Ö÷²¥´óÐã

Downloaded from www.bbc.co.uk/radio4

Ìý

THE ATTACHED TRANSCRIPT WAS TYPED FROM A RECORDING AND NOT COPIED FROM AN ORIGINAL SCRIPT.Ìý BECAUSE OF THE RISK OF MISHEARING AND THE DIFFICULTY IN SOME CASES OF IDENTIFYING INDIVIDUAL SPEAKERS, THE Ö÷²¥´óÐã CANNOT VOUCH FOR ITS COMPLETE ACCURACY.

Ìý

Ìý

IN TOUCH

Ìý

TX:Ìý 27.06.2017Ìý 2040-2100

Ìý

PRESENTER:Ìý ÌýÌýÌýÌýÌýÌýÌýÌý PETER WHITE

Ìý

PRODUCER:Ìý ÌýÌýÌýÌýÌýÌýÌýÌýÌýÌý LEE KUMUTAT

Ìý

Ìý

White

Good evening. ÌýOne of the lesser known effects of blindness is that it can have a major impact on some people’s sleep patterns.Ìý Tonight we are going to concentrate on why this is, and where current research is taking us. ÌýIt’s not immediately obvious but many people particularly those with no light perception at all struggle to establish a regular sleep routine. ÌýWe do know the reason for this.Ìý Natural light enables you to fix your body clock; but if you are deprived of the hormone melatonin, which is produced by natural light, your internal clock starts to go haywire.Ìý It can be weeks before it returns to normal.Ìý Well I said we knew the answers, but we do not know them all by any means.Ìý Later we will be hearing from one of the country’s leading experts on sleep and visual impairment. Ìý

Ìý

But first I think academics would acknowledge, the real experts.Ìý Here are some of the problems with sleep you have been telling us about.Ìý Mansell Griffiths slept perfectly well when he could see but after he lost his sight and all light perception in an accident he started to experience irregular sleep patterns.

Ìý

Griffiths

I can sleep possibly two or three hours, wake up at 12 o’clock at night and then be awake until 8 o’clock the next evening and again sleep for two or three hours and then wake up at 2 o’clock in the morning and it goes around and around like that.

Ìý

Kumutat

What do you have to do to get your sleep back into a good healthy cycle?

Ìý

Griffiths

I avoid coffee, tea, I take regular exercise, there are certain things I avoid eating like sugary snacks but – and when it gets at its worst I take melatonin.

Ìý

Kumutat

And when you are in a bad sleep cycle how does that impact your life?

Ìý

Griffiths

I can be very irritable, very bad tempered, I just can’t concentrate on anything.Ìý When it was at its worst before I started taking melatonin at one point I was actually contemplating suicide with it, it was that devastating.

Ìý

White

Well unlike Mansell, Jennifer Hodkinson has been totally blind since birth.

Ìý

Hodkinson

If I say sleep for about five hours I think that’s a good night for me, I’ve had a good night.Ìý However, on bad nights I just don’t sleep at all.

Ìý

Kumutat

How long can that go on for where you don’t sleep at all?

Ìý

Hodkinson

A week, two weeks, several weeks like that.

Ìý

Kumutat

And have you tried to get help?

Ìý

Hodkinson

I did, I asked if I could have some tablets and she was quite adamant she wouldn’t give me any.Ìý They did give me some once and I had about a fortnight’s supply of sleeping tablets but they weren’t very strong, she said they weren’t.Ìý It just gets to me after a while – I have no energy and I sometimes sort of feel depressed, sometimes really sort of slowed down, me brain is somehow – I’m sure I’m not functioning properly.

