Validating a Curvature-Based Marker of Cervical Carotid Tortuosity for Risk Assessment in Heritable Aortopathies.

BACKGROUND: Cervical arterial tortuosity is associated with adverse outcomes in Loeys-Dietz syndrome and other heritable aortopathies. METHODS AND RESULTS: A method to assess tortuosity based on curvature of the vessel centerline in 3-dimensional space was developed. We measured cervical carotid tortuosity in 65 patients with Loeys-Dietz syndrome from baseline computed tomography angiogram/magnetic resonance angiogram and all serial images during follow-up. Relations between baseline carotid tortuosity, age, aortic root diameter, and its change over time were compared. Patients with unoperated aortic roots were assessed for clinical end point (type A aortic dissection or aortic root surgery during 4 years of follow-up). Logistic regression was performed to assess the likelihood of clinical end point according to baseline carotid tortuosity. Total absolute curvature at baseline was 11.13±5.76 and was relatively unchanged at 8 to 10 years (fold change: 0.026±0.298, P=1.00), whereas tortuosity index at baseline was 0.262±0.131, with greater variability at 8 to 10 years (fold change: 0.302±0.656, P=0.818). Baseline total absolute curvature correlated with aortic root diameter (r=0.456, P=0.004) and was independently associated with aortic events during the 4-year follow-up (adjusted odds ratio [OR], 2.64 [95% CI, 1.02-6.85]). Baseline tortuosity index correlated with age (r=0.532, P<0.001) and was not associated with events (adjusted OR, 1.88 [95% CI, 0.79-4.51]). Finally, baseline total absolute curvature had good discrimination of 4-year outcomes (area under the curve=0.724, P=0.014), which may be prognostic or predictive. CONCLUSIONS: Here we introduce cervical carotid tortuosity as a promising quantitative biomarker with validated, standardized characteristics. Specifically, we recommend the adoption of a curvature-based measure, total absolute curvature, for early detection or monitoring of disease progression in Loeys-Dietz syndrome.

Auricular Vagus Nerve Stimulation Mitigates Inflammation and Vasospasm in Subarachnoid Hemorrhage: A Randomized Trial.

Background: Inflammation contributes to morbidity following subarachnoid hemorrhage (SAH). Transauricular vagus nerve stimulation (taVNS) offers a noninvasive approach to target the inflammatory response following SAH. Methods: In this prospective, triple-blinded, randomized, controlled trial, twenty-seven patients were randomized to taVNS or sham stimulation. Blood and cerebrospinal fluid (CSF) were collected to quantify inflammatory markers. Cerebral vasospasm severity and functional outcomes (modified Rankin Scale, mRS) were analyzed. Results: No adverse events occurred. Radiographic vasospasm was significantly reduced (p = 0.018), with serial vessel caliber measurements demonstrating a more rapid return to normal than sham (p < 0.001). In the taVNS group, TNF-α was significantly reduced in both plasma (days 7 and 10) and CSF (day 13); IL-6 was also significantly reduced in plasma (day 4) and CSF (day 13) (p < 0.05). Patients receiving taVNS had higher rates of favorable outcomes at discharge (38.4% vs 21.4%) and first follow-up (76.9% vs 57.1%), with significant improvement from admission to first follow-up (p = 0.014), unlike the sham group (p = 0.18). The taVNS group had a significantly lower rate of discharge to skilled nursing facility or hospice (p = 0.04). Conclusion: taVNS is a non-invasive method of neuro- and systemic immunomodulation. This trial supports that taVNS following SAH can mitigate the inflammatory response, reduce radiographic vasospasm, and potentially improve functional and neurological outcomes. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT04557618.

Federal and foundational research funding trends for cerebrovascular neurosurgeons: the decline of the cerebrovascular surgeon-scientist?

