from New Jersey "The Star-Ledger" newspaper page 3 Saturday, March 15,1997
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"BRAIN PACEMAKER" ENDS PARKINSON'S SHAKES
FDA Panel Recommends Approval Of Implant That Aids Some Patients Not Helped
By Drugs
By Lauran Neergaard
Associated Press
ROCKVILLE Md. --George Shafer's hands trembled so violently from
Parkinson's Disease that he couldn't button his shirt or feed himself --
until a powerful device implanted deep in his brain cut off the shakes with
electrical shocks.
Scientific advisers recommended unanimously yesterday that the Food and
Drug Administration approve the pacemaker-like brain implant to help
Parkinson's patients and other tremor sufferers who get no relief from drugs.
"It is a wonderful miracle," said Shafer, 65, of Fort Myers, Fla.,
holding out nearly motionless hands. "I even made a model airplane."
At least 500,000 Americans have Parkinson's disease, a degenerative
neurological disease in which patients suffer uncontrollable shakes, rigid
limbs and other worsening symptoms. About 2 million Americans have essential
tremor, a little-understood hereditary disease that causes similar violent
shaking but no other symptoms, said University of Kansas neurologist Dr.
William Koller.
The drug L-Dopa helps some Parkinson's symptoms, although its effects
wane over time. Only about 40 percent of essential tremor patients are
helped with medicines.
The shaking is so debilitating eventually destroying patients' ability
to work, even feed themselves - that some undergo dangerous surgery to
destroy a small part of the brain responsible for the trembling. But the
surgery can cause permanent problems with speech, movement and swallowing
Medtronic Inc. says it has a far less risky solution: "deep brain
stimulation." With the Activa system, doctors drill through the skull and
implant an electrode into the thalamus, a walnut-sized region deep in the
brain. The left side of the thalamus controls movement in the right side of
the body, and vice versa.
A wire runs just under the scalp down to the collarbone, where a
pace-maker-sized "pulse generator" is implanted. It sends electrical waves
-- custom set for each patient -- to the electrode, which blocks tremors by
emitting constant, tiny electrical shocks.
In studies of 120 patients here and in Europe, about half saw their
shakes disappear, Koller said. Others had different ranges of improvement:
only seven Parkinson's patients were worse a year later.
Unlike surgery, Activa is reversible: Simply turn it off by running a
magnet over the chest where the generator is implanted. Long did so
yesterday, and his hands immediately began shaking. Another swipe of the
magnet to turn the system back on, and 10 seconds later his hands were steady
again.
The effect was greatest for essential tremor, where testing showed
patients could write, pour liquids, without spilling and perform other tasks
significantly better after the implant.
The implant doesn't help Parkinson's patients as much, the FDA said.
That's because it only affects trembling, not other symptoms. So while
studies showed implant patients could now sit still, they could not write or
perform other tasks significantly better.
