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BRITISH BROADCASTING CORPORATION
RADIO SCIENCE UNIT
CASE NOTES
Programme 5. - Stroke
RADIO 4
TUESDAY 07/02/06 2100-2130
PRESENTER:
MARK PORTER
REPORTER: LESLEY HILTON
CONTRIBUTORS:
GILES DURWARD
MIKE RIPLEY
GARY FORD
VEJAYA GENAYSAN
LORRAINE BOYLE
SHAHEEN HAMDY
MAXINE POWER
PRODUCER:
ERIKA WRIGHT
NOT CHECKED AS BROADCAST
MUSIC
RIPLEY
It was Saturday night and I'd taken a DVD out of Pearl Harbour. Was sitting there and watching it and I seem to remember nodding off, dropping asleep, which was unusual for me, halfway through. And then at the end I stood up to turn the DVD player off and promptly fell over. My wife, who'd been sitting watching the film with me, turned to me and said: "How have you managed to get drunk without leaving the room?" Because that's exactly what it felt like - my speech was slurred and I was falling around - but I didn't sort of feel drunk at all. And I just thought oh I'm going to bed. And the next day things got worse and it felt as if I was drunk again and I began to walk into doorways and I thought this is it, I'm going - got to see a doctor. So it was actually Monday morning when I went to see the GP and I said to the doctor: "Is it possible to have a stroke whilst you're asleep and not know about it?" And she said yes it is, and yes you have.
PORTER
And then what happened?
RIPLEY
On the Monday morning I got to the hospital, I walked into casualty, I checked myself in and I was seen by a doctor in casualty who then sent me to the medical assessment unit. Now to get there I was put on a trolley and left there for about five hours. I'm convinced that I had my stroke lying on that trolley in a corridor because I walked into casualty but the next thing I remember is being in medical assessment and I couldn't walk and I couldn't talk and my left arm didn't work.
PORTER
So what had happened during Pearl Harbour?
RIPLEY
I think what was happening on the Saturday and Sunday were warning signs, which I just didn't know what they meant. And the main one happened actually when I was in hospital.
PORTER
Mike Ripley talking to me about the stroke he had three years ago. And although he's made an excellent recovery, he'd be the first to admit that's more to do with luck than judgement. Taking to your bed, as he did, is the last thing you should do if you think you have had a stroke, no matter how minor. And nowadays one would hope he wouldn't have been left on trolley in a corridor for five hours either! Time is of the essence - those first few hours are crucial.
FORD
If you look at somebody who has a severe stroke every minute that goes by they lose two million neurones, so time is really critical in terms of reducing the amount of loss.
PORTER
Professor Gary Ford. At the moment one in four stroke victims die within a month of their first stroke, and one in three of those who survive will be left dependent on others for at least some of their basic day-to-day needs. We will be hearing more from Professor Ford on the latest treatments for stroke that, if given quickly enough, can save lives and significantly reduce the risk of being left with some form of long term disability.
And while the majority of the 125,000 people who have a stroke every year in the UK are elderly, strokes can strike at any age. I'll be finding out why a thousand children a year have strokes, and why the diagnosis is often missed.
My guest in the studio today is Dr Giles Durward - who is a consultant in the Stroke Unit at Southampton General Hospital.
Giles, what's actually happening to the brain during a stroke?
DURWARD
What happens to the brain is the blood supply to the brain tissue is interrupted and brain tissue without a good blood supply rapidly degenerates and dies. The result of the death of the brain tissue is a loss of brain function and depending where in the brain that takes place will give you the deficits that are obvious for people to see.
PORTER
And that interruption's happening for what reason?
DURWARD
There are two main causes of stroke, one is due to a blocked artery supplying that part of brain, the other is a bleed into the brain tissue. Either way the loss of function and the death of the brain cells happens resulting in a deficit and it's not easy to tell clinically between the two types of stroke.
PORTER
So the blockage one we call ischaemic strokes, the burst blood vessel - leaking blood vessel - we call a haemorrhagic stroke. And you say you can't reliably tell the difference between the two?