OBJECTIVE: The number of cerebrovascular (CV) surgeons has grown with the rise of endovascular neurosurgery. However, it is unclear whether the number of CV surgeon-scientists has concomitantly increased. With increasing numbers of CV neurosurgeons in the US workforce, the authors analyzed associated changes in National Institutes of Health (NIH) and Neurosurgery Research and Education Foundation (NREF) funding trends for CV surgeons over time. METHODS: Publicly available data were collected on currently practicing academic CV surgeons in the US. Inflation-adjusted NIH funding between 2009 and 2021 was surveyed using NIH RePORTER and Blue Ridge Institute for Medical Research data. The K12 Neurosurgeon Research Career Development Program and NREF grant data were queried for CV-focused grants. Pearson R correlation, chi-square analysis, and the Mann-Whitney U-test were used for statistical analysis. RESULTS: From 2009 to 2021, NIH funding increased: in total (p = 0.0318), to neurosurgeons (p < 0.0001), to CV research projects (p < 0.0001), and to CV surgeons (p = 0.0018). During this time period, there has been an increase in the total number of CV surgeons (p < 0.0001), the number of NIH-funded CV surgeons (p = 0.0034), and the percentage of CV surgeons with NIH funding (p = 0.370). Additionally, active NIH grant dollars per CV surgeon (p = 0.0398) and the number of NIH grants per CV surgeon (p = 0.4257) have increased. Nevertheless, CV surgeons have been awarded a decreasing proportion of the overall pool of neurosurgeon-awarded NIH grants during this time period (p = 0.3095). In addition, there has been a significant decrease in the number of K08, K12, and K23 career development awards granted to CV surgeons during this time period (p = 0.0024). There was also a significant decline in the proportion of K12 (p = 0.0044) and downtrend in early-career NREF (p = 0.8978) grant applications and grants awarded during this time period. Finally, NIH-funded CV surgeons were more likely to have completed residency less recently (p = 0.001) and less likely to have completed an endovascular fellowship (p = 0.044) as compared with non-NIH-funded CV surgeons. CONCLUSIONS: The number of CV surgeons is increasing over time. While there has been a concomitant increase in the number of NIH-funded CV surgeons and the number of NIH grants awarded per CV surgeon in the past 12 years, there has also been a significant decrease in CV surgeons with K08, K12, and K23 career development awards and a downtrend in CV-focused K12 and early-career NREF applications and awarded grants. The latter findings suggest that the pipeline for future NIH-funded CV surgeons may be in decline.

Non-invasive Auricular Vagus nerve stimulation for Subarachnoid Hemorrhage (NAVSaH): Protocol for a prospective, triple-blinded, randomized controlled trial.

Background: Inflammation has been implicated in driving the morbidity associated with subarachnoid hemorrhage (SAH). Despite understanding the important role of inflammation in morbidity following SAH, there is no current effective way to modulate this deleterious response. There is a critical need for a novel approach to immunomodulation that can be safely, rapidly, and effectively deployed in SAH patients. Vagus nerve stimulation (VNS) provides a non-pharmacologic approach to immunomodulation, with prior studies demonstrating VNS can reduce systemic inflammatory markers, and VNS has had early success treating inflammatory conditions such as arthritis, sepsis, and inflammatory bowel diseases. The aim of the Non-invasive Auricular Vagus nerve stimulation for Subarachnoid Hemorrhage (NAVSaH) trial is to translate the use of non-invasive transcutaneous auricular VNS (taVNS) to spontaneous SAH, with our central hypothesis being that implementing taVNS in the acute period following spontaneous SAH attenuates the expected inflammatory response to hemorrhage and curtails morbidity associated with inflammatory-mediated clinical endpoints. Materials and methods: The overall objectives for the NAHSaH trial are to 1) Define the impact that taVNS has on SAH-induced inflammatory markers in the plasma and cerebrospinal fluid (CSF), 2) Determine whether taVNS following SAH reduces radiographic vasospasm, and 3) Determine whether taVNS following SAH reduces chronic hydrocephalus. Following presentation to a single enrollment site, enrolled SAH patients are randomly assigned twice daily treatment with either taVNS or sham stimulation for the duration of their intensive care unit stay. Blood and CSF are drawn before initiation of treatment sessions, and then every three days during a patient's hospital stay. Primary endpoints include change in the inflammatory cytokine TNF-α in plasma and cerebrospinal fluid between day 1 and day 13, rate of radiographic vasospasm, and rate of requirement for long-term CSF diversion via a ventricular shunt. Secondary outcomes include exploratory analyses of a panel of additional cytokines, number and type of hospitalized acquired infections, duration of external ventricular drain in days, interventions required for vasospasm, continuous physiology data before, during, and after treatment sessions, hospital length of stay, intensive care unit length of stay, and modified Rankin Scale score (mRS) at admission, discharge, and each at follow-up appointment for up to two years following SAH. Discussion: Inflammation plays a central role in morbidity following SAH. This NAVSaH trial is innovative because it diverges from the pharmacologic status quo by harnessing a novel non-invasive neuromodulatory approach and its known anti-inflammatory effects to alter the pathophysiology of SAH. The investigation of a new, effective, and rapidly deployable intervention in SAH offers a new route to improve outcomes following SAH. Trial registration: Clinical Trials Registered, NCT04557618. Registered on September 21, 2020, and the first patient was enrolled on January 4, 2021.

