A new technique using tiny electrodes on the brain may help people with Parkinson’s disease.
For the first time, a treatment for Parkinson’s disease may actually help stop its progression.
In new research presented at the Congress of Neurological Surgeons this month, deep brain stimulation (DBS) was shown to have significant beneficial effects when utilized in people earlier than previously believed.
“DBS is the first therapy to show disease-modifying effect — it can actually slow down cardinal features of Parkinson’s. There has been no therapy, drug or device that has ever been able to do that,” said Dr. Peter Konrad, a professor of neurological surgery and biomedical engineering at Vanderbilt University, in a press statement.
Konrad and his fellow researchers initially published their findings in the journal Neurology.
The research essentially presents two novel findings related to the use of DBS for Parkinson’s disease.
First, DBS can potentially be implemented earlier than current indications. Normally, DBS is reserved for people with mid- to late-stage Parkinson’s, when standard medication therapies are less effective.
Second, DBS can also slow progression of the disease and particularly one of Parkinson’s hallmark features: tremor.
In the study, researchers enrolled 28 people with Parkinson’s disease between the ages of 50 and 75 who had been taking medications for the disease. The group was divided into two: one that only took medication and one that took medication as well as received DBS.
At regular intervals, including the start of the trial, both groups stopped taking medication (and DBS) for one week — a “washout” period designed to capture a snapshot of the baseline of motor-related symptoms of Parkinson’s. Doctors will typically use a scoring system, such as the Unified Parkinson’s Disease Rating Scale, to assign values to various symptoms in order to generate an overall rating for the severity of the disease.
At the end of the two-year period, participants again went through a washout period. Those in the group that had only been taking medication showed significantly worse scores for the severity of resting tremor, while those who received both DBS and medication showed minimal change.
The group taking only medication also had a 2.6 times higher risk of tremor worsening than the group that received DBS.
A hallmark of Parkinson’s disease is that it progressively gets worse. The tremor will typically start in just a single limb and gradually spread to others. But in this study, the DBS group’s results were contrary to this conclusion.
In the DBS group, the number of affected limbs essentially stayed the same, while the number affected in the medication group doubled — meaning the disease had followed its typical course by spreading to another limb.
Dr. David Weintraub, director of functional neurosurgery at Northwell Health and assistant professor of neurosurgery at the Zucker School of Medicine at Hofstra Northwell, points out that even when DBS was inactivated for a week, the benefit remained.
“So that’s quite significant,” he said. “There seems to be benefit even early in the disease course, and it’s suggestive of a delay in the progress of one important component of Parkinson’s disease.”
Parkinson’s disease is a progressive neurodegenerative disease with no current cure. About 1 million people are expected to be living with the disease in the United States by 2020, with about 60,000 receiving the diagnosis every year.
Parkinson’s is easily identified through a cluster of motor features, including resting tremor, bradykinesia (moving slowly), and postural instability (balance problems).
While the results of the research are very exciting, Weintraub points out that they only deal with one of what are several key features of the disease.
“Most of the other scores were similar between the two groups. They were not significantly different, so that’s a limitation,” said Weintraub, who wasn’t affiliated with the study.
“That will temper a bit of the enthusiasm for this, but it is a very significant finding, because resting tremor is often a feature that is very hard to control with medication and that DBS is very good at controlling,” he said.
Early on, Parkinson’s symptoms are generally managed well enough through medication alone. This is one reason why DBS isn’t prescribed until later.
There are also risks associated with DBS that need to be considered by both doctors and patients. DBS is a surgical procedure in which electrodes are passed through small holes in the skull onto the brain. Serious complications can include bleeding of the brain, stroke, coma, infection, and even death.
“In order to take a very bold step of doing an open surgical procedure to treat this, we have to have confidence that we are going to help people more than they are going to be helped just by taking a medication,” Weintraub said.
The success of the trial has already opened doors for further research that could possibly change the indications for DBS and allow doctors to prescribe it earlier.
The U.S. Food and Drug Administration (FDA) has already granted approval for a much larger study of 300 participants across the United States. It will further examine whether or not early use of DBS is neuroprotective.
If the trial is successful, the FDA would change their current labeling indications of DBS to allow doctors to prescribe it in the early stages of Parkinson’s — a step researchers say could revolutionize treatment.
“This is an important step towards pushing the boundaries of when we can justify doing this surgery and making this intervention that will potentially have a huge impact on the hundreds of thousands of people with Parkinson’s disease who are in their early stage,” Weintraub said.
A new small study found evidence that deep brain stimulation (DBS) may help stop the progression of Parkinson’s disease symptoms.
Researchers think DBS may help people with later-stage Parkinson’s. In these people, medication may not mitigate or stop serious symptoms.