Parkinson's disease

Causes of Parkinson's disease

While it is known that the symptoms of Parkinson’s disease occur when many nerve cells in the substantia nigra area of the brain die, it is still unclear what causes these cells to die. A review of the latest research evidence from the Parkinson's UK suggests that a combination of genes and the environment may trigger the disease. Genetic research has identified genes which are linked to Parkinson’s and it is possible that in some cases of young-onset Parkinson’s, one or more of these genes may be abnormal. Other research has looked for environmental causes, for example toxins which have caused the dopamine producing cells to die.

Research suggests that the make-up of people’s genes might make them more likely to get Parkinson’s disease but only if they are exposed to other factors. Some people searched their family history and both recent and more distant events in their lives for possible causes.

Helen investigated her family history but could find no explanation for her PD.

Helen investigated her family history but could find no explanation for her PD.

Age at interview: 39
Sex: Female
Age at diagnosis: 33
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Well, I’ve talked to my family. Nobody in my family ever had it that we know of so I’ve looked through that, you know, that side of it. I didn’t think, I just think it’s being unlucky really in that I’ve ended up with it but I couldn’t most people end up with something in their lifetime don’t they so I the way I look at it is it’s not going to kill me. Might make me a little bit slower and, you know, disable me in certain ways but I’m grateful that can still live my life very well so.

Several members of Peter's family are known to have had Parkinson's; he wonders about the implications for his daughter.

Several members of Peter's family are known to have had Parkinson's; he wonders about the implications for his daughter.

Age at interview: 72
Sex: Male
Age at diagnosis: 67
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I asked him if Parkinson’s was hereditary. And there are two different views on this, but I think the main view is that that is possible. And we think that my father had Parkinson’s, but not absolutely certain. And one of his brothers was diagnosed with it just before he died. Well, he, I mean he was 82 when he died, so, but he was, he’d been diagnosed with it just. So I think there is a possibility that it’s something that I have inherited from my father’s side of the family.

 

Do you have any children?

 

Yes, I have a son and a daughter. And my daughter is so like me it just isn’t true and she worries to death about everything. And of course she’s, she’s obviously worried about it. But I’ve told her that she mustn’t worry about it because it doesn’t necessary, necessarily pass from father to daughter any more than it does father to son. And yet what I’ve found is, I don’t know how far your research has gone on this, but it seems to me there are more men that have it than, than there are women. I don’t know whether you’ve found that.

 

Yes, I think that is the case.

 

I mean I, obviously when we go to the meetings there are, there are females there with it, but the membership is, is predominantly men. So I don’t know what the reason for that is.
Gaynor does not know for certain what her grandfathers died from but her two grandmothers who both died in their nineties did not have Parkinson’s disease. She has accepted her consultant’s conclusion that it was just ‘the way the dice had fallen’. Stephen, having found no history of PD in his family looked at his life and found it blameless - he had never smoked, hardly ever drank and led an active life. Rafa on the other hand did wonder for a moment whether his very active life, in which he had trained and run in marathons, could have caused his PD. But his consultant quickly convinced him that this was unlikely.

Nicolas considered several possible causes for his Parkinson's disease.

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Nicolas considered several possible causes for his Parkinson's disease.

Age at interview: 47
Sex: Male
Age at diagnosis: 44
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Diagnosis made me think about causes. Could it have been a bang on the head when I jumped down the stairs when I was 11 or, when I was flying and a bag dropped out of the overhead locker and bumped me on the head. Was that the cause? I don’t know. My lifestyle was quite good. I kept fit. I ate healthily, drank in moderation. I don’t smoke or do drugs. Personality wise, I’m quite driven and time bound. My father’s health was not good, that made me think about that. But I don’t believe he had Parkinson’s disease, so I didn’t think there was anything hereditary there.
Several people believed very strongly that their Parkinson's disease might have been triggered by exposure to a substance later found to be harmful. Steve had worked for thirty years in a car factory and wondered if that had any bearing on his developing PD but he had also seen somewhere that there was an association between rhinitis (which he suffered from) and Parkinson’s disease.

Rex has looked for an explanation and believes he was exposed to toxic chemicals many years ago.

Rex has looked for an explanation and believes he was exposed to toxic chemicals many years ago.

