A mosaic of photos submitted by female neurosurgeons, overlaid with the shape of the female symbol. The mosaic is a demonstration of a crucial but underrepresented population in the neurosurgery workforce. © Sarah Woodrow, published with permission. See the article by Mulligan et al. (pp 1088–1097).
Investigators reviewed the clinical and angiographic results of the surgical treatment of the brain arteriovenous malformation (AVM) patients included in the randomized trial of the Treatment of Brain Arteriovenous Malformations Study (TOBAS). Surgical treatment was curative for 88% of patients. Permanent treatment-related complications occurred in 4%. TOBAS findings reflect real-world conditions, and the conclusions are generalizable to future AVM patients encountered in clinical practice.
Long-term outcomes after resection of hemorrhagic brainstem cavernous malformations (BSCMs) were evaluated retrospectively in 46 consecutive cases. At last follow-up (median 153 months), the modified Rankin Scale score of 0–2 was noted in 91% and a score of 0 in 39% of patients, and only a lower Lawton grade carried a statistically significant independent association with favorable long-term outcome. These results reconfirm the safety and efficacy of hemorrhagic BSCM resection and independently validate the Lawton grading system.
The authors evaluated the risk factors for 5-year prospective hemorrhage and developed a predictive nomogram based on an observational brainstem cavernous malformation (BSCM) series. The nomogram showed convincing predictive power and accurately differentiated patients from three different risk groups. This preoperative grading system quantitatively informs patients of their possibility of future hemorrhage and distinguishes aggressive cases from silent ones to provide new evidence for individualized therapeutic strategies.
The authors evaluated the impact of frailty on the outcomes of unruptured anterior circulation aneurysms and compared frailty with age and other comorbidity indexes. The frail patients had 50-60 times higher complication rates compared to their nonfrail counterparts. Frailty predicted the outcomes better than age and comorbidity indexes. This study stresses the importance of including the frailty assessment in preoperative planning.
This multicenter retrospective study aimed to describe the first large-scale North American real-world experience with the Flow Redirection Endoluminal Device (FRED) for treatment of intracranial aneurysms. The results suggest lower than previously reported efficacy and safety rates, including suboptimal occlusion rates at short- and mid-term follow-up evaluations and high in-stent stenosis and parent vessel occlusion rates. These findings warrant judicious use of this device until future prospective studies with longer follow-up durations better elucidate the outcomes of FRED treatment.
The authors examined brain arteriovenous malformation (AVM) flow and transit time on angiograms and correlated them with the obliteration response after Gamma Knife radiosurgery. They validated a feasible method in the clinical setting and showed that flow rate has an inverse correlation with obliteration rates. This could have considerable implications in the way neurosurgeons inform patients and set realistic expectations regarding latency times.
Researchers evaluated whether embolization before stereotactic radiosurgery was a negative factor for nidus obliteration in patients with brain arteriovenous malformations by equalizing basic characteristics with propensity score matching. Although embolization before stereotactic radiosurgery has been considered as a negative factor of nidus obliteration, it was not significantly associated with a low nidus obliteration rate after equalizing basic characteristics, including the original nidus volume before embolization.
Vestibular schwannomas (VSs) have no proven medical treatments. Previous literature shows that c-Jun N-terminal kinase (JNK) activity is elevated in VS cells and contributes to their survival. This study sought to test whether inhibiting JNK would reduce VS growth and survival. The JNK inhibitor AS602801 reduced proliferation and viability in primary cell cultures, patient-derived xenografts, and genetic mouse models of VS. Thus, JNK inhibitors may contribute to future therapies and should be studied further.
Cerebrospinal fluid in the lateral end of a vestibular schwannoma within the internal auditory canal is called a fundal fluid cap. This study evaluated its clinical impact on postoperative facial nerve function. The authors found that patients with a fundal fluid cap had a better chance of favorable facial nerve function after microsurgery. This radiographic sign can be used to predict the risk of postoperative facial nerve dysfunction and assist with preoperative decision-making regarding treatment strategy.
