Frontotemporal dementia

Expert reviewer Dr Rahul Bhattacharya, Consultant Psychiatrist
Next review due June 2022

Frontotemporal dementia is a condition affecting the brain. It is a rarer type of dementia, which is a term used to describe a set of symptoms, including problems with memory and thinking.

Frontotemporal dementia can affect how a person behaves, and how well they are able to speak and understand language.

What is frontotemporal dementia?

Frontotemporal dementia affects the frontal and temporal lobes of the brain – the areas generally associated with personality, behaviour and language. It probably accounts for fewer than one in 20 cases of dementia. However, it is one of the commonest causes of dementia in people under 65. It is most often diagnosed in people in their 50s and 60s, but can affect older people too.

Frontotemporal dementia used to be called Pick’s disease. But it is really a group of conditions and Pick’s disease is just one of these.

There are three main types of frontotemporal dementia, characterised by different main symptoms when the condition is diagnosed. Half to two-thirds of cases are the ‘behavioural type’, where the main dementia symptom is that people lose their inhibitions. In the second type, called the ‘aphasic type’, people lose the ability to speak fluently. In the third, called the ‘semantic type’, they typically forget words and their meaning and fail to recognise familiar objects.

There are also less common types, including one associated with motor neurone disease, and types associated with movement problems.

Frontotemporal dementia gradually gets worse over time. However, this can be very variable, with a prognosis of anything between two and 20 years.

Symptoms of frontotemporal dementia

There isn't a single answer to the question 'what is frontotemporal dementia?' The three main types of frontotemporal dementia have different symptoms. As well as the frontotemporal dementia symptoms described below, around one in six people may also have symptoms similar to motor neurone disease (MND) such as muscle twitching and muscle weakness.

Later in the course of frontotemporal dementia, some people may also have symptoms of Parkinson’s disease, but this isn’t common. Symptoms can include tremors, slowness of movement and a lack of facial expression.

Behavioural type frontotemporal dementia

Generally, with this type of frontotemporal dementia, behaviour is affected more than memory and mental abilities in the early stages of the condition. Among the main early symptoms is a loss of inhibitions. The person may no longer seem themselves. They may gradually stop interacting socially or carrying out their usual hobbies or work activities. They may behave inappropriately in social situations, or say things that are rude or tactless. Other signs of this type of frontotemporal dementia are:

• no longer looking after themselves in dress or personal hygiene
• lack of concern for other people and ability to understand their feelings
• difficulty planning, organising and making decisions
• repeating behaviour, having rituals and sticking rigidly to routines
• developing eating fads, overeating or an increasing liking for sweet foods

Sometimes people may also have speech symptoms, such as repeating what others say to them or stopping talking altogether.

In the later stages of the condition, people become increasingly less able to look after themselves. They may lose bladder or bowel control (incontinence).

Aphasic type frontotemporal dementia

Aphasic means losing the ability to speak, so the main symptoms of this type of frontotemporal dementia affect people’s speech. This may begin with speech becoming slow and hesitant. The person may make errors in grammar that they wouldn’t have made before they had frontotemporal dementia. They may also find it difficult to follow long sentences, even though they can understand the individual words. Other signs include:

• losing the ability to read and write
• stuttering
• having difficulty repeating words or sentences back to you

As the condition worsens, someone with aphasic type frontotemporal dementia may stop talking altogether.

Semantic type frontotemporal dementia

Semantics is the study of the meaning of words and phrases. So people with this type of frontotemporal dementia often forget the meanings of words. Unlike aphasic frontotemporal dementia, they can still speak fluently but they may ask what common words mean. They may also have difficulty recognising words when reading.

Memory is usually better preserved than with other types of dementia. But people with semantic type frontotemporal dementia may have trouble recognising familiar faces or things and ask what objects are used for.