Ìý

White

And Jennifer and Mansell were talking to Lee Kumutat. Ìý

Ìý

We’ve also heard from Neil Barnfather, who although he has been registered blind all of his life only finally lost his light perception in 2006.Ìý

Ìý

Barnfather

Ever since I’ve had difficulty regulating my sleep.Ìý Initially I thought it a reaction to my sight loss, the obvious emotional trauma and subsequent wakefulness of the associated thoughts.Ìý More recently though I finally decided to visit my doctor about my sleep patterns as I felt it was having an immense impact upon my life.Ìý I asked about melatonin, which some of my blind friends use to help regulate their sleep patterns.Ìý The GP’s response was that melatonin was not licensed for this purpose within the UK and that I couldn’t have it.Ìý So, like those friends, I purchased some online.Ìý A week later and my bottle of American melatonin arrived.Ìý I dutifully took a tablet about 30 minutes before I wished to fall asleep and, as if by magic, I fell asleep about 25 minutes later.Ìý The little fruity flavoured pills have been working their magic for me ever since.Ìý I’m now about eight months into taking them.Ìý I pay about $7 for 120 tablets.Ìý My exercise tracker reports that my sleep has gone from 1.2 hours per night to about seven and the difference in how I feel is immeasurable.

Ìý

White

Well what's clear from those testimonies is that the information about sleep problems associated with blindness is often very difficult to come by.Ìý Health professions often know less about it than you do.Ìý The Circadian Sleep Disorder Network is a support and advocacy group which wants to increase awareness of the problems.Ìý Lynn McGovern is a member of the network’s board and she told me more about the range pf problems they cover.

Ìý

McGovern

Well we know for a start that a rough average is that about 70% of people who are visually-impaired have some form of circadian sleep disorder.Ìý And one of the main reasons for that is that the circadian rhythm is controlled by photoreceptors in the eye, transmit light to the brain and then there’s a little kind of a pacemaker, if you will, within a part of the brain called the hypothalamus and that is supposed to control the sleep/wake cycle and its response to lightness and darkness.Ìý But unfortunately obviously if you’re visually-impaired that’s not going to work so well.Ìý So that’s part of the reason.Ìý However, interestingly 30% of people who have visual impairments don’t have any sleep disorders at all and lots of sighted people have circadian sleep disorders.Ìý So there’s a lot of unanswered questions basically in circadian research.

Ìý

White

Now one sleep disorder in particular, which we know affects visually-impaired people, is what’s known as the non-24 hour sleep/wake disorder, just explain what that is.

Ìý

McGovern

The non-24 hour sleep/wake disorder is a disorder where your sleep time is completely non-fixed.Ìý So that means that each day your sleep time will cycle an extra hour or two a day and then some people it actually varies by a few hours every day and eventually you’re actually cycling around the 24 hour clock.Ìý And it’s often misdiagnosed as severe insomnia because the person will go to their doctor and they’ll say – you know for two weeks there I had dreadful insomnia, I couldn’t sleep till noon or 7.00 a.m. but now my sleep is fine and I’ve been sleeping – oh I went to bed early tonight, I slept at 8.00 p.m. and now I’m sleeping at midnight and I’m okay.Ìý So in that way it seems like it can be periodic insomnia.

Ìý

White

Now there are other forms of sleep disorder, what are the most significant ones of those?

Ìý

McGovern

So 50% of people who are visually-impaired will have non-24 and then the other 20% is made of delayed sleep phase disorder and advanced sleep phase disorder.Ìý Now delayed sleep phase disorder is a condition where your bedtime is very late and society would generally say oh that sounds like a night owl.Ìý But the difference is a night owl might prefer to stay up till one or 2 or 3.00 a.m. but if they have to be up for 7.00 a.m. the next day for a nine to five office job it’s no problem for them to fall asleep between say 10.00 p.m. and midnight.Ìý Whereas someone who’s got a delayed sleep phase syndrome, even if they’re extremely sleep deprived, they cannot – their body will never fix the cycle, it just will not.Ìý And the other one is advanced sleep phase which is the opposite.Ìý So people’s bedtime is extremely early, generally between 6.00 p.m. and 8.00 p.m.Ìý And that is less common but the theory is perhaps it’s simply less common because it doesn’t tend to cause as much problems with occupations or family life.

Ìý

White

And what about the treatments that are available?

Ìý

McGovern

Treatments can be variable, as in melatonin, which is one of the most well-known ones, for years patients were prescribed large doses to kind of knock them out but then they discovered that actually a low dose of melatonin works much more effectively than a high dose taken at bedtime.Ìý Then another medication, and it’s very new, it was only 2015 it came out in Europe, and that is hetlioz and that basically acts on the melatonin receptors and it basically binds to them and activates them and that’s specifically for non-24.

