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Platelet aggregation is intimately associated with vascular inflammation and is commonly seen on routine histology studies of cerebral aneurysms. Platelets, when activated, have been shown to augment neutrophil response and the pro-inflammatory cascade. Platelet-neutrophil complexes have been found to aggravate atherosclerosis through a positive feedback loop. We hypothesized that targeting platelet aggregation and downstream inflammation could be used to prevent aneurysm formation and progression. First, we induced cerebral aneurysm formation in a previously described intracranial aneurysm model via carotid artery ligation, hypertension, and stereotactic elastase injection in C57BL/6 mice and analyzed vessels for lesion and thrombus formation. Raybiotech cytokine arrays were used to analyze 96 cytokines in induced murine aneurysms and 120 cytokines in human tissue samples. Cerebral aneurysm formation and inflammatory pathway were then studied in animals treated with IgG2 antibody (control), anti-GpIb antibody (platelet depletion), 1:10 DMSO:PBS (control), clopidogrel, anti-CXCR1/2 small molecule inhibitor, or anti-CXCL7 antibody. Bleeding assays and flow cytometry were used to evaluate platelet function in treated groups. CD31 + platelet aggregates are a common feature in human and mouse cerebral aneurysm specimens. Platelet ablation in mice prevents cerebral aneurysm formation (20% vs 100% in control antibody-treated mice, n = 5 each, p = 0.0476). Mice treated with 1 mg/kg clopidogrel develop significantly less aneurysms than controls (18% vs 73%, n = 11 and 11, respectively, p = 0.03). Semi-quantitative analysis of 96 different cytokines using Raybiotech arrays shows increased protein expression of CXCL7 in murine cerebral aneurysms when compared to controls. Treatment with clopidogrel results in reciprocal decrease in detected CXCL7. Targeting CXCL7-CXCR1/2 axis with 10 mg/kg reparixin (CXCR1/2 antagonist) significantly decreases cerebral aneurysm formation (11% vs 73%, n = 9 and 11, p = 0.0098) while treatment with 10 mg/kg SB225002 tends to decrease aneurysm formation (36% vs 73%, n = 11 vs n = 7, p = 0.11). Lastly, specific antibody blockade against CXCL7 using anti-CXCL7 antibody at 100 ug/mL significantly decreases cerebral aneurysm formation (29% vs 75%, n = 7 vs n = 8, p = 0.046). Platelet inflammation has an important role in cerebral aneurysm formation. Small molecule inhibitors targeting platelet CXCL7-CXCR1/2 inflammatory axis could be used to prevent cerebral aneurysm formation or progression., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: Arteriovenous malformations (AVMs) are the most common cause of spontaneous intracranial hemorrhage (ICH) in children, often leading to devastating complications. The current literature from the adult AVM population suggests that both younger age and associated aneurysms carry an increased risk of hemorrhagic presentation. However, detailed analysis of pediatric AVM-associated aneurysms and their link to ICH is relatively unknown, with the literature largely consisting of case reports. This study aimed to determine whether AVM-associated aneurysms predispose pediatric patients to ICH., Methods: A retrospective cohort study of 238 pediatric patients with AVMs who presented to the Children's Hospital of Pittsburgh from 1988 to 2023 was performed. Hospital records, patient charts, and radiographic imaging studies were reviewed for patient demographic characteristics, presentation status, and AVM architecture., Results: Of the 238 total patients, 44 (18.5%) children with AVM had associated aneurysms. There were 19 (38.8%) feeding artery aneurysms, 8 (16.3%) intranidal aneurysms, 21 (42.9%) postnidal aneurysms, and 1 (2.0%) unrelated aneurysm of 49 aneurysms. Five patients had venous varices. One hundred forty (58.8%) children presented with hemorrhage. Twenty-one of 44 (47.7%) patients with an AVM-associated aneurysm presented with hemorrhage, whereas 119 of 194 (61.3%) with a solitary AVM presented with hemorrhage (p = 0.10). On multivariate analysis, postnidal aneurysm (OR 0.36, p = 0.037) and an increased number of draining veins (OR 0.66, p = 0.049) were significantly associated with a decreased likelihood of hemorrhagic presentation. Deep venous drainage was associated with an increase in hemorrhagic presentation (OR 2.25, p = 0.0045) on multivariate analysis., Conclusions: Approximately one-fifth of children with AVMs in this study had accompanying aneurysms, and in this patient population, those with postnidal aneurysms and increased number of draining veins had a decreased incidence of hemorrhage on presentation. Feeding artery and intranidal aneurysms were not associated with an elevated risk of hemorrhagic presentation.

Objective: When the peritoneal cavity cannot serve as the distal shunt terminus, nonperitoneal shunts, typically terminating in the atrium or pleural space, are used. The comparative effectiveness of these two terminus options has not been evaluated. The authors directly compared shunt survival and complication rates for ventriculoatrial (VA) and ventriculopleural (VPl) shunts in a pediatric cohort., Methods: The Hydrocephalus Clinical Research Network Core Data Project was used to identify children ≤ 18 years of age who underwent either VA or VPl shunt insertion. The primary outcome was time to shunt failure. Secondary outcomes included distal site complications and frequency of shunt failure at 6, 12, and 24 months., Results: The search criteria yielded 416 children from 14 centers with either a VA (n = 318) or VPl (n = 98) shunt, including those converted from ventriculoperitoneal shunts. Children with VA shunts had a lower median age at insertion (6.1 years vs 12.4 years, p < 0.001). Among those children with VA shunts, a hydrocephalus etiology of intraventricular hemorrhage (IVH) secondary to prematurity comprised a higher proportion (47.0% vs 31.2%) and myelomeningocele comprised a lower proportion (17.8% vs 27.3%) (p = 0.024) compared with those with VPl shunts. At 24 months, there was a higher cumulative number of revisions for VA shunts (48.6% vs 38.9%, p = 0.038). When stratified by patient age at shunt insertion, VA shunts in children < 6 years had the lowest shunt survival rate (p < 0.001, log-rank test). After controlling for age and etiology, multivariable analysis did not find that shunt type (VA vs VPl) was predictive of time to shunt failure. No differences were found in the cumulative frequency of complications (VA 6.0% vs VPl 9.2%, p = 0.257), but there was a higher rate of pneumothorax in the VPl cohort (3.1% vs 0%, p = 0.013)., Conclusions: Shunt survival was similar between VA and VPl shunts, although VA shunts are used more often, particularly in younger patients. Children < 6 years with VA shunts appeared to have the shortest shunt survival, which may be a result of the VA group having more cases of IVH secondary to prematurity; however, when age and etiology were included in a multivariable model, shunt location (atrium vs pleural space) was not associated with time to failure. The baseline differences between children treated with a VA versus a VPl shunt likely explain current practice patterns.

