Seeing When You're Blind

ESL English Listening - Advanced ESL English Listening

 

[This is an ABC podcast]

Lynne Malcolm: Mary Lovett is 87 years old and she's blind, but sometimes she sees scenes like this:

Mary Lovett: It was like a video unravelling. Everybody was beautiful. The men were wonderfully dressed and really good-looking, and the girls were gorgeous, wonderful hats, wonderful hair, beautiful dresses and wonderful complexions. That was for quite a while. And anyway, one day one of the people winked at me and I thought this is not a fun thing, this is something else. I've been enjoying all this for quite a few years, it's not about fun, it's about something else.

Lynne Malcolm: Hello, welcome to All in the Mind, I'm Lynne Malcolm.

Today we explore what's sometimes referred to as the plaything of the brain for those who are blind. It's called Charles Bonnet syndrome.

Here's the late neurologist Oliver Sacks on his interaction with an elderly person in a nursing home.

Oliver Sacks: A few months ago I got a phone call from a nursing home where I work. They told me that one of their residents, an old lady in her 90s, was 'seeing things' and they wondered if she had gone bonkers or, because she was an old lady, whether she had had a stroke or whether she had Alzheimer's. And so they asked me if I would come and see Rosalie.

I went in to see her, it was evident straightaway that she was perfectly sane. She had been very startled and very bewildered because she had been seeing things, and she told me that she was blind, but now for the last few days she had been seeing things. So I said, 'What sort of things?' And she said, 'People in eastern dress and drapes, walking up and down stairs. A man who turns towards me and smiles, but he has huge teeth in one side of his mouth. Animals too. I see a white building, it's snowing, a soft snow.' I said, 'Is this like a dream?' She said, 'No, it's not like a dream, it's like a movie. It's got colour, it's got motion, but it's completely silent, like a silent movie. And it's a rather boring movie, all these people with eastern dress walking up and down, very repetitive, very limited.'

And I then said to her, 'I think I know what you have. There is a special form of visual hallucination which may go with deteriorating vision or blindness. This was originally described,' I said, 'right back in the 18th century by a man called Charles Bonnet, and you have Charles Bonnet syndrome. There is nothing wrong with your brain, there's nothing wrong with your mind, you have Charles Bonnet syndrome.'

Lynne Malcolm: Oliver Sacks.

Anne-Gabrielle Thompson is 91.

Anne-Gabrielle Thompson: Well, my experience of Charles Bonnet syndrome started a few years ago. I was coming back from a Toastmaster meeting, being driven by a friend because I'm blind, and suddenly on the side of the road I started seeing those piles about one cubic metre high, wide and long of timber. I kept seeing those piles of timber.

The second one quite a few weeks later, I was talking with my daughter while we were eating, sitting at the dinner table at my place, and suddenly this face appeared in front of me. And whenever I moved my eyes, the face was there. I couldn't say whether it was a man or a woman, it was a very handsome face with a very high forehead, longish wavy grey hair. And when we finished eating the face disappeared.

The third episode, lots of little children in pink and white striped pyjamas waving their bodies around, wriggling their bodies. I didn't have any more for a long time, and when I started having some again they were quite different, like lots of little insects crawling on my dining table.

Ross Brown: It was a beautiful day and I went outside to enjoy the sunshine, couldn't see the sky, couldn't see anything of course because I'm blind. But when I say I couldn't see the sky, looking skyward was covered with stars in the middle of the day, beautiful, a beautiful sight. And yet I knew they were not the true stars but they were apparent to me as stars. And since that time, that particular Charles Bonnet image has reappeared several times.

Lynne Malcolm: 87-year-old Ross Brown.

Ross Brown: I see ever so many interesting things. Shortly after I became blind I looked out the window one morning to the house next door and the house was not there, there was a huge pile of rubble with a lad about eight or nine years old running around on it. Of course this was not so, the house was there all right, but the image, the Charles Bonnet image, was of a heap of rubble.

I could give you another one, sitting at the breakfast table one morning and being aware of someone next to me, a man, very neatly dressed, and by looking at him I could see that he wore a very nice jacket and was about to pick up a utensil to eat his breakfast. But there was no one there, it was an image, possibly an image of my brother who died quite a few years ago, but it was a Charles Bonnet image.

Lynne Malcolm: Mary, Anne-Gabrielle and Ross all have Charles Bonnet syndrome.

Charles Bonnet syndrome is the experience of phantom visual images by people living with some form of acquired vision loss, who are otherwise sound of mind.

It was first described by Charles Bonnet in a paper he wrote in 1760 about his grandfather who had impaired sight and had unusual visions. It took nearly 200 years before the condition was named after Bonnet by Geneva neurologist George de Morsier.

