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Accurate preoperative mapping is crucial for maximizing tumor removal while minimizing damage to critical brain functions during brain tumor surgery. Navigated transcranial magnetic stimulation (nTMS), magnetoencephalography (MEG), and functional magnetic resonance imaging (fMRI) are established methods for assessing motor and language function. Following PRISMA guidelines, this systematic review analyzes the reliability, clinical utility, and accessibility of these techniques. A total of 128 studies (48 nTMS, 56 fMRI, 24 MEG) were identified from various databases. The analysis finds nTMS to be a safe, standardized method with high accuracy compared to direct cortical stimulation for preoperative motor mapping. Combining nTMS with tractography allows for preoperative assessment of short-term and long-term motor deficits, which may not be possible with fMRI. fMRI data interpretation requires careful consideration of co-activated, non-essential areas (potentially leading to false positives) and situations where neural activity and blood flow are uncoupled (potentially leading to false negatives). These limitations restrict fMRI's role in preoperative planning for both motor and language functions. While MEG offers high accuracy in motor mapping, its high cost and technical complexity contribute to the limited number of available studies. Studies comparing preoperative language mapping techniques with direct cortical stimulation show significant variability across all methods, highlighting the need for larger, multicenter studies for validation. Repetitive nTMS speech mapping offers valuable negative predictive value, allowing clinicians to evaluate whether a patient should undergo awake or asleep surgery. Language function monitoring heavily relies on the specific expertise and experience available at each center, making it challenging to establish general recommendations. [ABSTRACT FROM AUTHOR]

Background: Cold agglutinin disease (CAD) is an autoimmune hemolytic anemia that induces blood coagulation and hemolysis upon exposure to cold temperatures. Strict temperature control is essential to mitigate these effects, especially during surgical procedures where hypothermia is possible. Case presentation: A 57-year-old male, 165 cm and 72 kg, diagnosed with CAD, underwent cerebral vascular anastomosis. Intraoperatively, mean arterial pressure was maintained at or above 65 mmHg with phenylephrine administration, while body temperature was rigorously controlled between 36.5 °C and 37.5 °C using forced-air warming blankets and heated intravenous infusions. Despite these measures, thrombotic occlusion occurred, necessitating surgical thrombus removal, intravenous heparin administration, and irrigation of the surgical field with warmed saline followed by re-anastomosis. The anastomosis remained patent without recurrence of thrombus formation thereafter. Conclusion: Preventing hypothermia is extremely important in the anesthesia management of CAD patients. However, careful attention must also be paid to temperature regulation in the surgical field. [ABSTRACT FROM AUTHOR]

Epilepsy affects 50 million people worldwide and is drug-resistant in approximately one-third of cases. Even when a structural lesion is identified as the epileptogenic focus, understanding the underlying genetic causes is crucial to guide both counseling and treatment decisions. Both somatic and germline DNA variants may contribute to the lesion itself and/or influence the severity of symptoms. We therefore used whole exome sequencing (WES) to search for potentially pathogenic somatic DNA variants in brain samples from children with lesional epilepsy who underwent epilepsy surgery. WES was performed on 20 paired DNA samples extracted from both lesional brain tissue and reference tissue from the same patient, such as leukocytes or fibroblasts. The paired WES data were jointly analyzed using GATK Mutect2 to identify somatic single nucleotide variants (SNVs) or insertions/deletions (InDels), which were subsequently evaluated in silico for their disease-causing potential using MutationTaster2021. We identified known pathogenic somatic variants in five patients (25%) with variant allele frequencies (VAF) ranging from 3–35% in the genes MTOR, TSC2, PIK3CA, FGFR1, and PIK3R1 as potential causes of cortical malformations or central nervous system (CNS) tumors. Depending on the VAF, we used different methods such as Sanger sequencing, allele-specific qPCR, or targeted ultra-deep sequencing (amplicon sequencing) to confirm the variant. In contrast to the usually straightforward confirmation of germline variants, the validation of somatic variants is more challenging because current methods have limitations in sensitivity, specificity, and cost-effectiveness. In our study, WES identified additional somatic variant candidates in additional genes with VAFs ranging from 0.7–7.0% that could not be validated by an orthogonal method. This highlights the importance of variant validation, especially for those with very low allele frequencies. [ABSTRACT FROM AUTHOR]

The motor thalamus plays a crucial role in integrating and modulating sensorimotor information. Although voltage power spectral changes in the motor cortex with movement are well-characterized, corresponding activity in the motor thalamus, particularly broadband power change, remains unclear. The present study aims to characterize spectral changes in the motor thalamus during hand movements of 15 subjects undergoing awake deep brain stimulation surgery targeting the ventral intermediate (Vim) nucleus of the thalamus for disabling tremor. We analyzed power changes in subject-specific low-frequency oscillations (<30 Hz) and broadband power (captured in 65–115 Hz band) of serial field potential recordings. Consistent with previous studies, we found widespread decreases in low-frequency oscillations with movement. Importantly, in most subjects, we observed that sites with significant increases in broadband power were more spatially discrete, primarily involving the inferior recording sites within the ventral thalamus. One subject also performed an imagined movement task during which low-frequency oscillatory power was suppressed. These electrophysiological changes may be leveraged as biomarkers for thalamic functional mapping, DBS targeting, and closed-loop applications. NEW & NOTEWORTHY: We studied movement-associated spectral changes in human motor thalamus and observed focal increases in broadband power with movement. This biomarker may be used as a tool for intraoperative functional mapping, DBS targeting, and closed-loop device control. [ABSTRACT FROM AUTHOR]

Ambient ionization mass spectrometry was proved to be a powerful tool for oncological surgery. Still, it remains a translational technique on the way from laboratory to clinic. Brain surgery is the most sensitive to resection accuracy field since the balance between completeness of resection and minimization of nerve fiber damage determines patient outcome and quality of life. In this review, we summarize efforts made to develop various intraoperative support techniques for oncological neurosurgery and discuss difficulties arising on the way to clinical implementation of mass spectrometry‐guided brain surgery. [ABSTRACT FROM AUTHOR]

Biopsy emerges as a critical procedure for determining tumor types and establishing pathological diagnoses. This process encompasses two primary stages: planning and surgical intervention. During the planning stage, anatomical points in the patient's brain are marked based on MRI data, known to take an average of four hours. However, the accuracy deficiencies, subjective variations, and time consumption associated with manual marking reveal the critical need for an automated planning tool. In this study, we propose a biopsy planning method, entirely automated and incorporating cutting-edge deep learning architectures, on MRI and MRA data. The suggested approach aims to execute biopsy planning rapidly, consistently, and repeatably. The method consists of four main stages: 1) Removal of the brain's upper shell, 2) Tumor detection and target point determination, 3) Segmentation of the brain's vascular network, and 4) Combination of the three stages and risk calculation for optimal trajectory determination. This automatic method has been validated with 42 patient data in ITKTubeTK. Furthermore, this study, prepared as a "3D Slicer" plugin, is offered as a free computer-assisted tool for clinics. In subsequent phases of the research, integration of fMRI data is planned to further enhance risk calculation. [ABSTRACT FROM AUTHOR]

• Electrical stimulation in white matter induces delays in the evoked response due to slow conduction velocity. • The waveforms from white matter and cortical stimulation remain generally identical. • Responses to white matter and cortical stimulation differ on response times. • The relaxation of the N1 component is longer during cortical stimulations. • There is probable activation of intra-cortical axons during cortical stimulation. Direct cortical responses (DCR) and axono-cortical evoked potentials (ACEP) are generated by electrically stimulating the cortex either directly or indirectly through white matter pathways, potentially leading to different electrogenic processes. For ACEP, the slow conduction velocity of axons (median ≈ 4 m.s−1) is anticipated to induce a delay. For DCR, direct electrical stimulation (DES) of the cortex is expected to elicit additional cortical activity involving smaller and slower non-myelinated axons. We tried to validate these hypotheses. DES was administered either directly on the cortex or to white matter fascicles within the resection cavity, while recording DCR or ACEP at the cortical level in nine patients. Short but significant delays (≈ 2 ms) were measurable for ACEP immediately following the initial component (≈ 7 ms). Subsequent activities (≈ 40 ms) exhibited notable differences between DCR and ACEP, suggesting the presence of additional cortical activities for DCR. Distinctions between ACEPs and DCRs can be made based on a delay at the onset of early components and the dissimilarity in the shape of the later components (>40 ms after the DES artifact). The comparison of different types of evoked potentials allows to better understand the effects of DES. [ABSTRACT FROM AUTHOR]

