hallucinations) and may believe things that aren’t true (delusions), but these look and feel very real to the person experiencing them.
People with Lewy body dementia can benefit from physiotherapy and exercise physiology to help improve movement.
We don’t know what causes Lewy body dementia. Because of the similarities in symptoms, we think that Lewy body dementia and Parkinson’s disease are related diseases. However, in Lewy body dementia the difficulties with thinking are more prominent first, whereas in Parkinson’s disease the difficulties in movement are more prominent.
Read more about Lewy Body Dementia at Dementia Australia. and at the Lewy Body Dementia Association website
This video describes Lewy body dementia from the perspective of two couples experiencing it.
Fronto-temporal dementia
Fronto-temporal dementia is a less common type of dementia. People with fronto-temporal dementia have damage in the frontal and temporal lobes (regions) of their brains. People with fronto-temporal dementia often have symptoms that are different from other dementias. For this reason, clinicians may take longer to recognise, diagnose and treat this type of dementia. People with fronto-temporal dementia often have to educate others (including health professionals) about fronto-temporal dementia.
There are three subtypes of fronto-temporal dementia, each with a different pattern of symptoms.
- Semantic variant of primary progressive aphasia is a subtype of fronto-temporal dementia where the person starts to lose the meanings of words. People with semantic dementia have trouble expressing themselves with words, understanding language, reading and writing. They may benefit from speech therapy with experts in improving communication (see 3.11 Speech and occupational therapy). Brain changes start in the temporal lobe in semantic dementia.
- Progressive non-fluent aphasia is a subtype where the person has difficulty speaking fluently. People with progressive, non-fluent aphasia have trouble expressing themselves and following conversations. They may benefit from speech therapy with experts in improving communication (see 3.11 Speech and occupational therapy). Brain changes start in the temporal lobe in progressive non-fluent aphasia dementia.
- Behavioural-variant frontal dementia is a subtype where the person’s behaviour, mood or personality changes. People with behavioural-variant frontal dementia may become apathetic, socially disinhibited or socially unaware. They often have trouble with judgement, making decisions or problem solving. They might develop new habits that they do repeatedly, including eating and drinking different foods or drinks.
Read more about fronto-temporal Dementia at Dementia Australia. The Sydney University Frontier Clinic specialises in fronto-temporal Dementia.
Mixed dementia
People with mixed dementia have a combination of brain diseases, often Alzheimer’s disease and vascular brain changes. People with mixed dementia have a mixture of symptoms depending on the combination of brain diseases.
Read more about mixed dementia at the UK Alzheimer’s Society
Understanding more
Sometimes health professionals will refer to parts of the brain that are affected in dementia. The brain is incredibly complex, and dementia may affect one part of the brain more than others. You can learn what the different parts of the brain do by going to the interactive website Brainline.
You can click on different parts of a diagram of the brain and learn what that part is responsible for and problems that may occur if that part is damaged.