Ironically, Charles Bonnet's own sight deteriorated towards the end of his life, and he began to experience visions similar to those he'd described in his grandfather.

It's estimated that at least 25% of patients with significant visual impairment have had at least one Charles Bonnet Syndrome episode. That equates to around 125,000 Australians, but this number is almost certainly higher because the condition is often misunderstood and misdiagnosed.

Chris Plummer is a neurologist at St Vincent's Hospital in Melbourne and Associate Professor at the University of Melbourne. He describes the syndrome:

Chris Plummer: It's a condition that occurs with visual impairment from a lesion or abnormality anywhere along the visual pathway, so it can be from the eye, as in macular degeneration, to the visual cortex, as in a stroke. So the visual cortex is actually seated at the very back of the brain.

But to meet the diagnosis there needs to be three other criteria met. So the first one is that the hallucinations are recognised by the sufferer as not real. So initially due to the sometimes very confronting nature of the hallucinations, the sufferer might think they are real but ultimately they will appreciate that they are not. They are really illusions or phantom visions as opposed to delusions which is when the sufferer is not really able to distinguish them from reality.

At the second point is that they are purely visual, so it's almost like a silent movie in colour. And other sensory phenomena are absent. So patients can't hear what's going on. And this really adds to the oddity as patients can be confronted by typically noisy scenes, like some examples of speeding trains across the living room wall, or I've had a patient who saw laughing goats wearing overcoats. But there is absolutely no sound.

And the third thing, and this is very important, is that the hallucinations do not stem from any significant cognitive impairment such as Parkinson's disease or Alzheimer's disease because these conditions can cause visual hallucinations. But Charles Bonnet syndrome does not lead to any kind of dementia or certainly doesn't lead to Parkinson's disease or Alzheimer's disease, although sufferers might initially feel that they are dementing due to the very unusual nature of the hallucinations.

Lynne Malcolm: So what is believed to be happening in the brain, what's the mechanism that's going on?

Chris Plummer: Well, some ascribe it or compare it with phantom limb syndrome, but I'd emphasise that phantom limb can be quite a painful syndrome, but this is really a painless syndrome. But even so, the mechanism in the brain that's driving the visual hallucinations is not fully understood.

Probably the most favoured hypothesis is the so-called deafferentation hypothesis. Deafferentation is a term we use in neurology when referring to the loss of nerve signal input which we call the afferent pathway, to a neuron or group of neuronal cells. And when this occurs in the nervous system, the cells undergo some kind of physical and biochemical change that increases the likelihood that they spontaneously fire or discharge. So if enough of these neurons fire off in synchrony, it can create this spontaneous burst of electrical activity, and the patient will experience symptoms that actually correspond to the area in the brain that is auto activated, if you like.

So with vision loss, particularly if it's severe and if it's sudden, there will be a decrease in that afferent stimulation to the receiving cells in the visual cortex, and it leads to an increased risk of those cells firing off spontaneously. It is felt that it's this spontaneous firing off that probably gives rise to the visual hallucinations that patients experience. But it's still not fully understood.

Lynne Malcolm: Give me an idea of the range of types of hallucinations that you've heard from people.

Chris Plummer: Of the patients I've seen, probably the most common themes I've come across would be of insects, often giant insects such as spiders and ants crawling on walls and tables, like Anne's description. Children are common, usually running around in brightly coloured clothes or outfits like Anne and Ross described. Objects with very prominent geometric shapes, like brick buildings, trees, huge timber planks like Mary and Ross described. Landscapes are also not uncommon. Usually they are very scenic and inviting like Mary described. Faces are one of the more common visual hallucinations that are seen, often with very prominent eyes and teeth, and those areas in the brain are well represented in the secondary visual cortex. Anne and Mary had some of these experiences.

The other two visual episodes that patients can experience are miniatures, so they see little soldiers or Romans marching or riding in chariots, often with prominent headdress, things like elves and fairies on tiny trains or cars. And then you come down to the you might say downright bizarre, with things like goats walking through the lounge room wearing overcoats. I had one patient who described the carpet rolling up in front of them to form this giant anaconda snake and then it just slithered out of the room.

So despite the richness and variety of the hallucinations in Charles Bonnet, certain themes tend to overlap or be repeated across patients, and it's thought perhaps this is partly due to the different subspecialty areas of the visual network.

Lynne Malcolm: Chris Plummer.

Mary Lovett has had some real adventures with Charles Bonnet syndrome.

Mary Lovett: I could travel, I could travel just along the road and then come to a tunnel and then go looking out onto a beautiful vista. And I could fly over water and I could see towns and I could look down on it and I could look down on the water to see how it was running and how the creeks were. It's been fantastic. And I'm not a clever person, I'm not inventive, I don't have anything going for me, but these things have happened. I have enjoyed them.