Objective: Although Republic of Korea is an advanced country in medical technology with a successful treatment rate for serious diseases, such as cancer, and has improved technology for highly difficult surgery, many excellent medical doctors and physicians are struggling due to the recent unreasonable medical environment. Specialization in brain tumor surgery also faces challenges in Republic of Korea, including low financial incentives, legal threats, and limited career prospects. In response, the Korean Brain Tumor Society (KBTS) formed the Future Strategy Committee to assess these obstacles and propose solutions. Methods: A survey was conducted among the KBTS members to understand their perceptions and concerns across different career stages. Results: The findings revealed a decline in interest among chief residents in brain tumor surgery, owing to limited job opportunities and income prospects. Neurosurgical fellows expressed neutral satisfaction but highlighted challenges, such as low patient numbers and income. Faculty members with varying levels of experience echoed similar concerns, emphasizing the need for improved financial incentives and job stability. Despite these challenges, the respondents expressed dedication to the field and suggested strategies for improvement. Conclusion: The KBTS outlines a vision that focuses on practical excellence, comprehensive research, professional education, responsibilities, and member satisfaction. Addressing these challenges requires collaborative efforts among healthcare institutions, professional societies, and policymakers to support brain tumor specialists and enhance patient care. [ABSTRACT FROM AUTHOR]

Objective Methods Results Significance Somatic variants causing epilepsy are challenging to detect, as they are only present in a subset of brain cells (e.g., mosaic), resulting in low variant allele frequencies. Traditional methods relying on surgically resected brain tissue are limited to patients undergoing brain surgery. We developed an improved protocol to detect somatic variants using DNA from stereoelectroencephalographic (SEEG) depth electrodes, enabling access to a larger patient cohort and diverse brain regions. This protocol mitigates issues of contamination and low yields by purifying neuronal nuclei using fluorescence‐activated nuclei sorting (FANS).SEEG depth electrodes were collected upon extraction from 41 brain regions across 17 patients undergoing SEEG. Nuclei were isolated separately from depth electrodes in the affected brain regions (seizure onset zone) and the unaffected brain regions. Neuronal nuclei were isolated using FANS, and DNA was amplified using primary template amplification. Short tandem repeat (STR) analysis and postsequencing allelic imbalance assessment were used to evaluate sample integrity. High‐quality amplified DNA samples from affected brain regions, patient‐matched unaffected brain regions, and genomic DNA were subjected to whole exome sequencing (WES). A bioinformatic workflow was developed to reduce false positives and to accurately detect somatic variants in the affected brain region.Based on DNA yield and STR analysis, 14 SEEG‐derived neuronal DNA samples (seven affected and seven unaffected) across seven patients underwent WES. From the variants prioritized using our bioinformatic workflow, we chose four candidate variants in MTOR, CSDE1, KLLN, and NLE1 across four patients based on pathogenicity scores and association with phenotype. All four variants were validated using digital droplet polymerase chain reaction.Our approach enhances the reliability and applicability of SEEG‐derived DNA for epilepsy, offering insights into its molecular basis, facilitating epileptogenic zone identification, and advancing precision medicine. [ABSTRACT FROM AUTHOR]

Background: The safe timing window for surgery during the acute phase of inflammation due to traumatic brain injury (TBI) has not been studied extensively. We aimed to elucidate the relationship between the timing of surgery and changes in perioperative serum levels of inflammatory cytokines and factors associated to optimize TBI management in low-middle-income countries. Methods: A prospective cohort study was conducted among TBI Patients with depressed skull fractures with a GCS > 8 operated at different timing from injury and followed up peri-operatively. We collected the clinical-radiological data, as well as pre-and postoperative venous samples from participants; we then did Luminex Assay to quantify the serum levels of pro/anti-inflammatory cytokines using the kits of 96-well human cytokine "27-Plex-Assay (#M500KCAF0Y®)." We performed the analysis with STATA version 17 and R_studio applying both descriptive and inferential methods. Results: We enrolled 82 TBI patients with a median (IQR) age of 25.5 (20–34) years, and the majority were male (85.4%). There were 48.8% victims of assaults, and 73.2% had a post-resuscitation admission GCS of 14–15. There were 38 (46.3%) who were operated within 48 h of injury versus 44 (53.7%) after 48 h. Serum levels of TNF- α were significantly higher after surgeries done >48 h compared to those done ≤48 h (p = 0.0327); whereas, the difference in post-operative mean serum levels of IL-10 was significantly increased in patients who developed later SSI compared to those who did not (11.56 versus −0.58 pg./mL, p = 0.0489). In multivariate analysis, the history of post-traumatic seizure (PTS) was associated with a postoperative increase in TNF- α (p = 0.01), the hemoglobin of 10–12 with a postoperative decrease of IL-4 (p = 0.05); the presence of focal neurological deficit was associated with a significant postoperative increased of TNF-α, IL-6, and IL-4 (p = 0.05). The presence of extra-axial hemorrhage was associated with a postoperative increase of IL-10 (p = 0.05). Conclusion: Delayed surgical intervention beyond 48 h post-injury in mild–moderate TBI patients results in a significantly increased postoperative inflammatory response, as evidenced by elevated serum levels of TNF- α and IL-6. Neurological deficits, PTS, reduced hemoglobin rate, and extra-axial intracranial hemorrhage are factors associated with this heightened response. [ABSTRACT FROM AUTHOR]

Introduction: The long-term effects of surgery for subthalamic nucleus deep brain stimulation (STN-DBS) on cognitive aspects of motor control for people with Parkinson's disease (PD) are largely unknown. We compared saccade latency and reach reaction time (RT) pre- and post-surgery while participants with PD were off-treatment. Methods: In this preliminary study, we assessed people with PD approximately 1 month pre-surgery while OFF medication (OFF-MEDS) and about 8 months post-surgery while OFF medication and STN-DBS treatment (OFF-MEDS/OFF-DBS). We examined saccade latency and reach reaction time (RT) performance during a visually-guided reaching task requiring participants to look at and reach toward a visual target. Results: We found that both saccade latency and reach RT significantly increased post-surgery compared to pre-surgery. In addition, there was no significant change in Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III score. Discussion: We found detrimental post-surgical changes to saccade latency and reach RT. We discuss the potential contributions of long-term tissue changes and withdrawal from STN-DBS on this detrimental cognitive effect. [ABSTRACT FROM AUTHOR]

ABSTRACT Background Objective Methods Results Conclusion Women make up only 23% to 30% of recipients for deep brain stimulation (DBS) surgery for Parkinson's disease (PD), a discrepancy that is not accounted for by differences in disease incidence. One of the many factors that may contribute to this gap includes gender differences in decision‐making.The aim was to explore how women and men approach the decision for DBS in terms of informational needs, weighing risks and benefits, and decision‐making.Semistructured interviews were conducted with 33 participants with PD who had undergone DBS evaluation within the past 3 years. Data were analyzed using content analysis.Sixteen women and 17 men participated in interviews. We identified 4 key themes. First, information sources were similar between women and men, and they valued hearing personal experiences. Second, the motivations for DBS surgery were often very personal. Third, the decision‐making process occurred over time, sometimes years. Fourth, although many expressed fear of brain surgery, trust in the surgeon helped many overcome this fear. Women overall had less support than men during decision‐making and after surgery. Women also placed greater value on talking to other women who had undergone DBS, although they had a hard time finding these women. Men, on the contrary, were less often worried about support and valued numerical information when weighing risks and benefits.We found gender differences in information needs, support, motivating factors, and how patients weighed risks and benefits. These differences can be used to inform educational tools and counseling for DBS. [ABSTRACT FROM AUTHOR]

