Citations

Background Psychiatric disorders are increasingly contributing to global disability. Despite advances in conservative management, the prevalence of treatment-resistant cases remains high. Meanwhile, neurosurgery for psychiatric disorders (NPD) remains underused, largely due to strict regulations and historical concerns, particularly those related to neuropsychological side effects (NPSE). Objective To address this issue, we conducted a systematic review with meta-analysis to compare NPSE associated with radiofrequency ablative NPD to those observed in neuro-oncological, neurovascular and epilepsy surgeries. Methods PubMed, Embase and LILACS databases were searched in April 2024 for articles published in English/Spanish from 1990 to 2022, following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Results A total of 48 articles with 2678 participants were included. The frequency of transient and permanent NPSE in the NPD group ranged from 0.94% to 11.50% and 0.94% to 2.03%, respectively, comparable to the other surgical groups (epilepsy: 0.31–11.70%; vascular: 0.52–22.90%; oncology: 0.94–17.60% for transient NPSE; epilepsy: 0.31–12%; vascular: 0.40–1.96% and oncology: 0.84–1.48% for permanent NPSE). Regarding permanent NPSE, arguably the most critical consideration, the NPD group showed better outcomes in memory, language and social cognition than the epilepsy group, but worse outcomes in executive and perceptual-motor functions. Compared with the vascular group, the NPD group had better executive function but worse complex attention. Finally, the NPD group had fewer permanent deficits than the oncology group in executive function, complex attention and perceptual-motor domains, although language performance was lower. Conclusions Contemporary NPD apparently carries a similar risk of NPSE as other conventional neurosurgical procedures, challenging misconceptions and this unjustified barrier to its broader use.

Abstract Clinical interventions and neuroimaging in the subcortex require anatomical definitions that exceed the resolution and anatomical detail of currently available deformable brain atlases. Here, we introduce a high-resolution human brain atlas comprising 95 manually segmented grey and white matter structures as well as 82 white matter tracts compiled from a multitude of resources including ex-vivo MRI, histology, fibre dissections, and neuroanatomy textbooks. The atlas is defined at an isotropic resolution of 100 μm and can be precisely deformed to individual subject brain anatomy. By providing precise definitions of both grey and white matter structures within and around the basal ganglia, thalamus, subthalamus, midbrain and cerebellum, the atlas provides a foundational resource for stereotactic surgery and subcortical brain imaging research, as well as for development of next-generation neuromodulation strategies.

Background Deep brain stimulation (DBS) has been investigated for patients with drug-resistant epilepsy who are not candidates for resective surgery. Because different types of epilepsy involve distinct brain networks, numerous DBS targets have been explored, yet a comprehensive synthesis is lacking. Methods To provide a comprehensive overview of this expanding literature, we conducted a systematic review of studies for DBS in epilepsy, including case series, prospective and retrospective studies. We collected data on surgical targets, individual disease characteristics, outcomes and precise electrode placements. DBS electrode coordinates were gathered into a common template space and related to clinical outcomes. Results We included 124 studies, corresponding to 1210 patients and 20 distinct surgical targets. While the anterior (ANT) and centromedian (CM) nuclei of the thalamus remain the most studied, we also review less commonly used targets that show promise for specific forms of epilepsy and may warrant further investigation. Substantial variability in targeting strategies and electrode placement was observed within each of the target regions. Importantly, significant relationships between stimulation location and outcomes were identified for ANT-DBS and CM-DBS. For ANT-DBS, shorter distance to the mammillothalamic tract junction was associated with greater seizure reduction on both study-level and patient-level analyses (r=−0.55, p<0.001 and r=−0.51, p<0.001, respectively). For CM-DBS, localisation effects may be dependent on the form of epilepsy, with stimulation of the parvocellular CM being associated with better outcomes in generalised epilepsy. Conclusions Our results emphasise the importance of accurate targeting in DBS for epilepsy. Our database and atlas of DBS targets are made publicly available, potentially serving further meta-analytical work. PROSPERO registration number CRD420250649304.