In 1994, the use of interfacet spacer placement was for joint distraction, reduction, and fusion to supplement atlantoaxial or occipitocervical fixation. Here, we present a unique case of bilateral atlantoaxial interfacet fixation using cervical facet cages (CFC) in a pediatric patient with basilar invagination. In addition, we review the literature on atlantoaxial facet fixation. We present a 12-year-old boy with Wiedemann-Steiner syndrome who presented with multiple episodes of sudden neck jerking, described as in response to a sensation of being shocked, and guarding against neck motion, found to have basilar invagination with cervicomedullary compression. He underwent an occiput to C3 fusion with C1-C2 CFC fixation. We also conducted a literature review identifying all publications using the following keywords: "C1" AND "C2" OR "atlantoaxial" AND "facet spacer" OR "DTRAX." The patient demonstrated postoperative radiographic reduction of his basilar invagination from 6.4 to 4.1 mm of superior displacement above the McRae line. There was a 4.5 mm decrease in the atlantodental interval secondary to decreased dens retroflexion. His postoperative course was complicated by worsening of his existing dysphagia but was otherwise unremarkable. His neck symptoms completely resolved. We illustrate the safe use of CFC for atlantoaxial facet distraction, reduction, and instrumented fixation in a pediatric patient with basilar invagination. Review of the literature demonstrates that numerous materials can be safely placed as a C1-C2 interfacet spacer including bone grafts, titanium spacers, and anterior cervical discectomy and fusion cages. We argue that CFC may be included in this arsenal even in pediatric patients., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: Although keyhole transorbital approaches are gaining traction, their indications have not been adequately studied comparatively. In this study the authors have defined them also as transwing approaches-meaning that they use the different facies of the sphenoid wing for cranial entry-and sought to compare the four major ones: 1) lateral orbitocraniotomy through a lateral canthal incision (LatOrb); 2) modified orbitozygomatic approach through a palpebral incision (ModOzPalp); 3) modified orbitozygomatic approach through an eyebrow incision (ModOzEyB); and 4) supraorbital craniotomy through an eyebrow incision (SupraOrb), coupled with its expanded version (SupraTransOrb)., Methods: Cadaveric dissections were performed at the neuroanatomy lab. To delineate the skull base exposure, four formalin-fixed heads were used, with two sides dedicated to each approach. The outer limits were assessed via image guidance and were mapped and illustrated accordingly. A fifth head was dissected purely endoscopically, just to facilitate an overview of the transwing concept. Qualitative features were also rigorously examined., Results: The LatOrb proves to be more versatile in the middle cranial fossa (MCF), whereas the anterior cranial fossa (ACF) exposure is limited to a small area above the sphenoid ridge. An anterior clinoidectomy is possible; however, the exposure of the roof of the optic canal is suboptimal. The ModOzPalp adequately exposes both the ACF and MCF. Its lateral trajectory allows the inferior to superior view, yet there is restricted access to the medial anterior skull base (olfactory groove). The ModOzEyB also provides extensive exposure of the ACF and MCF, but has a more superior to inferior trajectory compared to the ModOzPalp, making it more appropriate for pathology reaching the medial anterior skull base or even the contralateral side. The anterior clinoidectomy is performed with improved visualization of the optic canal. The SupraOrb provides mainly anterior cranial base exposure, with minimal middle fossa. An anterior clinoidectomy can be performed, but without any direct observation of the superior orbital fissure. Some MCF access can be accomplished if the lateral sphenoid wing is drilled inferiorly, leading to its highly versatile variant, the SupraTransOrb., Conclusions: All the aforementioned approaches use the sphenoid wing as skull base corridor from a specific orientation point; hence these are designated as transwing approaches. Their peculiarities mandate careful case selection for the effective and safe completion of the surgical goals.

Background:  Chiari malformations, usually congenital, can rarely be associated with arteriovenous (AV) fistulas. We present the first case involving a type IV dural AV fistula with a Chiari type I malformation., Methods:  Retrospective chart review was performed to obtain pertinent details regarding history and examination, pathologic findings, and treatment course., Results:  A 63-year-old woman with a 2-year history of migraines presented with 5 months of occipital, right-sided headaches and neck pain exacerbated by Valsalva maneuvers. Computed tomography (CT) and magnetic resonance imaging (MRI) of the head showed a possible right occipital AV malformation, bilateral cerebellar subdural hygromas, and tonsillar crowding at the foramen magnum indicating an acquired Chiari type I malformation. Angiography demonstrated a Cognardtype IV right posterior occipital dural AV fistula supplied by bilateral middle meningeal and posterior meningeal arteries., Conclusion:  After treatment of the dural AV fistula, hygroma evacuation, and decompression of the acquired Chiari malformation, the patient's Valsalva-induced headaches abated., Competing Interests: None declared., (Thieme. All rights reserved.)

Significance: Diffuse correlation spectroscopy (DCS) is an optical method to measure relative changes in cerebral blood flow (rCBF) in the microvasculature. Each heartbeat generates a pulsatile signal with distinct morphological features that we hypothesized to be related to intracranial compliance (ICC)., Aim: We aim to study how three features of the pulsatile rCBF waveforms: the augmentation index (AIx), the pulsatility index, and the area under the curve, change with respect to ICC. We describe ICC as a combination of vascular compliance and extravascular compliance., Approach: Since patients with Chiari malformations (CM) ( n = 30 ) have been shown to have altered extravascular compliance, we compare the morphology of rCBF waveforms in CM patients with age-matched healthy control ( n = 30 )., Results: AIx measured in the supine position was significantly less in patients with CM compared to healthy controls ( p < 0.05 ). Since physiologic aging also leads to changes in vessel stiffness and intravascular compliance, we evaluate how the rCBF waveform changes with respect to age and find that the AIx feature was strongly correlated with age ( R healthy subjects = - 0.63 , R preoperative   CM   patient = - 0.70 , and R postoperative   CM   patients = - 0.62 , p < 0.01 )., Conclusions: These results suggest that the AIx measured in the cerebral microvasculature using DCS may be correlated to changes in ICC., (© 2024 The Authors.)

Background: A clinical concern exists that pediatric patients with whiplash-associated disorder (WAD) might have missed structural injuries or, alternatively, subsequently develop structural injuries over time, despite initially negative imaging findings. The primary objective of this study is to assess follow-up imaging usage for pediatric patients presenting with WAD., Methods: A retrospective review of 444 pediatric patients presenting to a level 1 pediatric trauma hospital from January 1, 2010 to December 31, 2019 was performed. Imaging was reviewed at the initial encounter and the 3- and 6-month follow-up appointments., Results: At the initial evaluation, children aged <6 years were more likely to receive radiographs (P = 0.007) and magnetic resonance imaging (P = 0.048) than were children aged 6-11 and 12-18 years. At the 3- and 6-month follow-up appointments, persistent neck pain was rare, representing <15% of patients at either time. Regardless of pain persistence, 80.2% of patients seen at the 3-month follow-up and 100% of patients at the 6-month follow-up underwent additional imaging studies. At the 3-month follow-up, children with persistent neck pain were more likely to undergo magnetic resonance imaging than were patients without persistent pain (P < 0.001). Also, patients with persistent neck pain were also more likely to not undergo any imaging evaluation (P = 0.002). Follow-up imaging studies did not reveal new structural injuries at either time point., Conclusions: Follow-up imaging for pediatric patients with low-grade WAD did not identify new structural pathology-in patients with or without persistent neck pain., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction and Hypothesis: Previous research has not evaluated patient experiences following vaginal reconstructive surgery using a same-day discharge model. The objective of this study was to describe patient experiences following major vaginal reconstructive surgery and same-day discharge., Methods: In this descriptive study, patients undergoing vaginal hysterectomy with pelvic reconstruction were preoperatively enrolled. Questionnaires detailing experience with same-day discharge, surgical recovery, and advice for prospective patients were completed. Our primary outcome was question 7 of the Surgical Satisfaction Questionnaire: Looking back, if you "had to do it all over again" would you have the surgery again? Descriptive statistics were performed, and correlations were performed with Spearman's rank test., Results: Sixty patients were enrolled; 54 underwent surgery. Eighty-seven percent of patients completed the 12-week questionnaire. At 12 weeks, 96% of patients (n = 45) would have the surgery again, and 91% (n = 42) were satisfied with the results of surgery. Twelve weeks postoperatively, the most common patient-reported complications were urinary tract infection (n = 8, 17%), catheter concerns (n = 5, 11%), and constipation (n = 5, 11%). When asked to list the best parts of their surgical experience, half of patients felt that this was the office staff or physician themselves (n = 24, 51%). When asked what advice they would provide to future patients, the most common responses included having a support person at home and taking time for recovery., Conclusions: In this sample of women receiving same-day discharge following vaginal hysterectomy with pelvic reconstruction, we present a unique insight into the most common patient concerns postoperatively. Rates of satisfaction and comfort were high., (© 2023. The International Urogynecological Association.)