Simple Summary: Visuospatial circuits (VS) must be preserved during brain tumours' excision. Navigated TMS is a valid tool to preoperatively map VS networks and to optimise functional preservation. In this work, we tested 27 patients with nTMS preoperative mapping and an experimental test for VS abilities, called VISA, demonstrating a good clinical outcome (functional recovery 80–98.86%) and a useful nTMS map for tractography reconstruction (with the main involvement of the second and the third branches of the superior longitudinal fasciculus). Finally, a comparison of nTMS and DCS points in awake surgery (n = 10 patients) documented a sensitivity (Se) of 12%, a specificity (Sp) of 91.21%, a positive predictive value (PPV) of 42%, a negative predictive value (NPV) of 66%, and an accuracy of ~63.7%. According to our preliminary results, nTMS is advantageous to study cognitive functions, minimising neurological impairment. Further analyses are needed to validate our data. Objective: Navigated transcranial magnetic stimulation (nTMS) has seldom been used to study visuospatial (VS) circuits so far. Our work studied (I) VS functions in neurosurgical oncological patients by using repetitive nTMS (rnTMS), (II) the possible subcortical circuits underneath, and (III) the correspondence between nTMS and direct cortical stimulation (DCS) during awake procedures. Methods: We designed a monocentric prospective study, adopting a protocol to use rnTMS for preoperative planning, including VS functions for lesions potentially involving the VS network, including neurosurgical awake and asleep procedures. nTMS-based-DTI tractography allowed the visualization of subcortical circuits. Statistical analyses on nTMS/DCS points were performed. Clinical results were collected pre- and postoperatively. Results: Finally, 27 patients with primitive intra-axial brain lesions were enrolled between April 2023 and March 2024. Specific tests and an experimental integrated VS test (VISA) were used. The clinical evaluation (at 5 ± 7, 30 ± 10, 90 ± 10 days after surgery) documented 33% of patients with neglect in the left hemisphere four days after surgery and, during the 3-month follow-up, preservation of visuospatial function/clinical recovery (90.62% in MMSE, 98.86% in the bell test, 80% in the clock test, and 98% in the OCS test). The surgical strategy was modulated according to the nTMS map. Subcortical bundles were traced to identify those most involved in these functions: SFLII > SLFII > SLFI. A comparison of the nTMS and DCS points in awake surgery (n = 10 patients) documented a sensitivity (Se) of 12%, a specificity (Sp) of 91.21%, a positive predictive value (PPV) of 42%, a negative predictive value (NPV) of 66%, and an accuracy of ~63.7%. Conclusions: Based on our preliminary results, nTMS is advantageous for studying cognitive functions, minimising neurological impairment. Further analyses are needed to validate our data. [ABSTRACT FROM AUTHOR]

Early detection of brain tumors is essential, and a biopsy is required to determine the type of tumors in the brain and is only possible after extensive brain surgery. Brain tumors can be identified and classified by clinicians with the aid of computational intelligence algorithms. Here, we developed an novel and intelligent automated system, known as, Spatial Adaptive Dart Optimized Network (SADO-Net) for the diagnosis of brain tumor using MRIs. This will allow medical professionals to identify tumors in their early stages with a high degree of accuracy. Before classifying the diseases, the preprocessed brain MRIs are segmented using the Spatial Pattern based Image Segmentation (SPISeg) technique. The type of brain tumor is then promptly and reliably identified using the Weight Optimized Deep Network (WODNet) Classification model. The adoption of the Darts Game based Optimization (DGO) method for feature reduction expedites the classification process. This work uses a range of metrics and popular public datasets such as BRATS 2018, BRATS 2019, BRATS 2020 and Figshare to compare and validate the performance of the proposed SADO-Net model in tumor identification. Based on the results, the SADO-Net model exhibits good performance, with an average accuracy of 99.2 % and a loss rate of 0.5 %. [ABSTRACT FROM AUTHOR]

We evaluated the capability of an AI application to independently detect, segment and classify intracranial tumors in MRI. In this retrospective single-centre study, 138 patients (65 female and 73 male) with a mean age of 35 ± 26y were included. 97 were diagnosed with an intracranial neoplasm, while 41 exhibited no intracranial pathology. Inclusion criteria were a 1.5 or 3.0T MRI dataset with the following sequences: T2 axial, T1 axial pre- and post-contrast with a slice thickness between 3 and 6 mm and no previous brain surgery. Image analysis was performed by two human readers (R1 = 5 years and R2 = 10 years of experience in brain MRI) and a deep learning (DL)-based AI model. Sensitivity, specificity and accuracy of the AI model and the human readers to detect and correctly classify brain tumors were measured. Histological results served as the gold standard. The AI model reached a sensitivity of 93.81% [87.02–97.70] and a specificity of 63.41% [46.94–77.88], while human readers reached 100% [96.27–100.00] and 100% [91.40–100.00], respectively. Human readers provided a significantly higher accuracy rate with R1 0.93 (95% CI: 0.88–0.97) and R2 0.98 (95% CI: 0.94, 0.99) vs. 0.74 (95% CI: 0.66–0.81) for the AI model (P -value <0.001). The underlying DL-based AI algorithm can independently identify and segment intracranial tumors while providing satisfactory results for establishing the correct diagnosis. Despite its current inferiority compared to experienced radiologists, it still experiences ongoing development and it is a step towards developing an artificial intelligence-augmented radiology workflow. [ABSTRACT FROM AUTHOR]

Background The utilization of preoperative embolization is a well-established method for reducing intraoperative blood loss during surgery of meningiomas. However, the exact indications and contraindications for this technique remain controversial. Objective The objective of this study is to determine the indications for preoperative embolization of brain meningiomas. Materials and Methods A retrospective analysis of 46 patients who underwent surgical resection of intracranial meningioma from 2020 to the end of 2022 was conducted. Preoperative magnetic resonance imaging (MRI) and computed tomography (CT) data were studied to assess their relationship with the volume of intraoperative blood loss. Results Invasive tumor growth and bone involvement (erosion, hyperostosis) were found to be the most significant factors influencing intraoperative blood loss (p = 0.001). Conclusion This study clearly demonstrates an association between preoperative imaging data and intraoperative blood loss, which may be useful in predicting massive bleeding during surgery. [ABSTRACT FROM AUTHOR]

Japanese neurosurgery faces challenges such as a declining number of neurosurgeons and their concentration in urban areas. Particularly in rural areas, access to neurosurgical care for patients with conditions, such as stroke, is limited, raising concerns about the collapse of regional healthcare. Robot-assisted surgical technologies have advanced in recent years, contributing to the improved precision and safety of deep brain surgery. This study proposes the "Artificial Intelligence (AI) and Robot-Assisted Surgery Moonshot Plan" for Japan, comprising 5 pillars: 1) establishment of regional medical centers, 2) development of remote surgery systems, 3) enhancement of robotic-assisted surgery training programs, 4) integration of AI technologies, and 5) promotion of industry-academia-government collaboration. In addition, strengthening the approach to spinal surgery is expected to revitalize regional medical centers, optimize the number of neurosurgeons, improve surgical skills, and promote minimally invasive surgery. This study analyzed the current status and challenges of Japanese neurosurgery through a literature review and statistical analysis. AI is used in various aspects of neurosurgery, including diagnostic support, surgical planning and navigation, treatment outcome prediction, intraoperative monitoring, robot-assisted surgery, and rehabilitation. However, challenges, such as data bias, ethical issues, costs, and regulations, remain. In Japan, issues such as the uneven distribution and decline of neurosurgeons, collapse of regional healthcare, and increase in the number of patients with spinal disorders due to aging have been highlighted. The "AI and Robot-Assisted Surgery Moonshot Plan" serves as a guide to overcome the challenges of neurosurgery in Japan and establish a sustainable medical system. [ABSTRACT FROM AUTHOR]

Intraoperative neurophysiological monitoring (IONM) is instrumental in mitigating neurological deficits following cranial and spinal procedures. Despite extensive research on IONM's ability to recognize limb-malposition-related issues, less attention has been given to other secondary neural injuries in cranial surgeries. A comprehensive multimodal neuromonitoring approach was employed during a left frontal craniotomy for tumor resection. The electronic medical record was reviewed in detail in order to describe the patient's clinical course. The patient, a 46-year-old female, underwent craniotomy for excision of a meningioma. Deteriorations in somatosensory evoked potential and transcranial motor evoked potential recordings identified both a mal-positioned limb as well as an infiltrated intravenous (IV) line in the arm contralateral to the surgical site. The IONM findings for the infiltrated IV were initially attributed to potential limb malposition until swelling and blistering of the limb were appreciated and investigated. The timely identification and management of the infiltrated IV and adjustment of limb positioning contributed to the patient's recovery, avoiding fasciotomy, with no postoperative neurological deficits. This case is the first published demonstration of the utility of IONM in detecting IV infiltration. This early recognition facilitated early intervention, saving the patient from a potential fasciotomy and enabling their recovery with no postoperative neurological deficits. The findings from this single case highlight the necessity for vigilant and dynamic application of IONM techniques to enhance patient safety and outcomes in neurosurgical procedures. Further research is needed to explore broader applications and further optimize the detection capabilities of IONM. [ABSTRACT FROM AUTHOR]

