Frontotemporal dementia: a common form of young-onset dementia
26 January 2021
Frontotemporal dementia (FTD) is the second most common form of young-onset dementia, with several different subtypes involving changes in behaviour, personality and language skills.
FTD was originally called Pick’s disease after the Czech psychiatrist who first identified it in 1892. Although FTD can develop at any age, it is most commonly seen in people aged 45-65. In this age group, it is the second most common dementia after early-onset Alzheimer’s disease, but in the general population it is a rare condition. FTD is an umbrella term for a group of diseases that affect the frontal and temporal lobes of the brain.
The frontal lobe is the largest of the brain’s four lobes and, as the name suggests, is located at the front of the brain. It controls a wide range of brain functions including personality, planning, judgement, problem-solving, emotional expression, and sexual behaviours. It also contains the Broca’s area, which is responsible for understanding language and producing speech.
Meanwhile, the temporal lobes – one on each side of the brain – play a vital role in memory, as well as processing sight and sound information. This means that one of their jobs is recognising objects and deciphering speech.
In FTD, diseases – often caused by the disruptive proteins tau and TDP43 – specifically attack the frontal and temporal lobes of the brain. Scientists don’t yet know why these proteins target those brain areas, as opposed to others. The particular brain cells within these areas that are destroyed will dictate the unique pattern of symptoms each patient experiences.
FTD can broadly be grouped into a behavioural variant and a language variant. The behavioural variant is the most common type of FTD and involves personality changes that can reduce a person’s inhibitions, making them behave more socially inappropriately and impulsively. The condition can also make people less emotional and increase their sexual behaviour.
By contrast, the language variant is characterised by aphasia – the technical term for difficulties in understanding and formulating both written and spoken language – specifically, primary progressive aphasia (PPA), which means the aphasia gets worse over time.
This is further broken down into semantic dementia and progressive nonfluent aphasia. People with semantic dementia may find it difficult to name objects and remember what different words mean. People with progressive nonfluent aphasia have speech difficulties but can understand language, although they may struggle with more long and complex sentences.
For example, people with progressive nonfluent aphasia may have difficulty formulating their own words, so will often speak more slowly and in very short sentences. They may have trouble finding the right words, so might leave out some words. They are also more prone to errors in grammar and pronunciation.
Speech and language therapy can help to improve the symptoms of language-variant FTD. The therapist works closely with the patient, their carers, and other health professionals to improve their communication. Mostly, speech and language therapy is provided by private clinicians, but if the person with dementia also has difficulty swallowing, then the service is offered by the NHS.
In addition, FTD can affect some people’s movement because the frontal lobe also controls primary motor function. This can cause overlaps with conditions like motor neurone disease, as movement becomes more difficult due to things like muscle weakness or stiffness. However, brain functions that are often associated with dementia like general memory and insight are not usually affected in FTD until the later stages.
While there are no medical treatments for FTD, there is lots of support available to help people live well with the condition. Rare Dementia Support provides lots of information, advice and support for people living with FTD including peer groups for the person diagnosed and their carers.
There is also a growing body of research emerging about FTD, utilising existing knowledge about conditions that share similar symptoms, such as motor neurone disease and stroke. You can stay up to date on the latest research into FTD on the Alzheimer’s Research UK website.