Objective: Multimodality treatment has been shown to be the optimal management strategy for pediatric arteriovenous malformations (AVMs). Deep AVMs represent a subset of AVMs for which optimal management may be achieved with a combination of radiosurgery and highly selective embolization, in the absence of compelling features requiring operative intervention. The objective of this study was to identify predictors of good functional outcomes in pediatric patients with deep AVMs., Methods: A retrospective cohort study of the outcomes of 79 patients with deep AVMs from January 1988 through December 2021 was performed. Deep AVMs were defined as those with the majority of the nidus centered in the basal ganglia, thalamus, or brainstem. Collected data included patient demographics and presenting symptoms, presenting modified Rankin Scale (mRS) score, radiographic findings and outcomes, management strategy, complications, and clinical outcomes as indicated by follow-up mRS score. A good outcome was defined as a follow-up mRS score ≤ 2, while a poor outcome was defined as a follow-up mRS score ≥ 3. Statistical analysis was performed to identify factors associated with functional outcomes., Results: With a mean follow-up duration of 85.6 months, there was a 72.2% angiographic obliteration rate, with 75.9% of patients having a good clinical outcome (mRS score ≤ 2). Presenting symptoms and radiographic characteristics were not significantly associated with long-term functional outcomes. There was a significantly higher rate of posttreatment hemorrhage in patients with a poor versus good outcome (11.8% vs 0%, p = 0.010). On multivariate logistic regression analysis, poor long-term functional outcome was only associated with poor presenting mRS score (p = 0.002)., Conclusions: Satisfactory angiographic obliteration rates and good long-term functional outcomes can be achieved for deep AVMs, with stereotactic radiosurgery as the cornerstone of multimodality treatment.

Within the sample of 181 patients with cervical CT, CT identified unstable injury with a sensitivity of 100% and specificity of 95%. CT identified operable injury at the CCJ with 86% sensitivity and 91% specificity. CT was considered the gold standard for identification of fractures. Together, the presence of CT imaging suggestive of unstable injury or persistent neurologic complaint had a 100% sensitivity and 81% specificity. Finally, across all patients MRI had 100% sensitivity and 89% specificity for detection of unstable injury requiring surgery., Competing Interests: None., (© 2023 The Authors.)

Mesial temporal lobe epilepsy (mTLE) is an important cause of drug-resistant epilepsy (DRE) in adults and children. Traditionally, the surgical option of choice for mTLE includes a frontotemporal craniotomy and open resection of the anterior temporal cortex and mesial temporal structures. Although this technique is effective and durable, the neuropsychological morbidity resulting from temporal neocortical resections has resulted in the investigation of alternative approaches to resect the mesial temporal structures to achieve seizure freedom while minimizing postoperative cognitive deficits. Outcomes supporting the use of selective temporal resections have resulted in alternative approaches to directly access the mesial temporal structures via endoscopic approaches whose direct trajectory to the epileptogenic zone minimizes retraction, resection, and manipulation of surrounding cortex. The authors reviewed the utility of the endoscopic transmaxillary, endoscopic endonasal, endoscopic transorbital, and endoscopic supracerebellar transtentorial approaches for the treatment of drug-resistant mesial temporal lobe epilepsy. First, a review of the literature demonstrated the anatomical feasibility of each approach, including the limits of exposure provided by each trajectory. Next, clinical data assessing the safety and effectiveness of these techniques in the treatment of DRE were analyzed. An outline of the surgical techniques is provided to highlight the technical nuances of each approach. The direct access to mesial temporal structures and avoidance of lateral temporal manipulation makes endoscopic approaches promising alternatives to traditional methods for the treatment of DRE arising from the temporal pole and mesial temporal lobe. A dearth of literature outlining clinical outcomes, a need for qualified cosurgeons, and a lack of experience with endoscopic approaches remain major barriers to widespread application of the aforementioned techniques. Future studies are warranted to define the utility of these approaches moving forward.

Objective: Persistent hydrocephalus following posterior fossa brain tumor (PFBT) resection is a common cause of morbidity in pediatric brain tumor patients, for which the optimal treatment is debated. The purpose of this study was to compare treatment outcomes between VPS and ETV in patients with persistent hydrocephalus following surgical resection of a PFBT., Methods: A post-hoc analysis was performed of the Hydrocephalus Clinical Research Network (HCRN) prospective observational study evaluating VPS and ETV for pediatric patients. Children who experienced hydrocephalus secondary to PFBT from 2008 to 2021 were included. Primary outcomes were VPS/ETV treatment failure and time-to-failure (TTF)., Results: Among 241 patients, the VPS (183) and ETV (58) groups were similar in age, extent of tumor resection, and preoperative ETV Success Score. There was no difference in overall treatment failure between VPS and ETV (33.9% vs 31.0%, p = 0.751). However, mean TTF was shorter for ETV than VPS (0.45 years vs 1.30 years, p = 0.001). While major complication profiles were similar, compared to VPS, ETV patients had relatively higher incidence of minor CSF leak (10.3% vs. 1.1%, p = 0.003) and pseudomeningocele (12.1% vs 3.3%, p = 0.02). No ETV failures were identified beyond 3 years, while shunt failures occurred beyond 5 years. Shunt infections occurred in 5.5% of the VPS cohort., Conclusions: ETV and VPS offer similar overall success rates for PFBT-related postoperative hydrocephalus. ETV failure occurs earlier, while susceptibility to VPS failure persists beyond 5 years. Tumor histology and grade may be considered when selecting the optimal means of CSF diversion., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: Reports published during the severe acute respiratory syndrome coronavirus 2 (Sars-CoV-2) pandemic suggest that hospitals potentially experienced an increased incidence in the presentation of abusive head trauma (AHT) in children; however, it remains unknown if the pandemic influenced the severity or need for neurosurgical intervention during this time., Methods: This study is a post hoc analysis of a prospectively collected database of pediatric patients who sustained traumatic head injuries from 2018 to 2021 and were treated at the Children's Hospital of Pittsburgh that was screened for concern of AHT at the time of presentation. Pairwise univariate analysis of AHT prevalence, Glasgow Coma Scale (GCS) score, intracranial pathology, and neurosurgical interventions was performed to investigate differences before, during, and after the initial lockdown in Pennsylvania, which was defined as March 23, 2020, to August 26, 2020., Results: Of 2181 pediatric patients who presented with head trauma, 263 (12.1%) with AHT were identified. Prevalence of AHT did not differ during (12.4% before vs 10.0% during, p = 0.31) or following (12.2% after, p = 0.92) lockdown. Need for neurosurgery after AHT remained unchanged during lockdown (10.7% before vs 8.3% during, p = 0.72) and after (10.5% after, p = 0.97). Patients did not differ in terms of sex, age, or race between periods. Average GCS score was lower after lockdown (13.9 before vs 11.9 after, p = 0.008) but not during (12.3, p = 0.062). In this cohort, mortality associated with AHT was 4.8 times higher during lockdown (4.3% before vs 20.8% during, p = 0.002) and returned to pre-lockdown rates thereafter (7.8%, p = 0.27). The primary contributor to mortality was ischemic brain injury (5% before vs 20.8% during, p = 0.005). Patients were 5.5 times more likely to undergo decompressive hemicraniectomy in the months after lockdown compared with prior (1.2% vs 6.6%, p = 0.035)., Conclusions: The authors have presented the findings of the first study to examine the prevalence and neurosurgical management of AHT during the Sars-Cov-2 lockdown in Pennsylvania. The overall prevalence of AHT was not affected by lockdown; however, patients were more likely to experience mortality or traumatic ischemia during lockdown. The GCS score of AHT patients was significantly lower, and these patients were more likely to require decompressive hemicraniectomy after the initial lockdown period.