Background: Transcranial Magnetic Stimulation–Electroencephalography (TMS-EEG) is a non-operative technique that allows for magnetic cortical stimulation (TMS) and analysis of the electrical currents generated in the brain (EEG). Despite the regular utilization of both techniques independently, little is known about the potential impact of their combination in neurosurgical practice. Methods: This scoping review, conducted following PRISMA guidelines, focused on TMS-EEG in epilepsy, neuro-oncology, and general neurosurgery. A literature search in Embase and Ovid MEDLINE returned 3596 records, which were screened based on predefined inclusion and exclusion criteria. After full-text review, three studies met the inclusion criteria. Two independent investigators conducted study selection and data extraction, with mediators resolving disagreements. The NHLBI tool was used to assess risk of bias in the included studies. Results: A total of 3596 articles were screened following the above-mentioned criteria: two articles and one abstract met the inclusion criteria. TMS-EEG is mentioned as a promising tool to evaluate tumor–brain interaction, improve preoperative speech mapping, and for lateralization epileptic focus in patients undergoing epilepsy surgery. Lack of detailed patient and outcome information preclude further considerations about TMS-EEG use beyond the potential applications of this technique. Conclusions: TMS-EEG research in neurosurgery is required to establish the role of this non-invasive brain stimulation-recording technique. Tumor–brain interaction, preoperative mapping, and seizure lateralization are in the front row for its future applications. [ABSTRACT FROM AUTHOR]

Hybrid depth electrodes are increasingly being used for epilepsy monitoring and human neurophysiology research. Microwires extending from the tip of the Behnke‐Fried (BF) electrode into (sub)cortical areas allow to isolate single neurons and perform microstimulation. Conventional CT or MRI visualize the entire microwire bundle as an artifact extending from the BF electrode tip with low resolution, without proper identification of individual microwires. We illustrate the first direct visualization method of individual microwires using high‐resolution photon‐counting CT (PCCT). Coregistration of the PCCT scan with a preoperative MRI can visualize individual wires directly in cortex, which is an advantage as it provides feedback on the accuracy of the implantation method and can guide future implantations. This PCCT technique allows for accurately depicting individual microwires which could be relevant for neuroscientific research through improved visualization and implantation of specific cortical and subcortical brain areas. Plain Language Summary: Researchers are using hybrid depth electrodes to study epilepsy and brain activity. These electrodes, called Behnke‐Fried (BF) electrodes, have microwires at the tip that can record single neurons and stimulate brain areas. Regular CT or MRI scans do not show the individual microwires clearly. The authors use a new high‐resolution photon‐counting CT (PCCT) technique, which can show each individual microwire in the brain. By combining PCCT with MRI, the authors can precisely see where the microwires are located. This could improve future implantation surgeries and brain research. [ABSTRACT FROM AUTHOR]

A common style of argument in the literature on free will and moral responsibility is the Manipulation Argument. These tend to begin with a case of an agent in a deterministic universe who is manipulated, say, via brain surgery, into performing some action. Intuitively, this agent is not responsible for that action. Yet, since there is no relevant difference, with respect to whether an agent is responsible, between the manipulated agent and a typical agent in a deterministic universe, responsibility is not compatible with the truth of determinism. This paper introduces some key types of manipulation cases, the schema for a manipulation argument against compatibilism, the hard‐line/soft‐line categories of responses to manipulation arguments, and various issues that have become important in discussions of manipulation cases and arguments. [ABSTRACT FROM AUTHOR]

Abstract Background Cold agglutinin disease (CAD) is an autoimmune hemolytic anemia that induces blood coagulation and hemolysis upon exposure to cold temperatures. Strict temperature control is essential to mitigate these effects, especially during surgical procedures where hypothermia is possible. Case presentation A 57-year-old male, 165 cm and 72 kg, diagnosed with CAD, underwent cerebral vascular anastomosis. Intraoperatively, mean arterial pressure was maintained at or above 65 mmHg with phenylephrine administration, while body temperature was rigorously controlled between 36.5 °C and 37.5 °C using forced-air warming blankets and heated intravenous infusions. Despite these measures, thrombotic occlusion occurred, necessitating surgical thrombus removal, intravenous heparin administration, and irrigation of the surgical field with warmed saline followed by re-anastomosis. The anastomosis remained patent without recurrence of thrombus formation thereafter. Conclusion Preventing hypothermia is extremely important in the anesthesia management of CAD patients. However, careful attention must also be paid to temperature regulation in the surgical field.

Parkinson's disease (PD) is primarily characterized by motor symptoms, but patients also experience a relatively high prevalence of non-motor symptoms, including emotional and cognitive impairments. While the subthalamic nucleus (STN) is a common target for deep brain stimulation to treat motor symptoms in PD, its role in emotion processing is still under investigation. This study examines the subthalamic neural oscillatory activities during facial emotion processing and its association with affective characteristics. Twenty PD patients who underwent subthalamic deep brain stimulation surgery performed a facial-expression-recognition task while STN local field potential (LFP) and frontal electroencephalography (EEG) were recorded. The facial-emotion-induced time-frequency decomposition of the STN-LFP and the frontal EEG, as well as the LFP-EEG coherence, were analyzed. Furthermore, the correlation between STN activities and affective characteristics was examined. Facial expressions elicited increased delta-theta-band and decreased alpha-beta-band activities in STN-LFP. Reduced alpha-beta-band LFP desynchronization was correlated with the severity of apathy. Increased theta-band and decreased alpha-beta-band EEG activities responded to facial emotion. Notably, lower coherence between STN-LFP and frontal EEG in delta-theta-band activity and alpha-band activity correlated with the degree of anhedonia. These results indicate that subthalamic activities during facial emotion processing are associated with apathy and anhedonia, emphasizing the cognitive-limbic function of STN and its role as a physiological target for apathy neuromodulation in PD. • STN-LFP and EEG activity during facial emotion processing in PD patients examined • Facial emotions increased delta-theta and decreased alpha-beta activities in STN-LFP • Reduced alpha-beta desynchronization correlated with higher apathy severity • Lower STN- LFP frontal-EEG coherence in delta-theta and alpha bands linked to anhedonia [ABSTRACT FROM AUTHOR]

Background Objective: Venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common complication in craniotomy patients and is associated with increased morbidity and mortality. The duration of surgery is a known risk factor. Other factors such as positioning and tumor entity have hardly been investigated or are controversial. In two pilot studies, the determination of plasma D-dimer concentration led to a high detection rate of DVT, while the use of intermittent pneumatic venous compression (IPC) drastically reduced the incidence of VTE. In the present study we investigated the efficacy of the two approaches, either alone or in combination, in a large patient cohort. Methods: 1759 patients who underwent elective craniotomy between 2009 and 2023 were retrospectively analyzed. The staggered use of D-dimer determination and intraoperative use of IPC resulted in 3 groups: Group 1: no procedure; Group 2: D-dimer evaluation; Group 3: IPC and D-dimer evaluation. If the D-dimer level was ≥ 2 mg/l (Fibrinogen equivalent units; FEU), venous ultrasound was performed. Age, gender, tumor entity, duration and extent of surgery, patient positioning, type of VTE were also recorded and analyzed. Results: The introduction of postoperative D-dimer evaluation increased the rate of detection of thrombosis from 1.7% in group 1 to 22.6% in group 2. The addition of IPC reduced the rate of thrombosis to 4.4%. Age, gender and patient positioning did not affect the rate of VTE. We were able to confirm the duration of surgery as an individual risk factor and showed that WHO grade 4 tumors and metastasis have an increased VTE risk. Conclusions: If D-Dimer levels are not analyzed routinely about 20% of craniotomy patients suffer from a clinically silent thrombosis. Each with the risk of fate PE. Intraoperative use of IPC during craniotomy dramatically reduces the risk of VTE. [ABSTRACT FROM AUTHOR]