The effect of transcutaneous auricular vagus nerve stimulation on cardiovascular function in subarachnoid hemorrhage patients: a safety study.

Introduction: Subarachnoid hemorrhage (SAH) is characterized by intense central inflammation, leading to substantial post-hemorrhagic complications such as vasospasm and delayed cerebral ischemia. Given the anti-inflammatory effect of transcutaneous auricular vagus nerve stimulation (taVNS) and its ability to promote brain plasticity, taVNS has emerged as a promising therapeutic option for SAH patients. 3,10,13 However, the effects of taVNS on cardiovascular dynamics in critically ill patients like those with SAH have not yet been investigated. Given the association between cardiac complications and elevated risk of poor clinical outcomes after SAH, it is essential to characterize the cardiovascular effects of taVNS to ensure this approach is safe in this fragile population 5 . Therefore, we assessed the impact of both acute taVNS and repetitive taVNS on cardiovascular function in this study. Methods: In this randomized clinical trial, 24 SAH patients were assigned to either a taVNS treatment or a Sham treatment group. During their stay in the intensive care unit, we monitored patient electrocardiogram (ECG) readings and vital signs. We compared long-term changes in heart rate, heart rate variability, QT interval, and blood pressure between the two groups. Additionally, we assessed the effects of acute taVNS by comparing cardiovascular metrics before, during, and after the intervention. We also explored rapidly responsive cardiovascular biomarkers in patients exhibiting clinical improvement. Results: We found that repetitive taVNS did not significantly alter heart rate, corrected QT interval, blood pressure, or intracranial pressure. However, taVNS increased overall heart rate variability and parasympathetic activity from 5-10 days after initial treatment, as compared to the sham treatment. Acutely, taVNS increased heart rate, blood pressure, and peripheral perfusion index without affecting the corrected QT interval, intracranial pressure, or heart rate variability. The acute post-treatment elevation in heart rate was more pronounced in patients who experienced a decrease of more than 1 point in their Modified Rankin Score at the time of discharge. Conclusions: Our study found that taVNS treatment did not induce adverse cardiovascular effects, such as bradycardia or QT prolongation, supporting its development as a safe immunomodulatory treatment approach for SAH patients. The observed acute increase in heart rate after taVNS treatment may serve as a biomarker for SAH patients who could derive greater benefit from this treatment. Trial registration: NCT04557618.

Conditioning-based therapeutics for aneurysmal subarachnoid hemorrhage - A critical review.

Aneurysmal subarachnoid hemorrhage (SAH) carries significant mortality and morbidity, with nearly half of SAH survivors having major cognitive dysfunction that impairs their functional status, emotional health, and quality of life. Apart from the initial hemorrhage severity, secondary brain injury due to early brain injury and delayed cerebral ischemia plays a leading role in patient outcome after SAH. While many strategies to combat secondary brain injury have been developed in preclinical studies and tested in late phase clinical trials, only one (nimodipine) has proven efficacious for improving long-term functional outcome. The causes of these failures are likely multitude, but include use of therapies targeting only one element of what has proven to be multifactorial brain injury process. Conditioning is a therapeutic strategy that leverages endogenous protective mechanisms to exert powerful and remarkably pleiotropic protective effects against injury to all major cell types of the CNS. The aim of this article is to review the current body of evidence for the use of conditioning agents in SAH, summarize the underlying neuroprotective mechanisms, and identify gaps in the current literature to guide future investigation with the long-term goal of identifying a conditioning-based therapeutic that significantly improves functional and cognitive outcomes for SAH patients.

Natural history and growth rate of intracranial aneurysms in Loeys-Dietz syndrome: implications for treatment.