DURWARD
No clinically from the story people give you there are no clear distinguishing features and that's why we're dependent on brain imaging to tell us what type of stroke someone's had.
PORTER
So what are the basic symptoms, what should we be looking for, what might someone experience?
DURWARD
Typically people experience a loss of function, so it may be the loss of use of one arm; the loss of use of one side of their body, so that they can't walk; the loss of speech, so that they may know what they want to say but can't get the words out; the loss of symmetry of their face, so one side droops. If it affects the posterior part of the brain it may just be loss of coordination. So there is always a loss of function and that's usually obvious to the individual.
PORTER
I've got an e-mail here that's doing the rounds at the moment and it's looking at trying to encourage people to recognise stroke and it says ask three simple questions: ask the individual to smile, ask the person to talk or to speak a simple sentence and ask him or her to raise both their arms. And presumably that's looking for the most likely deficits - you're likely to get a loss in one of those areas.
DURWARD
Yes this is the basis of the fast test, which is being promoted by the Stroke Association and is in use by a lot of ambulance services around the country, promoting the idea that stroke is a medical emergency and it can be easily recognised. And the fast test you look for symmetry of the face, you see if someone can raise both arms and see if they can speak. And if you test all three and there's one or more of those features then you're very likely to have had a stroke.
PORTER
But we still don't know whether it's a haemorrhagic or an ischaemic stroke and we'll be finding out later why that makes a significant difference. But the idea is to get a diagnosis as quickly as possible, the only way you're going to be reliably able to do that, presumably, is through scanning.
DURWARD
Yes, the diagnostic test which will tell you what type of stroke is a CT brain scan and the sooner that's done the sooner you have a clear diagnosis which you can then implement treatments for.
PORTER
Well patients of mine and I'm sure patients in your area of the country will be used to waiting many months to get scans for non-urgent causes, for things like knee troubles, I mean how easy is to get rapid emergency access to the scanners that you need?
DURWARD
In most hospitals CT scanning is available. It's upgrading stroke to the level of emergency and treating it in the same way as someone coming in with a heart attack would be treated. Anyone coming in with a heart attack will get an ECG, a heart tracing, within minutes of coming into a hospital door, stroke should be in the same category because the newer treatments we have need to be given very rapidly to be effective.
PORTER
Well one of those new treatments is the use of clot busting drugs or thrombolytics. They were originally developed to dissolve clots and restore blood flow through the blocked coronary arteries of people having heart attacks, clot busters literally melt away blockages in the circulation to the part of the brain affected by ischaemic stroke. Given early enough - before the damage to the brain becomes irreparable - they can save lives and prevent disability. Gary Ford is Professor of Pharmacology of Old Age at the University of Newcastle.
FORD
Patients who benefit are those who are treated within three hours and the earlier they're treated within three hours the better. The later we treat patients, this is even within the first three hours, the less benefit they're likely to get. So for example if you treat people within the first hour after their onset of symptoms with clot busting treatment for every two or three patients you treat you prevent one of them being left disabled, so it's very powerful. But the key thing they've got to have an ischaemic stroke which is due to loss of blood supply to part of the brain because of an obstruction of an artery with a clot supplying the brain. And thrombolytic therapy - clot busting therapy - works for the ischaemic stroke patient and should not be given to patients who have a haemorrhagic stroke, since it will increase bleeding and make things worse. And for that reason it's very important patients have a scan done as soon as possible after the onset of stroke symptoms.
PORTER
But I can imagine that getting somebody into hospital, scanning them, getting the result of a scan all within three hours is tricky.
FORD
It's difficult but most patients, if they have a significant stroke, witnesses nearby contacting emergency services very quickly, usually by calling 999, and for example in our own hospital the average time that patients arrive at the hospital door, when they contact the ambulance services, is just over one hour, so that still leaves quite a lot of time to be able to scan those patients, assess them and treat them within three hours.
PORTER
And the hazard, presumably, is uncontrolled bleeding.