Motivated by reported limitations of prior quality of life instruments, researchers developed a new disease-specific measure, the Vestibular Schwannoma Quality of Life Index, that consists of 40 items evaluating the impact of vestibular schwannoma diagnosis and its management on quality of life, satisfaction, and employment. Through shared decision-making, scores from this valid and reliable index can be used to assist patients and clinicians when selecting the optimal management for this disease.
In this report, the authors developed and evaluated the feasibility of resecting the temporal pole and mesial temporal structures through an endoscopic anterior transmaxillary (eATM) approach. This approach provides direct access to these structures, permitting selective resection without transgression of cerebral and potentially eloquent structures such as the temporal stem and lateral temporal neocortex. The eATM approach was successfully used in 4 patients with mesial temporal lobe epilepsy and all achieved Engel class Ia seizure freedom at 1-year follow-up or greater. This study demonstrates the safety and efficacy of the eATM procedure in carefully selected epilepsy patients.
Researchers used brief brain stimulation sessions and deep learning to localize where seizures originated in people with epilepsy. Typically, people must stay in the hospital for many weeks to properly localize seizure onset regions. However, these regions can be localized in less than an hour by using brief stimulation and deep learning. These techniques could rapidly expedite presurgical workup and augment surgical decision-making.
The authors set out to understand the importance of the proximity of deep brain stimulator contacts to the anterior thalamic nucleus–mammillothalamic tract (ANT-MMT) junction in determining the efficacy of deep brain stimulation in drug-resistant epilepsy. The researchers demonstrated that the accuracy in targeting this area is key in determining a positive clinical outcome. This study provides evidence that the ANT–MMT junction can be targeted for deep brain stimulator implantation in treating epilepsy.
The authors compared clinical courses of patients with Parkinson disease undergoing subthalamic nucleus (STN) deep brain stimulation (DBS) surgery through either awake or asleep targeting and correlated outcomes with estimates of structural and functional connectivity. Compared to awake STN DBS, asleep procedures achieved similarly optimal targeting based on clinical outcomes, electrode placement, and connectivity estimates with shorter duration of surgery. These results add to literature demonstrating similar clinical efficacy between awake and asleep DBS.
Researchers examined the 5-year clinical outcomes of patients with medically refractory essential tremor (ET) who had previously undergone MRI-guided focused ultrasound (MRgFUS) thalamotomy in a randomized, blinded, sham-controlled trial. Improvement in tremor control was measured at 73.1% from baseline with only mild or moderate side effects and no delayed complications. Unilateral MRgFUS thalamotomy demonstrates sustained and significant tremor improvement with an overall improvement in the quality of life of patients with medically refractory ET.
The authors investigated motor recovery after hypoglossal-to-facial nerve anastomosis in patients with facial nerve palsy. They conducted a systematic review of the literature and performed a patient-level analysis. Surgery was quite effective in restoring at least part of facial nerve functionality, with almost half the patients experiencing improvement by 3 or more points on the House-Brackmann scale. In this analysis, a shorter window from injury to anastomosis was associated with superior outcomes.
Researchers compared the rates of complications within 1 year and operating room (OR) time between nonoverlapping and overlapping functional neurosurgical procedures. There was no increased risk of complications or increased OR time in the overlapping procedures. This study indicates that the benefits of overlapping surgery, including increased access to specialty neurosurgical care, carry no increased risk of complication and no increased OR time.
Authors of this study aimed to identify radiological factors associated with intracranial hypertension following traumatic brain injury (TBI). The main finding was that patients with a Rotterdam CT score ≤ 2 and no sulcal effacement were unlikely to develop intracranial hypertension. Based on this study, patient selection criteria for intracranial pressure monitoring may be refined using radiological information following severe TBI.
Decompressive craniectomy is the standard of care for management of wartime severe head injury, which includes host-nation military partners and civilians. Reconstructive cranioplasty, often in austere and resource-limited environments, presents logistical and surgical difficulties. This retrospective observational study found that the use of custom synthetic cranial implants is a viable clinical option for reconstruction. Study outcomes can be used to inform existing wartime trauma guidelines as well as future neurosurgical care in austere environments.
