There are many conditions which cause dementia.

Different types of dementia can lead to different experiences and problems for the person with dementia and their loved ones. 

Not every person will experience all the symptoms and the problems linked to their type of dementia. Some people experience a mix of two types of dementia.

Types of Dementia:

Alzheimer's disease

Alzheimer’s disease is the most common and well-known cause of dementia. It is thought to cause over half of all cases. It is recognised by the build up of protein on the brain which forms plaques and tangles that stop the brain working as it should.

In general, with Alzheimer’s disease changes are gradual over time and the illness may last several years. At first, changes may be slight and as the illness goes on, the changes become greater.

Memory loss is often one of the first symptoms of this disease; however there are a range of early signs and symptoms including getting stuck for words, misplacing things regularly, losing track of time, changes in mood and behaviour and difficulty in finding the way, even in familiar places.

One of the first things I noticed, apart from her memory, was her ability to coordinate daily tasks was deteriorating. When she cooked a meal, she might cook the vegetables first and it could be hours afterwards that she would put the meat on. Anonymous, Galway.

Vascular dementia

Vascular dementia is the second most common type of dementia and it occurs when the blood supply to the brain is damaged. There are two main types of vascular dementia; one caused by stroke and the other by small vessel disease.

Multi-infarct dementia is a type of vascular dementia that is caused by small stokes. The strokes can be so tiny that no-one notices them happening, but the person may get worse quite suddenly and then not change again until the next stroke happens. As a result, the progression of this dementia is often described as happening in steps rather than steady gradual changes, such as in Alzheimer’s disease. People with vascular dementia will often have difficulty concentrating and communicating. They may have memory problems, but this may not be the first symptom. Depression is also common in people with this type of dementia.

Dementia with Lewy bodies

Lewy body dementia is a type of dementia that shares characteristics with both Alzheimer’s disease and Parkinson’s disease. Like Alzheimer’s disease symptoms progress gradually over several years. The person will experience many of the signs and symptoms of Alzheimer’s disease and may also experience muscle stiffness, trembling of the limbs and a tendency to shuffle when walking. They may also experience hallucinations (seeing things that are not there) and fall asleep during the day and then not sleep at night.

Fronto Temporal

Fronto-Temporal Dementia, including Picks Disease is a rare type of dementia. During the early stages, a person’s memory may be fine but their personality, behaviour and language skills can change. This dementia often causes a loss of insight and so the person may say and do things at the wrong time and in the wrong place. This can be embarrassing for family members and it is important to know that there is a physical cause for these changes. The progression of this dementia is unpredictable and in the later stages symptoms are similar to those of Alzheimer’s disease.

Other forms of dementia

Other forms of dementia include alcohol-related dementia such as Korsakoff’s Syndrome and Creutzfeld-Jacob Dementia. Some people with Down’s syndrome also develop dementia in middle age.

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About Alzheimer Ireland

The Society was founded in 1982 by a small group of people who were caring for a family member with Alzheimer's Disease or a related dementia. Find out what we docontact us and more

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We offer a range of services for people with Alzheimer's disease and other forms of dementia, their families and carers. All our services operate using the philosophy of person centred care.

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