Electrical Device Controls Some Epilepsy
Washington Post Staff Writer
Tuesday, March 24, 1998; Page Z07
An implantable medical device that sends an electrical jolt to the brain -- much the way a pacemaker controls the heart -- offers relief for a small number of people with difficult-to-treat epilepsy.
"The device provides new hope for these patients in terms of seizure control and improved quality of life," said Eli M. Mizrahi, associate professor of neurology and pediatrics at Baylor College of Medicine in Houston and chairman of the Epilepsy Foundation of America's professional advisory board.
An estimated 2.5 million Americans suffer from epilepsy, a chronic neurological disease that causes seizures -- brief interruptions in the normal electrical functions of the brain. Seizures can be as simple as staring off into space or severe enough to wrack the body with uncontrollable movements.
Medications control symptoms in about two-thirds of people with epilepsy. But for the remaining patients, anti-epileptic drugs either fail to work or are accompanied by such severe side effects, including drowsiness and poor concentration, that their use is very limited.
The new treatment -- called vagus nerve stimulation therapy -- was approved last July by the U.S. Food and Drug Administration for epileptic seizures that begin in one part of the brain and may remain there or spread to the entire brain, as happens in a grand mal seizure. It is not approved for the type of epilepsy that produces smaller seizures called petit mal. The device, which is manufactured by Cyberonics of Webster, Tex., has been implanted in about 300 patients since it was approved. Last week, Blue Cross/Blue Shield announced that it had evaluated the device and found that it met the requirements for coverage. It is up to individual plans, however, to decide whether to pay for the device, which runs about $15,000.
The new treatment involves surgically inserting the device -- which is about the size of a pocket watch -- just beneath the skin in the chest. Surgeons then thread tiny plastic electrical leads up the left side of the neck, wrapping them around a branch of the vagus nerve. The nerve stretches from the brain to the heart and abdomen and controls such functions as swallowing, heart rate and taste.
Vagus nerve stimulation therapy "is not a miracle cure," said Douglas Labar, who directs New York Hospital's Comprehensive Epilepsy Center. "But it is a different approach that provides some rewarding benefits for some patients."
Studies show that about one-third of the patients who get the device see the number of seizures they have cut in half. "That means that some people get fabulous improvement and actually become free of seizures and some people have no improvement," Labar said.
Introduced in 1988 by neurophysiologist Jacob Zabara and his colleagues at Temple University in Philadelphia, the device sends a 30-second signal to the brain every five minutes. Its development grew out of the observation that squeezing a limb can halt a seizure in some people with epilepsy, presumably because it sends a signal to the brain that interrupts the seizure. Zabara theorized that electrical stimulation of the vagus nerve might produce the same effect and tried it first in animal experiments.
Exactly why the device works is not understood, A number of researchers have shown that vagus nerve stimulation therapy can prevent seizures in some people and shorten their duration in others. A recent study by a team of researchers from the Veterans Administration Medical Center in West Los Angeles and Emory University in Atlanta found that the treatment increased blood flow to certain areas of the brain that control seizures. Dean K. Naritoku of Southern Illinois University reported preliminary evidence that the device may reduce metabolic activity of certain parts of the brain, which could stop seizures.
Doctors also can't tell why some patients are helped by the device while others are not. For this reason, "we select patients very carefully," said neurologist Bennett Lavenstein, whose practice at the Virginia Neurological Center in Fairfax was the first to use the device in the Washington area.
The leading candidates for the device are people whose seizures are not controlled by standard medications and those who have undergone brain surgery to remove damaged tissue and still not found relief. "It certainly would not be a first-line choice of treatment for patients with newly diagnosed epilepsy, and it may not be the first choice for patients who are good epilepsy surgery candidates," Mizrahi said.
Francine Findley-Bernal, 28, of Manassas, took the highest recommended doses of powerful anti-epileptic medications, including phenobarbital and Dilantin, and still suffered seizures -- a fact that worried her and her husband when she cared alone for their infant daughter, Ann Marie. Doctors proposed surgery to remove the part of her brain that had been damaged at birth from a meningitis infection and was known to trigger the seizures. But Findley-Bernal and her husband were reluctant to try the invasive procedure. "I told them, 'I don't think so,' " she said.