Background: Current approaches for mesial temporal lobe epilepsy may result in suboptimal seizure control and cognitive decline. An incomplete treatment of the epileptogenic zone and unnecessary violation of functional cortical and subcortical areas may contribute to suboptimal results., Objective: To describe and test the anatomic feasibility of a novel endoscopic anterior transmaxillary (ATM) approach to the temporal lobe and to compare the described technique to other transfacial approaches., Methods: Twenty-four cadaveric brain hemispheres fixed in formalin were used to study anterior temporal surface anatomy. Two additional hemispheres were fixed in formalin and then frozen for white matter dissections. Subsequently, bilateral dissections on 4 injected cadaveric heads were used to describe the endoscopic ATM approach and to evaluate various anterior endoscopic corridors for the temporal pole and mesial temporal lobe structures., Results: The ATM approach was considered superior because of direct visualization of the temporal pole and natural alignment with the mesial temporal structures. The mean exposure corridor covered 49.1° in the sagittal plane and 66.2° in the axial plane. The ATM allowed direct access lateral to the maxillary and mandibular nerves with an anterior-posterior trajectory aligned to the longitudinal axis of the hippocampus formation, allowing for a selective amygdalohippocampectomy with preservation of the trigeminal branches and the lateral temporal neocortex., Conclusion: The ATM approach is anatomically feasible, providing a direct and selective approach for the temporal pole and mesial temporal lobe structures, with a substantial angle of visualization because of its direct alignment with the mesial temporal lobe structures., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Background: Endoscopic endonasal skull base surgery (EESBS) is performed through a non-sterile corridor. Intracranial infection rates in a pediatric population have not been extensively studied and the exact effect of antibiotic prophylaxis on rates of infection after EESBS in pediatric patients remains unclear., Objective: The purpose of our study is to investigate risk factors for postoperative intracranial infection during EESBS in a pediatric population and help elucidate the role of antibiotic prophylaxis., Methods: We conducted a retrospective chart review of 99 consecutive patients under the age of 18 who underwent EESBS at our institution from 2013 to 2021. Centers for Disease Control and Prevention/National Healthcare Safety Network criteria for diagnosis of meningitis were used to identify postoperative intracranial infections., Results: The average age was 12.3 years (range 1.6-18) with 66 male patients and 33 female patients. 49 patients had an intraoperative cerebrospinal fluid (CSF) leak, of which 4 had a postoperative CSF leak. We identified 3 postoperative intracranial infections (3%), which were all meningitis cases. The infection rate was 6% (3/49) among those with intraoperative CSF leaks. All patients with meningitis had a postoperative CSF leak. All infections were transclival approaches (2 chordoma and 1 neurenteric cyst)., Conclusion: This investigation represents one of the largest pediatric endoscopic skull base surgery cohorts. EESBS is safe to perform in pediatric populations, but transclival approaches and postoperative CSF leaks are risk factors for postoperative meningitis.

Objective: Intracranial pressure (ICP) is an important therapeutic target in many critical neuropathologies. The current tools for ICP measurements are invasive; hence, these are only selectively applied in critical cases where the benefits surpass the risks. To address the need for low-risk ICP monitoring, the authors developed a noninvasive alternative., Methods: The authors recently demonstrated noninvasive quantification of ICP in an animal model by using morphological analysis of microvascular cerebral blood flow (CBF) measured with diffuse correlation spectroscopy (DCS). The current prospective observational study expanded on this preclinical study by translating the method to pediatric patients. Here, the CBF features, along with mean arterial pressure (MAP) and heart rate (HR) data, were used to build a random decision forest, machine learning model for estimation of ICP; the results of this model were compared with those of invasive monitoring., Results: Fifteen patients (mean age ± SD [range] 9.8 ± 5.1 [0.3-17.5] years; median age [interquartile range] 11 [7.4] years; 10 males and 5 females) who underwent invasive neuromonitoring for any purpose were enrolled. Estimated ICP (ICPest) very closely matched invasive ICP (ICPinv), with a root mean square error (RMSE) of 1.01 mm Hg and 95% limit of agreement of ≤ 1.99 mm Hg for ICPinv 0.01-41.25 mm Hg. When the ICP range (ICPinv 0.01-29.05 mm Hg) was narrowed on the basis of the sample population, both RMSE and limit of agreement improved to 0.81 mm Hg and ≤ 1.6 mm Hg, respectively. In addition, 0.3% of the test samples for ICPinv ≤ 20 mm Hg and 5.4% of the test samples for ICPinv > 20 mm Hg had a limit of agreement > 5 mm Hg, which may be considered the acceptable limit of agreement for clinical validity of ICP sensing. For the narrower case, 0.1% of test samples for ICPinv ≤ 20 mm Hg and 1.1% of the test samples for ICPinv > 20 mm Hg had a limit of agreement > 5 mm Hg. Although the CBF features were crucial, the best prediction accuracy was achieved when these features were combined with MAP and HR data. Lastly, preliminary leave-one-out analysis showed model accuracy with an RMSE of 6 mm Hg and limit of agreement of ≤ 7 mm Hg., Conclusions: The authors have shown that DCS may enable ICP monitoring with additional clinical validation. The lower risk of such monitoring would allow ICP to be estimated for a wide spectrum of indications, thereby both reducing the use of invasive monitors and increasing the types of patients who may benefit from ICP-directed therapies.

This section reviews the selection criteria and best practices for endoscopic cerebrovascular surgery, focusing on purely endoscopic endonasal approaches. Although these approaches still play a limited role in open vascular neurosurgery, they offer a robust and potentially safer technique for establishing visualization and vascular control of particular, well-selected pathologies, such as aneurysms of the proximal circulation; this requires strong, multidisciplinary experience with endoscopic anatomy and surgical technique, advanced reconstruction techniques, and instruments designed to be maneuvered within this relatively novel corridor and application., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: In mesial temporal lobe epilepsy (MTLE), the ideal surgical approach to achieve seizure freedom and minimize morbidity is an unsolved question. Selective approaches to mesial temporal structures often result in suboptimal seizure outcomes. The authors report the results of a pilot study intended to evaluate the clinical feasibility of using an endoscopic anterior transmaxillary (eATM) approach for minimally invasive management of MTLEs., Methods: The study is a prospectively collected case series of four consecutive patients who underwent the eATM approach for the treatment of MTLE and were followed for a minimum of 12 months. All participants underwent an epilepsy workup and surgical care at a tertiary referral comprehensive epilepsy center and had medically refractory epilepsy. The noninvasive evaluations and intracranial recordings of these patients confirmed the presence of anatomically restricted epileptogenic zones located in the mesial temporal structures. Data on seizure freedom at 1 year, neuropsychological outcomes, diffusion tractography, and adverse events were collected and analyzed., Results: By applying the eATM technique and approaching the far anterior temporal lobe regions, mesial-basal resections of the temporal polar areas and mesial temporal structures were successfully achieved in all patients (2 with left-sided approaches, 2 with right-sided approaches). No neurological complications or neuropsychological declines were observed. All 4 patients achieved Engel class Ia outcome up to the end of the follow-up period (19, 15, 14, and 12 months). One patient developed hypoesthesia in the left V2 distribution but there were no other adverse events. The low degree of white matter injury from the eATM approach was analyzed using high-definition fiber tractography in 1 patient as a putative mechanism for preserving neuropsychological function., Conclusions: The described series demonstrates the feasibility and potential safety profile of a novel approach for medically refractory MTLE. The study affirms the feasibility of performing efficacious mesial temporal lobe resections through an eATM approach.

