On Thu 12 Aug, Ida & Andre Kamphuis wrote:
>
Hello Ida, thanks for your reply. (By the way, if you have trouble with
the technical words and phrases, think what it is like for an Engineer
like me!) Perhaps it is good in one way, because any model which I dream
up HAS to be simple or I can't handle it. I work on the principle that If
the model can give a plausible account of some phenomenon that is an
encouraging result, so then I throw another set of observations at the same
model. If the model falters at explaining this new data, then out goes the
model, and I try from a different angle.
My present model has been stable for some time, and seems to be able to
explain everything that I can find. - Perhaps you might consider my
'explanation' of end-of-dose dyskinesia. First, let me say that I am
talking about my experience, which is a good deal milder than yours. At 21
years since diagnosis, I can reproduce (in myself) just about every symptom
you like, and I found one or two years ago, that I was beginning to
experience the end of dose or wearing off symptoms .The key point though
is that by referring to my model, I was able to understand the problem and
devise a technique to avoid it.
My model calls for me to take the minimum quantity of levodopa required
to control the PD Symptoms- Unless obstructed by forces such as Dyskinesias.
I then back off a shade, freeze the levodopa at that level, and as the PD
deteriorates further, I make up for the shortage of dopamine by adding
Permax to my diet. I reached the limit of levodopa 6 years ago, and
currently take exactly the same levodopa (75 mg every 2 hours) as I was
taking then, Plus 5 mg of Permax. I find it necessary to increase the
Permax by 0.5 mg every 6 months.
A key element of my model is that in a normal person, an excess of
levodopa to the brain has absolutely no effect, the reason being that the
other (healthy) dopamine-producing cells shut down some of their capacity
to compensate for the extra tablet-induced dopamine. in other words, the
system is what I as an engineer would call a closed-loop control system,
dedicated to controlling the rate of flow of dopamine to the appropriate
synapses at just the right level. A healthy brain will never experience
an excess flow of dopamine in its entire life, and I believe has no
defences against it.
Now we come to the PWP. let's say like you and me, with few if any
natural dopamine producing cells,and only getting dopamine via tablets.
Now you and I have studied our system requirements vey carefully, but
there are limits to the accuracy with which we can feed our system with
levodopa:- I found that I seemed to be producing just a little too much
dopamine through the day. Now the brain controls the Dopamine flow by
holding unwanted dopamine in dopamine receptors until it is required,
or decomposes and is re-cycled. these dopamine receptors have been
holding-back dopamine all day - very gradually, but enough. So we arrive
at the point where you have taken our last tablet, and some time later,
the dopamine receptors decide that if they don't release the dopamine
which they are holding, they are going to burst! Also, they cannot do
their job if they are stuffed to the gills, so the dopamine is expelled
in a great cloud and starts creating the dyskinesias which we know so well.
How did I stop it? - the timing of the event was much the same each day
so I simply did not take the last tablet before the event. This allowed
some of the dopamine to leak away, and once there were some vacant
receptors, the control system was back in business.
I am sorry to be so long-winded but if you have any thoughts on the above
(or you might like to read the proper story on
http://james.parkinsons.org.uk/brian.htm
I would value your comments.
Regards,
--
Brian Collins <[log in to unmask]>