OBJECTIVE: Loeys-Dietz syndrome (LDS) is a heritable aortopathy associated with craniofacial abnormalities and dilatation and dissection of the aorta and its branches, as well as increased risk for intracranial aneurysms (ICAs). Given the rarity of the disease, the authors aimed to better define the natural history and role for the treatment for ICAs in these patients. METHODS: The medical records of 83 patients with LDS were retrospectively reviewed to obtain clinical and genetic history and vascular imaging of the aorta, aortic branches, and intracranial vessels. Serial radiology reports and cervical and intracranial vascular images were reviewed to determine presence, location, and size of ICAs. RESULTS: In total, 55 patients (66.3%) had at least two screening intracranial vascular examinations, and 19 (22.9%) had at least 1 ICA detected. Aneurysms were typically small (mean ± SD 3.2 ± 1.8 mm). ICAs were most often located in the cavernous carotid, followed by the ophthalmic and anterior cerebral artery vessels. The rate of ICA growth was 0.43 ± 0.53 mm/year, similar to that of the general population. Three patients underwent intervention for an ICA, with 1 procedure complicated by stroke and resulting in transient hemiparesis. Several illustrative cases detail the authors' experience with ICA growth, de novo aneurysm formation, and ICA intervention in this rare patient population. CONCLUSIONS: ICAs in patients with LDS are common, are frequently small, and have a growth rate similar to that of unruptured ICAs in the general population. More aggressive or earlier intervention for asymptomatic ICAs identified in LDS patients compared with the general population is likely unwarranted based on the authors' experience at their institution.

A review of technological innovations leading to modern endovascular brain aneurysm treatment.

Tools and techniques utilized in endovascular brain aneurysm treatment have undergone rapid evolution in recent decades. These technique and device-level innovations have allowed for treatment of highly complex intracranial aneurysms and improved patient outcomes. We review the major innovations within neurointervention that have led to the current state of brain aneurysm treatment.

A challenging case of recurrent and progressive fusiform anterior circulation intracranial aneurysms: illustrative case.

BACKGROUND: Intracranial fusiform aneurysms are circumferential dilations of cerebral arteries that can lead to complications including ischemic stroke due to vessel occlusion, subarachnoid hemorrhage, or intracerebral hemorrhage. Treatment options for fusiform aneurysms have expanded significantly in recent years. Microsurgical treatment options include proximal and distal surgical occlusion and microsurgical trapping of the aneurysm, usually in association with high-flow bypass procedures. Endovascular treatment options include the placement of coils and/or flow diverters. OBSERVATIONS: Here the authors report a case of aggressive surveillance and treatment of a man with multiple progressive, recurrent, and de novo fusiform aneurysms of the left anterior cerebral circulation over 16 years. Because the long-term course of his treatment coincided with the recent expansion of endovascular treatment options, he underwent every type of treatment listed above. LESSONS: This case demonstrates the wide range of therapeutic options for fusiform aneurysms and how the treatment model for these lesions has evolved.

Relationship between phenotypic features in Loeys-Dietz syndrome and the presence of intracranial aneurysms.

OBJECTIVE: Loeys-Dietz syndrome (LDS) is a rare autosomal dominant condition characterized by aneurysms of the aorta, aortic branches, and intracranial arteries; skeletal and cutaneous abnormalities; and craniofacial malformations. Previous authors have reported that higher craniofacial severity index (CFI) scores, which indicate more severe craniofacial abnormalities, correlate with the severity of aortic aneurysm pathology. However, the association between syndromic features and the formation of intracranial aneurysms in LDS patients has yet to be determined. In this study, the authors evaluate the incidence of phenotypic abnormalities, craniofacial features, and Chiari malformation type I (CM-I) in a large LDS cohort and explore possible risk factors for the development of intracranial aneurysms. METHODS: This was a retrospective cohort study of all patients with LDS who had been seen at the Marfan Syndrome and Aortopathy Center at Washington University School of Medicine in St. Louis in 2010-2022. Medical records were reviewed to obtain demographic, clinical, and radiographic data. The prevalence of craniofacial, skeletal, and cutaneous pathologies was determined. Bivariate logistic regression was performed to identify possible risk factors for the formation of an intracranial aneurysm. RESULTS: Eighty-one patients with complete medical records and intracranial vascular imaging were included in the analysis, and 18 patients (22.2%) had at least 1 intracranial aneurysm. Patients frequently demonstrated the thin or translucent skin, doughy skin texture, hypertelorism, uvular abnormalities, and joint hypermobility typical of LDS. CM-I was common, occurring in 7.4% of the patients. Importantly, the patients with intracranial aneurysms were more likely to have CM-I (22.2%) than those without intracranial aneurysms (3.2%). The mean CFI score in the cohort with available data was 1.81, with higher means in the patients with the TGFBR1 or TGFBR2 disease-causing variants (2.05 and 3.30, respectively) and lower in the patients with the SMAD3, TGFB2, or TGFB3 pathogenic variants (CFI < 1). No significant CFI difference was observed in patients with or without intracranial aneurysms (2.06 vs 1.74, p = 0.61). CONCLUSIONS: CM-I, and not the CFI, is significantly associated with the presence of intracranial aneurysms in patients with LDS. Surveillance for intracranial aneurysms is essential in all patients with LDS and should not be limited to those with severe phenotypes. Long-term monitoring studies will be necessary to determine whether a correlation between craniofacial abnormalities and adverse outcomes from intracranial aneurysms (growth, intervention, or rupture) exists.