FORD
Yes, that is the major concern of treatment and why one has to select patients carefully who are not at high risk of bleeding. About 3% of patients get bleeding into the brain from clot busting drugs but the benefits of the treatment far outweigh that risk.
PORTER
And what about other treatments in the pipeline?
FORD
Well there are some interesting exciting developments with what are called neuro-protective drugs, which again have been developed to reduce the damage from ischaemic stroke. We've known for a long time from pre-clinical and laboratory studies that when the blood vessel to part of the brain is blocked there's an area of brain where the blood flow is reduced and if you can protect that with drugs you can reduce the amount of damage that occurs due to secondary processes that occur in those cells which are short of blood which leads to the death of those cells. There are other advantages, one is that these drugs, if they're safe, which they probably will be in patients who have haemorrhage, can be given before you get a scan - so you can get the treatment on board much more quickly. And in principle it would be possible to be able to give those drugs before the patient even got to hospital, the paramedics could give the drugs as they do for other acute emergency conditions.
PORTER
Professor Gary Ford. You're listening to Case Notes, I'm Dr Mark Porter and I am discussing strokes with my guest stroke specialist Dr Giles Durward.
Giles, it's good to hear about those sorts of advances but stroke prevention remains the key - how can we identify who is likely to have a stroke and what can we do about it?
DURWARD
Stroke has many risk factors in common with coronary heart disease that everyone's well aware of, such as blood pressure, smoking, diabetes, inactivity. And there are a few other more specific ones like an irregular heart rhythm which can generate clots in the heart which can get thrown off and get lodged in the brain.
PORTER
Let's quantify those risks. First of all the one we haven't mentioned there was of course having had a previous stroke and that might not have been diagnosed might it?
DURWARD
Yes you can have previous strokes or mini strokes, so-called TIAs - transient ischaemic episodes - where you have the same features as a stroke, you lose function, but that loss of function tends to be fairly short-lived, typically less than an hour. If that happens then you are in a very high risk group for having a completed stroke or a more serious stroke. The recurrent risk at one week now is estimated to be around 10%. So you need very rapid access to diagnostics and definition of the risk factors to enable adequate prevention and by doing this we may actually prevent strokes happening.
PORTER
And this is the people who've had TIAs in the past might have taken to their bed and thought I just felt a bit funny for an hour or a two, I had a bit of a funny head or dropped my teacup or whatever and then they wake up and they feel fine, so they never even report it to the doctor, but it's a key sign because it could herald a major stroke on the way.
What about high blood pressure, how - I mean the figure I was always - thought that people who got high blood pressure were seven or eight times more likely to have a stroke than somebody else, is that the next biggest risk factor?
DURWARD
Yes certainly, high blood pressure in the community is the highest risk factor for having a stroke. So it's something that we can modify and we can significantly reduce the instance of first stroke. So these are the primary prevention means, the factors we can intervene in, so that people don't have that TIA, they don't have the first stroke.
PORTER
I've got a list here of some of the risk factors and the relative risk. I mean if you're diabetic four to six times; if you smoke - we haven't mentioned smoking of course - you're about twice as likely to have a stroke; if you're sedentary two and a half times; poor diet, roughly two times as well. So there's lots of different risk factors there. But they're all - we can identify those and they're good for lots of other reasons, of course the same risk factors are often there for heart disease another big killer. But what can we do about them, I mean let's assume we stop somebody smoking and we get the inactive people active, what can we do with medicines and things that can actually intervene to reduce the risk?
DURWARD
Typically people on stroke - people at risk of stroke are likely to need intervention on multiple risk factors. So they will need the advice about smoking plus support in giving it up but they're likely to need medications for treatment of their blood pressure, treatment of raised cholesterol, tightening up of their diabetic control if they're diabetic and drugs such as aspirin to thin the blood and other agents which may be added in, in addition to aspirin. So that people will end up on a combination of medications, each designed to intervene on one risk factor. And the combination to substantially drop their risk of having a stroke.
