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Background: Effects of DBS on freezing of gait and other axial signs in PD patients are unclear.Objective: Secondary analysis to assess whether DBS affects these symptoms within a large randomized controlled trial comparing DBS of the STN combined with best medical treatment and best medical treatment alone in patients with early motor complications (EARLYSTIM-trial).Methods: One hundred twenty-four patients were randomized in the stimulation group and 127 patients in the best medical treatment group. Presence of freezing of gait was assessed in the worst condition based on item-14 of the UPDRS-II at baseline and follow-up. The posture, instability, and gait-difficulty subscore of the UPDRS-III, and a gait test including quantification of freezing of gait and number of steps, were performed in both medication-off and medication-on conditions.Results: Fifty-two percent in both groups had freezing of gait at baseline based on UPDRS-II. This proportion decreased in the stimulation group to 34%, but did not change in the best medical treatment group at 24 months (P = 0.018). The steps needed to complete the gait test decreased in the stimulation group and was superior to the best medical treatment group (P = 0.016). The axial signs improved in the stimulation group compared to the best medical treatment group (P < 0.01) in both medication-off and medication-on conditions.Conclusions: Within the first 2 years of DBS, freezing of gait and other axial signs improved in the medication-off condition compared to best medical treatment in these patients. © 2019 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Background: Parkinson's disease (PD) is frequently associated with behavioral disorders, particularly within the spectrum of motivated behaviors such as apathy or impulsivity. Both pharmacological and neurosurgical treatments have an impact on these impairments. However, there still is controversy as to whether subthalamic nucleus deep brain stimulation (STN-DBS) can cause or reduce impulsive behaviors.Objectives: We aimed to identify the influence of functional surgery on decision-making processes in PD.Methods: We studied 13 PD patients and 13 healthy controls. The experimental task involved squeezing a dynamometer with variable force to obtain rewards of various values under four conditions: without treatment, with l-dopa or subthalamic stimulation alone, and with both l-dopa and subthalamic stimulation. Statistical analyses consisted of generalized linear mixed models including treatment condition, reward value, level of effort, and their interactions. We analyzed acceptance rate (the percentage of accepted trials), decision time, and force applied.Results: Comparatively to controls, patients without treatment exhibited lower acceptance rate and force applied. Patients under l-dopa alone did not exhibit increased acceptance rate. With subthalamic stimulation, either with or without added l-dopa, all measures were improved so that patients' behaviors were undistinguishable from healthy controls'.Conclusions: Our study shows that l-dopa administration does not fully restore cost-benefit decision-making processes, whereas STN-DBS fully normalizes patients' behaviors. These findings suggest that dopamine is partly involved in cost-benefit valuation, and that STN-DBS can have a beneficial effect on motivated behaviors in PD and may improve certain forms of impulsive behaviors. © 2019 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]