Glioma refers to a highly prevalent type of brain tumor that is strongly associated with a high mortality rate. During the treatment process of the disease, it is particularly important to accurately perform segmentation of the glioma from Magnetic Resonance Imaging (MRI). However, existing methods used for glioma segmentation usually rely solely on either local or global features and perform poorly in terms of capturing and exploiting critical information from tumor volume features. Herein, we propose a local and global dual transformer with an attentional supervision U-shape network called DTASUnet, which is purposed for glioma segmentation. First, we built a pyramid hierarchical encoder based on 3D shift local and global transformers to effectively extract the features and relationships of different tumor regions. We also designed a 3D channel and spatial attention supervision module to guide the network, allowing it to capture key information in volumetric features more accurately during the training process. In the BraTS 2018 validation set, the average Dice scores of DTASUnet for the tumor core (TC), whole tumor (WT), and enhancing tumor (ET) regions were 0.845, 0.905, and 0.808, respectively. These results demonstrate that DTASUnet has utility in assisting clinicians with determining the location of gliomas to facilitate more efficient and accurate brain surgery and diagnosis. [ABSTRACT FROM AUTHOR]

Research into the function of deep brain structures has benefited greatly from microelectrode recordings in animals. This has helped to unravel physiological processes in the healthy and malfunctioning brain. Translation to the human is necessary for improving basic understanding of subcortical structures and their implications in diseases. The use of microelectrode recordings as a standard component of deep brain stimulation surgery offers the most viable route for studying the electrophysiology of single cells and local neuronal populations in important deep structures of the human brain. Most of the studies in the basal ganglia have targeted the motor loop and movement disorder pathophysiology. In recent years, however, research has diversified to include limbic and cognitive processes. This review aims to provide an overview of advances in neuroscience made using intraoperative and post‐operative recordings with a focus on non‐motor activity in the basal ganglia. [ABSTRACT FROM AUTHOR]

• N1 amplitude increases with intensity of bipolar stimulation but is not affected by interelectrode distance. • N1 delay is not significantly affected by stimulation intensity or interelectrode distance. • Axonal stimulation generates earlier and more evoked potentials than cortical stimulation. To identify optimal bipolar stimulation parameters for robust generation of brain evoked potentials (BEPs), namely the interelectrode distance (IED) and the intensity of stimulation (IS), in cortical and axonal stimulation. In 15 patients who underwent awake surgery for brain tumor removal, BEPs were elicited at different values of IED and IS, respectively: 5 mm-5 mA, 5 mm-10 mA, and 10 mm-10 mA. The number of BEPs elicited by stimulation, as well as the delays and amplitudes of the N1 waves were compared between the different groups of stimulation parameters and according to the stimulated brain structure (cortical vs. axonal). The amplitudes of N1 increased with the intensity of bipolar stimulation, either in cortical or axonal stimulation, while N1 peak delays were not affected by the stimulation parameters. Furthermore, axonal stimulation produced more N1s than cortical stimulation, with lower latencies. Understanding the relationship between stimulation parameters and BEP is of utmost importance to determine whether the generated N1 waves accurately reflect the underlying structural anatomy. Other factors, such as stimulation frequency or pulse width and shape, may also play a role and warrant further investigation. This study represents the first step in describing the influence of common bipolar stimulation parameters on robustness of BEPs by examining the impact of IED and IS on the N1 wave. [ABSTRACT FROM AUTHOR]

Our language affects patients' perceptions of therapies. In Parkinson's disease, emergent response fluctuations and dyskinesias typically trigger conversations around commencing an "Advanced Therapy" which carries notions of Advanced Disease. The patient, resolute in their commitment to fighting the disease, is misled. Chasing reassurance that their disease has not yet progressed considerably; they may therefore resist a potentially life-changing therapy. Instead, we should offer a "Smart Therapy". This term more accurately and positively describes therapies on offer that stabilize response fluctuations and improve quality of life, without a focus on the negative connotations of progression to more advanced disease. Plain Language Summary: The language we use with our patients affects their perception of a therapy on offer and their willingness to take it up. In Parkinson's disease when motor response fluctuations and dyskinesias become extremely challenging and disabling for patients despite medication optimization, it might prompt conversations with the patient in appropriate circumstances about offering an "Advanced Therapy" such as deep brain stimulation surgery or continuous infusion pumps. However, from the patient's perspective, putting up a steadfast fight against their disease, this label carries unwanted and misleading connotations of Advanced Disease. This can lead to hesitation from taking up these potentially life-changing therapies. Therefore, in this Commentary we propose a rebranding in line with other modern technology like smart phones and smart homes, emphasizing the positive and personalized features of these therapies, and focusing on the goal of stabilizing symptoms and improving quality of life. We should offer patients "Smart Therapies". It's time to Get Smart! [ABSTRACT FROM AUTHOR]

In clinical practice, neurosurgeons are often faced with problems raised by the anticoagulant therapy of patients with cerebral pathologies. They are routinely asked to decide between the risk of postoperative ICH and the benefit of therapeutic AC in high-risk situations and without strong guidelines. There are many controversial situations in which the neurosurgeon can be put in a dilemma regarding the best therapeutic attitude towards anticoagulation. The first question related to the anticoagulant treatment that the neurosurgeon asks before a brain intervention is: how long before the operation should the chronic anticoagulant therapy be stopped, under safe conditions? Another problem that neurosurgeons often face is that of postoperative anticoagulant treatment. One of the questions they frequently ask themselves is: how quickly can the anticoagulant treatment be introduced/resumed after brain surgery? In this presentation we will try to answer these important questions. For this, we will study patients with cerebral pathology who are on anticoagulation for various health issues (VTE, afib, hearth valves etc.). First of all, we have to assess the thrombosis risk for each patient. And we have: [ABSTRACT FROM AUTHOR]

Background: High hypericin-loaded polyvinylpyrrolidone (HHL-PVP) constitutes a novel approach to utilize the promising characteristics of hypericin for photodynamic diagnosis (PDD) and therapy (PDT) of brain tumors in an orally bioavailable formulation. The aim of this study was to investigate the ability of a Complementary Metal-Oxide-Semiconductor (CMOS) camera-based fluorescence imaging system to selectively visualize HHL-PVP in glioblastoma tissue even in the presence of 5-Aminolvevulinic acid (5-ALA) induced fluorescence, which is widely utilized in brain tumor surgery. Methods: We applied a previously established system with a non-hypericin specific filter for 5-ALA fluorescence visualization and a newly introduced hypericin-specific filter at 575–615 nm that transmits the spectrum of hypericin, but not 5-ALA fluorescence. Glioblastoma specimens obtained from 12 patients (11 with preoperative 5-ALA intake) were ex vivo incubated with HHL-PVP. Subsequently, fluorescence intensity and lifetime changes using both the non-hypericin specific filter and hypericin-specific filter were measured before and after HHL-PVP incubation and after subsequent rinsing. Results: While no significant differences in fluorescence signal were observed using the non-hypericin specific filter, statistically significant increases in fluorescence intensity (p = 0.001) and lifetime (p = 0.028) after HHL-PVP incubation were demonstrated using the hypericin-specific filter. In consequence, specimens treated with HHL-PVP could be identified according to the fluorescence signal with high diagnostic sensitivity (87.5%) and specificity (100%). Conclusions: Our CMOS camera-based system with a hypericin-specific filter is capable of selectively visualizing hypericin fluorescence in glioblastoma tissue after ex vivo HHL-PVP incubation. In the future, this technique could facilitate clinical investigations of HHL-PVP for PDD and PDT while maintaining the current standard of care with 5-ALA guidance. [ABSTRACT FROM AUTHOR]

Objectives: Resective surgery is a potential therapeutic option for select patients with intractable focal epilepsy. However, the presence of ictal onset zones within or surrounding highly functional brain areas presents a surgical challenge, leading to poor seizure and functional outcomes. This report describes our experiences with awake mapping-tailored resection of epileptogenic areas involving eloquent cortices and evaluates their feasibility, tolerance, limitations, and significance. Methods: The study included patients who underwent surgery for drug-resistant focal epilepsy at our center under awake conditions. The surgical approach aimed to achieve maximum resection of preoperatively defined epileptogenic zones, considering the boundaries defined by surrounding functional areas. We collected data on preoperative evaluations, intraoperative tests and seizures, postoperative status epilepticus, and neurological functional outcomes. Results: We included 22 patients, 10 of whom had non-lesional epilepsy. Language, motor function, and sensory function were at risk in 19, 9, and 4 patients, respectively. Resection was performed as planned in 14 (63.6%) patients, while modifications were necessary in 8 (36.4%) patients due to functional constraints. The mean follow-up duration was 29.8 months. Sixteen (72.7%) patients achieved Engel class Ia outcomes, indicating seizure freedom, while none of the patients experienced clinically significant permanent postoperative neurological deficits. Significance: Resective surgery with intraoperative brain mapping under awake conditions was a valid treatment option for achieving a cure in cases of drug-resistant focal epilepsy, even in situations in which the condition is considered inoperable due to the risk of significant postoperative neurological deficits. [ABSTRACT FROM AUTHOR]

