Dr Jonathan Rohrer, Consultant Neurologist, Dementia Research Centre
The term Primary progressive aphasia (PPA) refers to a group of disorders in which people develop progressive loss of their language abilities.
PPA falls within the frontotemporal dementia (FTD) group of disorders caused by loss of cells in the frontal and temporal lobes of the brain.
Within PPA three main patterns of language loss are recognised:
- Semantic dementia: people gradually lose their knowledge of words
- Progressive non-fluent aphasia (PNFA):people’s speech becomes effortful and they might say the wrong word or use the wrong grammar
- Logopenic aphasia (LPA): people start to develop pauses in their speech as they try to find the right word
There is a support group specifically for those affected by Primary Progressive Aphasia. To find out more, please visit the Primary Progressive Aphasia Support Group page.
This may also be called the semantic variant of primary progressive aphasia.
The first symptoms of SD are usually problems with language. These may include:
- Difficulty finding the right word - often substituting another word or a vague term such as ‘thing’ instead of the specific word.
- Loss of knowledge of what words mean or what objects are for.
- People may talk about things in a vague or ‘roundabout’ manner – referred to as ‘circumlocutory’ speech.
- Difficulty understanding what other people are saying.
- Problems with reading and writing.
Problems with language increase over time. There is a slow but progressive loss of vocabulary and the ability to understand what people are saying. Speech becomes increasingly vague and the quantity of speech tends to diminish.
With progression of the disease, changes in personality are more common in SD than the other types of PPA. These may include the development of a sweet tooth or other changes in eating, becoming obsessive, and disinhibited behaviour.
Later in the illness non-language functions become affected. In particular, the person may have increasing difficulty recognising familiar people or household items. There are also increasing problems carrying out normal daily living activities.
There is no single test that allows doctors to make a diagnosis of SD. Usually the diagnosis is made using a combination of clinical assessment, psychology testing and a brain scan. MRI scanning shows loss of brain cells in the temporal lobe, usually more on the left than the right.
Progressive non-fluent aphasia (PNFA)
This may also be called the nonfluent or agrammatic variant of primary progressive aphasia.
The first symptoms of PNFA are usually difficulties producing speech. These may include:
- Difficulty producing words - although the person knows what they want to say, speech may be effortful and words may come out distorted. This is due to difficulties in the co-ordination of the movements of speech and is sometimes called ‘apraxia of speech’.
- Difficulty organising words – the structure of the sentences may be affected with words being missed out and errors in the grammar.
- Together these factors make the speech sound distorted, slow and hesitant and difficult to understand.
As the disease progresses, people may develop other problems including:
- Reading, writing and spelling may be become more difficult.
- Understanding of language may become affected and the disease may spread to other areas of the brain causing problems such as changes in behaviour, organisational skills and memory.
- Some people with PNFA develop problems similar to Parkinson’s disease such as a tremor, difficulty using their hands or falls. These problems may be part of conditions called corticobasal degeneration (CBD) or progressive supranuclear palsy (PSP).
As with SD, there is no single test that allows doctors to make a diagnosis of PNFA. Usually the diagnosis is made using a combination of clinical assessment, psychology testing and a brain scan. MRI scanning shows loss of brain cells in the speech areas of the brain, particularly the frontal lobe on the left side.
In a small number of people PNFA is caused by a genetic problem. The genes that are known to cause problems are called progranulin (or GRN) and C9orf72.
This may also be called the logopenic variant of primary progressive aphasia.
The main symptoms of LPA are:
- Difficulty finding the right word. Speech contains pauses where the person stops what they are saying as they try to find the right word.
- Speech may become slow and hesitant and the pronunciation of words may be affected.
- As the problem progresses other cognitive functions such as calculation and memory are affected.
There is no single test that allows doctors to make a diagnosis of LPA. Usually the diagnosis is made using a combination of clinical assessment, psychology testing and a brain scan. Brain scanning shows loss of brain cells in areas further towards the back of the brain than the other PPA subtypes, particularly the area where the temporal and parietal lobes meet.
Like the other forms of PPA, why LPA develops in some people is unclear. Unlike the other types of PPA, in the majority of people where brain tissue has been examined under the microscope, the same pathology as Alzheimer’s disease has been found. LPA is therefore often thought to be an unusual form of early onset Alzheimer’s disease.
Frequently asked questions
How is a diagnosis of PPA made?
At most specialist clinics you will have a neurological assessment usually followed by a neuropsychological assessment by an experienced team of cognitive neurologists and neuropsychologists. Although these initial assessments can point towards a diagnosis of PPA, an MRI scan of the brain will also help with the diagnosis (see pictures above). In some circumstances a lumbar puncture (spinal tap) may be performed.
Is there a treatment for PPA?
There is no cure for PPA at the moment despite research efforts around the world. However, speech therapy to help with communication strategies, particularly in PNFA, is useful. Co-existing depression or behavioural problems can be treated symptomatically.
What causes PPA?
The symptoms of PPA are caused by loss of brain cells in the frontal and temporal lobes of the brain. However, the processes that lead to this loss are not well understood. It is known that there is an abnormal accumulation in the brain cells of certain proteins (known as TDP-43, and tau). What makes these proteins deposit, why they occur in particular areas and how their deposition leads to brain cell damage is still being not known.
Does PPA run in the family?
Some people with PNFA have a family history of the same condition or of frontotemporal dementia. Problems (mutations) in genes called progranulin and C9orf72 have been shown to be associated with PNFA. SD and LPA only rarely run in families.
What is the prognosis for people with PPA?
This is a difficult question to answer as there has been very little research into it and it can be extremely variable from person to person. However, we know that from the onset of symptoms many people will live over 10 years and for SD this can be over 15 years.
The PPA support group holds several meetings a year. A newsletter is published and circulated to members between meetings and the group offers the opportunity for contact with other people who have experienced a diagnosis of Primary Progressive Aphasia.
For more information please visit the PPA Support Group website (opens link) or contact our nurse coordinator Jill Walton:
- Email: email@example.com
- Telephone: 07592 540555