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Background Objective Methods Results Conclusions Impulse control disorders (ICD) are common side effects of dopaminergic treatment in Parkinson's disease (PD). Whereas some studies show a reduction in ICD after subthalamic nucleus deep brain stimulation (STN‐DBS), others report worsening of ICD or impulsivity.The aim was to study ICD in the context of STN‐DBS using an objective measure of decision‐making.Ten PD patients performed an effort‐based decision‐making task alongside neuropsychiatric and cognitive evaluation before and 4 months after STN‐DBS. Further, 33 PD patients underwent the same experimental procedures just once after an average 40 months of chronic STN‐DBS. Participants were examined preoperatively in the medication on state and postoperatively in the medication on/stimulation ON state. Mixed linear models were used to assess the impact of ICD and STN‐DBS on acceptance rate and decision time in the task while controlling for motor symptom burden, cognitive measures, and dopaminergic medication.Results revealed an increased willingness to exert high levels of effort in return for reward in patients with ICD, but acceptance rate was not modulated by chronic STN‐DBS. Further, ICD, cognitive processing speed, and STN‐DBS were all identified as positive predictors for faster decision speed. ICD scores showed a tendency to improve 4 months after STN‐DBS, without an increase in apathy scores.Chronic STN‐DBS and ICD facilitate effort‐based decision‐making by speeding up judgment. Furthermore, ICD enhances the willingness to exert high levels of effort for reward. Both STN‐DBS and dopaminergic medication impact motivated behavior and should be titrated carefully to balance neuropsychiatric symptoms. [ABSTRACT FROM AUTHOR]

Background: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) and globus pallidus internus (GPi) is an accepted therapy for Parkinson's disease (PD) with disabling motor complications. For elderly patients with poorer cognition and postural instability, GPi has been proposed as the preferable DBS target based on expert opinion, arguing GPi‐DBS may be less complicated by depression, apathy, worsened verbal fluency, and executive dysfunction, resulting in greater improvement in quality of life (QoL). However, data supporting such patient‐tailored approach are lacking. Objectives: The aims were to analyze whether the DBS target influences QoL in a PD cohort and a matched subgroup of frail patients with poor cognitive status and reduced postural stability, and whether other factors affect the QoL outcomes. Methods: In this retrospective study, we analyzed a single‐center cohort of 138 PD patients who received bilateral STN‐DBS (117) or GPi‐DBS (21) using the mentioned approach for target selection. All patients underwent standardized clinical evaluations of motor‐ and nonmotor signs as well as QoL before and 1 year after surgery. Results: DBS of both targets improved motor signs, dyskinesias, and pain. QoL improved without significant difference between the targets, but with a trend for greater improvement across all QoL domains in favor of the STN, even in an STN subgroup matched to the GPi group. Conclusion: Our results contradict the prevailing belief that GPi‐DBS is superior in frail PD patients with cognitive decline and postural instability, questioning the proposed patient‐tailored approach of DBS target selection. Further studies are needed for a data‐driven approach. [ABSTRACT FROM AUTHOR]

Background: Directional deep brain stimulation (DBS) allows for steering of the stimulation field, but extensive and time‐consuming testing of all segmented contacts is necessary to identify the possible benefit of steering. It is therefore important to determine under which circumstances directional current steering is advantageous. Methods: Fifty two Parkinson's disease patients implanted in the STN with a directional DBS system underwent a standardized monopolar programming session 5 to 9 months after implantation. Individual contacts were tested for a potential advantage of directional stimulation. Results were used to build a prediction model for the selection of ring levels that would benefit from directional stimulation. Results: On average, there was no significant difference in therapeutic window between ring‐level contact and best directional contact. However, according to our standardized protocol, 35% of the contacts and 66% of patients had a larger therapeutic window under directional stimulation compared to ring‐mode. The segmented contacts warranting directional current steering could be predicted with a sensitivity of 79% and a specificity of 57%. Conclusion: To reduce time required for DBS programming, we recommend additional directional contact testing initially only on ring‐level contacts with a therapeutic window of less than 2.0 mA. [ABSTRACT FROM AUTHOR]

