While deep brain stimulation has gained recognition by referring physicians as a treatment for Parkinson’s disease and other movement disorders, just half of the patients they recommend are appropriate candidates to begin this relatively new therapy immediately, researchers at Cedars-Sinai Medical Center in Los Angeles and The Mount Sinai Medical Center in New York say.
They looked back to a 2004 study, which found that just 5 percent of referrals then were good candidates; they compared their new figures and surmised that referring physicians have increased their awareness and acceptance of deep brain stimulation, a therapy in which electrical leads, linked to a control device, are surgically and precisely implanted to modulate defective nerve signals in the brain to calm symptoms of Parkinson’s and other movement disorders.
But physicians still often refer patients for this therapy before other treatment options have been exhausted or because they have unrealistically high expectations for it, said Michele Tagliati, MD, director of the Movement Disorders Program at Cedars-Sinai’s Department of Neurology. He is senior author of an Aug. 11 Archives of Neurology article and an expert in device programming, which fine-tunes stimulation for individual patients.
Of 197 patients referred for evaluation for deep brain stimulation, 50 percent were found to be good candidates for immediate therapy, 25 percent were possible future candidates and 24 percent were poor candidates because of other neurological or medical conditions. Analyzing the referral sources – movement disorder specialists, primary care physicians, general neurologists, other physicians and patients – the researchers found that movement disorder specialists referred more patients and most were good therapy candidates.
Over the four-year study period, which ended in late 2009, researchers noted that the number of patients referred for DBS therapy at earlier stages of the disease increased.
“The study does not address this change specifically and we have no proof, but we speculate that doctors became more liberal in sending patients for surgery for deep brain stimulation,” Tagliati said. “Maybe they are accepting this therapy more and sending patients earlier for it instead of at the very end stage of disease. While doctors may be sending some patients too early to be treated immediately with DBS therapy, it’s better to see these patients too early than too late. As long as they’re evaluated in a responsible, reputable movement disorders center, they can be reevaluated months or even years later and have the surgery appropriately timed. It isn’t always clear exactly what is the right time for this therapy, but especially for Parkinson’s disease, if the patient is amenable to medication changes, it is not appropriate to jump to the surgery right away.”
Deep brain stimulation was approved by the Food and Drug Administration for essential tremor in 1997, Parkinson’s disease in 2002, dystonia in 2003 and extreme cases of obsessive-compulsive disorder in 2009.
Tagliati has received teaching honoraria from Medtronic Inc., Allergan, BoehringerIngelheim, Glaxo and Novartis and consulting fees from St. Jude/Advanced Neuromodulation System, Inc., all of which were unrelated to this study.
Archives of Neurology: “Referring Patients for Deep Brain Stimulation,” Aug. 11, 2011.