Ìý

White

Lynn McGovern from the Circadian Sleep Disorder Network.Ìý

Ìý

Well someone who’s been researching these problems for many years is Russell Foster. ÌýHe is Professor of Circadian Neuroscience and Head of Ophthalmology at Nuffield Department of Clinical Neurosciences in Oxford.Ìý He told me more about how the eye processes light.

Ìý

Foster

I’ve been fascinated by how the eye can not only grab light to grab an image of our world but also grab dawn and dusk information to set the internal body clock to the external world.Ìý And without that light information then the body clock continues to tick but it drifts with time.Ìý And so for most humans we have a body clock that’s slightly longer than 24 hours, so without a daily light time cue we would tend to get up later and later and later on subsequent days.Ìý And what I was fascinated about is what are the receptors within the eye that can detect this light to regulate the internal body clock.Ìý And to our great surprise and I think the surprise of many people we discovered that it’s not the rods and the cones, the classical visual cells of the eye that’s detecting dawn and dusk information but it’s another class of light sensor within the eye, another photoreceptor.Ìý And it’s based upon the ganglion cells.Ìý Now the ganglion cells are those neurons within the eye whose axons leave the eye and form the optic nerve.Ìý And about one out of every 100 of those ganglion cells is directly light sensitive, picking up that light and firing off the information into the brain to set the internal clock to the external world.

Ìý

White

So what does this mean specifically for visually-impaired people who aren’t seeing light?

Ìý

Foster

An extreme end is if you have no eyes then there is no way you can use light to set the internal clock to the external world.Ìý There are devices being marketed at the moment which you stick in your ear and you illuminate the brain and they’re supposed to regulate the internal clock.Ìý There is no empirical evidence for that at all.Ìý And indeed all the studies that we have of individuals who have lost their eyes they fail to lock on to the external light dark cycle.Ìý And indeed what one needs to do is that if you’ve lost your rods and cones you need to check whether the photosensitive retinal ganglion cells are still there and working and then the advice should be absolutely to seek out sufficient daytime light, particularly morning light, even though you can’t see it, to regulate the internal body clock.Ìý So if you are visually blind but are still showing some vestigial pupil constriction that’s a good indication that those receptors are still there.Ìý But you have to use relatively bright light and rather than just flashing the pen torch you have to sort of leave it in place and then you see a relatively slow but full pupil constriction in many cases.

Ìý

White

And for the visually-impaired people who don’t have any light perception what does this mean, if you put it in human terms?

Ìý

Foster

Well if – it depends what you mean – you can have no light perception because you’ve lost your rods and cones but those photosensitive retinal ganglion cells can still be there and you still need to seek out that light.Ìý If you have no rods and cones and no photosensitive retinal ganglion cells then what happens is the body clock drifts with time.Ìý And so essentially internal time and external time are mismatched, it’s a bit like jetlag.Ìý And the consequences of disrupted sleep/wake we understand best in shift workers and there the long term effects of shift work can be really quite severe.Ìý There’s immune suppression, there’s higher rates of cardiovascular disease, diabetes too and a whole range of other pathologies.Ìý But also short term effects of a disrupted clock are feeling sleepy at the inappropriate time, the failure to process information, lacking in empathy and becoming overly impulsive and failing to see the consequences of actions.

Ìý

White

What kinds of treatment are there at the moment that are available to you?

Ìý

Foster

Well this is what’s so tragic, there’s very little and essentially what people have been thinking of is how can we provide a sort of biological replacement for light.Ìý Melatonin, that neuro-hormone from the pineal, which is released at night, has had a little bit of success in a relatively small number of individuals.Ìý If you take three milligrams of melatonin at night, let's say at 11 o’clock, that can reduce the time it takes to get to sleep and it can partially stabilise the sleep/wake cycle.Ìý So instead of a drifting pattern of sleep you tend to get up and go to bed at about the same time.Ìý It’s not effective in all people and it can take a long, long time before that entrainment, that setting of the internal clock to the melatonin signal actually occurs.Ìý So melatonin has had some partial success…

Ìý

White

And can I – before you move on – can I ask you about the dosages there because there seems to be some disagreement about what is a safe or a successful or an effective dose.

