Young onset dementia

This is the most common type of dementia, affecting more than 33% of all those with a diagnosis. It is caused by the formation of protein ‘plaques’ and ‘tangles’ in the brain which lead to nerve cell damage.

Most dementias, and especially Alzheimer’s disease, progress slowly.

The most common feature of Alzheimer’s disease is impaired memory. People with Alzheimer’s find it very difficult to learn new information and to remember it even over short spaces of time. In the early stages people may still have very good memory for events that happened a long time ago. Alzheimer’s can also affect attention, concentration and thinking and reasoning. There may also be problems with wordfinding and visual perception. Often, people with Alzheimer’s may not be as aware of their difficulties as others who know them well. Low mood, anxiety and dislike of new situations are also common features.Alzheimer’s disease usually progresses at a slow pace and people can live for many years following a diagnosis.

Vascular dementia accounts for about 20% of dementia cases. It can be caused by poor blood circulation in the brain (meaning that the cells do not receive enough oxygen) or bleeding in the brain. It can also occur as a result of a major stroke, or a series of strokes.

People with a history of high blood pressure, high cholesterol, diabetes, or heart problems are at increased risk of developing vascular dementia.

People with vascular dementia can experience changeable symptoms. They may be relatively stable for a period of time before showing a sudden deterioration that then stabilises.

Symptoms of vascular dementia will vary, depending on the parts of the brain that are affected.

Poor memory is likely to be a key feature.

People with vascular dementia may be able to learn new information, but they have significant difficulty with retrieving information from memory. Often, giving clues or hints can help people to find the information they are looking for.

Other symptoms may include slowed thinking, poor problem-solving and limited ability to focus. There may also be difficulties with word-finding and visual perception. People with vascular dementia are often aware of their problems and may experience anxiety and depression.

Treatment for vascular dementia may include trying to reduce the risk of further damage by managing blood pressure, cholesterol and diabetes.

It is not uncommon for people to be affected by both Alzheimer's Disease and Vascular Dementia.

This dementia affects about 10% of people with a diagnosis. It is caused by the development of small protein bodies called Lewy bodies that damage brain cells.

Common symptoms in this type of dementia include disturbances in movement such as shuffling and stiffness, visual hallucinations, fluctuations (ups and downs) in thinking ability and significant variation in attention and alertness. 

Depression and a general lack of interest are also common.

Memory problems may not be a major feature.

About 12% of dementia cases fall into this category.

Frontotemporal dementia (FTD) results from damage to specific parts of the brain (the frontal and temporal lobes), which are responsible for our behaviour, emotional responses and language skills.

The key symptom of this form of dementia is personality and behaviour change. A person with FTD may withdraw from social events and activities, neglect their personal hygiene and show a lack of judgement and disinhibition.

They may also develop ritualised behaviour (always needing to do things in a particular way) and often find it difficult to understand emotions in others and express their own emotions.

There may also be changes to eating patterns, such as overeating or a preference for sweet foods. In the early stages, this type of dementia is sometimes mistaken for a psychiatric condition or a 'mid-life crisis'.

Types of frontotemporal dementia

There are different types of FTD.

Behavioural variant FTD

This affects behaviour first. Some early changes you may notice include changes to motivation, personality or appetite.

Primary progressive aphasias

Primary progressive aphasias are a type of FTD. The most common are:

Progressive non-fluent aphasia

This affects language first. Early changes you may notice include:

• Finding it harder to pronounce words
• Leaving out words in sentences
• Struggling to understand more complex sentences

Semantic dementia

This also affects language first. Early changes you may notice include:

• Difficulty understanding the meaning of familiar words
• Struggling to find the right word and using descriptions instead
• Problems recognising familiar people or objects

Logopenic aphasia (LPA)

Someone with LPA might have difficulty finding the right word to say, although their ability to physically produce speech is not affected.

These word-finding difficulties can lead to long pauses in conversations. People with LPA can also get parts of words muddled up, for instance saying 'aminal' instead of 'animal'.

LPA is usually caused by the same proteins in the brain that cause Alzheimer's disease. Some people refer to it as an unusual (atypical) form of Alzheimer's disease.

Around 10% of dementias in young people are caused by a lack of vitamin B1 (thiamine), most commonly associated with alcohol abuse.

Around 20% of young people with dementia have a ‘rarer’ form of the condition.

Examples include conditions that can lead to dementia, including:

• Parkinson’s disease dementia
• Posterior Cortical Atrophy (PCA)
• CADASIL, Corticobasal degeneration (CBD)
• Fahr Syndrome
• Creutzfeldt-Jakob disease.