Background: Incorporating patient and public involvement (PPI) in research is crucial for ensuring the relevance and success of studies, yet it remains significantly underutilised in surgical research. Main body: This commentary presents insights from our neurosurgical research team's experience with establishing and working with a PPI group called "Science for Tomorrow's Neurosurgery" on research regarding novel intra-operative optical imaging techniques. Through collaboration with patient-focused charities, we have successfully incorporated patient perspectives into our work at each stage of the research pipeline, whilst adhering to core PPI principles, such as reciprocal relationships, co-learning, partnerships, and transparency. Conclusion: We highlight the specific value added to our work in terms of participant recruitment, research ethics and results dissemination. Plain English summary: Including patients and members of the public in medical research is really important. It helps make sure the research is useful and successful. Surprisingly, it's not used enough in surgical research. This article talks about how our team of brain surgeons and scientists worked with a group called "Science for Tomorrow's Neurosurgery" to include brain surgery patients in our research about new ways to look at the brain during surgery. We worked closely with charities that focus on helping patients with brain conditions, and we made sure to listen to what patients had to say every step of the way, from planning our research to sharing our results. We followed some important rules, like making sure everyone involved felt like they were being treated fairly, learning together, working together with different groups, and being honest and open. We found that having patients involved in the design and development really helped us find the right people to take part in our research, make sure we were doing things the right way, and share our findings in a way that made sense to everyone. [ABSTRACT FROM AUTHOR]

Background: Meningioma in the parasellar region may lead to visual impairment, so intraoperative neurological monitoring is essential for enucleation surgery. However, intraoperative neurological monitoring in pregnant women is challenging, as the anesthesia management must consider the effects and risks to the fetus. Remimazolam is a newly introduced intravenous anesthetic that has little effect on blood pressure. However, the effects of remimazolam on intraoperative neuromonitoring are little known. We treated a pregnant patient with parasellar meningioma who developed visual impairment, using remimazolam for anesthesia and intraoperative neurophysiological monitoring of the visual evoked potential. Case presentation: A 34-year-old woman who was 20 weeks pregnant presented with visual acuity disturbances. Neuroimaging demonstrated a parasellar meningioma, and rapid tumor growth and worsening of symptoms subsequently occurred. Craniotomy for tumor removal was performed under anesthesia with remimazolam, which allowed monitoring of the visual evoked potentials. Her visual acuity was restored postoperatively, and no adverse events occurred in the fetus. Conclusion: Our experience with intraoperative neuromonitoring of a pregnant woman in the third trimester showed that anesthesia with remimazolam allows safe brain surgery combined with intraoperative visual evoked potential monitoring. Further research is needed to determine the effects of remimazolam on the fetus, as well as the safe dosage and duration of exposure. [ABSTRACT FROM AUTHOR]

Objective: Intraventricular baclofen has been reported as an alternative to intrathecal baclofen for managing refractory spasticity and dystonia in some circumstances. In this report, we described a frame-based stereotactic approach for precisely positioning of the infusion catheter into the third ventricle. Material and methods: High resolution contrast-enhanced anatomical MR sequences was acquired prior to surgery for pre-planning. Catheter trajectory was planned to pass from the lateral ventricle to the third ventricle through the Foramen of Monro. The surgical procedure was adapted from the frame-based deep brain stimulation surgery. The Touch-Loc kit (SceneRay, China) was used to temporarily secure the catheter in place during the surgery. From July 2022 to December 2022, three patients suffering from intractable spasticity and/or secondary dystonia received IVB successfully using the described technique. Results: No severe adverse events, including death, intracranial hemorrhage, infection, catheter migration or fracture, were documented at the last follow-up (range: 12‒24 months). Transient side effects included mild nausea following the initiation of infusion or the increase in infusion rate. All three patients responded to the IVB. Conclusions: The described frame-based stereotactic technique for IVB catheter implant is feasible and could be quickly mastered by neurosurgeons in related fields. Larger prospective cohorts with longer follow-up periods are necessary to further evaluate the long-term safety and efficacy of this procedure. [ABSTRACT FROM AUTHOR]

AbstractBackgroundMethodsResultsConclusionsPatients with glioma often report language complaints with devastating effect on daily life. Analysing spontaneous speech can help to understand underlying language problems. Spontaneous speech monitoring is also of importance during awake brain surgery: it can guide tumour resection and contributes to maintaining language function. We aimed to investigate the spontaneous speech of patients with glioma in the perioperative period and the additional value of spontaneous speech analyses compared to standardised language testing.We elicited and transcribed spontaneous speech of eight patients with glioma elected for awake brain surgery preoperatively, intraoperatively and 2.0–3.5 months postoperatively. Linguistic errors were coded. Type Token Ratio, Mean Length of Utterance of words, minimal utterances, and errors were extracted from the transcriptions. Patients were categorised based on total error patterns: stable, decrease or increase during surgery. Reliable Change Index scores were calculated for all spontaneous speech variables to objectify changes between time points. Language performance on language tests was compared to spontaneous speech variables.Most errors occurred in lexico-syntax, followed by phonology/articulation, syntax, and semantics. The predominant errors were Repetitions, Self-corrections, and Incomplete sentences. Most patients remained stable over time in almost all spontaneous speech variables, except in Incomplete sentences, which deteriorated in most patients postoperatively compared to intraoperatively. Some spontaneous speech variables (total errors, MLUw, TTR) gave more information on language change than a standard language test.While the course of spontaneous speech over time remained relatively stable in most patients, Incomplete sentences seems to be a robust marker of language difficulties patients with glioma. These errors can be prioritised in spontaneous speech analysis to save time, especially to determine intra- to postoperative deterioration. Importantly, spontaneous speech analyses can give more information on language change than standardised language testing and should therefore be used in addition to standardised language tests. [ABSTRACT FROM AUTHOR]

Background/Objectives: Routine postoperative ICU admission following brain tumor surgery may not benefit selected patients. The objective of this study was to develop a risk prediction instrument for early (within 24 h) postoperative adverse events using machine learning techniques. Methods: Retrospective cohort of 1000 consecutive adult patients undergoing elective brain tumor resection. Nine events/interventions (CPR, reintubation, return to OR, mechanical ventilation, vasopressors, impaired consciousness, intracranial hypertension, swallowing disorders, and death) were chosen as target variables. Potential prognostic features (n = 27) from five categories were chosen and a gradient boosting algorithm (XGBoost) was trained and cross-validated in a 5 × 5 fashion. Prognostic performance, potential clinical impact, and relative feature importance were analyzed. Results: Adverse events requiring ICU intervention occurred in 9.2% of cases. Other events not requiring ICU treatment were more frequent (35% of cases). The boosted decision trees yielded a cross-validated ROC-AUC of 0.81 ± 0.02 (mean ± CI95) when using pre- and post-op data. Using only pre-op data (scheduling decisions), ROC-AUC was 0.76 ± 0.02. PR-AUC was 0.38 ± 0.04 and 0.27 ± 0.03 for pre- and post-op data, respectively, compared to a baseline value (random classifier) of 0.092. Targeting a NPV of at least 95% would require ICU admission in just 15% (pre- and post-op data) or 30% (only pre-op data) of cases when using the prediction algorithm. Conclusions: Adoption of a risk prediction instrument based on boosted trees can support decision-makers to optimize ICU resource utilization while maintaining adequate patient safety. This may lead to a relevant reduction in ICU admissions for surveillance purposes. [ABSTRACT FROM AUTHOR]

Nerves and blood vessels must be protected during brain tumor surgery, which has traditionally relied on microscopes. In the 2000s, endoscopes and related equipment were developed for neurosurgery. In this review, we aim to outline the role of endoscopes in brain tumor surgery and discuss the emerging use of exoscopes. The primary use of endoscopes in brain tumor surgery is in endoscopic endonasal surgery for pituitary tumors. By using the space within the sphenoid sinus, surgeons can insert an endoscope and instruments such as forceps or scissors through the nose to access and remove the tumor. Compared to microscopes, endoscopes can get closer to tumors, nerves, and blood vessels. They enable wide-angle observation of the skull base, making them valuable for skull base tumors as well as pituitary tumors. Endoscopes are also used in cases where a brain tumor is associated with hydrocephalus, allowing surgeons to correct obstructive hydrocephalus and perform tumor biopsies simultaneously. Exoscopy, a newer technique introduced in recent years, involves surgeons wearing special glasses and removing the tumor while viewing a three-dimensional monitor. This approach reduces surgeon fatigue and allows for more natural positioning during lengthy brain tumor surgeries. Future brain tumor surgeries will likely involve robotic surgery, which is already used for other organs. This is expected to make brain tumor removal safer and more accurate. [ABSTRACT FROM AUTHOR]