PORTER
Well age may be one of the biggest risk factors for strokes - basically the older you are the more likely you are to have one - but children can be affected too. Around a thousand children in the UK are thought to have a stroke very year, often for no apparent reason. Dr Vejaya Genaysan is senior lecturer in paediatric neurology at the Institute of Child Health at Great Ormond Street.
GENAYSAN
Half of these children have another medical condition that predisposes them or puts them at higher risk of having a stroke, these would be conditions such as sickle cell disease or congenital heart disease - other sort of complex medical problems.
PORTER
So these are problems that will predispose to clotting of the blood or sludging of the circulation?
GENAYSAN
Right, or abnormalities of the vessels, yes exactly. But the other half of children are completely well prior to the stroke. I mean in general in terms of demographic terms there are two main sort of peaks of incidents - one in the sort of pre-school toddler population and then again there's a rise in the sort of teenagers.
PORTER
We know that in adults the predisposing factor for most cases of stroke is narrowing of the circulation in the brain due to atherosclerosis. But that furring up process, although it does start depressingly early in life, it surely can't be a factor in children?
GENAYSAN
No, in fact we don't really see atherosclerosis associated with childhood stroke but in about 80% of children we see abnormalities of the brain circulation. But in many cases it's not really known why that happens. We think that factors such as infection are probably quite important and specifically there is an association with preceding chicken pox infection which people often find quite surprising.
PORTER
I'm interested in the link with chicken pox, is this something that happens during the acute illness or is it a result of previous illness, a complication that can happen months or years later?
GENAYSAN
Well I think the thing to emphasise is that chicken pox is very common and this is an extremely rare complication of chicken pox, probably affecting about 1 in 20,000 children who have chicken pox. It's an interesting association to us because it may tell us something about the mechanisms underlying stroke in this group. It can occur in the acute part of chicken pox but there is an association with chicken pox within the preceding year.
PORTER
And we think that's because it's resulting in some form of inflammation to the lining of the blood vessels?
GENAYSAN
Quite so, exactly yes.
PORTER
And what about the 50% who don't have any obvious identifiable cause, do they share anything in common?
GENAYSAN
Well I think these are children who are completely healthy but when we investigate them we do identify a range of risk factors which seem to come together in the individual child to cause a stroke. And those risk factors would be things like preceding chicken pox infection, anaemia for instance - other sort of factors like that.
PORTER
So presumably in quite a few children we never actually find an identifiable factor?
GENAYSAN
Disappointingly that is the case but I'm glad to say that as time goes on that proportion gets less and less and currently it's about 10%.
PORTER
Well let's look at the symptoms, what are the classic symptoms in children, are they any different from those that we'd see in adults?
GENAYSAN
Well the commonest symptom, as in an adult, would be a sort of weakness down one part of the body. But you know I think it's true to say that recognition is one of the major problems. A lot of parents say they take the child to the A&E department where they may see a doctor who's not that experienced in dealing with children and it can be quite difficult to think of stroke as a possible diagnosis.
PORTER
And presumably if you're looking at children, young children particularly, things like speech, affected speech, or even weakness in the body can be quite hard to elicit.
GENAYSAN
Yes exactly and some of those very classic symptoms you see in adults may not be apparent in babies or infants. And so, for instance, a child may just present with inability to wake, their inability to sit, seizures - something less typical than an adult presentation.
PORTER
Thirteen-year-old Charlie had a stroke shortly after his third birthday.
CHARLIE'S MUM
When Charlie had the stroke and he was just running round playing and the next thing he collapsed on the floor. I remember running over, picking him up, his mouth had all dropped and thinking he looks like he's had a stroke but obviously I thought, no, no way, not at three years old. And then I took him to Ealing Hospital who done some tests and they didn't think he'd had a stroke, they thought he might have suffered a fit or something. And then they kept us in there and about eight o'clock he got out of bed and collapsed again and I think that was the big one, so they needed an MRI scan. So off we went to Great Ormond Street where they found out that it was a blood clot because of a narrow artery in his brain. All his left side of his body is very, very weak but now he doesn't use his left hand at all.
