Parkinson’s brain surgery works in older patients, too

New findings expand benefits of electrode-implant surgery to those over age 70 and suggest that many side effects are short-term

Brain surgeon Kenneth Follett had never received thank-you cards from his patients after performing an operation — until he started putting electrodes in their brains.

Follett, who holds positions at the University of Nebraska Medical Center and the Veterans Affairs Medical Center in Omaha, is among a select group of surgeons who over the past decade have been treating Parkinson’s disease by installing two tiny electrodes in a patient’s brain.

The change these devices induce can be astonishing, he says. Parkinson’s is characterized by brain degeneration, marked by a shortage of the neurotransmitter dopamine. That shortage results in movement problems. After surgery, many patients are suddenly able to get around, do household chores and even go shopping, Follett says. “It has the potential to change people’s lives.”

Follett’s firsthand observations are now supported by clinical research. He and a team of fellow surgeons and scientists report in the Jan. 7 Journal of the American Medical Association that Parkinson’s patients randomly assigned to get medication plus the surgery show dramatic improvements, whereas patients getting just the best available medication do not.

The surgery, called deep-brain stimulation, isn’t new, having been first approved by regulators in 1997. But only one other study — reported by German scientists in 2006 — has tested the surgery against medication in a large, randomized trial. That study also showed benefits in patients who received both surgery and medication (SN: 9/2/06, p. 149).

Günther Deuschl, a neurologist at Christian Albrechts University in Kiel who led the German study, writes in JAMA that the new findings “have convincingly confirmed the six-month efficacy of deep brain stimulation for advanced Parkinson’s disease in the largest patient group studied thus far.”

The new findings also extend the benefits of surgery to older Parkinson’s patients, since one-fourth of the patients in the U.S. trial were age 70 or older. “They did as well as the younger patients” who underwent the surgery, Follett says.

What’s more, the new findings suggest that many worrisome side effects from the surgery fade over time.

The electrodes that doctors install — one on each side of the brain — are actually small, insulated wires that are connected to another wire that runs under the skin to a small battery beneath the skin of the torso. The electrodes are implanted into a part of the brain that normally acts as a relay station for messages. In Parkinson’s patients, a flurry of signals jam this message center, sending aberrant signals to muscles and causing tremors, muscle rigidity, paralysis and other problems. The electrodes send out a mild current that inhibits the stream of messages, relieving the clutter and calming muscle problems.

In the new study, researchers at 13 U.S. medical centers identified 255 people from 2002 to 2005 who had been taking medication for Parkinson’s disease for nearly 12 years, on average. Half were randomly assigned to get surgery and medication as needed. The others received medication only.

For six months, patients kept a log documenting how many hours per day they were able to move freely without paralysis, jerky motions or other problems. At the outset of the study, this time amounted to about seven hours a day, a number that went unchanged in those getting medication only. But patients assigned to surgery saw their free-movement time jump to 11 hours a day, on average, after six months. Over that time, these patients were also able to cut their medication intake by about half.

Fifteen medication-only patients experienced serious side effects, compared with 49 patients who underwent surgery. Complications from surgery tended to occur within three months of the procedure. Problems included headaches, falls, confusion, speech problems and slowed movement. One person who underwent surgery died of a brain hemorrhage within 24 hours.

But 99 percent of the side effects had resolved by six months as doctors remotely fine-tuned the intensity of the current being generated by the electrodes in each patient and modified each patient’s medication. “It’s a bit of a balancing act,” Follett says.

The challenge in using this surgery might be to determine earlier in the course of disease which patients would get the most benefit from the procedure, says neurosurgeon Robert Goodman of Columbia University in New York City. While medications such as levodopa are highly effective for years, many patients continue to lose mobility despite higher doses. And too much medication can bring on involuntary movements. Goodman estimates 10 to 20 percent of Parkinson’s patients fall into this trap. Those with true Parkinson’s disease — without dementia or other symptoms — would be good candidates for surgery, he says.

Despite the promising results, caution is in order, Deuschl says. He cites evidence that patients have an alarmingly high suicide rate in the first year following deep-brain stimulation surgery, a risk that lessens over time but still lingers after four years. There were no suicides in the six months patients were monitored in the new study. Further work to identify risk factors is needed, Deuschl says.

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