So when her physician proposed the possibility of vagus nerve stimulation therapy, she was eager even though she was warned that it might not work. Findley-Bernal had the device implanted on Feb. 25 at Inova-Alexandria Hospital, becoming the first person in Virginia to do so. Two days later, surgeons had to operate again when they discovered Findley-Bernal had an unusual extra branch of her vagus nerve. The device had been attached to the wrong branch and had to be reconnected.
Despite the glitch, Findley-Bernal is excited about the new technology. An administrative assistant who does temporary work, Findley-Bernal hopes to be able to drive again if the device controls her seizures, and she wants to go back to work full-time. "Just being able to get a normal life back is worth a shot instead of fooling around with more medicines," she said.
But two weeks after the procedure, she was still getting used to the vibrations, the brief hoarseness and the occasional coughing that the device caused as it activated every five minutes. "It feels like my Adam's apple is vibrating toward the middle," she said during a routine post-operative doctor's visit. "It gets annoying after a while."
The incisions in her chest and neck were also slightly sore and tender. "It feels like there is a swollen gland in my neck," she said.
Findley-Bernal watched as research coordinator Nancy Elling used a laptop computer to slightly increase the voltage the device sends to her brain.
Findley-Bernal also tested a small magnet that she carries with her to activate the mechanism when she feels a seizure coming on. She held the magnet over her blouse at the spot of her incision and felt it activate the device. "It feels very, very strong in the back of my throat," Findley-Bernal told Elling. "It's like I have something stuck in the back of my throat."
Still, Findley-Bernal said that she was glad she opted for the treatment. "My mother thought I was crazy to be the first one to have the operation here," she said. "But being the mother of an almost 9-month-old baby, I want to be able to do things independently."
Studies show that it often takes time for patients to adjust to the device. It may take up to a year and a half to see the full effects of the therapy. As part of long-term safety and efficacy monitoring, David Labiner and his colleagues at the University of Arizona studied 238 patients and found that patients can continue to improve as much as 18 months after the device was inserted.
Those who do not see improvement after 18 months often have the device removed. "Most people leave it in for a pretty good amount of time, hoping that it will help later," said New York Hospital's Labar, who has implanted nearly four dozen devices. "Most people try it for at least a year before they have it taken out, and there's no reason you can't do other things simultaneously, like trying other medications."
Even when vagus nerve stimulation therapy works, it does not eliminate the need for anti-epileptic drugs. The treatment "is not strong enough to work by itself," Labar said.
But it can cut the amount of medication needed. Studies suggest that between 33 and 50 percent of patients using the device can simplify their drug regimens. "They are not taking lower dosages, but they can take fewer drugs, for example, two drugs instead of three, or one drug instead of two," Labar said.
It is that hope that prompted Erinn Farver, 27, of Westminster, Md., to have the device inserted in December at the University of Maryland Medical Center in Baltimore. Farver, who was diagnosed with epilepsy at 12, takes five different medications and a total of 30 pills a day to control her seizures. "I've taken just about everything available on the market," she said. "I'm on an experimental drug right now that is not yet approved by the FDA, and just about everything I take either doesn't work or I have an allergic reaction to it."
Since having the device implanted, Farver has been able to stop several seizures, although not all of them. "It gives me a little more control over my seizures, and at least I can pull down the severity, although I cannot necessarily stop them," said Farver who is a part-time community college student. "I am glad that I did it."
Where the device may be particularly useful is in treating children with the most severe forms of epilepsy. Repeated seizures, sometimes as many as several hundred a day, can cause irreversible brain damage.
Although still not approved for use in children age 12 and younger, experimental use of the device has been promising. A recent study of three children under age 18 at the Research Institute of Kansas in Wichita resulted in "improved behavior within six weeks" for all three patients, researcher Patrice Rawlins reported in December at the annual meeting of the American Epilepsy Society in Boston. The changes were so profound that one mother reported: "I enjoy my son for the first time."
Other studies suggest that the device may be better at reducing seizures in children than in adults. "It represents," Labar said, "a treatment that in the future could be very useful."
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