Impact of Neurosurgery Research and Education Foundation awards on subsequent grant funding and career outcomes of neurosurgeon-scientists.

OBJECTIVE: The Neurosurgery Research and Education Foundation (NREF) provides diverse funding opportunities for in-training and early-career neurosurgeon-scientists. The authors analyzed the impact of NREF funding on the subsequent career success of neurosurgeons in obtaining research funding and academic achievements. METHODS: The NREF database was queried to identify NREF winners from 2000 to 2015. The award recipients were surveyed to obtain information about their demographic characteristics, academic career, and research funding. Only subsequent research support with an annual funding amount of $50,000 or greater was included. The primary outcome was the NREF impact ratio, defined as the ratio between NREF award research dollars and subsequent grant funding dollars. The secondary outcomes were time to subsequent grant funding as principal investigator (PI), clinical practice settings, and final academic position achieved. RESULTS: From 2000 to 2015, 158 neurosurgeons received 164 NREF awards totaling $8.3 million (M), with $1.7 M awarded to 46 Young Clinician Investigators (YCIs), $1.5 M to 18 Van Wagenen Fellows (VWFs), and $5.1 M to 100 resident Research Fellowship Grant (RFG) awardees. Of all awardees, 73% have current academic appointments, and the mean ± SD number of publications and H-index were 71 ± 82 and 20 ± 15, respectively. The overall response rate to our survey was 70%, and these respondents became the cohort for our analysis. In total, respondents cumulatively obtained $776 M in post-NREF award grant funding, with the most common sources of funding including the National Institutes of Health ($327 M) and foundational awards ($306 M). The NREF impact ratios for awardees were $1:$381 for YCI, $1:$113 for VWF, and $1:$41 for resident RFG. Awardees with NREF projects in functional neurosurgery, pediatric neurosurgery, and neuro-oncology had the highest NREF impact ratios of $1:$194, $1:$185, and $1:$162, respectively. Of respondents, 9% became department chairs, 26% became full professors, 82% received at least 1 subsequent research grant, and 66% served as PI on a subsequent research grant after receiving their NREF awards. CONCLUSIONS: In-training and early-career neurosurgeons who were awarded NREF funding had significant success in acquiring subsequent grant support, research productivity, and achievements of academic rank. NREF grants provide a tremendous return on investment across various career stages and subspecialities. They also appeared to have a broader impact on trajectory of research and innovation within the field of neurosurgery.

Phasic stimulation in the nucleus accumbens enhances learning after traumatic brain injury.

Traumatic brain injury (TBI) is a significant cause of morbidity and mortality worldwide. Despite improvements in survival, treatments that improve functional outcome remain lacking. There is, therefore, a pressing need to develop novel treatments to improve functional recovery. Here, we investigated task-matched deep-brain stimulation of the nucleus accumbens (NAc) to augment reinforcement learning in a rodent model of TBI. We demonstrate that task-matched deep brain stimulation (DBS) of the NAc can enhance learning following TBI. We further demonstrate that animals receiving DBS exhibited greater behavioral improvement and enhanced neural proliferation. Treated animals recovered to an uninjured behavioral baseline and showed retention of improved performance even after stimulation was stopped. These results provide encouraging early evidence for the potential of NAc DBS to improve functional outcomes following TBI and that its effects may be broad, with alterations in neurogenesis and synaptogenesis.

Trends in mechanical thrombectomy and decompressive hemicraniectomy for stroke: A multicenter study.