Introduction  The application of cranial tissue sealants to assist with postoperative closure is widespread, but data are lacking regarding its utility in endoscopic endonasal surgery (EEA). A prospective study was conducted to assess the effect of sealant usage on postoperative cerebrospinal fluid (CSF) leak rate following standard reconstruction. Methods  A prospective trial of sealant usage after endoscopic endonasal skull base surgery was performed from May 2016 to June 2019 at a tertiary referral cranial base center. This study enrolled 300 consecutive adult and pediatric patients with skull base pathology who underwent EES in which an intraoperative CSF leak occurred. Patients were sequentially stratified into equally sized groups who did or did not receive sealant as part of their reconstruction. Results  Three hundred consecutive adult and pediatric patients were enrolled in the study and had a confirmed intraoperative CSF leak. The intervention cohort with sealant (first 150 patients) had 21 postoperative CSF leaks (14% rate) compared with 9 postoperative CSF leaks (6% rate) in the control group without sealant ( p  = 0.02). On multivariate analysis, sealant usage was associated with a higher rate of postoperative CSF leak (odds ratio [OR] = 2.7; p  = 0.025). Male gender (OR = 2.4; p  = 0.04) and high-flow intraoperative CSF leak (OR = 3.1; p  = 0.038) were also found to be associated with postoperative CSF leak. Conclusion  Among all patients undergoing EES with an intraoperative CSF leak, the addition of sealant to standard closure techniques did not reduce the rate of postoperative CSF leaks., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Background: Chiari I malformations secondary to other causes represent a small subset of presenting symptomatic cases. Typically, the primary cause of the malformation is addressed first and results in resolution of the malformation and symptoms. However, in some cases, a patient may present with both a primary Chiari I malformation and another unrelated neurosurgical lesions., Objective: To present a unique case in which resection of a ventral tumor allowed for spontaneous resolution of a simultaneously noted dorsal Chiari I malformation., Methods: Pertinent data, including presenting symptoms, hospital course, surgical notes, preoperative images, and postoperative images, were collected using the electronic medical record., Results: We present a case of a 46-yr-old man with a Chiari I malformation in conjunction with a ventral cranio-cervical junction chordoma. Endoscopic endonasal resection of the chordoma and ventral foramen magnum decompression resulted in radiographic resolution of the Chiari malformation and resolution of his symptoms. Our report represents a rare case of ventral foramen magnum decompression as a treatment for Chiari I malformation., Conclusion: It is felt that the chordoma mass effect was not the source of the Chiari I malformation. Thus, both ventral and dorsal decompressions of the posterior fossa may be considered for Chiari I decompression in select circumstances., (© Congress of Neurological Surgeons 2021.)

Dr Dorothy Klenke Nash (1898-1976) became the first female neurosurgeon in the United States in 1928 and maintained her status as the country's only female neurosurgeon until 1960. She graduated with her medical degree from the Columbia College of Physicians and Surgeons in 1927 and then trained at the Neurologic Institute of New York under Dr Byron Stookey. During her training, she contributed to the advancement of neurosurgical practice through academic research. In 1931, she married Charles B. Nash, and together they had 2 children, George (1932) and Dorothy Patricia (1937). Dr Nash became a senior surgeon at St. Margaret's Hospital in Pittsburgh in 1942. Shortly thereafter, she joined the inaugural University of Pittsburgh Department of Neurosurgery led by Dr Stuart N. Rowe and became an instructor of neurosurgery at the University of Pittsburgh School of Medicine. In acknowledgment of her advocacy for public access to services for mental health and cerebral palsy, Dr Nash was recognized as a Distinguished Daughter of Pennsylvania (1953) and honored by Mercy Hospital (1957), Bryn Mawr College (1960), and Columbia University (1968). She retired from neurosurgical practice in 1965, at which time she devoted herself to her grandchildren and her Catholic faith. She died on March 5, 1976 at the age of 77. With unwavering tenacity, Dr Nash paved the way for all women in neurosurgery., (© Congress of Neurological Surgeons 2021.)

Objective: Congenital aqueductal stenosis (CAS) is a common etiology of hydrocephalus that occurs in a subset of infants and may be linked to an increased incidence of ophthalmological abnormalities and delayed developmental milestones. Although hydrocephalus is common and widely studied, sparse literature exists on patients with isolated (no identifiable genetic link) CAS along with analysis of ophthalmological manifestations. In this study, the authors sought to describe the ophthalmological abnormalities and delayed developmental milestones of patients with isolated CAS., Methods: Data of patients with CAS were prospectively entered and monitored in a surgical database maintained by the Department of Neurological Surgery at Children's Hospital of Pittsburgh from January 2005 to October 2016. Patients with a family history of congenital hydrocephalus, positive testing for genetic forms of aqueductal stenosis, other congenital abnormalities suggesting an underlying genetic syndrome, and stenosis/obstruction due to secondary causes were excluded from this study. Prenatal and perinatal history, CSF diversion history, and a variety of outcomes, including ophthalmological deficits and developmental milestones, were collected and analyzed., Results: A total of 41 patients with isolated CAS were identified, with a mean follow-up duration of 6 years. Among that cohort, 26 patients (63.4%) developed neuroophthalmological complications, which were further stratified. Fourteen patients (34.1%) developed strabismus and 11 (26.8%) developed astigmatism, and 1 patient (2.4%) with papilledema was recorded. Among patients with ophthalmological abnormalities, 76.9% had delayed developmental milestones (p = 0.045)., Conclusions: Patients with CAS were found to have increased risk of ophthalmological abnormalities requiring correction, along with an increased risk of delayed developmental milestones. Importantly, there was a significant correlation between the development of ophthalmological abnormalities and delayed developmental milestones that was independent of CSF diversion history. Larger patient cohort studies are required to explore whether earlier development of hydrocephalus, as is the case in CAS, causes elevated rates of neurological and ophthalmological complications, and if earlier CSF diversion correlates with improved outcomes.

