According to the Alzheimer’s Society in 2015,
eight hundred and fifty thousand people in the UK will have some form of dementia.
With the figure predicted to rise to one million by 2025.
It’s an often undiagnosed disease which is most common in older people
but it can occur as early onset in middle age.
For people with learning disabilities the condition can occur even earlier.
Dementia appears to be more frequent now because, partly because were much better at looking after old people.
People don’t die young so often now,
if you live to forty two hundred years ago you were an old person.
If you live to seventy five or eighty now, this is the normal life expectancy.
Alzheimer’s disease which is the commonest cause of dementia
doubles in prevalence with every five years we live over the age of sixty. So that people
in their eighties and above, one in five have dementia.
Essentially it means that the things that make us higher thinking beings, our memory,
our way of calculating, of planning, language. They are degenerating.
Dementia is anything which is affecting the brain and the loss of function of the brain
in such a way that, that things that we normally take for granted
for example our ability to remember things, times, dates, events,
to place ourselves in a location, to use words, to use language,
all of these things begin to disappear.
The most common early signs of dementia include memory problems, decline in communication skills,
recognition and coordination difficulties, disorientation, as well as changes in behaviour,
judgement and mood, and loss of daily life skills.
Dementia results from a loss of brain function. As we get older, in a normal brain
there is very little change with age.
What we see is if we take somebody who’s got normal ageing, this is their first scan
and we take a second scan a year later.
There’s very little change, it’s quite different in Alzheimer’s disease.
The brains of people with Alzheimer’s, the most common form of dementia, shrink dramatically.
There's devastation going on. Alzheimer’s disease is
destroying brain cells and the brain is shrinking.
Depending on where those changes are, for example if there in an area which is important for memory
then memory will be disturbed.
If they’re in an area that’s important for language then you will lose ability to understand words
or to be able to use language in the way that you perhaps might have done.
These are the observable changes but what’s happening in the brain to cause them?
Brain cells called neurons communicate with each other via electrical impulses
which trigger the release of chemicals called neurotransmitters.
These pass between the cells. Neuro transmitters pass between gaps in the neurons called synapses.
In Alzheimer’s abnormal protein deposits inhibit the neurotransmitters signals.
It’s common to see these protein deposits in affected brains build up into plaques and tangles.
Over time the plaques and tangles destroy neurons ability to communicate with each other.
They die off and functions like memory and thinking skills are affected.
That process of indigestible protein, lumps of stuff in between cells
actually affects the brain function, it affects the brain cells, communicating with each other and the brain cells start to die.
So, for example this area of the hippocampus which is sole layer to memory,
we see shrinking down and at the same time at a clinical level, people complain of forgetfulness.
The hippocampus is the area of the brain most important for memory.
Now this region here called the hippocampus has been long known to be important for storing and retrieving information,
and we were thinking about neurons and synapses and each of these regions
is connected by a pathway where there is a neuron at one end and synapse at the other.
And if we are storing information, pathways will be activated linking
the cortex to the hippocampus and we will learn for example the name…somebody’s name or a place or a location
and that information will be stored within the hippocampus.
And when we remember something pathways which bring it from this deep area, out into the cortex
into the conscious brain will allow us to remember something and understand the context in which we remembered it.
Now somebody with dementia and in particular Alzheimer’s disease, these pathways will be
severely interrupted and what's happening is where there would be a normal healthy pathway
to store or retrieve information, elements of this pathway are lost
and the cells are not working as well as they should so therefore when we try and store information,
the ability to store it may be lost and therefore also when we come to retrieve that information
we may not have been able to store it properly or we just not maybe able to access that information.
Alzheimer’s disease has a dramatic impact upon memory.
Modern imagining techniques have indicated ways to spot the disease in its very early stage.
If we look at the scan, what we see here, this is somebody with mild cognitive impairment,
the scan may not look that different to somebody with normal ageing
but if we look at the change here now just over a year,
if I flick forwards and back between these two scans, that’s the first scan, that’s the second scan.
