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First Person
With Each Advance in
Parkinson's, a Question
The Los Angeles Times;
Los Angeles, Calif.
Sep 2, 2002
JOEL HAVEMANN
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(Copyright The Times Mirror Company; Los
Angeles Times 2002. Allrights reserved.) |
People who
study brain disorders say they know more about Parkinson's
disease than just about any other. That's a tribute to the
brain's awesome complexity. The long list of unanswered
questions about Parkinson's is growing shorter at an agonizingly
slow pace.
To researchers,
each unanswered question is a challenge. They know that
Parkinson's cascade of symptoms--tremor, bad posture and
slowness of movement for starters--occurs because certain nerve
cells in the brain die. But no one knows what kills them, and
whoever finds the answer will become rich and famous. Whoever
finds a way to stop the process, thereby curing the disease,
will become 10 times more so.
But to
patients, the unanswered questions are a source of continual
frustration and unease. I know. I've had the disease for a dozen
years, and I've studied it about as carefully as a layman can.
And I still have great difficulty making choices about the
proper course of treatment.
When, for
example, should we start taking levodopa? This is the drug that
helps the brain make dopamine, the chemical that the dead brain
cells no longer manufacture. Dopamine is a critical part of the
circuits in the nervous system that enable ordinary movement.
One school of
thought is that levodopa, although it makes us feel good now, is
bad for our long-term health. The more we take it, the less
effective it becomes and the worse the side effects grow. After
some amount of total use, levodopa does more harm than good. If
this view is right, we should abstain from levodopa until
Parkinson's symptoms make us barely able to function.
Another view,
held by equally eminent scientists, is that levodopa does no
long-term damage and may even do good. True, its bad side
effects ultimately overtake its benefits. But the timing depends
on Parkinson's natural destruction of brain cells, not on how
much levodopa has been swallowed. If this view is right, it
doesn't matter how much levodopa we take during Parkinson's
early phases. In fact, if we refrain from taking levodopa too
long, we'll suffer some problems (muscle deterioration, for
example) that cannot be reversed when we finally take levodopa.
Who's right?
Darned if I know. Thirty of the world's leading Parkinson's
experts convened a meeting in Paris in 1998 to cut through the
uncertainty and develop a consensus that would guide
neurologists as they advise their patients. But the consensus
conference couldn't reach a consensus. The majority view was
that levodopa is not harmful in the long term and that it should
be used to preserve quality of life while the quality of life is
still worth preserving. But there was plenty of disagreement.
Three eminent American specialists, for example, said they had
seen no proof that levodopa does not kill cells in the
substantia nigra, the portion of the brain where dopamine is
produced.
In my
uncertainty, I try to take enough levodopa to keep
functioning--but no more. Sometimes I skimp too much. When that
happens at work, I close the door to my office and shake in
private until my next levodopa pill kicks in. If it happens
while I'm driving and there are no other drivers with me who can
take the wheel, I pull off the road and walk until I steady
down.
Sooner or
later, the pills can no longer lift us out of total misery. What
do we do then? The best answer as of today: See a brain surgeon.
But don't expect any easy choices. Uncertainty likewise clouds
the decisions about whether and when to undergo any of the
available brain surgeries.
One kind of
surgery aims at masking Parkinson's symptoms after the pills no
longer do the job. An electrode is lodged in one of several
parts of the brain, along a neural circuit that is overactive in
Parkinson's. From the electrode, a wire runs under the skin to a
pacemaker that is implanted under the collarbone. A magnet
passed over the pacemaker can turn the electrode to high, low or
off, depending on the need. Each jolt of electricity delivered
by the electrode has the effect of short-circuiting part of the
overactive circuits and restoring them to normal.
The operation
seems to work pretty well--when it works. Two of my friends
found themselves much more mobile after the operation was
performed on one side of their brains. But as with all
surgeries, particularly in the brain, there are dangers. As it
happens, both of my friends tried the same operation a second
time, on the other side of the brain. Both of them suffered
bleeding within the brain, and one had to stay in the hospital
for several weeks to recuperate. Another operation, at once more
experimental and more familiar, holds the potential to cure the
disease. Living brain cells from an aborted 7-week-old fetus are
injected into the damaged part of the brain and, if all goes
well, make themselves at home and replace the cells that have
died.
This operation,
which ran afoul of the anti-abortion movement, is all but
impossible to get today in the United States. But during the
Clinton administration, the government approved two trials of
the procedure, with half of the participants receiving fetal
cells and the other half, a control group, undergoing a sham
operation in which no cells were actually delivered. The
participants were told that those who underwent the sham
operation could get the real thing when the trial was over. (Dr.
Curt Freed, the lead researcher for this trial, has written a
lively account of fetal transplantation, called "Healing the
Brain.")
In keeping with
Parkinson's treatments, the trial yielded mixed results. The
good news is that the fetal cells took hold in most of the
patients. The bad news is that for a few, the cells took hold
with a vengeance and manufactured too much dopamine, which left
these patients with writhing motions (called dyskinesias) that
they couldn't easily control.
One of these
five is George Doeschner. He got the sham operation the first
time and chose to get the real thing when the trial was over.
Although he was judged to have a dopamine surplus after the real
operation, he was able to return to his job as an electrician in
downtown New York office buildings.
Last Sept. 11
found him on the 34th floor of the first of the two World Trade
Center towers to be struck by hijacked jets. Despite his
"disability," he walked down 33 flights of stairs to safety
before the tower collapsed. Now, nearly a year later, he's still
working, and a couple of months ago he had his first job back in
the financial district. "From where I was working, I had a great
view of the hole in the ground," he said. "It was spooky."
And the trial
produced a further ambiguity.
Although the
fetal cells thrived in nearly all of those who received them,
they seemed to relieve the symptoms only of those 60 and
younger. Doeschner was 55 when he had the operation, but I'm now
59. Does that mean I have to move fast or it will be too late to
benefit from this form of treatment? I think not; I suspect that
the magic 60-year-old line was a product of the trial's design,
not of any magical change that occurs in Parkinson's brains at
age 60.
But the 60-year
threshold introduces a new uncertainty. On the one hand, I'd
like to wait as long as possible to get this operation. That
might give researchers time to figure out what kind of cells to
use (brain cells grown from stem cells may work better than
fetal cells), how many of them to use and exactly where to put
them. On the other hand, I don't want to wait so long that the
fetal cells won't relieve my symptoms.
Which is the
right course? Darned if I know.
Joel Havemann, an editor in The Times' Washington bureau,
is the author
of "A Life Shaken: My Encounter With Parkinson's Disease"
(Johns Hopkins University Press, 2002). |