Exploring Expanded Labeling for DBS for Parkinson's

FDA in October approved new labeling for Medtronic, Inc.’s deep brain stimulation (DBS) Therapy systems for Parkinson’s disease. The new expanded labeling has focused attention on Quality of Life and Motor Function Improvements associated with the therapy.

Data submitted to the FDA in support of the new labeling show a 21 percent improvement in Parkinson’s disease related quality of life with DBS compared to medication alone at six months and a 28 percent improvement in activities of daily living at six months compared to medication alone.

The data also show that DBS treatment provides added improvement in total motor function, including shaking, stiffness, and movement difficulties from Parkinson’s disease: 15 percent improvement with Medtronic DBS therapy vs. two percent with medication alone.

Additionally, the new labeling and the data establish long-term safety and efficacy for Medtronic DBS therapy for advanced Parkinson’s disease through 36 months, a development the company suggests will further support the already extensive access and insurance coverage for the therapy.

William Marks, MD, Professor of Neurology at the University of California, San Francisco, was an investigator in the VA/NINDS trial of DBS for Parkinson’s disease. He spoke with Practical Neurology about the new labeling and its clinical implications for neurologists.

What’s behind the new labeling for DBS for Parkinson’s?

Initial FDA clearance in 2002 of DBS for Parkinson’s disease made the treatment available to patients, but the initial labeling narrowly focused on basic motor outcomes and there was interest in further exploring the effects of treatment, suggests Dr. Marks. The labeling is now “more comprehensive,” he notes, and reflects what many neurologists— and patients—have seen in practice.

“The experience with DBS for Parkinson’s disease has been very similar to what we have seen with a lot of other treatments that have presented a paradigm shift,” Dr. Marks says. “It takes some time for the clinical evidence to accumulate to the tipping point where practicing neurologists would be aware of the treatment, understand the clinical benefits, and understand the patients who are candidates. The accumulated weight of evidence now is compelling for neurologists.”

Dr. Marks says there are three primary criteria for DBS candidates:

• The patient has been diagnosed with idiopathic Parkinson’s Disease.
• Motor symptoms, though still responsive to levodopa, are inadequately or inconsistently controlled by an optimized medication regimen.
• The patient is troubled by their motor symptoms.

The final criterion may be commonly overlooked. “Ask patients, ‘Are you satisfied with your motor symptom control provided by medication?’,” Dr. Marks urges. “If the answer is no, then DBS should be considered.”

What does the expanded labeling mean for clinical neurologists and the patients they treat?

In light of the new labeling and increased awareness of the basic criteria for use of DBS for Parkinson’s disease, clinical neurologists should be open to identifying potential candidates and, “give appropriate patients the opportunity to be evaluated by a DBS center,” Dr. Marks says.

“The key point is that neurologists need to be thinking one or two steps ahead,” Dr. Marks says. “Clinicians need to introduce the concept and provide some early education before the patient absolutely needs it.” Importantly, he says, clinicians should look to DBS whenever possible as an intervention to “maintain function rather than rescue the patient from severe disability.”

It can take substantial time for the patient to progress from becoming aware of and educated about DBS, being evaluated for their candidacy, and then going on to device implantation, Dr. Marks notes. If neurologists wait too long to make that referral, the patient risks continued deterioration and impaired quality of life.

Early education of the patient by the neurologist should focus on the concept of DBS being ‘a pacemaker for the brain’ and the potential benefits of DBS therapy, Dr. Marks notes. These include reduction in rigidity, bradykinesia, tremor, motor fluctuation, and dyskinesia. This results in improved daily function and quality of life, as highlighted in the updated labeling. The team at the DBS center can assist the referring neurologist in evaluating the patient in depth and explaining additional benefits and potential risks.