On Tuesday this week I swallowed a small white pill with my breakfast. An act that was simultaneously mundane, momentous and remarkable.
Mundane because it was
just like popping an aspirin.
Momentous for me
personally because it marked the start of the rest of my life spent relying daily
on medical science.
And remarkable because
of what the innocuous small tablet does.
Thanks to Wikipedia I
understand that Parkinson’s is caused by the death of cells in a small,
presumably primitive, region deep in the brain called the substantia
nigra. Nobody knows why the 400,000 or
so cells start getting overrun by unwanted blobs of protein called Lewy bodies, or how to stop their inevitable depletion,
but what science does know is that the dopamine manufactured by these cells
gets sent to the striatum from where it gets sent to other areas of the brain
via a series of dopamine pathways.
The dopamine thus
supplied is used to control a number of functions, most notably motor control
(hence the tremor and mobility problems with Parkinson’s and in my case double
vision problems), the digestive system (hence my constipation), the olfactory
system (hence my loss of smell), and the pleasure systems of the brain (hence
my recent lack of enjoyment exercising, despite having been a runner for many
years).
The remarkable thing
is that these symptoms can be substantially controlled for several years by
relatively simple chemicals that can simply be swallowed.
Dopamine itself can’t be
taken because it is stopped by the blood-brain barrier, a membrane surrounding
the brain that stops neurotoxins getting in.
So the normal treatment is with a chemical called levodopa, which can
cross the blood-brain barrier and is converted into dopamine by the cells in the
substantia nigra. My mother has been
taking levodopa since she was diagnosed last year, and has responded well. Levodopa also comes naturally in broad beans
and cephalopod (squid and octopus) ink but in that form usually gets broken
down by the liver before it can get to the brain.
The only problem with
levodopa treatment is that its efficacy fades after a few years as the dopamine
producing cells continue dying, and unpleasant side effects start to take
over. For an older person with Parkinson’s
this doesn’t matter so much but for someone like myself with decades to go, a
different treatment is needed.
Dr T prescribed a
dopamine agonist for me. This is a sort
of artificial dopamine that locks onto the receptors in the nervous system,
tricking them into thinking they have been triggered by the real thing. The effect is somewhat similar to levodopa:
the brain behaves as if it has enough dopamine to control motor function, but
again, the drugs don’t work forever.
I had wanted to wait
until I saw the professor before starting treatment; I have an appointment
with him next week. However, my symptoms
were getting too difficult to manage with at work, most significantly feeling
shattered every day due to disturbed sleep, and I felt I had to start taking something.
There have been some
side effects. I sometimes feel nauseous
and light-headed and I get the occasional headache. Paradoxically the medicine makes me drowsy,
though the better quality of sleep at night means I am able to now function
better at work. Clara and I are both
worried about other potential side-effects, namely over-excitation of areas of
my brain responsible for “reward” behaviour.
This could lead to gambling addiction (bankrupting the household
finances…) and hypersexuality (chasing young girls around the office…), but
thankfully there are no signs of either so far!
Right now I am not
sure how I feel about the pramipexole tablets that, despite being generic
versions manufactured in Slovenia, cost me £300 for eight weeks’ supply. They have already started to improve my
quality of life, but I also read on Wikipedia about the nasty effects of
Dopamine Agonist Withdrawal Syndrome, which can even result in the desire for
suicide… It’s not dissimilar, I imagine,
to being a cocaine addict, or worse.
So, for now I am doing
well but, in time, I may come to resent my dependency on the little white
pills…
