Journal of neurosurgery最新文献

Objective: The objective was to evaluate the stability of stimulation current delivered by deep brain stimulation (DBS) systems during MRI scanning and to assess whether configuration-dependent variability in induced current may undermine the interpretability of functional MRI (fMRI) acquired during active stimulation.

Methods: The authors measured the electrical output of 2 current-controlled DBS systems in a standardized phantom during 3-T MRI acquisition. Stimulation was delivered in both monopolar and bipolar configurations, with the DBS systems on and off. Induced current was recorded using a custom MRI-conditional setup, and peak amplitudes were quantified across multiple sequences, including gradient-intensive fMRI protocols. All data were normalized to baseline output and analyzed using Cohen's d to assess the magnitude of MRI-induced current deviation.

Results: Monopolar stimulation during MRI exhibited significant current fluctuations, with induced amplitudes ranging from -3.2 to +3.9 mA and frequent polarity inversion. These distortions were sequence dependent and most pronounced during fMRI acquisition. In contrast, bipolar stimulation demonstrated stable output with minimal deviation from programmed parameters. The variability observed in monopolar output was not attributable to impedance shifts and was consistent across both DBS systems tested.

Conclusions: MRI-induced current substantially alters the effective output of monopolar DBS, introducing uncertainty into any concurrent fMRI acquisition. Although functional imaging was not directly performed in human subjects, these findings imply that the observed blood oxygen level-dependent (BOLD) response during monopolar stimulation likely reflects the distorted, not programmed, stimulation. Bipolar configurations avoid this confounder and should be preferred when interpreting fMRI data acquired during DBS.

Objective: Magnetic resonance-guided focused ultrasound (MRgFUS) is increasingly recognized as an effective treatment option for patients with medication-refractory essential tremor (ET). Indirect coordinates of the ventral intermediate nucleus of the thalamus, as well as the dentato-rubro-thalamic tract (DRTT) originating from the ipsilateral dentate nucleus, known as the "nondecussating DRTT" (nd-DRTT), are commonly used as targets for sonication. Anatomically, the DRTT originating from the contralateral dentate nucleus, referred to as the "decussating DRTT" (d-DRTT), constitutes the predominant component of the two fiber populations. However, the d-DRTT is rarely visualized using conventional diffusion tensor imaging (DTI) because of the technical challenges associated with resolving crossing fiber orientations. Probabilistic tractography enables the differentiation of crossing fibers, thus allowing for visualization of both the d-DRTT and nd-DRTT. Authors of this study aimed to evaluate whether the d-DRTT delineated by probabilistic tractography represents an anatomical target more important than indirect coordinates or the nd-DRTT.

Methods: Consecutive patients with medically refractory ET who underwent unilateral MRgFUS thalamotomy at a single institution between May 2022 and August 2024 were analyzed. Tremor severity was assessed using the Clinical Rating Scale for Tremor Part B, and the percentage improvement at 3 months after treatment was calculated as an indicator of functional recovery. Probabilistic tractography of the DRTT was performed post hoc using preoperative diffusion MRI and Bayesian modeling (BedpostX) and probabilistic tracking (ProbtrackX). The distances between the sonicated lesion as detected on postoperative MRI and each of the following were compared: indirect coordinates, nd-DRTT, and d-DRTT. Subgroup analysis was performed on patients with a peak lesion temperature ≥ 55°C. Pearson correlation was used to assess the relationships between distance metrics and clinical outcomes.

Results: Probabilistic tractography successfully visualized the d-DRTT in all 28 patients included in the study. The d-DRTT was more lateral than both the indirect coordinate and the nd-DRTT (p < 0.01 for both), with a nonsignificant tendency for a more anterior position relative to the nd-DRTT (p = 0.054). Among the patients with a peak lesion temperature ≥ 55°C, the distance between the sonicated lesion and the d-DRTT showed a strong correlation with clinical outcomes, whereas that between the lesion and nd-DRTT showed a moderate correlation; the indirect coordinates showed no significant correlation.

Conclusions: Probabilistic tractography successfully visualized the d-DRTT, and its location appears to capture the "tremor-relevant" neural pathway more accurately than either the indirect coordinate or the nd-DRTT.

Objective: Ventricular entry (VE) during resection can maximize high-grade glioma (HGG) resection, but it remains unclear whether tumor contiguity to the ventricles or VE increases the risk of leptomeningeal metastasis (LM) and/or worsens overall survival (OS).

Methods: To clarify the role of VE and tumor location in LM incidence and OS, the authors retrospectively reviewed the charts of patients who underwent their first resection of supratentorial HGG at The University of Texas MD Anderson Cancer Center between 1993 and 2021. OS and time to LM diagnosis were estimated using the Kaplan-Meier method; their associations with patient and treatment variables, including the tumor proximity to the ventricle, were assessed via Cox regression analysis.