How frontotemporal dementia develops

Generally, frontotemporal dementia develops very slowly. On average, people have the condition for eight to 10 years. However, frontotemporal dementia can be very variable. It tends to develop more slowly in the aphasic and semantic type than in the behavioural type. Generally, it develops more quickly in people who have Parkinson’s or motor neurone symptoms along with frontotemporal dementia. Those with motor neurone symptoms may live with the condition for only three to five years, even if they have dementia treatment.

Generally with frontotemporal dementia, changes in personality, behaviour and language appear first, depending on which type of frontotemporal dementia it is. Because symptoms may be mild at first and worsen slowly, it may take some time before frontotemporal dementia in the early stages is fully diagnosed.

As the condition develops, people may begin to develop more problems with memory and may become confused and disorientated. The three distinct types of frontotemporal dementia tend to ‘come together’ in terms of symptoms as they progress. For example, people with the behavioural type will eventually develop problems with language and those with the other types will eventually develop more changes in behaviour.

Difficulty planning and knowing how to carry out familiar tasks will mean that people with frontotemporal dementia will find it more difficult to manage day-to-day life. They’re likely to need help with more basic daily care, such as washing and dressing. Because the condition worsens over time, eventually many people need to be looked after all the time, which is often only possible in residential care.

You may have heard about different stages of dementia. However, this isn’t very useful in managing or treating frontotemporal dementia. There’re a few different staging systems, but they were really developed for use in Alzheimer’s disease research, to compare clinical trial results more easily.

Causes of frontotemporal dementia

The cause of frontotemporal dementia is damage to the frontal and temporal lobes of the brain. The frontal lobe is the part of the brain that deals with thought, decision-making and planning. The temporal lobe handles hearing and understanding of speech and language. Doctors don’t fully understand what causes the damage to these parts of the brain.

In around four out of 10 cases, frontotemporal dementia runs in families. Studying these familial cases, doctors have found specific changes in genes. They don’t know exactly how many cases of frontotemporal dementia are due to these changes. Current research estimates that it is between one in four and one in five.

Researchers have also found some typical features in brain cells of people with frontotemporal dementia. There are abnormal deposits of certain types of protein. There are abnormal deposits of both these proteins in Alzheimer’s disease too, so doctors know that they can be linked to dementia.

We don’t fully understand how the changes to genes and the abnormal protein deposits lead to the symptoms of frontotemporal dementia.

Treatment for frontotemporal dementia

There is sadly no cure for frontotemporal dementia, but there are medicines that may help with symptoms. There are also other therapies that may improve life for a person with frontotemporal dementia.

Medicines

There are also no medicines that can specifically be used as frontotemporal dementia treatment. The medicines used to treat Alzheimer’s disease have not been shown to work in frontotemporal dementia, so doctors are unlikely to prescribe them.

Treatment is usually focused on supporting the person with frontotemporal dementia and their carers, and on managing symptoms. So, the medicines someone is prescribed will depend on how the condition is affecting them and their behaviour. They may have:

• medicines for anxiety, such as lorazepam, if they are agitated, irritable or restless
• medicines called selective serotonin reuptake inhibitors (SSRIs) for depression or compulsive behaviour, such as fluoxetine (Prozac)
• other anti-depressants that have a sedative effect, to help with sleep problems
• medicines that are normally used for epilepsy, as they can help with excitability, restlessness and impulsive behaviour

Quite a few of the medicines used to manage frontotemporal dementia symptoms have sedative effects: they can make people drowsy and less responsive. It’s important with any type of dementia not to over-medicate or give too many medicines that have a sedative effect. This can increase confusion or memory problems. The doctor will regularly review medicines to make sure the person isn’t taking too many.

Other therapies for frontotemporal dementia

There are several other ways that life can be improved for people with frontotemporal dementia and their families. Physiotherapy and occupational therapy can help to keep the person with dementia mobile and to make sure their home environment is as safe as possible. Speech therapy can help people with language and with any difficulties swallowing.

For carers, understanding how the condition is likely to affect the person with the dementia can make it easier to prevent problems and cope with them when they arise. Caring for someone with frontotemporal dementia can be particularly demanding and stressful, so it’s important that carers look after themselves.