Symptoms
The word “aphasia” means a language disorder caused by brain damage, but there are different types of aphasia. Firstly, there is “logopenic” aphasia, which is an atypical form of Alzheimer’s disease where people have difficulties with searching for the right word, although their ability to physically produce speech is not affected.
These word-finding difficulties can lead to long pauses in conversations. People with logopenic aphasia can also get parts of words muddled up, for instance saying “aminal” instead of “animal”.
More unusually, semantic dementia, which is a form of FTD, affects a person’s “semantic memory”, their knowledge-store of what objects are, and what words mean. If you said to somebody with semantic dementia “What did you have for breakfast?” they might say: “What’s breakfast?” People with semantic dementia can speak quite fluently – but they may seem to use more general words, such as “thingy”.
There is a third type of aphasia known as progressive non-fluent aphasia, also a type of FTD, where a person has problems speaking, constructing sentences and using grammar. Their speech might sound very slow or physically difficult, or they may get the order of words in a sentence mixed up. Difficulties with word order and sentences can be present in writing as well as speech.
If you suspect a family member has PPA, a specialist will examine progressive language decline, plus a neurological examination, neuropsychological testing for language and cognition, and brain imaging.
Treatment
Speech and language therapy can help in the early stages. As logopenic aphasia is typically caused by the plaques and tangles of Alzheimer’s disease, people could benefit from future Alzheimer’s drugs.
4. Posterior cortical atrophy (PCA, or Benson’s syndrome)
PCA literally means back of the brain shrinkage, which results in visual problems seeing what and where things are. This is an issue with “brain sight”, not “eyesight” – the information from their eyes is transmitted, but gets misinterpreted. The most common cause of PCA – in more than 90 per cent of cases – is Alzheimer’s disease, but for reasons we don’t yet fully understand, the disease targets the visual networks at the back of the brain rather than the memory networks at the sides first.
Symptoms
A person in their 40s might go to the doctor and say: “I can’t see properly.” The GP thinks they are too young for dementia, so the patient gets sent to the ophthalmologist. They will try loads of glasses but none of them work.
For example, we once met a gentleman with PCA in his 50s whose first symptom was having difficulty playing badminton. Strikingly, he could see the shuttlecock when it was moving during the rally, but couldn’t find it when it was stationary on the floor. We determined that he had this form of Alzheimer’s that affects the visual centres in the back of the brain.
Many others describe having difficulties with driving and parallel parking. Memory is relatively preserved in PCA. The average age of diagnosis with PCA is 58, but the youngest person I’ve seen was 25.
Treatment
For the majority where Alzheimer’s disease is the underlying cause, existing and new symptomatic and disease-modifying treatments should be beneficial.
5. Familial Alzheimer’s disease
A small proportion of those with Alzheimer’s – fewer than 1 per cent – have a form that is directly inherited, with children of someone with the gene mutation having a 50:50 chance of inheriting the gene and almost certainly developing the condition if they do. Symptoms can start in a person’s 30s, 40s or 50s.
Symptoms
As with typical Alzheimer’s disease, the first symptoms tend to be memory loss alongside new difficulties with planning or performing calculations emerging as the disease spreads.
Treatment
A diagnosis of FAD comes with extra burdens: those at risk may be caring for a relative when they find out, and may need to access specialist genetic counselling and support.
Many of our research trials involve these incredible people – this work is vital as we can test potential treatments before damage has occurred in the brain and symptoms emerge to determine whether the underlying disease might be slowed.
6. Lewy body dementia (LBD)
This is an umbrella term that includes dementia with Lewy bodies and Parkinson’s disease dementia.
LBD is caused by a build-up of proteins called “Lewy bodies” in the brain. Lewy body dementia may account for up to10 per cent of all dementia and is typically a later-onset condition, after the age of 65.
Symptoms
LBD can affect thinking and memory, and also cause visual hallucinations – seeing things that are not there such as children and small animals – as well as movement changes similar to Parkinson’s disease such as slowness, stiffness and tremors. People with LBD also experience cognitive fluctuations, with memory and thinking difficulties varying from day to day or even hour to hour.
Treatment
Dementia drugs such as cholinesterase inhibitors are used to manage cognitive symptoms. Levodopa – a Parkinson’s medication – can help manage motor symptoms, whilst clinical trials are looking for new treatments to slow the progression of LBD.
As told to Miranda Levy
Rare Dementia Support, part of the UCL Queen Square Institute of Neurology in London, has been supporting people with rare dementia for over a decade and now has 10,000 members. This summer, the service will be opening The Hilary and Galen Weston Rare Dementia Support Centre in Bloomsbury, London, the first centre of its kind in the world, in partnership with UCL and The National Brain Appeal.