Abstract Deep brain stimulation (DBS) of the subthalamic nucleus improves motor symptoms in patients with Parkinson’s disease. Using functional MRI, optimal DBS response networks have been characterized. However, neural activity associated with Parkinsonian symptoms is magnitudes faster than what can be resolved by this method. Although both spatial and temporal domains of these networks appear crucial, no single study has yet investigated both domains simultaneously. Here, we aimed at closing this gap by analysing electrophysiological data from a total of n = 127 hemispheres. Using subthalamic local field potentials that were recorded concurrently alongside whole-brain magnetoencephalography in a multi-centre cohort of patients who underwent subthalamic DBS for the treatment of Parkinson’s disease (n = 100 hemispheres), we analysed the DBS response network in both spatial and temporal domains. In every cortical vertex, cortico-subthalamic coupling was correlated with stimulation outcomes. This network spatially resembled functional MRI-based findings (R = 0.40, P = 0.039) and explained significant amounts of variance in clinical outcomes (βstd = 0.30, P = 0.002), whereas theta–alpha and low beta coupling did not show significant associations with DBS response (theta–alpha: βstd = −0.02, P = 0.805; low beta: βstd = −0.08, P = 0.426). The ‘optimal’ high beta coupling map was robust when subjected to various cross-validation designs (10-fold cross-validation: R = 0.29, P = 0.009; split-half design: R = 0.31, P = 0.026) and was able to predict outcomes across DBS centres [R = 0.74; P(1) = 8.9 × 10−5]. We identified a DBS response network that resembles the previously defined MRI network and operates in the high beta band. Maximal connectivity to this network was associated with optimal DBS outcomes and was able to cross-predict clinical improvements across DBS surgeons and centres.

AbstractBackgroundStimulation‐induced dyskinesias (SID) from deep brain stimulation (DBS) of the subthalamic nucleus (STN) and globus pallidus internus (GPi) are uncommon; however, they are increasingly recognized. Once considered transient and indicative of effective neuromodulation, SID are now seen as potential therapy‐limiting side effects, akin to internal capsule activation. The mechanism and anatomical basis for SID remain poorly understood.MethodsWe conducted a retrospective study of individuals with Parkinson's disease with STN or GPi DBS who experienced SID in the dopaminergic medication OFF state during the monopolar review 1‐month post‐implantation.ResultsWe analyzed 137 monopolar stimulation observations (105 GPi, 32 STN). In the GPi cohort, discriminative fiber tract analysis showed a strong association between SID and the modulation of subthalamo‐pallidal fibers. This correlation was confirmed using leave‐one‐out and five‐fold cross‐validation. We further validated this model by predicting SID in independent STN and GPi cohorts, with the GPi‐based model accounting for significant variance in SID occurrence in both cohorts.ConclusionsSID from STN or GPi DBS likely shares a common pathway via subthalamo‐pallidal connectivity. DBS modulation of these fibers correlates with SID, as confirmed by multiple cross‐validation methods. These findings suggest that the fibers are part of a more extensive and yet‐to‐be‐fully‐characterized dyskinesia network. © 2025 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Objective With a growing appreciation for interindividual anatomical variability and patient‐specific brain connectivity, advanced imaging sequences offer the opportunity to directly visualize anatomical targets for deep brain stimulation (DBS). The lack of quantitative evidence demonstrating their clinical utility, however, has hindered their broad implementation in clinical practice. Methods Using fast gray matter acquisition T1 inversion recovery (FGATIR) sequences, the present study identified a thalamic hypointensity that holds promise as a visual marker in DBS. To validate the clinical utility of the identified hypointensity, we retrospectively analyzed 65 patients (26 female, mean age = 69.1 ± 12.7 years) who underwent DBS in the treatment of essential tremor. We characterized its neuroanatomical substrates and evaluated the hypointensity's ability to predict clinical outcome using stimulation volume modeling and voxelwise mapping. Finally, we determined whether the hypointensity marker could predict symptom improvement on a patient‐specific level. Results Anatomical characterization suggested that the identified hypointensity constituted the terminal part of the dentatorubrothalamic tract. Overlap between DBS stimulation volumes and the hypointensity in standard space significantly correlated with tremor improvement ( R 2 = 0.16, p = 0.017) and distance to hotspots previously reported in the literature ( R 2 = 0.49, p = 7.9e‐4). In contrast, the amount of variance explained by other anatomical atlas structures was reduced. When accounting for interindividual neuroanatomical variability, the predictive power of the hypointensity increased further ( R 2 = 0.37, p = 0.002). Interpretation Our findings introduce and validate a novel imaging‐based marker attainable from FGATIR sequences that has the potential to personalize and inform targeting and programming in DBS for essential tremor. ANN NEUROL 2022;91:613–628