So it was all pretty make-believe, it's all beautiful, everything is beautiful, everybody is beautiful. But over the years people could look old, and looking at them long enough, they would become young. I know this is all ridiculous but this is how it is. And it's the same with looking at someone that's young, they could also become old, or their features changed, they became old. That was all the beautiful time, and this is still wonderful times but everybody is different. People are wearing different hats. I don't get to speak to them, I only get to look at them, and I don't get to look at one individual for a long time because it's a complete change of men and women just appearing.

Lynne Malcolm: I asked neurologist Chris Plummer what determines the nature or the characteristics of the Charles Bonnet images people see.

Chris Plummer: This is another really interesting feature of the condition but, again, it's not well defined. But it's thought that the nature of the hallucinations is dependent on the specific area of the visual cortex that has undergone this deafferentation. So there is actually two main areas that make up the visual cortex at the back of the brain, one is primary and one is secondary.

So the primary cortex looks after the central visual acuity, such as recognition of lines, dots, dashes, geometric patterns and contrast definition. So deafferentation of this area might be responsible for the simpler hallucinations that some patients describe. And the other area is the secondary visual cortex that mediates colour, things like facial recognition, intricate movements. So deafferentation of this area might give rise to the more complex hallucinations that Charles Bonnet syndrome is better known for.

Lynne Malcolm: Chris Plummer.

You're with All in the Mind on RN, I'm Lynne Malcolm. Today, the little-known condition called Charles Bonnet syndrome. It's where people who are blind or with severely impaired sight, have visions or hallucinations.

Ross Brown: Most of them refer to some incident perhaps that has occurred.

Lynne Malcolm: Ross Brown.

Ross Brown: I'll tell you one which is quite astounding. When I was a child actually, I lived at a place called West Ryde in Sydney. And I went to high school at Strathfield. Now, at that time there was no place called West Ryde, it was simply called Ryde. And the image that I had, and this is only a few months ago, was of the train indicator was lying on the platform and it had the various stations between Strathfield and West Ryde, which is only about five stations or something. But interestingly enough it didn't show West Ryde, it showed Ryde.

And I thought about that and I thought that's strange because Ryde became West Ryde about two years after that. In other words, just before the war, and this was before that. So I must have seen that at that time in its old form of Ryde, and that was in the memory. And I don't know whether you know about this Charles Bonnet syndrome, but when the brain is not receiving signals, messages from the eyes, it draws upon the memory in some people, and it draws upon these pictures which are as vivid as can be. So that's what I'm stuck with.

Lynne Malcolm: I asked neurologist Chris Plummer how the images people see with this syndrome relate to their memories from the past, before they lost their sight.

Chris Plummer: Yeah, this is a very good question. It's suspected that there must be some visual memory or memory fragment that has kind of been, you might say, encoded in the person's visual network that becomes revitalised but that's often embellished. And this is because people who are born blind do not actually experience the syndrome. A lot of the hallucinations…perhaps this is because they seem so otherworldly, they don't seem to carry as much personal meaning, so the more common description that patients give is that it's a bit like watching this vivid often surreal silent film, and the patients see themselves as being detached from the activity or the scene, although they might be tempted to be drawn into it initially.

Lynne Malcolm: People with Charles Bonnet syndrome are not usually disturbed by the images they see, in fact they can find them quite fascinating and entertaining, but Mary Lovett recalls one time when it started to get the better of her.

Mary Lovett: When I was training with my cane, I said to the instructor that honestly I just have to give in, I have to go home because these beautiful houses were too close to me, they were crowding me, really too close to me, I couldn't cope with just walking or what I was doing. And she brought me home.

And the only other time that I've had that it actually bothered me and that was probably about six or eight weeks ago, I just got up and got organised, but the day was too close, something dark was stopping me from moving, I just thought of felt I was being enclosed by something. So I periodically just laid down for a couple of days. Whatever it was was dark, and it was sort of when the fires were on and whether this was affecting me or not I don't know, but it was this darkness that I couldn't handle.

Lynne Malcolm: Mary eventually joined a support group for the vision impaired through the Charles Bonnet Syndrome Foundation in Melbourne.

Mary Lovett: I hadn't told my husband, I hadn't told my family. I wouldn't have told anybody because they would have thought straight off 'you're crazy'.

Lynne Malcolm: Were you worried about the way people would respond to you?

