Pacemaker for the brain eases Parkinson's

Minimally invasive surgery can swiftly offer relief from disease's major symptoms

Health & Fitness

September 26, 2004|By Carolyn Poirot | By Carolyn Poirot,Knight Ridder / Tribune

For William Chappell, brain surgery to control the twitching, poor balance, blurred speech and muscle rigidity of Parkinson's disease "was just so easy -- a piece of cake."

And, "this was brain surgery!" the Fort Worth, Texas, resident says, as if he can't quite believe it.

Before the surgery, Chappell, 60, sometimes had difficulty separating the symptoms of Parkinson's from the side effects of a combination of drugs he was taking: He took drugs for Parkinson's, several drugs for general anxiety and drugs to stay awake -- because being on so many drugs made him drowsy.

"I was having a miserable time with medication," he says. "I started going steadily downhill on the drugs prescribed for me. Deep brain stimulation has really saved my life and given me additional quality of life."

Deep brain stimulation involves implanting fine wire electrodes deep inside the brain. The wires are attached to pacemakers implanted under the skin of the upper chest, usually one under each shoulder blade. This pacemaker for the brain system gives off tiny sparks of electricity that interfere with faulty nerve cell communications in the brain and help control involuntary muscle movements.

Originally developed for idiopathic tremor and now used to treat Parkinson's as well as dystonia, a neurological condition that causes involuntary muscle contractions, deep brain stimulation may someday be used to curb a person's appetite, control addictions and cure Tourette's syndrome.

"Part of the beauty of this is that you can focally affect the brain. When you give drugs by mouth, they affect the total brain and you get side effects in parts of the brain you don't want to affect," says Dr. Padraig O'Suilleabhain, assistant professor of neurology at the University of Texas Southwestern Medical School, who prescribed deep brain stimulation for Chappell.

"If we could target drugs precisely the way we can electrical currents, we could do the same thing with drugs," O'Suilleabhain says. "Deep brain stimulation has the advantage of better targeting, and you can turn it on and off in an instant -- not true of drugs."

The best candidates

Deep brain stimulation (DBS) can be thought of as an electronic version of Sinemet, the standard drug for Parkinson's disease, says Dr. Cole Giller, associate professor of neurological surgery and radiology at UT Southwestern. He implanted Chappell's electrodes and brain pacemakers almost a year ago.

"Electrical and chemical signals overlap and interact in the brain," Giller says. "Think of this as giving [the patient] an electronic version of Sinemet without complications and side effects. It makes perfect sense because the brain is an electrical organ."

Good candidates for surgery are those who initially responded well to drug therapy, Giller says.

DBS doesn't cure Parkinson's, but it relieves major symptoms well enough that most patients are glad they went through the procedure, says Giller, who has done about 130 of the procedures using a tiny flashlight device he developed with engineers at the University of Texas at Arlington to guide placement of the electrodes.

"We use a little microfiber flashlight to analyze where we are in the brain, to tell gray matter from white, to keep track of the different layers and differentiate structures so we get the probes exactly where we want them very quickly," Giller says. "It is surprisingly safe."

And, because patients are only partially sedated, advanced age is not a major risk, says Giller, who has implanted the devices in patients who are in their late 80s.

DBS improves quality of life with significant reduction of symptoms in people with Parkinson's and idiopathic tremor 75 percent to 80 percent of the time, doctors say. (Results are not quite as good for dystonia.)

In DBS, high-frequency electrical pulses are programmed and "turned on" about a month after the initial surgery, and once the stimulation is properly adjusted, not much follow-up is needed until the pacemaker's batteries are worn out in four to 10 years, depending on how much stimulation was used.

When the system is activated, the effect is often very quick and dramatic. A severe tremor can disappear right before your eyes, O'Suilleabhain says.

Cost of treatment

The U.S. Food and Drug Administration approved electrical stimulation therapy for Parkinson's disease about 18 months ago. It works in much the same way as making permanent surgical lesions deep in the brain to destroy the parts that are causing symptoms of Parkinson's, but it can be adjusted on a continuing basis for the maximum therapeutic value, and it can be reversed.

Compared with surgical ablation (tissue destruction), stimulation is less invasive and has fewer serious side effects and complications, O'Suilleabhain says. It is easier, safer, adjustable, removable and allows for future surgical advances. It requires two to three days of hospitalization, he says.

Neither treatment actually stops the destruction of nerve cells and progressive loss of dopamine in the brain, which is at the root of Parkinson's, but both procedures slow the progression of the disease and can help control symptoms.

Cost is about $70,000 -- $20,000 for the electrical system itself, and $50,000 for surgical and hospital fees. Insurance, including Medicare, usually covers the treatment.

Resources

For more information about pacemakers for the brain, go to www.medtronic.com.

For more information on Parkinson's and other movement disorders, go to Worldwide Education and Awareness for Movement Disorders at www.wemove.org.

For additional information about dystonia, go to www.spasmodictorticollis. org.

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