Skip to 0 minutes and 8 seconds Next let’s look at MRI scans from individuals with dementia. Here we are looking at the brain as if looking into the face of the person. On the left side is a healthy older person and next to them is a scan from a person with Alzheimer’s disease. We can see that there is even more space in the ventricles and around the brain showing that the disease has caused the brain to shrink more rapidly than happens in normal ageing. There are also more spaces in the lower part of the brain which are part of the temporal lobes. The red arrows point to a structure called the hippocampus which is a vital part of the brain for our memory.
Skip to 0 minutes and 51 seconds This part of the cortex is needed to allow us store memories so we can remember things for a long period of time. In the person with Alzheimer’s disease the hippocampus has shrunk away and the brain function will be lost. This is one of the changes in the brain which Alzheimer’s disease causes and is responsible for the person’s difficulties with memory. Events which happened in the past before the disease took hold are already stored in the person’s memory and can be recalled, but without a functioning hippocampus, new and current events in the life of the person cannot be easily remembered.
Skip to 1 minute and 27 seconds On the right hand side here is the scan from a person with a different type of dementia called dementia with Lewy bodies. We can see that in this person the hippocampus has been affected much less, which is a characteristic of dementia with Lewy bodies and means that people with this type of dementia have less problems with memory than people with Alzheimer’s disease. When we look at what happens to not just one person, but at groups of people with Alzheimer’s disease we get a clearer picture of where the brain is being affected. We can use the MRI scans to look at every part of the brain to see where the disease is damaging the brain structure.
Skip to 2 minutes and 6 seconds Here we are looking at each of the hemispheres of the brain from the side. The grey coloured image shows the brain and the red and yellow colours show where the brain is shrinking because of the effect of the disease. The hotter the colour, the more of the cortex layer has been lost in the people with Alzheimer’s disease compared to healthy people of the same age. On the right hand side we see what happens in the brain of a person with dementia with Lewy bodies. We can see that the damage to the surface of the brain is confined to smaller areas compared to the people with Alzheimer’s disease.
Skip to 2 minutes and 41 seconds This tells us that the two types of dementia are the result of different processes at work in the brain tissue. Since different regions are involved, the symptoms experienced by people with the different types of dementia will also be different. Let us now look at the white matter tracts which join the areas of the cortex into networks. These tracts are also damaged by the disease in people with dementia. We are looking here at a view of the brain close to the centre. Researchers have used MRI to measure how much damage there has been to the white matter tracts, again comparing the people with dementia against healthy people of the same age.
Skip to 3 minutes and 23 seconds The blue areas here show where the tracts have been damaged in people with Alzheimer’s disease. This means that some of the connections between different parts of the brain will be partly disconnected. The image on the right hand side again shows that there is a different pattern of damage to the white matter tracts in people with dementia with Lewy bodies. We also know that the damage to the white matter tracts does cause symptoms. This image is from a research study where the scientists measured the damage to the white matter in people with dementia with Lewy bodies and compared this with their ability to think of words (a test called verbal fluency).
Skip to 4 minutes and 0 seconds Looking at the orange area in the scan - the more damage to these brain areas that was found, the more difficult it was for the person to think of and say words. Our research using the latest scanning technologies allow us to have greater awareness of what is happening in the brain, the symptoms that occur as a result of damage to different parts of the brain, and the damage to the networks that connect them. This knowledge helps us to understand the cause of the multiple communication challenges that face people living with dementia
Dementia and the brain
Professor Andy Blamire presents examples of brain scans from people affected by Alzheimer’s disease and dementia with Lewy bodies.
From these scans, we can see that damage to the brain is much more severe in people with dementia than we would expect in normal ageing. They help us understand why someone with dementia experiences difficulties with particular tasks and functions.
Our research using the latest scanning technologies allows us to have greater awareness of what is happening in the brain, the symptoms that occur as a result of damage to different parts of the brain, and the damage to the networks that connect them.
This helps us to understand the cause of the multiple communication challenges that face people living with dementia.
How does this video affect the way you think about dementia?
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