The authors aimed to characterize the burden of neurotrauma in a rural neurosurgery practice in a sub-Saharan African low- and middle-income country. Head and spinal injuries in young males, mainly caused by road accidents and particularly motorcycle crashes, formed the bulk of this rural neurosurgery workload. This paper is likely one of the few data-driven scientific reports on this subject from rural settings in the global literature.
The authors studied the performance of a newly developed convolutional neural network (CNN) for automated detection and characterization of subdural hematoma (SDH). The Viz.ai SDH CNN performed exceptionally well at identifying and quantifying key features of SDH in an independent validation imaging data set. The findings will lay the foundation for future development of the CNN including more complex assessments with additional features that go far beyond the simple image analysis task.
The authors apply a novel forecasting method to find the most accurate projection of when gender parity in the field of neurosurgery may be achieved. This study found that female neurosurgeons would not reach the same proportion as male neurosurgeons until the year 2177 when compared to the overall physician workforce and, alarmingly, until 2267 compared to the entire US. population. The authors discuss strategies to disrupt and accelerate this current projected rate of growth.
The study used historical data to appraise the specialist neurosurgical workforce and training capacity in Africa and projected the workforce capacity by 2030. Africa, especially sub-Saharan Africa, currently has a significant deficit in neurosurgical workforce and training and will be unable to meet global targets by 2030 at current growth trends. Scaling up neurosurgical training would help to meet this target, and requires concerted collaborative efforts from continental, regional, and national agencies, and international organizations.
Researchers wanted to understand the effect of implementing a night float system on resident operative experience. Transitioning to a night float call system at their institution increased overall resident operative cases, particularly for the lead resident surgeon. Based on the results of this study, the authors support the use of a night float call system, in certain situations, to consolidate night call, which increases junior resident–level educational opportunities and senior resident cases.
The authors conducted a survey of individuals graduating from Committee on Advanced Subspecialty Training (CAST)–accredited fellowships in the past 5 years to characterize their experiences with and perspectives on the fellowship application process. Respondents agreed that a more standardized application timeline would be beneficial and indicated that postgraduate year (PGY) 5 or PGY6 was the appropriate time to interview for a fellowship. This study emphasizes improvements for the fellowship application process in neurosurgery.
The researchers queried partners of neurosurgery residents to assess their perspective on how neurosurgery residency affects their relationship. Satisfaction with the resident's work-life balance was an independent predictor of relationship satisfaction. These findings may allow residency programs to better tailor well-being initiatives to support residents' home lives as well as work lives.
The authors trace the origin, evolution, and legacy of terminology of the hippocampal artery of Uchimura. Uchimura's 1928 description of arteries that feed Ammon's horn brought international attention to epilepsy and the structure of the hippocampus, including evidence that the hippocampal vasculature is variable and vulnerable. The authors describe how a vital hippocampal artery became the nexus between details of ultrastructure, cerebral localization and function, disease correlation, and development of selective surgical treatment of the hippocampus.
A new minimally invasive approach was developed to allow access to the jugular foramen without resection of the eustachian tube. The endoscopic endonasal approach was combined with the novel third-nostril approach to achieve better exposure of the infrapetrous and ventral jugular foramen regions without mobilizing the eustachian tube. This study introduced a novel approach to the infrapetrous region with minimal risk of damaging the eustachian tube.
The aim of this study was to determine an optimal follow-up imaging surveillance strategy in terms of cost-effectiveness after resection of nonfunctioning pituitary adenomas with curative intent.
An individual-level state-transition microsimulation model was used to simulate costs and outcomes associated with three postoperative imaging strategies over a lifetime time horizon: 1) annual MRI surveillance, 2) tapered MRI surveillance (annual surveillance for 5 years followed by surveillance every 2 years), and 3) personalized surveillance (annual surveillance for 5 years followed by surveillance every 2 years when MRI shows remnant disease/postoperative changes, and surveillance at 7, 10, and 15 years for disease-free MRI). Transition probabilities, utilities, and costs were estimated from recent published data and discounted by 3% annually. Model outcomes included lifetime costs (2022 US dollars), quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs).
