A progressive brain disease
Frontotemporal dementia affects personality, behaviour and language, often while memory stays relatively unaffected in the early stages.
Frontotemporal dementia tends to affect the front and side parts of the brain first and is a common cause of young-onset dementia, accounting for approximately 10 per cent of dementia cases in people under 65.
What is frontotemporal dementia?
Frontotemporal dementia (FTD) is so-called because it affects the frontal and temporal lobes of the brain, which are important for personality, social behaviour and language. Because of this, it often presents differently to other types of dementia.
Changes in behaviour and personality are a common mode of presentation. A person may:
- become less socially aware
- develop repetitive habits or routines
- lose interest in things they used to enjoy
- say or do things that seem out of character or inappropriate
- seem less caring towards others.
These changes are usually noticed by family and friends because the person themselves has limited insight into their symptoms.
Other patients with FTD can present with speech or language disturbances. A person may have:
- dysfluent speech
- impaired use of grammar
- loss of word and object knowledge
- word-finding difficulty.
These subtypes or phenotypes of FTD are often considered under the umbrella of primary progressive aphasia. The early symptoms of FTD can be mistaken for a mental health condition, stress or a mid-life change, especially as it often affects people at a younger age than other types of dementia. This often leads to a delay in making the diagnosis.
Over time, all subtypes of FTD can affect the following areas to varying extents:
- independence with everyday tasks
- language (word-finding, understanding or speaking fluently)
- memory (usually later in the condition)
- personality and behaviour (social awareness, empathy, impulse control)
- planning and decision-making.
What happens in the brain?
FTD occurs when the frontal and temporal lobes gradually shrink (or become atrophic). This is caused by a buildup of abnormal proteins inside brain cells, most often a protein called tau or another called TDP-43 (this pathology is different to that of Alzheimer’s disease).
Over time, this build-up disrupts how these brain regions work, leading to the changes in behaviour, personality and language seen in frontotemporal dementia.
What increases the risk of frontotemporal dementia?
FTD has a stronger genetic link than some other common causes of dementia, though most cases occur without a clear inherited cause.
Factors that can’t be changed include:
- age – FTD is one of the more common causes of young-onset dementia. Factors that may be modifiable are far less well established for FTD than for Alzheimer’s disease or vascular dementia, since it is less strongly linked to cardiovascular or lifestyle-related risk factors.
- family history – a minority of cases of FTD have a strong family history of the disease
- specific genetic changes – mutations in certain genes (for example, C9orf72, MAPT and GRN) are identified in a small proportion of cases, particularly where there is a strong family history. Genetic counselling may be recommended if this is suspected.
When to seek help
If a family member has been diagnosed with FTD and their behaviour has become unmanageable, you can:
- call Emergency on 000, if the behaviour seems unsafe
- contact the Dementia Behaviour Management Advisory Service (DBMAS) on 1800 699 799. They offer a support service and provide advice on how to handle problematic behaviour in patients with dementia.
- speak to your GP, or Healthdirect on 1800 022 222 for guidance. The family member should be referred for an assessment by a neurologist or neuropsychologist.
Common patient questions
No, they are different diseases with different underlying brain changes. FTD usually affects behaviour, personality or language first, while Alzheimer’s disease usually affects memory first.
FTD predominantly affects the frontal and temporal lobes, which are important for behaviour and language, so these symptoms dominate the clinical picture early on. Memory disturbances may also be present, but they are usually much less obvious and problematic than the changes in behaviour and language.
Yes, it’s one of the more common causes of dementia in people under 65. Symptoms are sometimes mistaken for stress, depression, or relationship difficulties before a diagnosis is made. See young-onset dementia.
Sometimes. A meaningful proportion of cases are linked to a family history or specific genetic changes, more so than in Alzheimer’s disease, though most cases still occur without a clear inherited cause.