Access to the latest research — for scientists and people living with PD alike — in PDF's new scientific journal.
Statement by the Parkinsonís Disease Foundation on the New Study on the Efficacy and Safety of Deep Brain Stimulation for Parkinsonís Disease
New York, NY - Jan 06 2009
The article released today in Journal of the American Medical Association (JAMA) concerns the largest and most comprehensive investigation ever conducted on the use of surgery for advanced Parkinson’s disease (PD). (Please read below to see the story as reported in the media earlier today). Comparing the surgical technique known as deep brain stimulation (DBS) with the best-available medical therapy – medication adjustment performed by specialists in Parkinson’s disease - the study confirms convincingly that DBS substantially increases a person’s “on time” – that is, the amount of time during the day when a person with Parkinson’s is at maximum function and mobility - by almost five hours a day.
Notably, the study also shows that this improvement holds for people with Parkinson’s over 70 years of age as well as for those who are younger. However, the study also documents a higher number of adverse events for the individuals who underwent DBS, including confusion, headache, speech problems, gait disturbances and falling. Most of these complications were temporary, and resolved by the six-month follow-up point.
The results of this large study confirm the findings of prior, smaller studies, and reinforce the current standards of medical practice. DBS remains the most significant advance in the treatment of PD over the last decade, but many questions remain unanswered, including the optimal timing of surgery and the long term ( > five years) outcome of DBS. As for all major interventions, the potential benefits of surgery must be carefully weighed against the possible risks, taking into account the unique needs and circumstances of the individual.
Christopher Goetz, M.D., Chair of the Parkinson’s Disease Foundation’s Medical Policy Committee, had the following reaction to the new report:
“This study is important because it provided a comparison between two groups of people, one of which underwent deep brain stimulation and another which instead received the best available medical therapies. The follow-up time of six months is short, but typical of usual evaluations for new drugs. The amount of increased “ON time” in the surgically treated group was substantial (almost five hours), which is much greater than that demonstrated with new medications that have been developed for the improvement of Parkinson’s motor fluctuations. The disturbing reality; however, is that serious adverse events were much higher in the group that received DBS than in the group that received the best available medical therapies. Therefore, clinicians and patients must weigh the risks of surgery carefully as they consider surgery or continued medical treatment for Parkinson's disease.”
To learn more about Deep Brain Stimulation, you can read PDF's educational booklet, Deep Brain Stimulation for Parkinson's Disease, written by Blair Ford, M.D.
The Parkinson’s Disease Foundation (PDF) is a leading national presence in Parkinson’s disease research, education and public advocacy. We are working for the nearly one million people in the US who live with Parkinson’s by funding promising scientific research to find the causes of and a cure for Parkinson's while supporting people with Parkinson’s, their families and caregivers through educational programs and support services. Since its founding in 1957, PDF has funded over $75 million worth of scientific research in Parkinson’s disease, supporting the work of leading scientists throughout the world.
A study of brain-stimulation technology for patients with advanced Parkinson's Disease showed treatment helped battle symptoms better at six months than drugs and therapy did, but also caused many more adverse events such as infections.
The study, released Tuesday by the Journal of the American Medical Association, is one of the first to measure this technology against the best- available medical treatment. Participants received deep-brain stimulation systems made by Medtronic Inc. (MDT), which won Food and Drug Administration approval to sell the technology for Parkinson's in 2002.
The study was financially backed by the Department of Veterans Affairs, the National Institute of Neurological Disorders and Stroke and Medtronic.
Parkinson's is a chronic and progressive movement disorder that can cause tremors, issues with balance, speech and movement and several other symptoms. It tends to strike older people, and there are currently nearly one million Americans with the disease, according to the Parkinson's Disease Foundation.
Medication can help, although not all patients respond and medication can lose effectiveness while causing more side effects over time, according to researchers involved with this study. Doctors have also been using stimulation devices to treat patients for the last decade or so. Medtronic's system was approved for a different use in 1997, but doctors can choose to use devices for so-called off-label purposes.
The technology involves implanting a pacemaker-like device in the chest and then running wires deep into patient's brain, where energy is used to stimulate areas linked to movement issues. Medtronic's system today is approved for essential tremor, Parkinson's and another movement disorder called dystonia, and the company is aiming to win approval for epilepsy, depression and obsessive- compulsive disorder.
Total costs to get a system implanted are about $60,000.
Neuromodulation is small but growing business at Medtronic, which is most well-known for heart devices. The company's neurological implants business pulled in $1.07 billion in revenue in the company's most recent fiscal year, which ended in late April 2008, representing 8% of the overall sales tally. In addition to deep-brain stimulation, the neurological implants include nervous system stimulation systems for chronic pain and drug-infusion systems.
Medtronic is thus far the only company with an approved deep-brain stimulation system, although St. Jude Medical Inc. (STJ) has a device and plans to seek approval to treat multiple disorders as well.
The study in question enrolled 255 patients at 13 hospitals who were then divided randomly between two main groups. In one group, patients got the Medtronic device implanted in one of two different areas of the brain, while patients in the other group were treated with the best-available medical therapy, including drugs and physical therapy.
The goal was to try to give patients more "on time," or time when treatment is effective and motor-function problems abate. After six months, patients with the brain implants gained an average of 4.6 hours per day of on time, versus no gains at all in the medical-therapy group. Patients with deep-brain stimulation had improved motor function and scored significantly better on a quality-of-life measure.
These gains were balanced by much higher rate of adverse events - at 40% vs. 11% - for patients with the implants. Common complications included infections at the surgical site, often where the power generator is implanted in the chest, which is common with deep brain stimulation. There were also reports of psychiatric disorders and a higher rate of falls, among other issues.
The falls were surprising, and may be linked to the fact that patients felt much better and did too much physically, said Dr. Frances M. Weaver, lead author on the study and also deputy director of the Midwest Center for Health Services and Policy Research at the Hines VA Hospital near Chicago.
The study's findings show "you really have to consider the risks and the benefits" of this therapy for each patient, she said in an interview. Serious events were resolved in 99% of cases within six months.
In one potentially important finding, researchers found the rate of serious adverse events from deep-brain stimulation weren't markedly different among older patients. Older and younger patients also saw similar benefits from the therapy.
The age-related data might prove helpful because there is some bias today against using the technology in older patients for fear of complications and fewer benefits, according to Weaver and William J. Marks Jr., another study investigator.
Marks, who directs the Parkinson's Disease Center at the San Francisco Veterans Affairs Medical Center, and is a Medtronic consultant, said some centers today won't give this therapy to patients over age 70. One quarter of patients in this study were over that age, however.
By Jon Kamp, Dow Jones Newswires; 617-654-6728; firstname.lastname@example.org
Source Date: Jan 06 2009
Source Publication: CNNMoney.com
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