Going deep in the brain to help Parkinson’s patients
A surgical procedure that sends electrical shocks deep into the brain has given new hope to people suffering from the severe effects of Parkinson’s disease and other motor disorders.
While this procedure—known as Deep Brain Stimulation, or DBS—does not cure Parkinson’s, it has revolutionized the therapy of advanced Parkinson’s patients, says Gordon Baltuch, associate professor of neurosurgery who practices at HUP and Pennsylvania Hospital. The procedure has been conducted at Penn for about 10 years and has been performed on about 600 patients.
“This is for disease modification and, for the moment, it’s the best disease modifier that’s come out for[Parkinson’s patients],” he says. “We’re treating the symptoms of Parkinson’s disease; we’re not treating the disease itself. We just impact the motor system; we don’t impact cognition.”
For many Parkinson’s patients, the symptoms of the disease and side-effects from drugs are incredibly debilitating. They include slowness of motion, rigidity and freezing up. “For a lot of people, the motor problems are the main things,” Baltuch says.
After undergoing DBS, the average patient still has to take medications, but can cut the amount of meds by as much as 50 percent. Some patients who have had the treatment, meanwhile, have been able to suspend taking medications entirely.
During the four- to six-hour operation—during which the patient is awake—surgeons drill two dime-sized holes behind the patient’s hairline and run wires into a portion of the brain that is, according to Baltuch, about the size of a Rice Krispie. Those wires are connected to pacemakers, implanted beneath the patient’s clavicle, that are adjusted to modulate the brain circuitry and offset symptoms of the disease, including tremors.
The treatment has staying power, too. Patients who received DBS therapy 10 years ago are doing well today, says Baltuch. He hopes technology will improve to equip the devices with rechargeable batteries, rather than batteries that must be changed every three to five years.
Baltuch notes the procedure is not as successful in older Parkinson’s patients, especially as their cognitive functions begin to fail. DBS also does not stop some of the later effects of the disease, including dementia or trouble swallowing that makes a feeding tube a necessity. And while DBS carries the potential of a high reward—specifically, better quality of life—Baltuch cautions that any brain surgery also comes with considerable risks, including a stroke or seizure, and infected or broken implants.
“Taking pills has got a really low complication rate, compared to surgery,” says Baltuch. “Anytime you’re sticking needles in someone’s brain, they can have a stroke and they can die from it.”
The procedure is invasive, but not destructive, says Baltuch, and is totally reversible—the device takes only about 10 minutes to remove from the body.
While DBS is done primarily on advanced Parkinson’s patients, the therapy has also been approved for people with essential multiple sclerosis tremor and dystonia. Researchers have also done DBS on patients with epilepsy, but only on an investigative basis.
Penn researchers will begin a trial later this year to test the effectiveness of the surgery on patients with severe depression who have failed to respond to drugs and multiple courses of shock therapy.
Originally published March 27, 2008
