L-dopa for Parkinson's Disease

Deep Brain Stimulation (DBS) of the Subthalamic nucleus (STN) is an established treatment for patients with advanced Parkinson's disease (PD). STN DBS improves dopaminergic drug-responsive motor symptoms, thus allowing a reduction of post-operative drug dose. However, a considerable variation in the extent of dopaminergic drug reduction has been reported, with values ranging from 20% to 100%. Both L-dopa and DAs 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. Aim of our study is to compare the efficacy and the tolerability of L-dopa monotherapy versus DAs monotherapy after STN DBS over a 3-month follow up period. This study is a prospective, single blind parallel trial comparing L-dopa monotherapy and DAs monotherapy after STN DBS. Patients will be enrolled in pairs, with one patient randomly assigned to L-dopa monotherapy and the other to DA monotherapy after STN DBS (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 3-month follow up visit after surgery. In spite of an improvement of the motor condition many patients develop apathy and depression following surgery ("Neurosurgery in Parkinson's disease: the doctor is happy, the patient less so"). This study will shed light on the best way to manage patients after STN procedure, thus contributing to a further improvement of the surgical outcome in a population of young and motivated patients (those commonly receiving STN DBS), eventually bringing them closer to a normal personal and social life. 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.