Objective  Previous work categorized skull base chordoma (SBC) into three genetic risk groups based on 1p36 and homozygous 9p21(p16) deletions, accounting for a wide variability in prognosis (A = low-risk, B = intermediate-risk, C = high-risk). However, it remains unclear how these groups could guide management. Study Design  By integrating surgical outcome and adjuvant radiation (AdjXRT) information with genetic data on 152 tumors, we sought to develop an evidence-based management algorithm for SBC. Results  Gross total resections (GTRs) were associated with improved progression free survival (PFS) in all genetic groups. For Group C tumors, GTR and AdjXRT independently contributed to PFS (multivariate Cox proportional hazard ratio [HR] = 0.14, p  = 0.002, and HR = 0.40, p  = 0.047, respectively). For Group B tumors, AdjXRT improved outcomes only when GTR was not feasible (log-rank p  = 0.008), but not following GTR (log-rank p  = 0.54). However, 24 of 25 Group A tumors underwent GTR, and AdjXRT for these did not confer any benefit (log-Rank p  = 0.285). The high GTR rates in Group A could be explained by smaller tumor sizes (mean = 0.98cc/4.08cc/4.92cc for Group A/B/C, respectively, p  = 0.031) and lack of invasiveness. Group A tumors were also more frequently diagnosed in young people ( p  = 0.002) as asymptomatic lesions ( p  = 0.001), suggesting that they could be precursors to tumors in higher risk groups. Conclusion  Genotypic grouping by 1p36 and homozygous 9p21(p16) deletions can predict prognosis in SBC and guide management. GTR remains the cornerstone of SBC treatment and can be sufficient without AdjXRT in low and intermediate risk tumors. Low-risk tumors are associated with a less invasive phenotype, which makes them more amenable to GTR., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Endoscopic suturectomy combined with supplementary techniques such as spring-assisted expansion and cranial molding helmets for the correction of craniosynostosis is growing in popularity due to the reduced scar burdened, decreased morbidity, and reduced overall cost. The authors present their technique for the correction of isolated coronal craniosynostosis. The use of dedicated endoscopic tools and lit endoscopes permits enhanced visualization and technical ability, particularly at the distal portions of the suturectomy, and may reduce operative time and cerebrospinal fluid leak risk. The video can be found here: https://vimeo.com/515401366., Competing Interests: Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this publication., (© 2021, The Authors.)

Objective: Myelomeningocele (MMC) is frequently complicated by symptomatic hydrocephalus, necessitating early permanent CSF diversion and revision surgeries. Shunt infections are a common cause of shunt malfunction. This study aims to characterize long-term shunt-related outcomes of patients undergoing MMC closure., Methods: A total of 170 patients undergoing MMC closure between the years of 1995 and 2017 were identified from a retrospective review of a prospectively populated surgical database at the Children's Hospital of Pittsburgh. Patients who underwent MMC closure and required ventriculoperitoneal (VP) shunt insertion met criteria and were included in the primary study analysis. Analysis with a Fisher exact test was performed for categorical variables, and Mann-Whitney U-tests were utilized for numerical data., Results: Of the 158 total patients undergoing MMC closure and meeting inclusion criteria, 137 (87%) required VP shunt insertion. These 137 patients demonstrated a shunt revision rate of 21.1% per person-year and a shunt infection rate of 2.1% per person-year over a mean follow-up of 10.8 years. Patients had a mean of 3.4 ± 0.6 shunt surgeries prior to their first infection. Patients undergoing immediate shunt removal, external ventricular drain placement, or shunt replacement after clearing the infection had lower rates of subsequent infections than patients who initially were managed with shunt externalization (p < 0.001). Placement of a shunt at the time of MMC closure was not found to be a risk factor for infection. Of patients with initial shunt placement after the implementation of the Hydrocephalus Clinical Research Network protocol in 2011, the authors' institution has had a shunt infection rate of 4.2% per person-year and a revision rate of 35.7% per person-year., Conclusions: This study describes long-term outcomes of shunted MMC patients and factors associated with shunt infections. Most patients underwent multiple revisions prior to the first shunt infection. Shunt externalization may be ineffective at clearing the infection and should be avoided in favor of early shunt removal and external ventricular drainage, followed by shunt replacement once infection is demonstrated to have cleared.

Introduction: Endoscopic endonasal surgery (EES) has been slower to gain popularity in early childhood due to anatomical challenges. We sought to describe the safety and efficacy of EES in early childhood., Methods: All patients younger than 7 years who underwent EES at a large Cranial Base Center from 2002 to 2019 were reviewed as a retrospective cohort study., Results: Thirty-six patients underwent EES before the age of 7 years. Four patients had two-stage EES. Two patients required combined transcranial and endonasal approaches. The mean age at the time of initial surgery was 4 years (range: 1-6). Twenty patients were male, and 16 were female. Of 21 tumors intended for resection, 11 patients had gross total resections, and 10 had near total (>95% tumor removed) resections. Nine patients (43%) had recurrences, of which 6 were craniopharyngiomas (p = 0.01). There was no difference in recurrence rates based on the degree of resection (p = 0.67). Three cerebrospinal fluid (CSF) leaks occurred following primary EES (8%). Following an increase in nasoseptal flap usage (31-52%) and CSF diversion (15-39%) in 2008, there was only one CSF leak out of 23 patients (4 vs. 15%; p = 0.54). Postoperatively, 1 patient developed a permanent new cranial neuropathy, and 1 patient developed a permanent visual field cut. Six patients developed permanent postoperative panhypopituitarism, of which all were craniopharyngiomas (p < 0.001). The mean follow-up was 64 months., Conclusions: Early childhood EES is both safe and technically feasible for a variety of pathologies., (© 2021 S. Karger AG, Basel.)

Objective: We sought to compare our large single-institution cohort of postnatal myelomeningocele closure to the 2 arms of the Management of Myelomeningocele Study (MOMS) trial at the designated trial time points, as well as assess outcomes at long-term follow-up among our postnatal cohort., Methods: A single-institutional retrospective review of myelomeningocele cases presenting from 1995 to 2015 at Children's Hospital of Pittsburgh was performed. We compared outcomes at 12 and 30 months to both arms of the MOMS trial and compared our cohort's outcomes at those designated time points to our long-term outcomes. Univariate statistical analysis was performed as appropriate., Results: One-hundred sixty-three patients were included in this study. All patients had at least 2-year follow-up, with a mean follow-up of 10 years (range 2-20 years). There was no difference in the overall distribution of anatomic level of defect. Compared to our cohort, the prenatal cohort had a higher rate of tethering at 12 months of age, 8 versus 1.8%. Conversely, the Chiari II decompression rate was higher in our cohort (10.4 vs. 1.0%). At 30 months, the prenatal cohort had a higher rate of independent ambulation, but our cohort demonstrated the highest rate of ambulation with or without assistive devices among the 3 groups. When comparing our cohort at these early time points to our long-term follow-up data, our cohort's ambulatory function decreased from 84 to 66%, and the rate of detethering surgery increased almost 10-fold., Conclusions: This study demonstrated that overall ambulation and anatomic-functional level were significantly better among our large postnatal cohort, as well as having significantly fewer complications to both fetus and mother, when compared to the postnatal cohort of the MOMS trial. Our finding that ambulatory ability declined significantly with age in this patient population is worrisome for the long-term outcomes of the MOMS cohorts, especially given the high rates of cord tethering at early ages within the prenatal cohort. These findings suggest that the perceived benefits of prenatal closure over postnatal closure may not be as substantial as presented in the original trial, with the durability of results still remaining a concern., (© 2021 S. Karger AG, Basel.)