Ìý

Foster

Yes the doses recommended that I’m aware of is around about three milligrams.Ìý You can buy melatonin of course in the United States at a range of different concentrations and there is some evidence that the higher the concentration you can actually be less effective at stabilising the sleep/wake timing systems.Ìý So I think the agreed dosage is around about three milligrams. Although I am aware of studies where lower than three milligrams has also been effective.Ìý The thing about melatonin is that there’s very little evidence that high doses can cause you any harm.Ìý So I think of the drugs that are around it’s relatively safe, of course no drug is completely safe but we don’t have any clear indications that it will cause harm at higher doses than three milligrams.

Ìý

White

And of course some people worry, who can’t get the dose they want, can’t get a prescription because they can buy it online but they’re wondering about the quality of what they’re buying.

Ìý

Foster

And I think that’s – you really must do it through the GP because some of the stuff you buy online can be melatonin extracted from sheep pineals or cow pineals and of course then there’s the danger of prion disease.Ìý So you really mustn’t do that.Ìý And of course there’s synthetic melatonin available and that’s the most commonly purchased form.Ìý But I think it’s always really important to try and go through the GP if you’re going to take any form of medication.

Ìý

White

And there is a newer treatment, isn’t there, now available?

Ìý

Foster

Yes I mean there’s a series of different drugs that are sort of hitting the melatonin pathway.Ìý There was one called circadin, which is a prolonged release melatonin like drug.Ìý And there may be some subtle effects at regulating sleep/wake timing but it wasn’t statistical in the early trials, so I don’t think circadin is now an option.Ìý And the most recent one is tasimelteon.

Ìý

White

Which is also called hetlioz I think?

Ìý

Foster

Yeah I believe so, yes.Ìý And the studies that were published associated with that suggested that in the blind, showing non-24 hour sleep/wake patterns, after five weeks 20% of the individuals showed an improvement in their sleep.Ìý But that was based upon a questionnaire survey rather than empirical measures of sleep/wake timing.Ìý And I think we’ve got to be very careful about how we measure sleep.Ìý So in our anophthalmics, our individuals who have no eyes, we have assays, we’ve asked them what’s your sleep/wake like and they’ve said it’s fine.Ìý And then when you measure sleep/wake it’s actually very, very severely disrupted.Ìý And there are some individuals when their partner, for example, who’s been away will come back they’ll then start to show a sleep/wake pattern that is sort of more matched on to their partner’s and so we thought fantastic, it means that there’s non-light way of regulating the clock but if you look at the underlying biology and hormone profiles they’re actually drifting with time.Ìý So what’s happening is that these individuals are forcing a sleep/wake pattern upon themselves.Ìý I mean we’ve got to find something better.

Ìý

White

Let me just stay with this for a moment because so much of what listeners have said to us comes back to this point about a. they tell us how difficult it makes their life and b. they tell us how difficult it is to get the right treatment for it.Ìý What would you suggest people should do to get a proper diagnosis?

Ìý

Foster

It’s so tough.Ìý There’s lots of ways that one can do it oneself by using simple rest activity recording devices.Ìý And you can get an empirical measure of your sleep/wake timing or keeping a sleep diary, noting when you got up, when you went to bed.Ìý And you can gather that information for yourself and get a pretty good idea of what’s going on.Ìý Going through the GP to get that would be pretty tricky for most practices.Ìý And the service tends to be referral to a sleep clinic and because there are so few sleep clinics available the waiting list for that is huge.Ìý And the good news – it’s not all bleak – the good news is that if human subjects behave like some of the mouse studies that we’ve undertaken then I think there’s every hope that we will genuinely have a pharmacological replacement for light in the coming years but it’s not there yet.

Ìý

White

That’s Professor Russell Foster.

Ìý

Well as you can hear it's an intriguing topic and if you would like to listen to a longer version of that interview, it will be on the podcast available on our website later this week.Ìý

Ìý

And we would like to hear more of your experiences – both about coping with disturbed sleep on a day to day basis and about getting treatment.Ìý You can call our Action Line on 0800 044 044 for 24 hours after the programme and you can email in touch@bbc.co.uk. ÌýÌýThat’s it, from me, Peter White, producer Lee Kumutat and the team goody bye.