Under base case assumptions, annual surveillance yielded higher costs and lower health effects (QALYs) compared with the tapered and personalized surveillance strategies (dominated). Personalized surveillance demonstrated an additional 0.1 QALY at additional cost ($1298) compared with tapered surveillance (7.7 QALYs at a cost of $12,862). The ICER was $11,793/QALY. The optimal decision was most sensitive to the probability of postoperative changes on MRI after surgery and MRI cost. Accounting for parameter uncertainty, personalized surveillance had a higher probability of being a cost-effective surveillance option compared with the alternative strategies at 79%.
Using standard cost-effectiveness thresholds in the US ($100,000/QALY), personalized surveillance that accounted for remnant disease or postoperative changes on MRI was cost-effective compared with alternative surveillance strategies.
The objective of this report is to demonstrate the feasibility and versatile clinical potential utility of the combination of an irrigating ventriculostomy catheter with a bolt-based multimodality monitoring system for patients with aneurysmal subarachnoid hemorrhage. The system was found to be technically feasible to place, allowing for additional clinical utility and versatility for patient management with a single twist-drill access point. Such a system provides a new, minimally invasive option for monitoring brain physiology as well as the potential for new therapeutic approaches for subarachnoid hemorrhage including irrigating out blood products or local medication delivery.
Hearing and facial nerve function preservation is very high after surgical removal of intracanalicular vestibular schwannomas. In this series, 2 different types of intracanalicular vestibular schwannoma according to the position of the cranial nerves within the internal auditory canal were found. Tumors arising dorsal to the nerves (T1A type) had better surgical results than those arising between the nerves (T1B type). Preoperative identification of these tumors may help in choosing better treatment.
The authors investigated the prognostic significance of brain invasion (BI) in atypical meningioma and redefined the clinical behavior of BI in otherwise benign meningioma (benign meningioma with BI). An important finding was that benign meningioma with BI typically had an intermediate prognosis and could be differentiated from benign meningioma and classical atypical meningioma. The results suggest the insufficient importance placed on the diagnostic effect of BI in grading atypical meningioma in the latest WHO classification and thus fail to support the WHO decision on this classification.
Despite antiepileptic drugs, more than 30% of people with epilepsy continue to have seizures. Patients with such drug-resistant epilepsy (DRE) may undergo invasive treatment such as resection, laser ablation of the epileptogenic focus, or vagus nerve stimulation, but many are not candidates for epilepsy surgery or fail to respond to such interventions. Responsive neurostimulation (RNS) provides a neuromodulatory option. In this study, the authors present a single-center experience with the use of RNS over the last 5 years to provide long-term control of seizures in patients with DRE with at least 1 year of follow-up.
The authors performed a retrospective analysis of a prospectively collected single-center database of consecutive DRE patients who underwent RNS system implantation from September 2015 to December 2020. Patients were followed-up postoperatively to evaluate seizure freedom and complications.
One hundred patients underwent RNS placement. Seven patients developed infections: 2 responded to intravenous antibiotic therapy, 3 required partial removal and salvaging of the system, and 2 required complete removal of the RNS device. No postoperative tract hemorrhages, strokes, device migrations, or malfunctions were documented in this cohort. The average follow-up period was 26.3 months (range 1–5.2 years). In terms of seizure reduction, 8 patients had 0%–24% improvement, 14 had 25%–49% improvement, 29 experienced 50%–74% improvement, 30 had 75%–99% improvement, and 19 achieved seizure freedom. RNS showed significantly better outcomes over time: patients with more than 3 years of RNS therapy had 1.8 higher odds of achieving 75% or more seizure reduction (95% CI 1.07–3.09, p = 0.02). Also, patients who had undergone resective or ablative surgery prior to RNS implantation had 8.25 higher odds of experiencing 50% or more seizure reduction (95% CI 1.05–65.1, p = 0.04).
