A much better version of the one I sent previously...jmr
Thalamic Stimulation Suppresses Tremors, Is Safer Than Thalamotomy
MINNEAPOLIS, MN -- February 17, 2000 -- Electrical stimulation of the
thalamus, the brain's communication center, suppresses drug-resistant
tremor from Parkinson's disease and Essential Tremor as effectively as
thalamotomy, an irreversible surgical procedure that destroys part of
the thalamus, according to a study published in today's issue of
the New England Journal of Medicine. What's more, treating tremor with
thalamic stimulation resulted in greater functional improvement and
fewer adverse effects among the patients in the study.
"The results of this study suggest benefits of thalamic stimulation over
thalamotomy for treating patients with severe tremor that medication
cannot control," according to Erwin B. Montgomery, Jr., M.D., a
neurologist specializing in movement disorders at the Cleveland Clinic
Foundation. "Not only is thalamic stimulation just as effective as
thalamotomy in suppressing tremor, it's also reversible, adjustable and
better at restoring patients to fuller, more active lives."
Tremor -- the disabling, involuntary rhythmic shaking of the limbs or
other parts of the body -- is the only symptom of Essential Tremor and
one of the cardinal symptoms of Parkinson's disease. The two conditions
afflict more than 1.5 million people in the United States.
The two-year study, conducted in Amsterdam by a team of researchers from
the Academic Medical Center and the Netherlands Institute for Brain
Research, involved 68 patients -- 45 with Parkinson's disease, 13 with
Essential Tremor and 10 with multiple sclerosis -- whose tremor could
not be controlled adequately with medication. The patients were divided
at random into two groups. Half received thalamic stimulation; the other
half underwent thalamotomy.
While both groups experienced similarly high levels of reduction in
their tremor, patients who received thalamic stimulation outscored those
who underwent thalamotomy on measures assessing improvements in 15
activities of daily living, including domestic tasks, leisure or
work-related activities, and outdoor activities. In the study, 91
percent of the thalamic stimulation group and 79 percent of the
thalamotomy group experienced total or almost complete suppression of
their tremor after treatment.
"Thalamic stimulation resulted in greater improvement in function than
thalamotomy, according to both objective and subjective measures," the
researchers write. "Patients in the thalamic stimulation group had a
clinically relevant improvement in their ability to perform the
activities of daily life. No such overall improvement was evident in the
thalamotomy group."
Adverse effects such as slurred speech and gait or balance abnormalities
were more common among patients in the thalamotomy group than in the
thalamic stimulation group -- 16 patients compared to six, respectively,
after six months. "For many patients," according to the study, "the
benefit derived as a result of tremor control [using thalamic
stimulation] outweighs the side-effects of treatment."
Thalamic stimulation for the treatment of tremor became commercially
available in the United States in August 1997 when the FDA cleared
Medtronic Activa(R) Tremor Control Therapy, the first new approach to
treating tremor in 30 years. The therapy has been available in Europe,
Australia and Canada since 1995, and thousands of people worldwide have
received it.
Activa Tremor Control Therapy delivers mild electrical stimulation to
the thalamus to block the errant brain signals that cause tremor. The
implanted system includes an insulated wire lead that is surgically
implanted deep within the thalamus. The lead is connected by an
extension wire under the skin to a neurostimulator (similar to a cardiac
pacemaker), also implanted under the skin near the collarbone.
Patients control the stimulation by passing a hand-held magnet over the
implanted neurostimulator to turn it on or off, or to increase or
decrease stimulation depending on their tremor suppression needs. To
achieve maximum benefit, physicians can adjust the stimulation
non-invasively using a console programmer to deliver the precise
stimulation
needed for each individual patient.
Patients interested in Activa Tremor Control Therapy should consult
their physician or a neurologist specializing in movement disorders to
discuss risks and benefits and to assess whether this therapy is
appropriate for them.
Essential Tremor, the most common neurological disease in the United
States, affects at least one million Americans. In addition, more than
500,000 people suffer from tremor associated with Parkinson's disease, a
progressive and degenerative neurological condition.
Copyright © 1999 P\S\L Consulting Group Inc. All rights reserved.
All contents Copyright (c) 1998 P\S\L Consulting Group Inc. All rights
reserved.
--
Judith Richards, London, Ontario, Canada
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