CHARLIE
It won't open, it can't release it itself. Sometimes it goes up in the air, you have to like lie on my hand.
CHARLIE'S MUM
His left arm and his left leg's very weak. But he gets on well don't you?
CHARLIE
Yeah.
GENAYSAN
I think there's good data now to show that at least two thirds of children who have a stroke have impairments in day-to-day life compared with their peers. And I think it's important to recognise that many of these would be relatively invisible to the casual observer. So they may not have an obvious movement problem or an obvious speech problem but relative to peers they may have difficulties in terms of their school - educational attainments - or particularly in terms of emotional and behavioural functioning. But again about two thirds of children do have a movement problem and that would be by far the most common sort of outcome after a stroke.
PORTER
Dr Vejaya Genaysan talking to me earlier.
Giles, we should put this in context. It's quite unusual for children to have strokes, presumably you get to see some teenagers in your unit?
DURWARD
Very rarely. I can think of one in the last five years.
PORTER
Okay. Assuming somebody has a stroke, we've done what we can for them acutely, in the first day or two, what happens then, what can we do to encourage rehabilitation, to get them back on their feet?
DURWARD
We now think the rehabilitation should start as soon as someone enters hospital because we're trying to prevent complications and promote an environment where recovery can occur. But we need to pay close attention to issues such as feeding because a significant number of strokes have swallowing difficulties and if that's not picked up at an early stage people can develop pneumonias and as soon as you have other problems recovery is delayed. So rapid assessment of someone's ability to swallow is vital in their early rehabilitation.
PORTER
Is this encouraging the part of the brain that's been damaged to repair itself or is that finished now, is it looking at other parts of the brain taking over tasks that were previously the responsibility of the damaged part?
DURWARD
The damaged part usually dies completely and recovery is by a process of adaptation and recruiting of other parts of the brain to take over those previous functions because brain dies very rapidly and if you don't restore the blood supply to the brain that bit of brain doesn't recover.
PORTER
As a rough guide, in terms of recovery, looking at duration, if for instance somebody's still got a pronounced weakness in their arm at six months does that mean it's going to be permanent? Can we look at these sort of landmarks and decide when people are going to be left with a permanent disability?
DURWARD
The majority of recovery occurs within the first three months post-stroke and if someone has a weakness at the end of that period they're likely to continue to have weakness. The degree of that weakness may vary and we do see improvements 18 months, two years after a stroke and so it's not the end of the process, it's the start of adapting to living with the effects of stroke.
PORTER
Well you mentioned swallowing there, we sent Lesley Hilton to a rehabilitation unit at Hope Hospital in Salford to find out more about their novel approach to helping people swallow normally again.
HILTON
It's likely that around half of all patients who have a stroke will be left with swallowing difficulties. For some this will be a short term problem but others will never be able to swallow. Patients have to be tube fed because of the risk of food and drink getting into the lungs and causing infection. Pneumonia is a common complication for them.
Lorraine Boyle was only 28 when she had a major stroke 10 years ago while working as a nurse. She regained consciousness to find a feeding tube up her nose which she was determined to get rid of as soon as possible.
BOYLE
I couldn't swallow so everyday the dietician would come and see if I could take anything and I was always just coughing. So I used to have this tube and I used to think I've got to get rid of this tube. And in my mind - there's so many people who have a stroke who have a tube because they don't have their swallowing. So that was my first obstacle in my way is to get the tube out.
HILTON
Patients who lose the ability to swallow are the ones whose stroke has only affected the side of the brain responsible for that activity. That can be either side depending on the individual. Dr Shaheen Hamdy from the University of Manchester is researching how strokes affect the swallowing mechanism and thinks that the undamaged side of the brain can adapt itself to a certain extent to restore the ability to swallow.