Responsive neurostimulator implantation achieved 50% or more seizure reduction in approximately 80% of patients. Even in patients who did not achieve seizure freedom, significant improvement in seizure duration, severity, or postictal state was reported in more than 68% of cases. Infection (7%) was the most common complication. Patients with prior resective or ablative procedures and those who had been treated with RNS for more than 3 years achieved better outcomes.
Researchers calculated the mortality and morbidity rates of 250 patients with 276 cavernous carotid aneurysms (CCA) from a relatively large single-center cohort. Of the CCAs, 73% were symptom free during a mean follow-up of 7.2 years, and the incidence of symptoms increased with aneurysm size, suggesting that treatment of CCAs should be considered mainly if the aneurysm is symptomatic or grows during the follow-up period. The findings of this study will help clinicians with decision-making regarding the management of CCAs.
In this study the authors reviewed the mechanisms behind trigeminal neuralgia (TN), which are poorly understood. Human studies thus far have suggested heterogeneous pathogenic mechanisms, as follows: 1) channelopathy-genetic studies have identified mutations found in only a small number of patients with TN; 2) oxidative stress disorders-reactive oxygen species are increased across numerous pain conditions including TN; and 3) inflammation-insight from patients with multiple sclerosis who have TN has suggested an inflammatory component. This study is valuable because it may help to indicate the role of precision-based therapies in treating TN.
The All Patients Refined Diagnosis Related Group (APR-DRG) system is widely used to determine hospital reimbursement and to monitor quality; however, APR-DRG methods are proprietary and have not been validated for neurosurgical disease. Using the SPARCS databases (2012-2020) for intracranial hemorrhage, the authors identified limited performance of APR-DRG modifiers for predicting mortality, disposition, and hospital costs. This study provides the first critical evaluation of the APR-DRG system in a neurosurgical cohort and identifies limitations for use in this population.
Researchers retrospectively assessed predictors of new seizures in patients undergoing stereotactic radiosurgery (SRS) for brain metastases. Larger planning target volume, tumor histology (melanoma, gastrointestinal cancer, and head and neck cancers), and prior seizures were the most significant factors associated with post-SRS seizures. Future prospective studies are needed to determine the true prognostic nature of these factors in predicting seizures following SRS for brain metastases.
Strokes affect almost 13 million new people each year, and whereas the outcomes of stroke have improved over the past several decades in high-income countries, the same cannot be seen in low-income and lower-middle-income countries. This is the first study to identify the availability of diagnostic tools along with the rates of stroke mortality and other poststroke complications in low-income and lower-middle-income countries.
A review of the literature was completed with a search of the MEDLINE, Embase, and Scopus databases, with adherence to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies were included if they reported any outcomes of stroke in low-income and lower-middle-income countries as designated by the World Bank classification. A meta-analysis calculating pooled prevalence rates of diagnostic characteristics and stroke outcomes was completed for all endpoint variables.
A total of 19 studies were included, of which 6 came from Ethiopia, 3 from Zambia, and 2 each from Tanzania and Iran. Single studies from Zimbabwe, Botswana, Senegal, Cameroon, Uganda, and Sierra Leone were included. A total of 5265 (61.7%) patients had an ischemic stroke, 2124 (24.9%) had hemorrhagic stroke, with the remaining 1146 (13.4%) having an unknown type. Among 6 studies the pooled percentage of patients presenting to hospital within 1 day was 48.37% (95% CI 38.59%–58.27%; I2 = 97.0%, p < 0.01). The pooled in-hospital mortality rate was 19.81% (95% CI 15.26%–25.31%; I2 = 91%, p < 0.01), but was higher in a hemorrhagic subgroup (27.07% [95% CI 22.52%–32.15%; I2 = 54%, p = 0.05]) when compared to an ischemic group (13.16% [95% CI 8.60%–19.62%; I2 = 87%, p < 0.01]). The 30-day pooled mortality rate was 23.24% (95% CI 14.17%–35.70%; I2 = 93%, p < 0.01). At 30 days, the functional independence (modified Rankin Scale score 0–2) pooled rate was 13.10% (95% CI 7.50%–21.89%; I2 = 82%, p < 0.01).
