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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.

Introduction: Deep brain stimulation (DBS) is an established therapy that can significantly improve patients’ quality of life in several disorders. Besides its benefits, hardware-related problems including erosion and wound infections are well known problems. In the present series, we describe a novel phenomenon manifesting as denial for hardware-related skin erosion in patients with movement disorders benefiting from DBS in various targets.

Methods: Patients were collected from two large DBS cohorts over a period of 28 years. The skin erosion was identified upon the occasion of a routine follow-up with the patients apparently being unaware/not noticing its occurrence. Demographic, clinical, and operative data were analyzed. Additionally, the hardware-related skin erosion and its time of diagnosis, as well as the consecutive treatment, were registered.

Results: Overall, 5 patients were identified with denial for hardware-related skin erosion. Three were men; two were women. The mean age at surgery was 66 years (range, 54–78). Three patients had dystonia; 2 patients had Parkinson’s disease. DBS targets were the globus pallidus internus and various thalamic nuclei. All patients benefited markedly from chronic DBS (mean improvement of 76.7% according to the specific rating scales). The hardware-related skin erosion was diagnosed at a median follow-up of 18 months after DBS implantation (range, 5–264 months). Despite multiple surgical attempts at preservation, the neurostimulation system was ultimately explanted in 3 patients.

Conclusion: Denial toward hardware-related skin erosion in DBS, most probably denial, is a rare but potentially serious complication during chronic DBS.

Background: New sophisticated deep brain stimulation (DBS) systems enabling steering of current and aiming at improving further motor outcome and decreasing side effects have virtually replaced old omnidirectional systems, despite being more labor-intensive and expensive.

Objectives: The objective was to evaluate whether modern directional DBS resulted in better motor improvement compared to “old” omnidirectional DBS.

Methods: Publications on subthalamic nucleus (STN)-DBS from the “old” period were compared to modern publications, focusing on severity of motor symptoms at baseline and motor outcome at various intervals after surgery.

Results: Although patients from old DBS era had a more advanced disease at baseline than those treated with modern DBS hardware, they benefitted more from STN-DBS and showed a higher percentage decrease in dopaminergic medication.

Conclusions: The new directional DBS does not result in better motor outcome compared to the older omnidirectional DBS. However, it may, in some cases, contribute to decreasing some side effects of stimulation such as dysarthria.

Background: subperception (paresthesia-free) dorsal root ganglion (DRG) stimulation is increasingly used for focal neuropathic pain, but sham-controlled evidence remains limited. We conducted a randomized, double-blind, sham-controlled crossover trial with enriched enrollment design in established DRG-stimulation responders.

Methods: In this single-center trial, adults with chronic peripheral neuropathic or nociplastic pain with implanted DRG system and sustained response (≥50% pain reduction for ≥3 months on stable stimulation settings and medication) were randomized 1:1 to active→sham or sham→active stimulation. Participants completed two 5-day treatment periods separated by a 24-hour washout with stimulation off. Active stimulation was delivered at 90% of the perception threshold, and sham was stimulation off. The primary outcome was median pain intensity on a 0–10 Numeric Rating Scale (NRS). Secondary outcomes included patient satisfaction and Patient Global Impression of Change (PGIC) domains. Analyses used Wilcoxon signed-rank tests with Hodges-Lehmann estimates.

Results: In 20 randomized patients, pain intensity was lower during active than sham stimulation (median NRS 3.0 (IQR 2.0–4.0) vs 6.0 (IQR 4.0–7.0); Hodges-Lehmann median difference, −2.5; 95% CI −3.0 to −2.0; p<0.001). Patient satisfaction and all PGIC domains favored active stimulation. Two participants terminated one treatment period early per prespecified criteria; available data were retained. No serious or device-related adverse events were reported.

Introduction: Probabilistic Stimulation Maps (PSMs) are increasingly employed to identify brain regions associated with optimal therapeutic outcomes in Deep Brain Stimulation (DBS). However, their reliability and generalizability are challenged by the limited size of most patient cohorts and the inherent variability introduced by different statistical methods and input data configurations. This study aimed to investigate the geometrical variability of Probabilistic Sweet Spots (PSS) as a function of both the number of patients (nPat) and the number of stimulations per patient (nStim), and to model a stability boundary defining the minimum data requirements for obtaining geometrically stable PSS.

Methods: Three statistical approaches–Bayesian t-test, Wilcoxon test with False Discovery Rate (FDR) correction, and Wilcoxon test with nonparametric permutation correction–were applied to two patient cohorts: a primary cohort of 36 patients undergoing DBS for Parkinson’s Disease (PD), and a secondary cohort of 61 patients treated for Essential Tremor (ET), used to assess generalizability. Stimulation test data was collected intra-operatively for the first cohort and post-operatively for the second one. Geometric stability was evaluated based on variability in PSS volume extent and centroid location.

Results: The analysis revealed a non-linear trade-off between nPat and nStim to yield stable PSS. A stability boundary was defined, representing the minimum combinations of nPat–nStim required for anatomically robust PSS. Among the tested methods, the Bayesian t-test achieved stability with smaller sample sizes (∼15 patients) and demonstrated a consistent performance across both cohorts. In contrast, the Wilcoxon-based methods showed variable behavior between cohorts, which differed in symptom type and testing phase (intra-operative testing vs. post-operative screening).

Discussion: The proposed PSS stability boundary provides a practical reference for designing DBS studies and stimulation screening protocols aimed at probabilistic mapping. The Bayesian t-test emerged as a reliable method across both cohorts, supporting its potential in studies with limited sample sizes and scenarios where the method needs to be readily generalized to varying symptoms. These findings underscore the importance of considering both cohort size and stimulation count in probabilistic DBS mapping and call for further investigation into method-specific sensitivities to clinical and procedural factors.

This case report presents positive outcomes from deep brain stimulation (DBS) targeting the bed nucleus of the stria terminalis (BNST) in two patients with treatment-resistant depression and generalized anxiety disorder. DBS effects in the medial forebrain bundle (MFB) area were unclear. Further research into DBS's efficacy when comorbid anxiety is present is required.

To compare awake and asleep deep brain stimulation (DBS) surgery for Essential Tremor (ET), we conducted this retrospective cohort study of patients consecutively operated with DBS targeting the caudal Zona incerta (cZi). 37 underwent surgery awake and 55 asleep. Tremor before surgery and on/off stimulation one year after surgery were evaluated using the Essential Tremor Rating Scale (ETRS). Procedural time, electrode localization, stimulation parameters and adverse events were noted and compared. ETRS scores were similar at baseline between the groups except for contralateral arm tremor, which was slightly worse in the awake group. Total ETRS, contralateral arm tremor and activities of daily living scores showed no significant difference between the groups on-stimulation at one-year follow-up. Compared to the awake group, the asleep group had shorter procedural time and lower stimulation parameters. There were no intracranial haemorrhages nor surgery site-infections. Both groups showed a good improvement of tremor at one-year follow-up. Image-guided DBS surgery targeting the cZi enables safe and efficient asleep surgery for ET.