Fixing Your Brain
When pills fail, electrical implants can mend brains damaged by Parkinson's, stroke, and depression
About 70 percent of patients who get the procedure get some benefit. Lawson still responds to levodopa for short periods, and that's a big predictor of success, according to Matthew Stern, director of the Parkinson's Disease and Movement Disorders Center at Pennsylvania Hospital in Philadelphia. "It means the circuits are still working to some extent." Another key is using those mapping electrodes in surgery. Some hospitals instead rely on brain scans alone, and Stern says that makes it less likely that they will hit the target.
Deep brain stimulation can hit the target for another movement disorder that can contort the entire body: dystonia. When 52-year-old Michael Withey was an auto-assembly-line worker in Michigan about 15 years ago, his neck started to twist around to the right. His back went in the opposite direction--and stayed there. "The pain," Withey recalls, "was tremendous." Nothing really helped. Not painkillers, not Botox injections to relax his muscles. "Basically," he says, "I became a shut-in."In 2002, he had brain stimulation surgery on part of the movement circuit called the globus pallidus. "It wasn't like I got better right away. But after about three months," he recalls, "I noticed the pain was going. Then my posture got better. I'm back to doing normal things."
Not everyone gets back to normal, however. Pat Brogan, 38, had an electrode implant in 2004. Today, he's still hurting and still on lots of medications that make him woozy. "It has helped some," says Brogan, who lives in Hazleton, Pa. "The pain is down. But I'm not where I want to be."
Stroke is yet another disease in which brain stimulation, albeit a less invasive kind, seems to help people recover movement. "What's amazing is that we can see changes in the brain, and in people's abilities, several years after their strokes," says Helmi Lutsep, a neurologist at Oregon Health and Science University in Portland. Lutsep has been testing an implant called a cortical stimulator on people with partial paralysis after a stroke caused by a blood clot. The electrode is placed just above the brain surface over the motor cortex. "We don't have to go deeper," Lutsep says, "because that's where the damage is."
During the six-week trial, the 16 patients had been doing intensive physical and occupational therapy, along with a matched group of stroke patients without stimulators. At the end, the stimulator group showed motion improvements ranging from 15 to 30 percent; those without the device ranged from 0 to 12 percent.
Those small numbers can mean a huge difference. June Wallace, 77, tried regular rehab after her stroke but still struggled. Then, as part of an earlier trial, she got an implant. "I had pretty much switched to my left hand for everything," she says, "because I couldn't do much with the right. But after three weeks with the implant, I noticed I could pick things up with the right. Now I drive my car. I'm at least 90 percent back to normal." A larger study, now underway, may bring the device closer to FDA approval in the next few years.
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