Background: Effects of subthalamic nucleus deep brain stimulation (STN-DBS) on neuropsychiatric symptoms of Parkinson's disease (PD) remain debated. Sensor technology might help to objectively assess behavioural changes after STN-DBS. Case presentation: 5 PD patients were assessed 1 before and 5 months after STN-DBS with the Movement Disorders Society Unified Parkinson's Disease Rating Scale part III in the medication ON (plus postoperatively stimulation ON) condition, the Montreal Cognitive Assessment, the Questionnaire for Impulsive-Compulsive Behaviors in Parkinson's Disease Rating Scale present version, the Hospital Anxiety and Depression Scale and the Starkstein Apathy Scale. Steps taken per hour, nighttime spent in bed and time spent outside were monitored with a smartwatch and ambient sensors placed in patient homes for an average of 20 days pre- and postoperatively. Postoperative improvement in ICDs and concomitant anxious-depressive symptoms was observed in 3 patients and was accompanied by a decrease in steps taken per hour, as well as an increase in nighttime spent in bed. In the two patients without baseline ICDs, mild anxiety and apathy improved postoperatively, and no new neuropsychiatric symptoms occurred. Steps taken per hour did not decrease in these cases and nighttime spent in bed improved in one of the patients, but decreased in the other, who had experienced pain during OFF-phases at night before STN-DBS. Conclusion: Changes in neuropsychiatric symptoms are associated with distinct activity patterns after STN-DBS, and wearable and ambient sensors may aid to capture those gradual shifts in behavior. [ABSTRACT FROM AUTHOR]

Treatment-resistant depression is a severe form of major depressive disorder and deep brain stimulation is currently an investigational treatment. The stimulation's therapeutic effect may be explained through the functional and structural connectivities between the stimulated area and other brain regions, or to depression-associated networks. In this longitudinal, retrospective study, four female patients with treatment-resistant depression were implanted for stimulation in the nucleus accumbens area at our center. We analyzed the structural and functional connectivity of the stimulation area: the structural connectivity was investigated with probabilistic tractography; the functional connectivity was estimated by combining patient-specific stimulation volumes and a normative functional connectome. These structural and functional connectivity profiles were then related to four clinical outcome scores. At 1-year follow-up, the remission rate was 66%. We observed a consistent structural connectivity to Brodmann area 25 in the patient with the longest remission phase. The functional connectivity analysis resulted in patient-specific R-maps describing brain areas significantly correlated with symptom improvement in this patient, notably the prefrontal cortex. But the connectivity analysis was mixed across patients, calling for confirmation in a larger cohort and over longer time periods. [ABSTRACT FROM AUTHOR]

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for advanced Parkinson's disease. Stimulation of the hyperdirect pathway (HDP) may mediate the beneficial effects, whereas stimulation of the corticospinal tract (CST) mediates capsular side effects. The study's objective was to suggest stimulation parameters based on the activation of the HDP and CST. This retrospective study included 20 Parkinson's disease patients with bilateral STN DBS. Patient‐specific whole‐brain probabilistic tractography was performed to extract the HDP and CST. Stimulation parameters from monopolar reviews were used to estimate volumes of tissue activated and to determine the streamlines of the pathways inside these volumes. The activated streamlines were related to the clinical observations. Two models were computed, one for the HDP to estimate effect thresholds and one for the CST to estimate capsular side effect thresholds. In a leave‐one‐subject‐out cross‐validation, the models were used to suggest stimulation parameters. The models indicated an activation of 50% of the HDP at effect threshold, and 4% of the CST at capsular side effect threshold. The suggestions for best and worst levels were significantly better than random suggestions. Finally, we compared the suggested stimulation thresholds with those from the monopolar reviews. The median suggestion errors for the effect threshold and side effect threshold were 1 and 1.5 mA, respectively. Our stimulation models of the HDP and CST suggested STN DBS settings. Prospective clinical studies are warranted to optimize tract‐guided DBS programming. Together with other modalities, these may allow for assisted STN DBS programming. [ABSTRACT FROM AUTHOR]

Background: Although recently introduced directional DBS leads provide control of the stimulation field, programing is time-consuming.Objectives: Here, we validate local field potentials recorded from directional contacts as a predictor of the most efficient contacts for stimulation in patients with PD.Methods: Intraoperative local field potentials were recorded from directional contacts in the STN of 12 patients and beta activity compared with the results of the clinical contact review performed after 4 to 7 months.Results: Normalized beta activity was positively correlated with the contact's clinical efficacy. The two contacts with the highest beta activity included the most efficient stimulation contact in up to 92% and that with the widest therapeutic window in 74% of cases.Conclusion: Local field potentials predict the most efficient stimulation contacts and may provide a useful tool to expedite the selection of the optimal contact for directional DBS. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]