Age at interview: 70
Sex: Male
Age at diagnosis: 63
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I think I was incubating this condition years ago. Because I think the incubation period can be anywhere between ten and fifteen years. But I can’t prove it, but I have got my, I firmly believe that it was due to misuse of pesticides as a young man which I was farming in those days and organophosphates were coming out and they were, we didn’t observe the, the instructions on the label. There was a new condition, the new solution to problems and sheep dips and fly dressings and we did abuse them and I think that’s probably what’s started off my Parkinson’s.

And it has been said hasn’t it that it could be environmental?

Yes. Yes. Yes. There are studies ongoing now. I mean I can’t prove anything at all. It is just I have this feeling in my bones that that’s what started it. There is no history of it in my family at all. So where it has come from I don’t know. You do ask yourself, “Why me?”

Angela knows she has no family history and is convinced that her Parkinson's was caused by being exposed to the organophosphates her husband worked with.

Angela knows she has no family history and is convinced that her Parkinson's was caused by being exposed to the organophosphates her husband worked with.

Age at interview: 59
Sex: Female
Age at diagnosis: 55
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One thing that I did find though, which was quite helpful, was that I've actually researched how I might have come about getting it in the first place. And it's fairly certain in my case that it's organophosphate poisoning from when I was courting and I first got married in the 60s and 70s. People, I come from Manchester and I've been a city dweller. My husband had long slow exposure to organophosphates which were in common use in every area of agriculture, we had stock. There's no history of Parkinson's or anything like it in either side of my family going back as far as I can trace, no shaking palsy, no, nothing like it at all. And I've been doing family tree research, as you do when you get to a certain age, and there's no history of anything like it anywhere in the family so I'm convinced that that is the cause of it in my case. But I understand that there are debates about the genetics and the propensity and so on.

Alun is not prepared to blame a pesticide when his wife and he were both equally exposed to it.

Alun is not prepared to blame a pesticide when his wife and he were both equally exposed to it.

Age at interview: 58
Sex: Male
Age at diagnosis: 49
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Never thought about it, no because it’s happened, there’s no going back. There’s no point worrying about what it might have been. My wife has theories like it was glandular fever, or pesticides, because we stayed with our friends once and they had woodworm. And they had painted all the wood with a chemical and we were sleeping in that room. But then my wife hasn’t got Parkinson’s so I don’t believe that.

 

I don’t worry about what’s caused it. I just think what would, what sort of cure would I like. If I could be cured and stop now that would almost be satisfactory. If I could take it back a year or two, I’d be quite happy with that, so it all depends whether the cures can stop it, roll it back or prevent it.

Geraldine is intrigued by the curious coincidence that several of her contemporaries from university have early-onset PD.

Geraldine is intrigued by the curious coincidence that several of her contemporaries from university have early-onset PD.

Age at interview: 60
Sex: Female
Age at diagnosis: 42
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I had a father who had a very high anxiety levels and people with Parkinson’s disease often do have that, not helped by the medication which all have the side-effects of anxiety too. And I had had glandular fever very badly just before I went to university so I had to do my A-levels at home in bed so my immune system was down when I went to university. And while I was at university in Durham there was a lot of hoo-ha about the chemical waste from Sellafield the nuclear plant. So the reason I say this is that because when I was at Durham there was only seventeen of us. We were the first year ever to do a sociology degree there and out of seventeen of us four of us have early onset Parkinson’s disease which is a pretty high incidence when you consider the number overall of people with early onset Parkinson’s disease in the country. So maybe there was something around at that time, you know, and having my immune system weak the chemicals affected me, I don’t know but that gave me something to rationalise it with.
Several people speculated about the possibility that stress had been precipitated their condition. Judie had had a series of distressing events and can’t help feeling that they may have started it all off. For Humphrey and Mari it was important to be able to be confident that his developing Parkinson’s disease was in no way connected with their daughter's serious accident shortly before his symptoms began.

Mari appreciated the danger of regarding the stress of their daughter's accident as in any way responsible for his Parkinson's disease.

Mari appreciated the danger of regarding the stress of their daughter's accident as in any way responsible for his Parkinson's disease.