Objective: During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, endoscopic endonasal surgery (EES) is feared to be a high-risk procedure for the transmission of coronavirus disease 2019 (COVID-19). Nonetheless, data are lacking regarding the management of EES during the pandemic. The object of this study was to understand current worldwide practices pertaining to EES for skull base/pituitary tumors during the SARS-CoV-2 pandemic and provide a basis for the formulation of guidelines., Methods: The authors conducted a web-based survey of skull base surgeons worldwide. Different practices by geographic region and COVID-19 prevalence were analyzed., Results: One hundred thirty-five unique responses were collected. Regarding the use of personal protective equipment (PPE), North America reported using more powered air-purifying respirators (PAPRs), and Asia and Europe reported using more standard precautions. North America and Europe resorted more to reverse transcriptase-polymerase chain reaction (RT-PCR) for screening asymptomatic patients. High-prevalence countries showed a higher use of PAPRs. The medium-prevalence group reported lower RT-PCR testing for symptomatic cases, and the high-prevalence group used it significantly more in asymptomatic cases.Nineteen respondents reported transmission of COVID-19 to healthcare personnel during EES, with a higher rate of transmission among countries classified as having a medium prevalence of COVID-19. These specific respondents (medium prevalence) also reported a lower use of airborne PPE. In the cases of healthcare transmission, the patient was reportedly asymptomatic 32% of the time., Conclusions: This survey gives an overview of EES practices during the SARS-CoV-2 pandemic. Intensified preoperative screening, even in asymptomatic patients, RT-PCR for all symptomatic cases, and an increased use of airborne PPE is associated with decreased reports of COVID-19 transmission during EES.

Objective: Pediatric skull base chordoma is a rare entity that is traditionally considered to display aggressive behavior with an increased risk of recurrence. There is an absence of literature examining outcomes in the pediatric population in general and using the endoscopic endonasal approach (EEA)., Methods: The authors retrospectively reviewed all patients with skull base chordomas presenting by the age of 18 years to the Children's Hospital of Pittsburgh or the University of Pittsburgh Medical Center from 2004 to 2019. Clinical outcomes, the number and location of recurrences, and progression-free survival time were determined., Results: Twenty patients met the study criteria. The most common presenting complaints were diplopia (n = 7), headache (n = 6), and swallowing difficulty (n = 4). Three cases were incidentally discovered. Twelve patients underwent single-stage EEA alone, 2 patients had two-stage EEA, and 6 patients had combined EEA with open far-lateral or extreme-lateral approaches. Fourteen patients underwent gross-total resection (GTR), and 6 patients had near-total resection. Larger tumors were more likely to require staging or a combined approach (86% vs 7%) and were less likely to receive GTR (33% vs 86%) but had comparable recurrence and mortality rates. Five patients developed CSF leaks requiring reoperation, 2 patients developed a permanent abducens nerve palsy, 1 patient suffered an internal carotid artery injury, 1 patient developed an epidural hematoma, and 1 patient developed a subdural empyema. Four (20%) patients had recurrence during follow-up (mean radiographic follow-up 59 months and mean time to local recurrence 19 months). Two patients with recurrence underwent further resection, and 1 patient elected to stop treatment. Both patients who underwent repeat resection experienced a second recurrence, one of whom elected to stop treatment. Both patients who died had an elevated Ki-67 (p = 0.039), one of whom developed de-differentiated histology. A third patient died of progressive spinal metastases without local recurrence and is one of 2 patients who developed postoperative spinal metastases. Both patients whose tumors became de-differentiated progressed from tumors with an initial Ki-67 of 15 or greater (p = 0.035) and received prior radiotherapy to the bulk tumor (p = 0.03)., Conclusions: The majority of pediatric skull base chordomas, when managed at a specialized center with a goal of GTR, may have a better outcome than traditionally believed. Elevated Ki-67 rates may predict poor outcome and progression to de-differentiation.

Introduction: Medical student involvement opportunities and educational experiences with surgical residents during medical school have been shown to increase the chance of students deciding to specialize in surgical specialties. This study aims to determine the effect of a neurosurgery elective during the second preclinical year on student interest and opinion of neurosurgery., Methods: Thirty-nine students completed opinion-based surveys and factual knowledge quizzes during a neurosurgical elective course over 3 iterations, which included lecture and skills lab instruction. Pre- and post-course surveys used the Likert scale, with a score of 1 corresponding to the most negative opinion and a score of 10 corresponding to the most positive opinion, in order to measure various aspects including interest in neurological surgery, understanding of the field, and perception of female inclusion in the field. Weekly pre- and post-lecture quizzes assessed practical knowledge of neurosurgical topics., Results: A higher percentage of students rated neurosurgery highly as a career possibility (⩾8/10 interest level) post-course (58.6%) compared to pre-course (45.7%). Post-course, students reported a significantly increased mean understanding of neurosurgery on the Likert scale compared to pre-course (6.1 ± 1.7 vs 4.4 ± 2.0; P  = .001). Knowledge based-content assessment revealed a significant increase in overall correct answers after lectures (mean pre  = 3.85, mean post  = 5.05, P  = .001). Inclusion of female instructors in the second and third iteration of the course resulted in a significant increase in students' perception of female inclusion in the field of neurosurgery (7.6 compared to 5.6, P  = .01)., Conclusions: Early exposure to subspecialties may assist in making important career decisions. The implementation of this neurosurgical elective improved medical students' perception of the field and enhanced knowledge of the lectures and procedures. This study can be used as a framework for implementation of this curriculum at other institutions., Competing Interests: Declaration of conflicting interests:The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2020.)

Esthesioneuroblastomas are uncommon tumors in pediatric patients and are typically treated with multimodal therapy. Changes in gross tumor quality and character in response to adjuvant treatment have not been clearly reported. We report the case of a 15-year-old female with a diagnosis of Kadish stage C esthesioneuroblastoma who was treated with neoadjuvant chemotherapy and surgical resection. The patient's tumor demonstrated cytoreduction after chemotherapy but also was found to have calcified. A combined trans-frontal sinus craniotomy with endoscopic endonasal resection was performed and resulted in negative margins and good clinical outcome.

Surgical treatment of deep or difficult to access lesions represents a unique and significant challenge for pediatric neurosurgeons. The introduction of stereotactic magnetic resonance-guided laser interstitial thermal therapy (LITT) over the last decade has had a dramatic impact on the landscape of pediatric neurosurgery. LITT provides a safe and effective option for children with epilepsy from hypothalamic hamartoma that represents a ground-breaking new therapy for a condition which was historically very difficult to treat with previous neurosurgical techniques. LITT has also been used as an alternative surgical technique for mesial temporal sclerosis, focal cortical dysplasia, MR-negative epilepsy, cavernoma-related epilepsy, insular epilepsy, and corpus callosotomy among other epilepsy etiologies. In some cases, LITT has been associated with improved cognitive outcomes compared to standard techniques, as in mesial temporal lobe epilepsy. Initial experiences with LITT for neuro-oncologic processes are also promising. LITT is often attractive to patients and providers as a minimally invasive approach, but the differences in safety and clinical outcome between LITT and traditional approaches are still being studied. In this review, we examine the emerging indications and clinical evidence for LITT in pediatric neurosurgery.

