A Functional Network Target for Tic Reduction During Thalamic Stimulation for Tourette Syndrome

It is unclear which functionally connected networks need to be modulated via DBS to obtain optimal tic reduction in Tourette Syndrome (TS). We assessed treatment response of 15 patients with TS undergoing thalamic DBS six and twelve months postoperatively. For each time point, functional connectivity maps seeding from stimulation sites were calculated based on a normative functional connectome. Resulting maps were analyzed in a voxel-wise mixed model for repeated measurements to identify patterns of connectivity associated with tic reduction. Available are the raw map, where each voxel contains the t-value derived from the linear mixed effect model. An additional map that is limited to voxels with a p <0.05 is also provided

Progress and challenges in deep brain stimulation for obsessive-compulsive disorder

This narrative review summarizes the recent literature on deep brain stimulation for treatment resistant obsessive-compulsive disorder highlighting both progress and challenges of this novel treatment. Common targets of psychiatric deep brain stimulation involve both white matter trajectories (anterior limb of the internal capsule, inferior thalamic peduncle, and medial forebrain bundle) and grey matter subcortical nuclei (nucleus accumbens, nucleus subthalamicus, and bed nucleus of the stria terminalis) each of which have been reported with a relevant beneficial effect on obsessive-compulsive symptoms. The mechanisms of action are only partially understood but increasing evidence points towards network effects involving the prefrontal cortex, the striatum and possibly anxiety-related anatomical structures. Deep brain stimulation is a promising therapeutical technique for otherwise treatment refractory patients, but many major issues are unresolved and thorough investigations are needed. Relevant topics for future investigations include treatment predictors and therapeutical augmentation. An international registry of patients treated with deep brain stimulation could improve our understanding of adverse events and target specific effects. In order to step forward, researchers must face inconvenient questions and outperform the status quo of clinical research in this field. (C) 2018 Elsevier Inc. All rights reserved

Target-Specific Effects of Deep Brain Stimulation for Tourette Syndrome: A Systematic Review and Meta-Analysis

Background: Extended research has pointed to the efficacy of deep brain stimulation (DBS) in treatment of patients with treatment-refractory Tourette syndrome (TS). The four most commonly used DBS targets for TS include the centromedian nucleus-nucleus ventrooralis internus (CM-Voi) and the centromedian nucleus-parafascicular (CM-Pf) complexes of the thalamus, and the posteroventrolateral (pvIGPi) and the anteromedial portion of the globus pallidus internus (amGPi). Differences and commonalities between those targets need to be compared systematically. Objective: Therefore, we evaluated whether DBS is effective in reducing TS symptoms and target-specific differences. Methods: A PubMed literature search was conducted according to the PRISMA guidelines. Eligible literature was used to conduct a systematic review and meta-analysis. Results: In total, 65 studies with 376 patients were included. Overall, Yale Global Tic Severity Scale (YGTSS) scores were reduced by more than 50 in 69% of the patients. DBS also resulted in significant reductions of secondary outcome measures, including the total YGTSS, modified Rush Video-Based Tic Rating Scale (mRVRS), Yale-Brown Obsessive Compulsive Scale (YBOCS), and Becks Depression Inventory (BDI). All targets resulted in significant reductions of YGTSS scores and, with the exception of the CM-Pf, also in reduced YBOCS scores. Interestingly, DBS of pallidal targets showed increased YGTSS and YBOCS reductions compared to thalamic targets. Also, the meta-analysis including six randomized controlled and double-blinded trials demonstrated clinical efficacy of DBS for TS, that remained significant for GPi but not thalamic stimulation in two separate meta-analyses. Conclusion: We conclude that DBS is a clinically effective treatment option for patients with treatment-refractory TS, with all targets showing comparable improvement rates. Future research might focus on personalized and symptom-specific target selection.</p

Open-label trial of anterior limb of internal capsule-nucleus accumbens deep brain stimulation for obsessive-compulsive disorder: insights gained

Background For more than 15 years, deep brain stimulation (DBS) has served as a last-resort treatment for severe treatment-resistant obsessive-compulsive disorder (OCD). Methods From 2010 to 2016, 20 patients with OCD (10 men/10 women) were included in a single-centre trial with a naturalistic open-label design over 1 year to evaluate the effects of DBS in the anterior limb of the internal capsule and nucleus accumbens region (ALIC-NAcc) on OCD symptoms, executive functions, and personality traits. Results ALIC-NAcc-DBS significantly decreased OCD symptoms (mean Yale-Brown Obsessive Compulsive Scale reduction 33%, 40% full responders) and improves global functioning without loss of efficacy over 1 year. No significant changes were found in depressive or anxiety symptoms. Our study did not show any effect of ALIC-NAcc-DBS on personality traits or executive functions, and no potential outcome predictors were identified in a post hoc analysis. Other than several individual minor adverse events, ALIC-NAcc-DBS has been shown to be safe, but 35% of patients reported a sudden increase in anxiety and anhedonia after acute cessation of stimulation. Conclusions We conclude that ALIC-NAcc-DBS is a well-tolerated and promising last-resort treatment option for OCD. The cause of variability in the outcome remains unclear, and the aspect of reversibility must be examined critically. The present data from one of the largest samples of patients with OCD treated with DBS thus far support the results of previous studies with smaller samples