I know many carers have said that what they find most distressing is the visual hallucinations. And knowing what causes those I think is very helpful. Yes certainly, it’s probably one of the most common symptoms in dementia with Lewy bodies. It’s probably affecting about 80%, 90% of people with DLB at some point in time. They would, for example, look out into the garden and they would see that the bushes started turning into workmen. So sometimes, it’s sort of what we call “illusions” or they’re in these sort of transformations of normal what we call “precepts” or seeing things into something else. And on other occasions, they can just arise de novo.
And another patient was sitting and telling me it was a bit like being in a cinema with all these silent actors coming in off the side and into the screen and trying to say something to him but him not really understanding what was going on. Now often, these hallucinations can be quite distressing. On other occasions, they’re actually quite comforting. For example, if they’re of a dead relative, it might be quite comforting to see your spouse that’s passed away. But on other occasions, the images can be extremely distressing. The insight into whether these are real or not real can vary quite a lot.
Some people with dementia with Lewy bodies are aware that they may be not so real and they may be able to deal with that a little bit better. Others might not be able to. And I’m sure the examples of laying out dinner for family members who are not there is a classic example of this phenomenon. So I suppose it varies. And I think another factor which I haven’t mentioned is that for carers, it can be particularly distressing. So even if it’s not that bad for the person with dementia with Lewy bodies themselves, for the carers, having to deal with this on a daily basis can be really problematic. People often ask me in clinic.
They say, “Well, what should I do about– should I challenge them about the hallucinations?” I have to say generally, challenge doesn’t work, particularly when there’s a lack of insight. Similarly, I wouldn’t say going along with the hallucination is helpful, either. Often, what is useful is perhaps to change topic. Leave the room. Come back into the room. Or actually when you’re speaking to the person who’s got the hallucinations, perhaps focus their attention on something else which is important to them. So get them to turn– rather than focusing on the person that they’re seeing in front of them or an animal or whatever, focusing on something else.
You mentioned a little bit about these fluctuations in cognition. And certainly, that’s my experience when I’ve had friends with dementia. One minute, they can be having a conversation and then just half an hour later, they’ve suddenly changed completely and perhaps are experiencing visual hallucinations and something quite distressing. So tell us a little bit more Well, I suppose the first thing to say is that fluctuations are common across lots of different dementias. They’re just much more evident in dementia with Lewy bodies. You can get them in vascular dementia, as well, sometimes in Alzheimer’s, although the fluctuations that you might see in Alzheimer’s are perhaps more related to environmental challenges. So let’s say you’re in an environment where there’s lots happening.
It’s just information overload and so that person just gets very confused. And so caregivers might say, Oh, yeah, they looked as though they got really bad there when that happened. Probably in dementia with Lewy bodies and to a certain degree in vascular dementia, it’s probably what we would call more intrinsic or internal. So literally, as you say, they’re talking away, seem to be absolutely fine, and then dip right down and then can recover quite quickly again or take a bit longer. So there’s real marked variation from where they are here to here. Now, they may not be entirely normal here but sometimes, they can be quite good.
And it can be a very challenging symptom because it’s very hard to predict. Each part of your brain is not in isolation. The back of your brain talks to the front of your brain, to the side of your brain. They’re all in constant communication, forming networks, working together to achieve a particular goal. And what we think is that the communication in these networks breaks down transiently and then comes back online.
Again, thinking back, I can think of somebody who’s got dementia with Lewy bodies literally telling me their symptoms, discussing something, and then it just stops. And they look like they freeze. And then, next minute, it comes back. And it’s almost like there’s this gap. There’s this sort of dissolution of the networks and then them coming back online again and that can happen really very quickly. Of course, there’s longer time scales in these oscillations or fluctuations but it can happen on a minute by minute, second by second basis.
Depression is said to be an early symptom of dementia with Lewy bodies, as it is with Parkinson’s disease, which, as I’ve said, is a close cousin. What is called “depression” is often apathy. It’s loss of drive. It’s loss of mental engagement. It’s loss, to some extent, then of interest with people and actually depressed, in the sense that they’re miserable, tearful, and negative in their outlook. They’re simply switched off. So what they need is to be maintained in a sort of window of environmental stimulation, which is not nothing and not too much. It’s somewhere in the middle. And some carers are extremely good at this. I think they learn by experience that they need to keep a steady level of stimulation.
It hasn’t got to be monotonous. It needs to change every so often and that keeps things going along at the right level.
When you dream and you’re running around fighting that monster or whatever, the brain is actually sending signals to actually say, Don’t move. Don’t move. Don’t move. But in REM sleep behaviour disorder, that inhibition or block breaks down. So you start acting out, thrashing in the bed, shouting out. It can get very extreme and in some cases, bed partners get injured as a consequence. Family members have adapted their own sleep cycles so that they sleep a little bit more during the day when the person with dementia is sleeping and then they get up when the evening time is more problematic. I think, again, sometimes when it’s completely dark, that’s a real issue, particularly with the hallucinations.
Sometimes, switching on the lights can be beneficial to normalise the situation, having a drink, having a conversation, breaking that situation and just trying to deal with that.