A Jolt Of Relief From Parkinson's Disease

Medtronic's pacemaker-like brain implant stops the shaking

For two decades, Howard Zirkle fought a losing battle against Parkinson's disease. The Minster (Ohio) diesel mechanic was forced to retire at age 55 because uncontrollable trembling of his arms and hands prevented him from steadying a screwdriver or wrench. At home, Zirkle needed his wife's help to button his shirt, pour his coffee, and brush his teeth. "It was very embarrassing," says Zirkle, now 72. "I would walk around with my hands in my pockets so people wouldn't see the shaking."

These days, though, Zirkle says he's getting relief. A tiny electrical device implanted in his brain in early January sends a pattern of rapid-fire signals that seem to override signals from the hyperactive nerve cells that cause Zirkle's tremors (diagram). Called Activa, the device is being tested on Zirkle and other Parkinson's patients by Minneapolis-based Medtronic Inc., a leading supplier of heart pacemakers. "We're taking our electrical stimulation therapy and using it for diseases that haven't been treated in the past," says Medtronic Chief Executive William W. George.

BIG PLANS. Now, Activa may come into widespread use. A Food & Drug Administration panel was expected to recommend approval of the device on Mar. 14. To bolster its case, Medtronic submitted raves from Zirkle and other patients. "I'm eating with a fork like I did 20 years ago," crows Zirkle. "And I can fill a cup of coffee without spilling a drop."

Medtronic, which successfully launched Activa in Europe in 1995, has big plans for the product in the U.S. An estimated 2 million Americans suffer from Parkinson's and related illnesses such as Essential Tremor. According to the National Institutes of Health, the diseases cost Americans $6 billion a year in medicine and treatment. Medtronic expects U.S. sales to hit about 10,000 annually within five years. At $10,000 per Activa, that would amount to $100 million in annual sales for $2.4 billion Medtronic (No.31 on the new BUSINESS WEEK 50--page 91). "It proves that Medtronic's outlook is bright beyond pacemakers and defibrillators," says Gregory J. Simpson, an analyst with A.G. Edwards in St. Louis.

Activa does have drawbacks. It's fully effective against Essential Tremor, but alleviates only one symptom of Parkinson's: the tremors. Left untreated are rigidity in the limbs and joints, slowness in movement, and impaired balance and coordination. Also, because implanting Activa involves brain surgery, there's the risk of hemorrhaging and strokes. Potential side effects, while generally mild, can include tingling in the limbs, slurred speech, slight paralysis, and loss of balance.

"FRUSTRATING." Essential Tremor and Parkinson's occur when there is a degeneration of neurons that make dopamine, a substance that enables communication among the brain cells involved in the control of movements. The reduced level of dopamine damages those brain cells. Neurologists are largely dissatisfied with the progress they've made in treating the disease. Companies are experimenting with a variety of approaches, from gene therapy to transplants of neurons from fetal-pig brains. "This has been an incredibly frustrating illness to treat," says Dr. Jean M. Hubble, director of the Parkinson's Disease Center at Ohio State University, who participated in the FDA's Activa trials. "That's why Medtronic's technology is so remarkable."

In addition to using Activa, Medtronic is attacking Parkinson's with SynchroMed, its drug-infusion system. Working with biotech drugmaker Amgen Inc., it is developing a way to use SynchroMed to deliver Amgen's nerve-growth factor to brain cells. The companies are hoping that will reduce the degeneration of dopamine-producing cells.

But it's Activa and other electrical stimulators that have Medtronic executives most excited. On the list for development: pacemaker-based devices for incontinence, sleep disorders, and obesity. A few well-timed electri-cal jolts, it seems, can work medical miracles.

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