Dementia: it’s not all about Alzheimer’s or memory
by Dr Laura Phipps, Science Communications Manager, Alzheimer’s Research UK.
It’s a common misconception that dementia is all about Alzheimer’s and that it’s all about memory loss. Alzheimer’s may be the most common cause of dementia and memory loss one of the most common symptoms of Alzheimer’s but it’s nowhere near the whole picture of dementia.
Here at the Alzheimer’s Association International Conference in the US, we’ve been hearing about progress in research into other dementias as well as understanding some of the ‘atypical’ symptoms of dementia that can have such a big impact on someone’s life.
Rarer forms of dementia
Newcastle-based dementia researcher Prof Ian McKeith was awarded a lifetime achievement award for decades of pioneering research to characterise dementia with Lewy bodies (DLB), including setting up a world-wide consortium of DLB researchers to develop consistent approaches to diagnose the condition.
We’ve also heard a lot about progress in frontotemporal dementia (FTD). Dr Bruce Miller at the University of California in San Francisco recalls how, when starting out in research, he was advised not to bother focusing his research into FTD – a rarer young-onset dementia historically known as Pick’s disease. Since then he explained how the field had exploded in terms of our understanding of FTD and the biology driving it.
We now know that there are clinical subtypes of FTD, including those that predominantly affect:
- behaviour (behavioural variant FTD)
- language function (semantic dementia, progressive non-fluent aphasia and logopenic aphasia).
We also know that each of these subtypes can be associated with different underlying biological changes in the brain.
Researchers presented data from a large international study of people with genetic forms of FTD called GENFI, led in the UK by Dr Jonathan Rohrer at University College London. This research showed that in people with genetic forms of FTD, changes on brain scans can be detected around 10 years before symptoms start. This important study aims to track some of the very earliest changes in the brain in FTD to identify key windows of opportunity to test potential new treatments.
One of the hallmark changes associated with forms of FTD include the presence of an abnormal form of the protein, tau. Tau seems to go awry not only in FTD and in Alzheimer’s but in other rarer dementias including corticobasal degeneration, progressive supranuclear palsy, and in dementia associated with repeated severe head injuries.
At the conference, we heard exciting developments from researchers designing ways to image tau using brain scans, as well as those engineering new treatment approaches to target it. Over the next few years, as this pioneering work develops, we will be watching closely to see how effective they could be at helping people with these forms of dementia.
Looking beyond memory loss
One of the characteristic symptoms in FTD is a change in behaviour and personality. These changes include:
- apathy or losing interest in life
- losing the ability to understand or empathise with other people’s emotions
- behaving inappropriately
- developing obsessions or rituals
- changes in food preferences, including craving for particular foods.
People with FTD tend not to have problems with memory at first, in contrast to people with ‘typical Alzheimer’s’.
Understanding these symptoms and why different people experience them is not only important for guiding clinical awareness and diagnosis but in helping to unpick what’s going on inside the brain.
To complicate matters further, we heard from researchers studying a rare form of Alzheimer’s that is also associated with some of these behavioural changes. However, when the team from Amsterdam looked at what was happening in the brain in these people, they found distinct hallmarks of Alzheimer’s and not FTD. This finding suggests that two distinct diseases in the brain can result in similar ‘atypical’ behavioural symptoms. Grappling with these symptoms is not only challenging to researchers trying to make sense of them, but incredibly hard for friends and family, which is why understanding them is so important.
Humour and music
We heard from two UK-based researchers from the Alzheimer’s Research UK UCL Research Network using humour and music to study rarer dementias in more detail.
Dr Camilla Clark developed tests of humour – comparing slapstick humour to more abstract satirical jokes and studied whether people’s responses were altered between different types of dementia. Hear her talk more about her research below.
We also caught up with Dr Catherine Slattery who was using music to study changes in brain networks in people with early-onset forms of Alzheimer’s. She and colleagues at UCL were using familiar and non-familiar tunes as well as those that follow regular or irregular patterns to identify changes in brain networks in people with this form of the disease. Other UCL researchers presented data that people with different forms of dementia show different impairments in their ability to derive pleasure from listening to music, a symptom that may people looking after someone with dementia may be able to relate to.