Results: The authors identified 884 patients: 390 (44%) had VE and 444 (50%) had ependymal contact (EC) tumors. Eighty-two percent of patients with VE had EC, while only 25% of those without VE had EC (p < 0.0001). On multivariate analysis, VE did not significantly predict LM (hazard ratio [HR] [95% CI] 1.32 [0.57-3.04], p = 0.520) or OS (HR 1.03 [0.87-1.22], p = 0.744). However, EC significantly increased LM risk (HR 3.97 [1.43-11.01], p = 0.008) and worsened OS (HR 1.33 [1.1-1.6], p = 0.003). Although patients with VE had an overall lower complete resection rate compared to those without VE (63% vs 72%, p = 0.005), VE improved the extent of resection among EC tumors with 58% having complete resection (vs 47% of EC tumors without VE).

Conclusions: Tumors with EC predict higher LM risk and shorter OS, while VE during resection does not increase LM risk or worsen OS. Surgeons can use VE to maximize resection of supratentorial HGGs without increasing the risk of subsequent LM.

Objective: Jugular fossa schwannomas are rare tumors arising from the lower cranial nerves. Their complex anatomical location poses significant surgical challenges. This study presents the authors' experience with the suprabulbar approach, refined through cadaveric dissections, as a safe and effective technique to achieve gross-total resection of jugular fossa schwannomas, while preserving the lower cranial nerves and minimizing the risk of postoperative morbidity.

Methods: The suprabulbar step-by-step approach was performed bilaterally on 8 formalin-fixed cadaveric heads, and anatomical measurements were obtained to assess the variability of the presigmoid infralabyrinthine surgical window. A retrospective analysis was conducted of the records of 22 patients with jugular fossa schwannomas who underwent resection between 1994 and 2024. Pre- and postoperative data were reviewed to assess the intraoperative technique and surgical outcomes.

Results: Of 22 tumors, 20 (91%) were classified as type D, while 1 tumor each was classified as type A and type B. Gross-total resection was achieved in 77% of cases. There were no deaths or permanent neurological deficits. Transient lower cranial nerve deficits occurred in 14% of patients, all of which resolved during the follow-up period (mean 31.4 months). One perioperative complication was recorded as a suspected CSF leak. Overall, 64% of patients experienced improvement in preoperative neurological deficits. Three (14%) patients had confirmed tumor recurrence, all of whom underwent successful reoperation.

Conclusions: The suprabulbar approach, guided by meticulous anatomical planning, provides a reliable and versatile route for the resection of jugular fossa schwannomas. It enables fascicle-sparing resection through a safe window in the presigmoid dura, preserving critical structures, including the labyrinth and facial nerve, while facilitating decompression of the jugular bulb. Its versatility lies in the ability to combine intradural access with neck dissection in a single-stage procedure, allowing for maximal tumor removal for large and giant tumors and minimizing cranial nerve morbidity.

Objective: Despite advancements in neurosurgery and intensive care that reduce overall mortality, poor-grade aneurysmal subarachnoid hemorrhage (aSAH; patients with World Federation of Neurosurgical Societies [WFNS] grades IV and V) remains a significant clinical challenge and is associated with persistently high mortality rates. The aim of this study was to assess the long-term outcomes of patients with poor-grade aSAH and to identify factors influencing patient prognosis to guide clinical management.

Methods: A multicenter, observational cohort study was conducted across 12 regional centers in northern China. The study included patients with poor-grade aSAH admitted from 2017 to 2020. The baseline data included demographics, clinical presentation, aneurysm characteristics, and treatment modalities. Outcome data, including survival status, mortality along with its associated causes and timing, and modified Rankin scale (mRS) scores, were collected prospectively at the last medical follow-up. Changes in case fatality over time were quantified with weighted linear regression. Survival analysis was performed to estimate survival and hazard ratios for death. Binary logistic regression was performed to estimate the odds ratio for dependency (mRS scores 3-5).

Results: Among the 1589 enrolled patients, 1339 were successfully followed up, with a mean follow-up of 26.37 months. Among them, 61.5% (824/1339) were dependent or died. The overall mortality rate was 51.1% (684/1339), and 21.4% (140/655) of the survivors were dependent. The risk factors for mortality included age ≥ 65 years, previous history of stroke, and WFNS grade V. Additionally, conservative treatment and endovascular treatment were identified as risk factors and protective factors, respectively, compared with surgical treatment. WFNS grade V and middle cerebral artery aneurysms were independent risk factors for dependency.

Conclusions: Although there has been a downward trend in recent years, the long-term mortality rate for patients with poor-grade aSAH has remained significantly high at 51.1%, with 21.4% of survivors being dependent. Active aneurysm treatment, to the extent possible, is crucial for improving the prognosis of these patients.

Objective: Trigeminal neuralgia (TN) secondary to multiple sclerosis (MS) is a debilitating condition with limited treatment options. Partial sensory rhizotomy (PSR) has been utilized as a surgical intervention, although its efficacy and durability remain unclear. This study evaluates the long-term outcomes of PSR alone and in combination with microvascular decompression (MVD) or internal neurolysis (IN) in patients with TN secondary to MS.