Purpose: Due to brain shift during bilateral deep brain stimulation (DBS) surgery, placement of the second electrode may be subjected to more error than that of the first electrode. The authors aimed to investigate the accuracy of second electrode placement in this setting. Materials and methods: Fifty-five patients with Parkinson's disease who underwent bilateral DBS surgery (110 electrodes) were retrospectively evaluated. The targets were subthalamic nucleus (STN) and globus pallidus interna (GPi) in 40 and 15 cases, respectively. Preoperative planning and postoperative electrode images were co-registered to compare the error margin between the two sides. Results: There is a statistically significant difference in the directional axis error along the y axis only when comparing each laterality (posterior 0.04 ± 1.21 mm vs anterior 0.41 ± 1.07 mm, p = 0.006). There is no significant difference of other error parameters, final track location, and number of microelectrode recording passes between the two sides. In a subgroup analysis, there is a significant difference in directional axis error along the y axis only in the STN subgroup (posterior 0.40 ± 1.05 mm vs anterior 0.18 ± 1.04 mm, p = 0.003). Conclusion: Although a statistically significant difference in directional axis error along the y axis was found between first and second electrode placements in the STN group but not in the GPi group, its magnitude is well below the clinically significant threshold. [ABSTRACT FROM AUTHOR]

Background: Intraoperative ultrasound (iUS) imaging has emerged as a promising adjunct in glioma surgery with both, 2-dimensional (2D) as well as navigated 3-dimensional (n3D), modes increasingly being used. Methods: We analyzed our decade-long experience of 1075 brain tumor (807, 75% gliomas) cases operated using iUS. A retrospective chart and electronic records review was performed. The primary aim was to understand the patterns of use of iUS mode and its purpose of application (as a localizing tool or as a resection control modality) as well as to evaluate its impact on the extent of resection. Results: The use of iUS increased over time, especially with the introduction of n3DUS though 2DUS remained the more commonly used mode (63%) overall during this period. For biopsies (156 cases), both 2D, as well as n3D iUS, were used as a localizing tool only. Lesion localization was the major purpose for use of iUS even for tumor resections (61%). Resection control was performed more often for gliomas (46.5% compared to 16.5% in non-glial tumors). n3DUS was the preferred modality as a resection control tool irrespective of histological class. GTR (gross total resection) was achieved in 53.1% cases overall, while in glial and non-glial tumors it was 44.7% and 80.7%, respectively. GTR was higher when iUS was used as a resection control modality. The US and MR defined EOR (extent of resection) showed substantial agreement (κ = 0.678) with high diagnostic accuracy of 84% for glial tumors. In glial tumors, iUS was used more often in eloquent tumors and GTR rates were slightly higher than when iUS was not used. Conclusion: iUS is a versatile tool and is a useful surgical adjunct for glioma surgeons. Besides its proven benefit as a localizing tool, when used as a tool for resection control it improves the resection rates. n3DUS may offer benefits over 2DUS as a resection control modality, though the evidence is still evolving. [ABSTRACT FROM AUTHOR]

Introduction: Treatment‐resistant depression (TRD) is a condition in which patients suffering from depression no longer respond to common methods of treatment, such as anti‐depressant medication. Neurosurgical procedures such as ablative surgery, deep brain stimulation, and vagus nerve stimulation have been used in efforts to overcome TRD. Objectives: This review aims to provide an overview of the side effects of neurosurgery performed in clinical studies related to depression. Methods: A literature search was conducted through PubMed, MEDLINE, EMBASE, Ovid, and ClinicalTrials.gov databases. Results: This review selected 10 studies for ablative surgery, 12 for deep brain stimulation, and 10 for vagus nerve stimulation, analyzing their side effect profiles of neurosurgery for TRD. The major side effects of each type of neurosurgery were identified, such as incontinence and confusion for ablative surgery, headaches and increased suicide ideation for deep brain stimulation, and voice hoarseness and dyspnea for vagus nerve stimulation. Conclusion: The review discusses the merits and demerits of neurosurgery as a treatment option for TRD. It also suggests new insights into decreasing the burden of these neurosurgical side effects so that they can be a viable, high‐efficacy treatment method for TRD. [ABSTRACT FROM AUTHOR]

Background Despite high long-term survival rates, pediatric low-grade gliomas (pLGGs) are linked with significant tumor- and treatment-associated morbidities that may persist throughout life. The aims of this descriptive cross-sectional pilot study were to characterize health conditions among a cohort of patients with pLGG and explore the feasibility of quantifying disease burden and healthcare resource utilization (HRU). Methods Optum® Market Clarity Data were used to identify patients aged ≤18 years with an ICD-10 code for brain neoplasm, ≥1 physician notes, and with evidence of pLGG recorded between January 1, 2017 and June 30, 2018. Outcomes including health characteristics, HRU, medications, and procedures were assessed at 6-month intervals over 36 months. Results One hundred and fifty-four patients were identified with pLGG and over half experienced headache/migraine, respiratory infection, pain, or behavioral issues during the 36-month study period. The most common comorbidities were ocular/visual (including blindness), mental health disorders, seizures, and behavioral/cognition disorders. Most symptoms and comorbidities persisted or increased during the study period, indicating long-term health deficits. HRU, including speciality care visits, filled prescriptions, and administered medications, was common; 74% of patients had prescriptions for anti-infectives, 56% antiemetics, and 52% required pain or fever relief. Sixty-five percent of patients underwent treatment to control their pLGG, the most common being brain surgery. Little decline was observed in medication use during the study period. Conclusions Patients with pLGG have complex healthcare needs requiring high HRU, often over a long time. Patients need to be optimally managed to minimize disease- and treatment-related burden and HRU. [ABSTRACT FROM AUTHOR]

Background/Objectives: Functional MRI (fMRI) is widely used to assess language lateralization, but its application in patients with brain tumors can be hindered by cognitive impairments, compensatory neuroplasticity, and artifacts due to patient movement or severe aphasia. Gray matter volume (GMV) analysis via voxel-based morphometry (VBM) in language-related brain regions may offer a stable complementary approach. This study investigates the relationship between GMV and fMRI-derived language lateralization in healthy individuals and patients with left-hemisphere brain tumors, aiming to enhance accuracy in complex cases. Methods: The MRI data from 22 healthy participants and 28 individuals with left-hemisphere brain tumors were analyzed. Structural T1-weighted and functional images were obtained during three language tasks. Language lateralization was assessed based on activation in predefined regions of interest (ROIs), categorized as typical (left) or atypical (right or bilateral). The GMV in these ROIs was measured using VBM. Linear regressions explored GMV-lateralization associations, and logistic regressions predicted the lateralization based on the GMV. Results: In the healthy participants, typical left-hemispheric language dominance correlated with higher GMV in the left pars opercularis of the inferior frontal gyrus. The brain tumor participants with atypical lateralization showed increased GMV in six right-hemisphere ROIs. The GMV in the language ROIs predicted the fMRI language lateralization, with AUCs from 80.1% to 94.2% in the healthy participants and 78.3% to 92.6% in the tumor patients. Conclusions: GMV analysis in language-related ROIs effectively complements fMRI for assessing language dominance, particularly when fMRI is challenging. It correlates with language lateralization in both healthy individuals and brain tumor patients, highlighting its potential in preoperative language mapping. Further research with larger samples is needed to refine its clinical utility. [ABSTRACT FROM AUTHOR]