Age at interview: 60
Sex: Female
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The interesting thing about the fact that it came near my daughter’s accident was that that actually produced what I think happens with other Parkinson’s patients which is that it’s not that uncommon for there to be a life event which seems to be very close and possibly to cause or get associated with the onset of Parkinson’s, particularly for younger onset people.

 

And I think one of the things we had to cope with was finding out about that. Finding out whether that was true and when I read, I remember reading all this stuff about well, actually Parkinson’s can be latent for ten years until you see the first symptom, and I think his consultant said that firmly. And then you read about what actually might be happening that, you know, you’d been magnificently balancing your neurotransmitters and then something happens which doesn’t just cause the disease, but means that you can’t do the balancing act anymore. And than kind of made sense but the important thing was for us as a family to really believe that it wasn’t daughter’s accident which had caused father’s intractable illness.

 

And that was quite tricky because sometimes people, my other daughter might say, you know, “And and everything was all right until.” Or something that sounded like that and it was really important to deal with that and not make that part of the problem.

Philip is inclined to blame his past indiscretions for his PD.

Philip is inclined to blame his past indiscretions for his PD.

Age at interview: 58
Sex: Male
Age at diagnosis: 54
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To be quite honest a lot of the time… when I was young I used to ride in steeple chases and I had a lot of falls. And for a long time I convinced myself that if I had any problems in that way they were caused by a heavy fall on the head and I am not entirely certain that that is not true. It used to be called being punch drunk. You can’t be certain and certainly when one was a twenty-one year old amateur jockey riding whatever one could take you were slightly inclined to brush the side effects under the carpet for fear that anyone might discover. So you would expect to have got the shakes through too many cigarettes or too many gin and tonics. But I don’t think it was. In the start, there may well have been some minor brain damage.

David suspects the high strength antibiotics he took for a serious infection some years ago could be to blame but also questions why everyone doesn't have PD.

David suspects the high strength antibiotics he took for a serious infection some years ago could be to blame but also questions why everyone doesn't have PD.

Age at interview: 54
Sex: Male
Age at diagnosis: 48
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But now over the first six months one of the things I think a lot of people do is is try and look back and see where it started. Why did I get Parkinson’s? And what caused it and, as we know, there are there could be many causes of Parkinson’s and none of them are quite clear. But it some of the things I’ve read led me to believe that about five or six years previous to being diagnosed I’ve had a serious kidney and prostate infection which took a long time to clear up and I was on very high strength anti-biotics.

 

And there has been some links between anti-biotics and Parkinson’s due to toxin release in the death of bacterial cells maybe so I hung on to that as a possibility but whether or not that’s actually true, you know, remains to be seen and and in the end of the day, it doesn’t really matter what caused it. I’ve got it now and that and that’s that.  

 

The question shouldn’t be “Why did I get Parkinson’s Disease?” The question should be, “Why haven’t you got it?” And it may be the case that everybody gets Parkinson’s disease so the question then arises not as why do some people get it. Some people don’t. The question should be why do some people get it sooner than other people. In effect you live long enough you will get it.
Most people accepted that they will never know why they developed the condition.

Tom wonders if people should be worrying so much about causes when what is really needed are cures.

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Tom wonders if people should be worrying so much about causes when what is really needed are cures.

Age at interview: 40
Sex: Male
Age at diagnosis: 27
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I think people are people are obsessed with the, with the causes of the disease when actually maybe the cause is not, is perhaps ought not what we want to focus on. I think it’s important to find a cause because people say “You can’t find the cure without the cause”. But I would argue that because actually with Parkinson’s I think there are so many causes and that everyone’s probably got different causes to their disease. Actually why not go to the end game and try and find the cure. That may be just as easy as, as looking at all the causes. So I think as much, as much research should be going into the cure as to the reasons why. And what’s the point of fiddling around with all those sort of minutae of what might be causing one person’s Parkinson’s disease if there are treatments now which have been shown to, to help. We should more focused on what people are experiencing today than what, than trying to build all the blocks to, to find the sort of, the every minutiae of, of detail about the disease in order to find the perfect cure. Maybe, maybe we don’t need something that’s perfect now maybe we need something that’s just can manage the disease for people.

Last reviewed May 2017.
Last updated May 2017.

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