Methods: The records of patients who underwent PSR for TN secondary to MS between 2012 and 2023 were retrospectively analyzed. Patients were categorized into four groups: first PSR, redo PSR, PSR+MVD, and PSR+IN. Demographics, prior treatments, pain outcomes, time to recurrence, and complications were analyzed.

Results: A total of 30 patients undergoing 37 procedures were included in the analysis. Patients had undergone another procedure for the treatment of TN on the ipsilateral side prior to 33 of 37 procedures (89.2%). Immediate postoperative pain relief was achieved in 89.2% of cases, with no significant differences between groups. Pain recurred at a mean of 1.64 ± 1.71 years, with no significant differences seen between groups. At the final follow-up (mean 3.14 ± 2.58 years), 75% of PSR+MVD and 100% of PSR+IN cases remained pain free, while 52.3% of first PSR cases required additional procedures. Complication rates did not significantly differ between groups.

Conclusions: PSR is an effective salvage procedure for TN secondary to MS, particularly in patients with prior failed treatments. Combining PSR with MVD or IN may enhance long-term pain relief without increasing complication rates. Future prospective studies are needed to validate these findings.

Objective: Stroke care disparities related to race and ethnicity have been well-documented, with African American populations experiencing higher stroke incidence and receiving less timely treatments like intravenous tissue plasminogen activator (tPA). Telemedicine, particularly telestroke, has emerged as a potential solution to address geographic and racial disparities in acute stroke care, yet some studies have reported persistent racial differences in treatment. This retrospective study was conducted to analyze data from a telestroke network consisting of a hub hospital and 38 spoke centers in Pennsylvania.

Methods: Patients who had presented with acute ischemic stroke and required a virtual consult with a neurovascular specialist were included in the study. The data collected from electronic medical records included baseline characteristics, stroke-related variables, treatment details, and outcomes. Descriptive statistics, chi-square tests, and a Kruskal-Wallis test were used to analyze the data. In addition, univariate and multivariable logistic regression analyses were performed to evaluate the association between race and key outcomes.

Results: A total of 4256 patients were included, of whom 2925 were White and 1122 were African American. On multivariable logistic regression, African American patients, as compared to White patients, were less likely to undergo mechanical thrombectomy (OR 0.58, 95% CI 0.35-0.96, p = 0.03) and were more likely to be discharged to rehabilitation (OR 1.39, 95% CI 1.06-1.84, p = 0.01), with no significant differences in tPA administration or death between the two racial groups.

Conclusions: The study results suggest that African American patients are significantly less likely to undergo mechanical thrombectomy and more likely to be discharged to rehabilitation compared with their White counterparts, despite similar rates of tPA administration and death. These findings highlight persistent disparities in advanced stroke interventions and postacute care, emphasizing the need to address structural and socioeconomic barriers to ensure equitable treatment and recovery for all patients.

Objective: Improved operating room (OR) efficiency provides greater patient throughput, reduced costs, and maximal patient care. The aim of this study was to quantify and compare OR turnover efficiency across neurosurgical and otorhinolaryngology (ENT) specialties using artificial intelligence (AI) cameras.

Methods: A prospective study was conducted after obtaining IRB approval. AI-powered cameras documented operative turnover processes for cranial, spinal, and ENT cases at a tertiary academic center during a 30-day period. The software initiated recording when a patient exited the OR, and stopped recording upon entry of the subsequent patient, ensuring patient anonymity. Parameters included instrument tray count and personnel tracking. Turnover subprocesses were classified into clearing, cleaning, waiting, and instrument setup.

Results: The AI model successfully itemized turnover parameters for 53 operative turnovers (6 cranial, 32 spinal, and 15 ENT cases). Case duration averaged 175.4 (SD 86.1) minutes for cranial, 120.4 (SD 50.8) minutes for spinal, and 67.6 (SD 34.6) minutes for ENT cases. The overall average was 111.7 (SD 58.1) minutes. The mean turnover durations were 56.6 (SD 9.3) minutes for cranial cases, 52.2 (SD 20.3) minutes for spinal cases, and 40.4 (SD 15.5) minutes for ENT cases (p = 0.079). Clearing, cleaning, and waiting did not reveal any significant differences between specialties. A multivariate analysis did not reach significance after comparing the different ORs or different intragroup surgeons. Instrument setup duration emerged as the greatest determinant of variability: mean 38.3 (SD 13.4) minutes for cranial cases, 27.7 (SD 11.7) minutes for spinal cases, and 17.1 (SD 8.3) minutes for ENT cases (p = 0.0005). Instrument setup was significantly correlated with the number of instrument trays (R2 = 0.33, p < 0.0001), adding 2.7 minutes per additional tray.

Conclusions: AI vision systems provided automated comparisons of OR turnover parameters, highlighting distinct bottlenecks in cranial, spinal, and ENT cases. Optimizing instrument setup through tray rationalization represents a cost-effective intervention that warrants further investigation.