First came pacemakers. Now exotic implants are bringing new hope to victims of epilepsy, paralysis, depression, and other diseases
Reed S. Kohn has donated his brain to science. An epileptic since he was 8 years old, Kohn has tried everything from experimental drugs to harrowing surgery to control his seizures. Time and again, neurosurgeons have taken out bits of his brain that spark his hallucinations, or auras, and have severed nerves that enable aberrant electrical impulses to arc from lobe to lobe and generate a full-blown seizure. They have also run filaments to a nerve in his neck and to the core of his brain to microshock the disease into submission. Inevitably, though, the illness reemerges, corrupting a new clump of brain cells, and he is disabled once again. A college grad and certified computer programmer, Kohn lives with his parents at age 34 and has never had a job. Since his first seizure in 1978, he figures he has had 10,000 more.
His life may get better. Last fall, Kohn underwent his 12th operation. First, doctors scrutinized images of his brain as it malfunctioned. Then, guided by these scans, they wired electrodes to eight “hot spots” deep in his brain, and implanted under his skull a pacemaker-like device from NeuroPace Inc. in Mountain View, Calif. About the size of a microcassette tape and only a bit heavier, it houses a microprocessor programmed to detect the brain-wave pattern that precedes a seizure. Whenever this pattern arises, it immediately zaps the trigger sites with tiny jolts of electricity. The goal is to override his abnormal synapses and restore normal brain activity before Kohn is even aware that a seizure is brewing.
Since the operation on Oct. 14, Kohn has been averaging 10 to 15 seizures a month, down from 50 to 70. As a veteran guinea pig, Kohn knows that it takes at least six months before anyone can truly gauge how well a treatment works, so he doesn’t want to rush to judgment. “I’m feeling pretty good,” he says. His doctors, who believe they can lower that rate by tinkering with the device’s settings, are less guarded. “We’ve been looking for solutions for a long time,” says Dr. Richard W. Byrne, a neurosurgeon at Rush University Medical Center in Chicago who installed the device. “This could be it.”
Forty-five years ago, doctors successfully implanted a cardiac pacemaker for the first time in the U.S., providing long-term hope for millions of people with heart disease and creating what has become a hugely profitable — and still fast-growing — $10 billion-a-year business. Now, electrical therapy may be approaching an historic transition. Using advances in pacemaker technology, researchers and doctors are finding that rapid-fire bursts of low-voltage electricity can alleviate symptoms in an astonishing number of illnesses in many other parts of the human body. Scourges such as depression, post-stroke paralysis, migraines, sleep apnea, angina, obesity, tinnitus, and digestive tract disorders all may be treated with neurostimulators by the end of the decade. If early-stage experiments pan out, Alzheimer’s disease, obsessive-compulsive disorder, Tourette’s syndrome, bulimia, and other brain ailments could be next.
Many doctors are thrilled by this emerging vision of the body electric because it provides fixes beyond the ken of the medical mainstream. Life sciences today are heavily swayed by recent advances in molecular biology. The Human Genome Project and other well-funded efforts have cracked some of the inner workings of genes and the biochemical pathways of disease. In contrast, science has paid less attention to the role of electricity, which governs everything from the ethereal transmission of thought to the rhythmic music of the heart. The race to design and test new implantable devices could help correct this imbalance.
The high-tech implants are neither cheap nor risk-free. For one thing, they must be replaced every 5 to 10 years. Why they work is also still something of a mystery. What’s more, neurostimulation won’t cure most diseases, even though it eliminates or alleviates some symptoms. Doctors note that much of the research is in an early stage. It could be 10 years before they can say for sure if some devices are a fix — or a flop.