February 16, 2001
Doctors Believe Brain Pacemakers
Can Treat Wide Range of Illnesses
By THOMAS M. BURTON
Staff Reporter of THE WALL STREET JOURNAL
The era of electrical pacemakers for the brain is dawning.
Neurologists and neurosurgeons are finding that small electrical currents
applied to central regions deep in the brain can be useful in treating a wide
range of neurological and mental illnesses.
Already, neurological devices implanted in patients are used to treat
tremors associated with Parkinson's disease and give relief to those with
severe pain. Now doctors have begun to explore uses of electrical brain
stimulation for epilepsy, for mental illnesses such as obsessive-compulsive
disorder and even for depression and addiction.
Medtronic Inc. of Minneapolis, the world leader in cardiac pacing, is
expected to win approval soon from the Food and Drug Administration to
use its neurological pacemaker to treat more symptoms of Parkinson's
disease, such as the rigidity, falling spells and uncontrollable twisting
motions. Small medical studies are also under way for treating epilepsy and
OCD with the Medtronic device, known as the Soletra. Doctors also are
considering the possibility of trials for patients with depression and
Typically, the brain pacemaker is placed in the patient's chest, with a wire
surgically threaded through a 3/4-inch hole in the skull, deep into the brain.
For now, the device delivers a small impulse of electricity, either in
occasional bursts or steady current, to a particular region of the brain.
Medtronic hopes to develop machines that will sense abnormal electrical
activity in the brain, and respond with appropriate therapy. That prospect is
sparking doctors' hope the devices' use can be expanded.
"We're at the cusp of a new era," says neurologist Erwin B. Montgomery of
the Cleveland Clinic, who soon will begin treating obsessive-compulsive
patients with the electrical devices. "Basically the brain is an electrical
device, and there is growing awareness that OCD and several other
conditions are related to abnormalities of electrical circuits."
Of course, this is brain surgery. Implanting
the devices can have dangerous side
effects including postsurgical bleeding in
about 2% of patients, which can lead to
fatal strokes in rare instances. So the
devices are intended only for patients who
are suffering severe symptoms and who
haven't been helped by drugs. With OCD,
about 70% of patients improve with
antidepressant treatment. But there are at
least hundreds of thousands of such
patients whom drugs don't help.
For depression sufferers, the stimulation
would be a subtler means of interfering
with brain signals than electric-shock
treatment. And Nicolas Schiff, a
neurologist at Cornell University's Weill
Medical College, envisions electrical brain
stimulation helping revive semivegetative
patients who have survived strokes and major trauma. "What deep brain
stimulation does is push people into a better state and keep them there
longer," he says. "And these are patients who are likely to be completely
overlooked." He hopes to conduct a U.S. clinical study.
Dee Silver, medical director of the San Diego chapter of the American
Parkinson Disease Association, says the Medtronic devices can lead to
Some doctors are taking a wait-and-see attitude. "These devices are just
the first step toward more sophisticated devices," says John G. Milton, a
neurology professor at the University of Chicago Hospitals. "It works for
some people, but that doesn't mean it will work for all." He says that a next
generation of devices that are able to sense what the brain is doing "could
lead to something very important."
The first breakthroughs about treating Parkinson's tremors with electrical
currents occurred in France. In 1987, Alim-Louis Benabid, a neurosurgeon
in Grenoble, discovered accidentally that electricity applied to the thalamus,
in the center of the brain, could stop Parkinson's tremors. At the time, he
was using an electrical probe during surgery on an awake patient to "map"
the functions of different brain regions. When an electrical current touched
the thalamus, Dr. Benabid feared he had injured the patient, and
apologized. The startled patient asked why, since the tremors had ceased.
Soon after, Dr. Benabid began implanting neurological pacemakers for
Parkinson's tremors. Many patients who were shaking so uncontrollably that
they couldn't hold a teacup began to experience relatively normal lives.
Dr. Benabid has worked with Medtronic ever since, and now is using the
technique on multiple sclerosis and other diseases that involve tremors. He
has also had success treating patients with refractory epilepsy.
More recently, doctors have found that other Parkinson's symptoms can be
controlled with electricity applied to nearby brain structures, the subthalamic
nucleus and the globus pallidus. Ali Rezai, a neurosurgeon at the Cleveland
Clinic, says deep brain stimulation reduces tremors by more than 90% and
other Parkinson's symptoms like rigidity and writhing motions by about 60%.
"As far as helping these patients, this is a dramatic advance," he says. He
describes similar improvement in patients with debilitating pain from strokes
and nerve-crushing injuries.
Medtronic first began about 30 years ago to apply some of this
electrical-stimulation technology to the central nervous system, stimulating
the spinal cords of patients with severe pain. It has the field essentially to
itself now, though Cyberonics Inc. of Houston treats epilepsy with electrical
stimulation to a nerve in the neck.
Doctors have particularly high hopes for treating epilepsy with neurological
pacemakers, though that use is still being investigated.
"Epilepsy is an electrical storm in the brain, and it should be possible in
theory to disrupt seizures by changing the epileptic electrical pattern," says
neurologist Robert S. Fisher of Stanford University Medical Center. Though
drugs and other surgery help many patients, "We have about half a million
people in the U.S. alone for whom no existing treatment really works," Dr.
Many such patients cannot get through an hour of their lives without a
seizure. So far, 10 patients with electrical devices have been followed for
several months at hospitals like Johns Hopkins in Baltimore and the
University of Pennsylvania. "People seem to have about a 75% reduction in
seizure frequency," says Dr. Fisher, who is heading a study of the
treatment. He says the "most exciting" hope for electrical therapy will occur
when devices are able to detect an oncoming seizure and respond to it with
the proper current.
Steven Rasmussen, a psychiatry professor at Brown University Medical
School in Providence, R.I., says about 375,000 Americans with progressive
and debilitating obsessive-compulsive disorder are candidates for surgery,
including the installation of an electrical device.
In a small pilot study so far, says Dr. Rasmussen, about 50% of patients
who fail to respond to other treatment, improve with deep brain stimulation.
Because of the public furor over lobotomies in the past, doctors are going
slowly with surgical techniques. But because electrical stimulation is both
adjustable and reversible, there are fewer concerns regarding this therapy.
Even so, only a handful of leading hospitals are trying it in
obsessive-compulsive patients. Brown University is one, and the Cleveland
Clinic soon will begin such treatment. Cleveland Clinic neurosurgeon Dr.
Rezai notes these patients are often unable to work or go to school; he
says they can take eight hours to wash up, or check the locks in their
houses hundreds of times and be unable to stop doing so.
Beyond OCD, Dr. Rasmussen predicts that there are a number of other
opportunities in the psychiatric field for the use of electrical
devices-including addictions that can't be controlled by drugs. "There is
undoubtedly a neurocircuitry in these psychiatric conditions," he says.
Write to Thomas M. Burton at firstname.lastname@example.org
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