Look at this increase, this black area there's the ventricles, that space, fluid filled space within the brain,
that’s enlarging. Look at the sp….the space around the hippocampus here, that’s our…
our memory store, that’s just shrinking down.
If we look around the temple lobes to do with language, the front or the parietal lobes,
thinking, calculation, spelling, they’re all shrinking.
If we take a series of scans of somebody in the very earlier stages of Alzheimer’s disease,
here’s the brain scan at the beginning, here’s another brain scan of the same person eighteen months later,
then a further eighteen months. So there’s thirty six months across here, that’s the three years,
that…that three years is often an insidious period of change when remarkably people may have some
mild symptoms and they may not even get a diagnosis.
Look in this blown up magnified section here, what's happening to the hippocampus…
devastating destruction. Dementia just reflects the…what's happened to the person to the brain, 81 00:07:33,170 --> 00:07:39,190 that syndrome of cognitive decline. Alzheimer’s disease is a pathological definition.
The second most common cause of dementia is vascular dementia. A condition linked to the blood vessels
in the brain rather than the brain cells themselves.
This is caused either by lots of strokes within the brain, sometimes quite small ones or a…
a cutting off of the blood supply to the brain in general
and this will cause various regions of the brain to die and become dysfunctional.
Vascular dementia is… quite commonly occurs at the same time as Alzheimer’s disease
so it can be difficult to say whether somebody has purely Alzheimer’s disease or purely vascular dementia
where they can have sometimes a balance between the two.
These white blobs that we see here, that’s destruction. That will be a vessel having had…
being blocked or having less blood supply to that part of the brain
and little tiny patches get eaten out but as you progress, as the burden of this vascular damage
gathers then you start, the thought processes slow down, the connection gets more difficult,
the loss of memory, the loss of planning. The speech, the gait problems,
the emotional ability, th…the fact that you may get more frustrated, you rapidly change your mood.
They’re all part of that vascular dementia.
The diagnosis of dementia is not straight forward. There are no direct diagnostic tests
and dementia affects individuals in a range of ways.
A GP should be consulted in the first instance in order to assess a person and to provide help
with the diagnosis. A GP is the usual person to make a referral to a specialist.
During life, Alzheimer’s disease in particular is a diagnosis of exclusion.
You rule out everything else and what you have left is likely to be Alzheimer’s disease.
We importantly need to exclude depression.
We then will go on and we’ll do imaging to exclude the rare case of a brain tumour,
try and quantify how much vascular damage - is this really vascular dementia or is it Alzheimer’s disease.
In some situations we will do measures of brain activity. Could seizures be mimicking Alzheimer’s disease or something like that?
Early diagnosis and research are being helped by MRI or magnetic resonance imaging
which gives a very detailed view of the brain.
Scanning MRI scans in particular are starting to give people a little bit
better certainty on the diagnosis.
The real test for Alzheimer’s disease is still very, very clinical.
So it is actually asking somebody, taking good history, examining them
and the imaging is just helping us to be able to make diagnosis slightly earlier and there are novel techniques
that are still really in the research stage where we can actually do scans that look for
the specific proteins that’s called amyloid imaging.
To be able to see in life what's going on in the brain, not just in terms of the structural degeneration
but also the proteins that may be driving that destructive process.
Apart from the care that everyone living with dementia will need, drugs used in the treatment of Alzheimer’s disease
can temporarily improve symptoms and slow down the progression for some people.
They cannot however, provide a cure.
The real research drive is not just to try and make the brain work a bit harder
or bit better, which is what these tablets do, more to try and find things that will hold this dreadful destructive process
and will do, that all the pathological hallmarks, amyloid plaques
the neuron destruction are occurring many years before anybody’s ever diagnosed.
So there is a window where theoretically we could intervene to preserve brain tissue and
brain function at the stage when I think all of us would like it preserved.