Levodopa Versus Dopamine Agonist after Deep Brain Stimulation in Parkinson's Disease
Rapid Response Innovation Awards, 2014
Study Rationale: † † † † † † † † ††
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an established treatment for patients with advanced Parkinson's disease (PD). STN DBS improves motor symptoms, thus allowing a reduction of drug dose. However, most studies described the pharmacological therapy exclusively in terms of levodopa equivalents, with no further specification of the different agents used. Both levodopa and dopamine agonists can be used, however, there are no formal studies examining which type of antiparkinsonian medication may be more effective and/or better tolerated following STN DBS.
Our hypothesis is that dopamine agonists may be more efficacious than levodopa in treating non-motor symptoms after surgery (e.g., apathy and nocturnal restlessness), thus further improving quality of life following surgery. On the other hand, in comparison to levodopa, dopamine agonists may be associated with more side effects (e.g., impulse control disorders and mania) and less effective motor control.
This study is a prospective, single-blind parallel trial comparing levodopa monotherapy and dopamine agonist monotherapy after STN DBS. Patients will be enrolled in pairs, with one patient randomly assigned to one therapy and on to the other (20 patients for each study arm). Treatment assignment will be unmasked for the patient, but will be blinded for the neurologist programming DBS and evaluating the patient. Another neurologist will be in charge of medication adjustments. Primary outcome is the change in severity of non-motor symptoms as assessed by the Non-motor Symptoms Scale (NMSS) at a three-month follow-up visit after surgery. †
Impact on Diagnosis/Treatment of Parkinsonís Disease: † † † † † ††
In spite of an improvement of motor conditions, many patients develop apathy and depression following DBS surgery. This study will shed light on the best way to manage patients after STN DBS procedure, thus contributing to a further improvement of the surgical outcome.
Next Steps for Development:
Results of our study may provide new insights in the management of advanced PD after STN DBS, further leading to development of future larger trials.
INTERIM PROGRESS REPORT
This study is recruiting volunteers. Learn more at†https://foxtrialfinder.michaeljfox.org/trial/4016/.
Associate Professor, Department of Medicine, Division of Neurology at University of Toronto, Toronto Western Hospital
Location: Toronto, Ontario, Canada