A severe healthcare disparity is present in low-income and lower-middle-income countries, where there is delayed diagnosis of strokes and increased rates of poor clinical outcomes for these patients.
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Similarly, new language-based AI models have been gaining popularity with an impressive knowledge base. In particular, OpenAI’s natural language processing (NLP) model ChatGPT
In performing modified in utero spina bifida (SB) repair in lambs, the authors compared the conventional method for closure with cryopreserved human umbilical cord (HUC) as a meningeal patch. The lambs with HUC meningeal patch repair had better function preservation and reduced spinal cord tethering and regeneration of the arachnoid layer than the lambs with conventional repair. The clinical significance of this finding is that the use of HUC as the meningeal patch in humans may transform in utero SB repair and other neurosurgical procedures that require graft material.
The authors aimed to explore the feasibility and efficiency of interrupted intraarterial selective cooling infusion (IA-SCI) combined with mechanical thrombectomy in patients with acute ischemic stroke (AIS). Interrupted IA-SCI for patients with AIS symptoms treated with mechanical thrombectomy seems to be safe and associated with favorable functional outcomes. Authors of this study developed a novel method of SCI called "interrupted IA-SCI" in stroke patients and are the first to show its safety and feasibility in patients undergoing mechanical thrombectomy.
TO THE EDITOR: Cerebral vasospasm after subarachnoid hemorrhage (SAH) and the associated delayed ischemic neurological deficits have always been a huge concern for neurosurgeons who are responsible for the clinical management of SAH. Clazosentan is an endothelin receptor antagonist that seems to be effective in preventing vasospasm. Endo et al.
The authors' results represent the long-term follow-up of unruptured untreated brain arteriovenous malformations (bAVMs) in a real-life cohort. In contrast to the ARUBA study's 0% mortality in the medical management arm, the long-term follow-up AVM-related mortality rate amounted to an unacceptable 8% among conservatively managed AVMs in our cohort. Even in the post-ARUBA era, active treatment options should be offered to patients with unruptured bAVMs. Tailored patient counseling should weigh the natural course of unruptured bAVMs against specific treatment-associated complication rates.
The authors investigated postoperative results in a consecutive cohort of 108 patients who underwent awake resection for giant lower-grade glioma (LGG) > 100 cm3. Three months after surgery, all patients but one had a normal neurological examination, with 85.1% of patients having returned to work. The mean extent of resection was 88.9% ± 7.0%, with a median survival of 138 months. Resection of huge LGGs can be reproducibly achieved with patients under awake mapping, with favorable long-term functional and oncological outcomes.
Patients with familial cavernous malformations (FCMs) and their families are concerned about future outlook. Over a 10-year follow-up period, rates of prospective hemorrhage and new seizure after diagnosis were 4.0% and 1.2% per patient-year, respectively. Eighty-three percent of patients were independent (modified Rankin Scale score ≤ 2) at the last follow-up. These findings provide clinically useful information on hemorrhage rate, seizure rate, and functional outcome and are helpful to practicing physicians when counseling patients with FCM and their families.
This study evaluated the feasibility and utility of intraprocedural diffusion and T2-weighted imaging during magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy. Diagnostic diffusion and T2-weighted sequences were obtained during the MRgFUS procedure without a dedicated head coil in place. Intraprocedural imaging showed an accurate lesion location when compared with immediate postprocedural imaging. These findings may help the operator understand, in real time, the ablation zone and inform difficult clinical decisions on when to complete the ablation procedure.
Investigators reviewed a large cohort of patients who underwent endoscopic endonasal odontoidectomy for ventral cervicomedullary junction stenosis. In this cohort, the largest to date, the authors found that the endonasal corridor allowed for excellent decompression that yielded symptom resolution, early extubation, and return to oral feeding. They further defined radiographic parameters that allowed prediction of extent of dens resection, thus providing an outcome prediction tool to other neurosurgeons interested in further exploring this technique.
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