Mary Lovett: Absolutely. I didn't really want to know what other people thought because if they thought I was crazy, I was crazy. But when I took it to our local group, and there were probably about five people that actually listened to what I said and, look, the five of them…one lady that she got caught in a fishbowl and she had a lot of trouble getting out. And then her daughter sitting next to her and she said, 'Mum, remember'…no, it was her auntie, she said, 'Auntie, remember the people that were coming out of the ceiling? What about that man?' And so then the other one had a bike and the bike kept going from one side of the room to the other room, and he said that's all that happened, but it did happen. It was a bit different.

Dorothy…I just can't remember what Dorothy said but she said like it was some things happening but she said, 'I ignored it because I couldn't think what it would be, so I just didn't tell anybody, I didn't do anything.' Nobody tells anybody. And one of the other ladies, her dad was in a nursing home and she said they keep complaining that he is seeing people walking on a wall. And so I said, perhaps you should check, does he have dementia? She said, 'No, no, he's just blind. He keeps seeing people walking on the wall.' And so I said to her, well, ask the nurses do they think that perhaps he might have Charles Bonnet syndrome, which nobody had heard of and they thought it was a bit funny too.

Lynne Malcolm: Mary Lovett.

Chris Plummer explains how to best support or treat those who are disturbed by the syndrome.

Chris Plummer: Probably again the first point is early diagnosis and explanation to the patient that the condition leads to no harm, doesn't cause dementia or lead to psychiatric illness, but the condition usually recedes over time. There are factors, lifestyle factors that can diminish the intensity of the episodes, such as avoiding sensory deprivation really. So the classic scenario is the elderly patient who is living alone in a low-lit house with a fairly sedentary lifestyle. So anything they can do to improve environmental stimulation, enhance environmental stimulation can diminish the frequency of these attacks. Strengthening social network can help. Engaging in distracting activities like more regular physical exercise can help.

There are some tricks that have been reported to help that some investigators have found and these include purposeful eye-roving or scanning the room when they experience the hallucinations, and sometimes sustained eye-closure can abbreviate the attacks. Medication unfortunately hasn't reliably been found to reduce the attacks, there are really just anecdotal reports because one problem is the lack of proper randomised controlled trials to judge the efficacy of medication in larger groups. Drugs such as antiseizure medications have helped some of my patients, but the problem is that a lot of these medications have side effects that can be worse than the actual syndrome.

I might mention there is an excellent charitable support foundation called the Charles Bonnet Syndrome Foundation that offers great advice on all aspects of the condition. Probably the other final point is anything that can be done to optimise the patient's vision, that can help. So there are reports of patients who have had cataracts and experience Charles Bonnet syndrome and had surgery, and their Charles Bonnet hallucinations have vanished with surgery.

Lynne Malcolm: And just lastly, what is the value of understanding this syndrome, of understanding it further and doing more research in it?

Chris Plummer: The point is that we don't fully understand how the visual system works in its entirety in health. We don't really understand how the brain sees, as the networks involved are enormously complex, we certainly don't fully understand it. And as with many conditions in neurology, key insights into how these systems work can be gained from situations where something goes awry somewhere in the network, as in Charles Bonnet syndrome.

So functional MRIs, I've mentioned before, can help delineate which areas in the visual pathway give rise to some types of hallucinations. And in the future we might be able to target and modulate these abnormal networks with mild electrical stimulation or magnetic pulse stimulation, something that's not invasive, or even in very severe cases localised drug delivery devices, the sort of things that are actually being used in the treatment of medically resistant epilepsy.

Lynne Malcolm: Dr Chris Plummer, neurologist from St Vincent's Hospital in Melbourne and Associate Professor at Melbourne University.

Anne-Gabrielle Thompson: I am interested in how the human body behaves, Lynne, so I've never been frightened.

Lynne Malcolm: And how have people reacted to you when you report that you're seeing these things?

Anne-Gabrielle Thompson: Oh they just listen to me because I present it as some form of entertainment, frankly speaking. It doesn't hurt me, it is not painful. No, I never worry about what people think about me.

Lynne Malcolm: That's a very good position to be in.

Ross Brown: It's a fascinating thing. Oh, and I must tell you too, that there are occasions when the images present themselves as spectrums of light, so that even though my blindness causes blackness, when these light images appear, they are in perfect colour, and I get images over the whole colour spectrum, just like little squares right across. So I can still remember clearly what colours look like. It sounds silly I know but that happened. It is, it's fascinating.

Lynne Malcolm: Thanks to Ross Brown, Anne-Gabrielle Thompson and Mary Lovett for telling us about their experiences with Charles Bonnet Syndrome.

For more help and support, head to the Charles Bonnet Syndrome Foundation website, and we'll put that link on the All in the Mind site as well.

Our producer is Diane Dean and sound engineer is Emrys Cronin.

I'm Lynne Malcolm. Thanks for joining us, till next time

-Australian Broadcasting Corporation