HAMDY
Our belief is that the reason for that recovery taking place is likely to relate to how the brain is rewired over the course of time. Now we've conducted some studies using a number of imaging modalities - the main one we've used is something called magnetic stimulation. And what we've found is that if you look at patients over time who show recovery in terms of their swallowing, there is some evidence to suggest that the side of the brain that was unaffected by the stroke, the unaffected hemisphere, shows recovery, shows some changes - a sort of reorganisation if you will - it expands out in terms of its representation for swallowing and our belief is that that increase in representation is compensating and causing the recovery to take place.
HILTON
Dr Hamdy has invented a device to try and kick start the swallowing mechanism again and is running a clinical trail of it at Hope Hospital.
HAMDY
First of all I'm just going to ask you to just relax. Okay? Now this tube will go over the back of your nose, into your throat and you're going to feel some discomfit as it goes down. So when I pass this through if you can just keep on swallowing, keep on swallowing.
HILTON
It works on the basis that swallowing is stimulated by feeling the sensation of something in the throat.
HAMDY
Okay, I think it's in the right position now, okay. I'm just going to switch the box on. And I'm just going to turn the stimulator on now. And I'm just going to fire away a few stimuli.
The technology that we are actually using involves the passage of a tube into the back of the throat and the tube has electrodes on it which can deliver the stimuli which are electrical. So a subject swallows this catheter and if it's a stroke patient then we usually pass it through the nose into the back of the throat and most patients don't have a problem with that, it's not much bigger than a nose to gastric tube so it's reasonably well tolerated. It's then hooked up to a device that delivers the stimulation to the back of the throat, so a sort of low level of electrical pulses, and then we run that for a period of time - a few minutes normally - and we deliver that on a regular basis.
HILTON
Dr Hamdy's patients receive three to five sessions of the treatment and so far the trial is showing around one in four people are getting long term benefit from it.
Patients who can't swallow can become socially isolated and that can lead to depression. Anecdotal evidence shows that given a choice between being able to eat and drink but becoming vulnerable to chest infections, or being tube fed, most patients prefer to take their chances and enjoy their food. Maxine Power is a speech therapist at Hope Hospital.
POWER
The thing that they really do report most is a feeling of how heavily it impacts on all of their social life because I think we all of us conduct a lot of our conversations with our friends and family around a meal table. And even where swallowing is recovering and where we can encourage people to do more, there is often a reluctance to actually eat and drink in public for fear of them coughing, choking or not being able to cope which I think is often a sort of hidden side of swallowing difficulties that we as clinicians maybe sometimes don't pay enough respect to.
HILTON
Lorraine Boyle, in common with many other stroke patients, has learned how to swallow again. She used her will power and started with soft food like yoghurt and rice. But the prospect of living on that forever drove her to eat a normal diet again, although she still has to be careful how she eats.
BOYLE
Everything's fine now. I can eat anything but even today I haven't - say if I've had a lunch and I might have just had it too quick I sometimes have it going the wrong way, so it's into my lungs.
PORTER
Lorraine Boyle talking to Lesley Hilton.
Giles, let's end by summarising the gold standard management of a suspected stroke. First of all, what should the people - the public - themselves do?
DURWARD
I think it's the recognition of the symptoms that someone may have had a stroke.
PORTER
But are the public and are GPs, in particular, aware that we should be now treating - aware enough that we should now be treating stroke as a medical emergency? I mean people realise when they get chest pain now they just dial 999, that's the right way to deal with that.
DURWARD
I think the public awareness isn't quite there yet. The Stroke Association have had a big publicity campaign but it hasn't quite penetrated through yet.
PORTER
This is the concept of talking about stroke as a brain attack isn't it.
DURWARD
It's a brain attack, it's an acute medical emergency, it needs to be treated in the same way as a heart attack is - get to hospital, get diagnosed, get to a specialist unit.
PORTER
We're getting there but must try harder.
DURWARD
Indeed.
PORTER
Okay, Giles we've got to leave it there, thank you very much.
Next week's programme is all about being too hot or too cold - I'll be finding out why we develop high temperatures when we are ill, and what, if any, evolutionary gain they offer. And I'll be travelling to Oxford to discover how Viagra is being investigated as a possible treatment for the cold, painful hands and feet caused by Raynaud's disease.
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