Objective: The study of pediatric arteriovenous malformations (pAVMs) is complicated by the rarity of the entity. Treatment choice has often been affected by the availability of different modalities and the experience of the providers present. The University of Pittsburgh experience of multimodality treatment of pAVMs is presented., Methods: The authors conducted a retrospective cohort study examining 212 patients with pAVM presenting to the University of Pittsburgh between 1988 and 2018, during which patients had access to surgical, endovascular, and radiosurgical options. Univariate analysis was performed comparing good and poor outcomes. A poor outcome was defined as a modified Rankin Scale (mRS) score of ≥ 3. Multivariate analysis via logistic regression was performed on appropriate variables with a p value of ≤ 0.2. Seventy-five percent of the cohort had at least 3 years of follow-up., Results: Five patients (2.4%) did not receive any intervention, 131 (61.8%) had GKRS alone, 14 (6.6%) had craniotomies alone, and 2 (0.9%) had embolization alone. Twenty-two (10.4%) had embolization and Gamma Knife radiosurgery (GKRS); 20 (9.4%) had craniotomies and GKRS; 8 (3.8%) had embolization and craniotomies; and 10 (4.7%) had embolization, craniotomies, and GKRS. Thirty-one patients (14.6%) were found to have poor outcome on follow-up. The multivariate analysis performed in patients with poor outcomes was notable for associations with no treatment (OR 18.9, p = 0.02), hemorrhage requiring craniotomy for decompression alone (OR 6, p = 0.03), preoperative mRS score (OR 2.1, p = 0.004), and Spetzler-Martin score (OR 1.8, p = 0.0005). The mean follow-up was 79.7 ± 62.1 months. The confirmed radiographic obliteration rate was 79.4% and there were 5 recurrences found on average 9.5 years after treatment., Conclusions: High rates of long-term functional independence (mRS score of ≤ 2) can be achieved with comprehensive multimodality treatment of pAVMs. At this center there was no difference in outcome based on treatment choice when accounting for factors such as Spetzler-Martin grade and presenting morbidity. Recurrences are rare but frequently occur years after treatment, emphasizing the need for long-term screening after obliteration.

This is the case of a 76-year-old woman presenting with progressive right vision loss consisting of a right eye temporal field cut and severe visual acuity loss. An MRI was performed showing a suprasellar mass for which she had been referred to our center for an endoscopic endonasal approach. The tumor was found to be densely adherent to adjacent structures, and an ophthalmic artery and A1-A2 junction injury were sustained during resection. The management of intraoperative vascular injuries is described. The video can be found here: https://youtu.be/JJY6nYKTCSg., Competing Interests: Disclosures The author reports no conflict of interest concerning the materials or methods used in this study or the findings specified in this article., (© 2020, The Authors.)

Awake craniotomies are a crucial tool for identifying eloquent cortex, but significant limitations frequently related to patient tolerance have limited their applicability in pediatric cases. The authors describe a comprehensive, longitudinal protocol developed in collaboration with a certified child life specialist (CCLS) in order to enhance patient experiences and develop resiliency related to the intraoperative portion of cases. This protocol includes preoperative conditioning, intraoperative support, and postoperative positive reinforcement and debriefing. A unique coping plan is developed for each prospective patient. With appropriate support, awake craniotomy may be applicable in a wider array of preadolescent and adolescent patients than has previously been possible. Future prospective studies are needed to validate this approach.

Objective: The authors conducted a study to identify clinical features of cranial base chondrosarcomas that will predict tumor progression after resection., Methods: The authors performed a retrospective study at a tertiary referral cranial base center. Patients who underwent resection of cranial base chondrosarcomas between January 2004 and December 2018 were followed longitudinally. The main outcome measure was progression-free survival (PFS)., Results: A total of 41 patients were treated for histopathologically proven "conventional" cranial base chondrosarcomas during the study period, and the median PFS was 123 months for the cohort. Univariate analysis was performed on clinical, anatomical, and radiographic parameters collected for each patient. Features that were statistically significant were fed into a multivariate regression model, which revealed two independent predictors of PFS: patient age and encasement of 3-4 major arteries (> 25% of the vessel wall surrounded by tumor). Using these two variables of age and multiple arterial vessel encasement, the authors generated a risk stratification model using a simple point system to predict PFS in patients with cranial base chondrosarcomas. Based on these two factors known preoperatively, this model could stratify patients into high-risk (10% of patients), intermediate-risk (68% of patients), and low-risk (22% of patients) subgroups corresponding to dramatically distinct median PFS (1.8 years, 10.2 years, and no progression, respectively)., Conclusions: In patients with cranial base chondrosarcomas, age and artery encasement are variables known preoperatively that can powerfully predict tumor progression, define operative goals, and aid in selecting postoperative adjuvant therapy.

Craniocervical instability due to chronic atlantoaxial dissociation presents the challenge of providing adequate decompression, reduction, and fixation to promote long-term stability while avoiding iatrogenic vertebral artery dissection or entrapment. The authors present one patient with chronic atlantoaxial dissociation and basilar invagination treated via Goel's technique and with bilateral vertebral artery mobilization. There was substantial decompression and reduction postoperatively and the patient was discharged with a stable examination. Vertebral artery mobilization at the C1-2 junction can be safely performed via a standard midline suboccipital incision and dissection without vertebral artery injury. The video can be found here: https://youtu.be/VS1Mt1dBLO4., Competing Interests: Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this publication., (© 2020, Michael M. McDowell, Andrew Venteicher, Ezequiel Goldschmidt, Maximiliano Nuñez, David O. Okonkwo, and Paul A. Gardner.)

Ventral masses of the craniocervical junction threaten the medulla and upper spinal cord leading to lower cranial nerve dysfunction and myelopathy. Traditional transoral and newer endonasal approaches can access ventral pathology in this region, though both remain challenging due to the competing goals of achieving sufficient decompression, yet mitigating risk to nearby critical neurovascular structures. Transoral approaches have traditionally been avoided for degenerative pseudotumor which generally slowly regresses following posterior fixation. Here, we present two cases of patients with significant retroodontoid degenerative pseudotumor and pannus causing dysphagia and myelopathy. The first patient was found with a large broad pannus requiring a wide decompression extending from lower clivus to inferior aspect of the C1 arch and odontoid process. The second patient had a more focal mass effect due to pannus and synovial cyst at the level of the inferior half of C1 and midodontoid. Both patients underwent an endoscopic endonasal transodontoid approach for immediate decompression followed by a posterior C1-C2 fusion. In these surgical videos, we highlight anatomic considerations in this critical area, demonstrate nuances of technique, and outline strategies to avoid complications and maximize exposure. The link to the video can be found at: https://youtu.be/19I-GQYGIr4 ., Competing Interests: Conflict of Interest Dr. Gardner reports other from SPIWay, LLC, outside the submitted work; Dr. Snyderman reports other from SPIWay, LLC, outside the submitted work.

Introduction  Facial weakness can result from surgical manipulation of the facial nerve. Intraoperative neuromonitoring reduces functional impairment but no clear guidelines exist regarding interpretation of intraoperative electrophysiological results. Most studies describe subjects with facial nerves encumbered by tumors or those with various grades of facial nerve weakness. We sought to obtain the neurophysiological parameters and stimulation threshold following intraoperative facial nerve triggered electromyography (t-EMG) stimulation during microvascular decompression for trigeminal neuralgia to characterize the response of normal facial nerves via t-EMG. Methods  Facial nerve t-EMG stimulation was performed in seven patients undergoing microvascular decompression for trigeminal neuralgia. Using constant current stimulation, single stimulation pulses of 0.025 to 0.2 mA intensity were applied to the proximal facial nerve. Compound muscle action potentials, duration to onset, and termination of t-EMG responses were recorded for the orbicularis oculi and mentalis muscles. Patients were evaluated for facial weakness following the surgical procedure. Results  Quantifiable t-EMG responses were generated in response to all tested stimulation currents of 0.025, 0.05, 0.1, and 0.2 mA in both muscles, indicating effective nerve conduction. No patients developed facial weakness postoperatively. Conclusions  The presence of t-EMG amplitudes in response to 0.025 mA suggests that facial nerve conduction can take place at lower stimulation intensities than previously reported in patients with tumor burden. Proximal facial nerve stimulation that yields responses with thresholds less than 0.05 mA may be a preferred reference baseline for surgical procedures within the cerebellopontine angle to prevent iatrogenic injury., Competing Interests: Competing Interests Statement The authors have no personal or institutional interest with regards to the authorship and/or publication of this manuscript., (© Thieme Medical Publishers.)