Frontotemporal dementia refers to a group of disorders caused by progressive degeneration of the frontal and/or temporal lobes of the brain. The majority of FTD cases occur between the age of 45 to 64, and the disease affects both men and women. The initial symptoms of FTD depend on which part of the brain is first affected.
- The frontal lobes are involved in planning, attention, decision-making, mood and empathy. Damage to this region results in changes to personality and behaviour. This is known as behavioural-variant FTD (bvFTD).
- The temporal lobes are involved in understanding and expressing language. Damage to this region causes the decline of language skills. This is known as primary progressive aphasia (PPA), of which there are three variants: semantic dementia, progressive nonfluent aphasia, and logopenic aphasia.
The rate of decline varies, and can range from 2 to 20 years. As the disease progresses, more symptoms in behaviour, language or movement may appear, as more regions of the brain are affected. Unfortunately, there is currently no cure for FTD, nor treatments to slow or stop disease progression. However, there are strategies to manage FTD symptoms that can help to maintain and improve quality of life for the person affected and their loved ones. For more details of the subtypes of FTD and other related disorders, see below.
There are a number of tests that are used to arrive at a diagnosis of frontotemporal dementia.
A specialist (e.g. a neurologist) will conduct a clinical assessment, where they ask about symptoms and any similar diseases in family history.
The specialist will also look at thinking, memory, and language, and conduct a physical examination to look for signs of MND or parkinsonism.
A neuropsychologist may perform more detailed tests of thinking, language and memory to provide a more complete picture of your abilities and identify specific problems to help establish the diagnosis. Brain imaging, typically using an MRI scan, looks for signs of change in the frontal and temporal lobes of the brain. Confirmed change in these areas is important for an accurate diagnosis of FTD.
Behavioural-variant FTD (bvFTD) accounts for about half of all FTD cases. bvFTD is characterised by personality changes, inappropriate social behaviour, and decline in self-control and empathy. People with bvFTD typically lack insight into their behavioural changes and the impact of their behaviour on those around them. Symptoms include:
- Impulsive spending
- Making rude comments
- Aggressive outbursts
- Neglect of personal hygiene
- Loss of interest or motivation to engage in work, hobbies, relationships
Loss of Empathy
- Withdrawing from social interaction
- Failure to recognise emotions of loved ones
- Indifference to emotional events e.g. weddings, funerals
Compulsive or ritualistic behaviour
- Repeating words or phrases
- Sticking to routines
Changes in diet or eating habits
- Binge eating
- Increased preference for sweet food
- Eating only specific foods
- Increased alcohol or cigarette consumption
Primary Progressive Aphasia
Primary progressive aphasia (PPA) is characterised by the gradual impairment of language skills, including the ability to speak, read, write, and understand language. PPA is further divided into three subtypes, depending on the specific language skills that are affected:
For people with semantic dementia (SD), the ability to understand the meaning of single words is gradually lost. They tend to have difficulty finding the right words and omit or substitute words, resulting in vague speech. Speech production and grammar remains intact, so people with semantic dementia may speak fluently but with little meaning. As the disease progresses, people affected by SD may develop difficulties in recognising objects and faces.
Progressive nonfluent aphasia
For people with progressive nonfluent aphasia (PNFA), the ability to produce fluent speech becomes gradually impaired. Speech becomes slow and effortful, and the person may stutter or pronounce words incorrectly. Some people may slur their words. Spelling and reading also becomes difficult.
Non-language functions, including the ability to understand speech, tend to be preserved in the early stages of the disease.
For people with logopenic aphasia, finding the correct words while they are speaking is difficult. Unlike people with semantic dementia, they can still recall the meaning of words, but speak hesitantly as they search for the right words.
Their speech is usually not effortful or distorted, unlike people with PNFA. Their attention span for words is also affected, making it difficult to repeat phrases and sentences. As the disease progresses, they may have difficulties comprehending longer, more complex sentences.
FTD with parkinsonism
Parkinsonism is a movement disorder, characterised by slowed movements (bradykinesia), stiffness in the arms and legs (rigidity), or tremors.
Parkinson’s disease is the most common form of parkinsonism, but there are other disorders that produce very similar symptoms, known as atypical parkinsonian disorders.
Two of these atypical parkinsonian disorders – corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP) – may occur in people with FTD.
Corticobasal syndrome (CBS)
Corticobasal syndrome (CBS), also known as corticobasal degeneration, may start with movement, cognitive, or language problems.
Motor symptoms usually begin in one hand, arm or leg, which may feel stiff or shake. Movement of the limb may be slower than usual or difficult to control. While it usually begins on one side of the body, the disease gradually affects both sides.
Language problems experienced may include trouble finding the right words, naming objects, or producing speech. Writing also becomes difficult, particularly if movement in the hands is affected.
Progressive supranuclear palsy (PSP)
Progressive supranuclear palsy (PSP) is characterised by trouble with balance, leading to frequent falls. People affected by PSP have a stiff, upright posture with a tendency to fall backwards.
Another characteristic symptom of PSP is the progressive inability to move the eyes from side to side or up and down. As a result, people with PSP may experience problems reading, making eye contact, going down stairs or eating their food because of inability to move their gaze.
PSP also affects movement of the mouth, tongue and throat. This results in difficulty in conversing with others, as speech becomes slow or slurred (dysarthria), and also causes difficulty swallowing food and liquids (dysphagia), which can lead to pneumonia.
FTD with motor neurone disease
Motor neurone disease (MND), also known as amyotrophic lateral sclerosis (ALS), affects the nerves that control movement in the arms and legs and allow people to speak and swallow.
Symptoms of MND include:
- Muscle weakness and atrophy
- Fasciculations - brief, uncrontrollable twitching of muscles
- Prolonged muscle contraction, causing stiffness
- Slurred speech
- Problems swallowing
About 1 in 10 people with FTD also develop motor neurone disease (FTD-MND). This is more common in people with behavioural variant FTD, and occasionally in people with progressive nonfluent aphasia. People who have FTD-MND may experience a more rapid decline in physical and cognitive abilities, compared to people with FTD alone.Back to top