About dementia Types of dementia Types of dementia There are over 200 types of dementia, each with their own characteristic symptoms. Understanding the specific diagnosis of a loved one can help come to terms with it and help to know what to expect. Alzheimer’s disease Alzheimer’s disease is the most common type of dementia, affecting more than half of people diagnosed with dementia. The disease causes physical permanent damage to individual brain cells due to the build-up of proteins causing Plaques and Tangles. The number of damaged cells progressively increases over time, which means that brain function, including memory, gradually deteriorates and everyday tasks become more and more difficult. This decline may begin slowly and can happen over a number of years. Alcohol-related dementia Alcohol-related dementia, which includes Korsakoff’s syndrome, is caused by a lack of vitamin B1 which particularly affects short-term memory. Heavy drinkers may not be able to absorb the vitamin well, resulting in impaired memory and other symptoms. Stopping alcohol consumption halts the condition and combined with the right treatment may even reverse it. Fronto-temporal dementia There are a number of variants of fronto-temporal dementia, including Pick’s disease and Semantic Dementia. These are caused by damage to the front and sides parts of the brain, which can result in behavioural and mood changes and people may find it difficult to judge situations or plan ahead. Problems in short-term and autobiographical memory are not as common, although general knowledge about the world can be impaired. This type of dementia is more likely to affect people under 65, and can have an impact on the personality of a person, as they often exhibit inappropriate and impulsive behaviour. Lewy body dementia Lewy body dementia affects about 10% of people with dementia and is caused by tiny, round deposits (known as Lewy bodies) that damage the nerve cells in the brain. This is linked with low levels of neurotransmitters and the connections between nerve cells is lost, which causes the brain to function less efficiently in sending and receiving messages. The effects of this can be sporadic, so symptoms can vary quite a lot day to day. As well as affecting memory, other symptoms can include hallucinations and mobility problems. Mixed dementia 10% of people diagnosed with dementia have mixed dementia, a combination of Alzheimer’s disease and vascular dementia. The symptoms will include elements of both. Vascular dementia Vascular dementia is the second most common type of dementia and is caused when the blood supply to the brain is damaged or cut off. This results in the death of some brain cells and can happen either suddenly after a stroke, or more gradually after a series of ‘mini-strokes’ or ‘infarcts’, which can sometimes be so small that they unnoticed to begin with. The blood supply can also be compromised by the thickening of the blood vessel walls in the brain, which reduces blood flow to the brain. People with vascular dementia may start to forget things and find day-to-day life harder to cope with. It can also affect mobility and coordination. Progression of symptoms occurs generally in a stepped development, where symptoms may change overnight rather than gradually over an extended period of time.