Background: Glioma tumor is the most common primary brain tumor and extent of resection of this tumor plays a significant role in the survival rate of the patients. Intraoperative ultrasound (IOUS) has become a convenient technique in brain tumor surgery due to its non-invasiveness, affordability, and real-time imaging capabilities, making it appealing to neurosurgeons, and assists neurosurgeons in identifying the tumor's location and adjacent structures during surgery. Materials & Method: This study was done prospectively, in Rasul Akram and Shahada-ye-Haftam Tir hospitals, Tehran, Iran, and evaluated IOUS's use in 20 patients with brain glioma between 2019 and 2022. Simple random sampling was used to select patients. The resection was performed using IOUS, and the extent of resection was assessed through imaging. We used SonoSite convex ultrasound probe with bandwidth of 10-3 MHz and scan depth of 3 to 18 cm. Results: The study found that with ultrasound guidance, the average mass resection rate was 89.3%. The use of ultrasound during surgery improved the resection rate compared to previous studies. Motor complications observed in 15% of patients after surgery included paralysis and verbal deficits, while the rate of meningitis was low. The average length of hospitalization for patients was 10 days, and the average intraoperative bleeding was 344 cubic centimeters. Conclusion: Ultrasound can be a valuable tool in resection of brain glioma as it provides real-time imaging and assists in tumor resection, and detect adjacent structures. However, it should be used in conjunction with other monitoring modalities. Further studies are necessary to explore the full potential and limitations of IOUS in neurosurgery. [ABSTRACT FROM AUTHOR]

Hydrocephalus, characterized by progressive expansion of the CSF-filled ventricles (ventriculomegaly), is the most common reason for brain surgery. 'Communicating' (i.e. non-obstructive) hydrocephalus is classically attributed to a primary derangement in CSF homeostasis, such as choroid plexus-dependent CSF hypersecretion, impaired cilia-mediated CSF flow currents, or decreased CSF reabsorption via the arachnoid granulations or other pathways. Emerging data suggest that abnormal biomechanical properties of the brain parenchyma are an under-appreciated driver of ventriculomegaly in multiple forms of communicating hydrocephalus across the lifespan. We discuss recent evidence from human and animal studies that suggests impaired neurodevelopment in congenital hydrocephalus, neurodegeneration in elderly normal pressure hydrocephalus and, in all age groups, inflammation-related neural injury in post-infectious and post-haemorrhagic hydrocephalus, can result in loss of stiffness and viscoelasticity of the brain parenchyma. Abnormal brain biomechanics create barrier alterations at the brain–CSF interface that pathologically facilitates secondary enlargement of the ventricles, even at normal or low intracranial pressures. This 'brain-centric' paradigm has implications for the diagnosis, treatment and study of hydrocephalus from womb to tomb. [ABSTRACT FROM AUTHOR]

Purpose: This study presents the morphological variation of falx cerebelli, which helps to identify the possible variations in the presence of the occipital sinus in the posterior margin of the fold whose damage during midline incision of posterior cranial fossa surgeries may lead to internal hemorrhage. Method: The study was conducted on 48 cranial cavities exploring the falx cerebelli. Variations in the number of folds, its proximal and distal attachments, and the drainage pattern of the occipital sinus were evaluated by histological processing of the upper 1/3rd section of the falx fold. Results: The variation in the number of folds recorded are single folds in 87.5%, double folded in 8.3%, and multiple folds (five and seven folded) in 4.2% of the cases. The variation in the proximal and distal attachments in single falx folds showed three combinations: Ramified triangular in 66.7%, both ramified type in 12.5%, and both triangular type in 8.3% of the cases. Double and multiple folds showed ramified and triangular types of variation in their attachments. Histological findings showed the presence of occipital venous sinuses in most of the single falx fold. Two aberrant venous sinuses were seen in a double and five-folded falx cerebelli. Conclusions: This study records the variations in the morphology of falx cerebelli. The histological data of this study sheds light on the drainage pattern of venous sinuses in the area whose negligence during midline incisions of brain surgeries may increase the possibility of hemorrhage. [ABSTRACT FROM AUTHOR]

Background: Periventricular pediatric low-grade gliomas (pLGG) present a surgical challenge due to their deep-seated location, accessibility, and relationship with the subcortical network connections. Minimally invasive parafascicular approaches with tubular brain retractors (port brain surgery) have emerged, in recent years, as an alternative to conventional microsurgical and endoscopic approaches for removal of periventricular tumors. Objectives: To describe the minimally invasive approach with tubular brain retractors for periventricular pLGG, its technique, applications, safety, and efficacy. Methods: In this article, we describe the port brain surgery techniques for periventricular pLGG as performed in different centers, with different commercialized tubular retractor systems. Illustrative cases followed by a literature review are analyzed, with a detailed description of different approaches or techniques, comparing their advantages and disadvantages with contemporary microsurgical and endoscopic approaches. Conclusions: The port brain surgery with micro-exoscopic vision and endoscopic assistance, for the treatment of deep-seated lesions such as periventricular pLGG, is an alternative for achieving a functionally safe—gross total or subtotal—tumor resection, obtaining adequate tissue for pathological examination. This technique could offer a new dimension for a less-invasive, safe, and effective access to deep-seated tumors, offering the possibility to lower morbidity in experienced hands. [ABSTRACT FROM AUTHOR]

Alpha-synuclein (αSyn) forms pathologic aggregates in Parkinson's disease (PD) and is implicated in mechanisms underlying neurodegeneration. While pathologic αSyn has been extensively studied, there is currently no method to evaluate αSyn within the brains of living patients. Patients with PD are often treated with deep brain stimulation (DBS) surgery in which surgical instruments are in direct contact with neuronal tissue; herein, we describe a method by which tissue is collected from DBS surgical instruments in PD and essential tremor (ET) patients and demonstrate that αSyn is detected. 24 patients undergoing DBS surgery for PD (17 patients) or ET (7 patients) were enrolled; from patient samples, 81.2 ± 44.8 µg of protein (n = 15), on average, was collected from surgical instruments. Light microscopy revealed axons, capillaries, and blood cells as the primary components of purified tissue (n = 3). ELISA assay further confirmed the presence of neuronal and glial tissue in DBS samples (n = 4). Further analysis was conducted using western blot, demonstrating that multiple αSyn antibodies are reactive in PD (n = 5) and ET (n = 3) samples; truncated αSyn (1–125 αSyn) was significantly increased in PD (n = 5) compared to ET (n = 3), in which αSyn misfolding is not expected (0.64 ± 0.25 vs. 0.25 ± 0.12, P = 0.046), thus showing that multiple forms of αSyn can be detected from living PD patients with this method. [ABSTRACT FROM AUTHOR]

Background: During epilepsy surgery, it is equally important to record electrocorticography (ECoG) for detecting epileptogenic activity and guiding brain resection, and to evaluate neuromonitoring data, particularly motor evoked potentials (MEP), for avoidance of postoperative neurological complications. However, sevoflurane, which is commonly used during recording of ECoG, may attenuate the MEP response. It enforces anesthesiologists and neurosurgeons to select one anesthetic agent over another, facilitating either ECoG or MEP monitoring. Case presentation: In the presented case of a 20-year-old man, who underwent surgery for temporal lobe epilepsy, a novel technique of neuroanesthesia was introduced, integrating initial induction of the total intravenous anesthesia (TIVA) with propofol (effect-site concentration, 2.3–3.0 μg/ml), its subsequent switching to sevoflurane (end-tidal concentration, 2.5%) for ECoG recording, and further change back to TIVA for MEP monitoring during brain resection. Conclusions: Intraoperative switch of anesthetic agents according to specific intraoperative requirements may be useful for cases of brain surgery requiring both ECoG recordings and MEP monitoring. [ABSTRACT FROM AUTHOR]

In neuroendoscopy, an assistant surgeon holds the endoscope while the operating surgeon performs brain surgery using surgical instruments in both hands. The assistant surgeon's task can be strenuous over time, especially in long surgeries, and unsteadiness or tremor might affect the visualization quality that the operating surgeon depends upon. Existing mechanical and pneumatic arms offer limited flexibility. We propose a robotic assistant as a third hand to the surgeon. It holds the endoscope and can be moved freely or held in place. As a proof of concept, we attached a neuroendoscope to an offthe- shelf robot with a custom handle, including a force/torque (F/T) sensor. We qualitatively identified the requirements for the third hand with a surgeon as a participant. We also quantitatively identified the range of forces applied by the endoscope to act as a retractor on two brain phantoms while visualizing the surgical site. With our proof of concept study, we could show the feasibility of robotic assistance in neuroendoscopy. Based on our observations, we found that an intuitive input device to switch the different robot modes, a second F/T sensor to measure the surgeon's input and tissue interaction separately, and a differently shaped precision grip handle represent promising improvements to our third hand prototype. [ABSTRACT FROM AUTHOR]