BACKGROUND AND PURPOSE: Acute ischemic stroke has increasingly become a procedural disease following the demonstrated benefit of mechanical thrombectomy (MT) for emergent large vessel occlusion (ELVO) on clinical outcomes and tissue salvage in randomized trials. Given these data and anecdotal experience of decreased numbers of decompressive hemicraniectomies (DHCs) performed for malignant cerebral edema, we sought to correlate the numbers of strokes, thrombectomies, and DHCs performed over the timeline of the 2013 failed thrombolysis/thrombectomy trials, to the 2015 modern randomized MT trials, to post-DAWN and DEFUSE 3. MATERIALS AND METHODS: This is a multicenter retrospective compilation of patients who presented with ELVO in 11 US high-volume comprehensive stroke centers. Rates of tissue plasminogen activator (tPA), thrombectomy, and DHC were determined by current procedural terminology code, and specificity to acute ischemic stroke confirmed by each institution. Endpoints included the incidence of stroke, thrombectomy, and DHC and rates of change over time. RESULTS: Between 2013 and 2018, there were 55,247 stroke admissions across 11 participating centers. Of these, 6145 received tPA, 4122 underwent thrombectomy, and 662 patients underwent hemicraniectomy. The trajectories of procedure rates over time were modeled and there was a significant change in MT rate (p = 0.002) without a concomitant change in the total number of stroke admissions, tPA administration rate, or rate of DHC. CONCLUSIONS: This real-world study confirms an increase in thrombectomy performed for ELVO while demonstrating stable rates of stroke admission, tPA administration and DHC. Unlike prior studies, increasing thrombectomy rates were not associated with decreased utilization of hemicraniectomy.

Immediate Postoperative Electroencephalography Monitoring in Pediatric Moyamoya Disease and Syndrome.

BACKGROUND: Moyamoya disease and syndrome are progressive steno-occlusive cerebrovascular diseases that manifest clinically with ischemic episodes. There is evidence for the use of electroencephalography (EEG) in preoperative and long-term postoperative evaluation of these patients, as well as in the intraoperative period to monitor for changes correlated with perioperative ischemic events. However, the utility of EEG in the immediate postprocedure time period has not previously been described. METHODS: We review six patients who underwent pial synangiosis from 2017 to 2019. EEGs from the preoperative, intraoperative, and immediate postoperative period were evaluated, as well as clinical examination changes and subsequent interventions. RESULTS: Six patients with postoperative EEG monitoring following pial synangiosis were included. EEG data was collected preoperatively, intraoperatively, and continuously postoperatively. Preoperatively, five of six patients had normal background activity on EEG, whereas one of six had hemispheric asymmetry. Three patients had new or worsening hemispheric intracerebral asymmetry on EEG during the immediate postsurgical period. Two of these had no clinical manifestations of ischemia, and one had transient left facial weakness. All three underwent blood pressure augmentation with improvement in the asymmetry on EEG and clinical improvement in the symptomatic patient. CONCLUSIONS: Although widely accepted as a useful tool during the preoperative and intraoperative periods of evaluation and management of moyamoya disease and syndrome, we propose that the use of continuous EEG in the immediate postoperative period may have potential as a useful adjunct by both detecting early clinical and subclinical intracranial ischemia.

Case report of mesenteric strangulation secondary to longstanding ventriculoperitoneal shunt catheter.

BACKGROUND: Ventriculoperitoneal (VP) shunts are the most common treatment for hydrocephalus in both pediatric and adult patients. Complications resulting from the abdominal portion of shunts include tube disconnection, obstruction of the shunt tip, catheter migration, infection, abdominal pseudocysts, and bowel perforation. However, other less common complications can occur. The authors present a unique case of a patient with a longstanding VP shunt presenting with an acute abdomen secondary to knotting of the peritoneal portion of the catheter tubing. CASE DESCRIPTION: A 13-year-old male with past medical history significant for myelomeningocele, requiring ventriculoperitoneal shunt placement at 18 months of age, presented to an outside hospital with chief complaint of abdominal pain. Cross-sectional imaging revealed spontaneous knot formation within the shunt tubing around the base of the small bowel mesentery. He was then transferred to our facility for general and neurosurgical evaluation. His abdominal exam was notable for diffuse distension in addition to tenderness to palpation with guarding and rebound. Given his tenuous clinical status and peritonitis, he was emergently booked for abdominal exploration. He underwent bowel resection, externalization of his shunt, with later re-anastomosis and shunt internalization. He eventually made a full recovery. DISCUSSION: Given the potential for significant bowel loss with this and other shunt-related complications, this case serves as a reminder that even longstanding VP shunts should be considered in the differential diagnosis of abdominal pain in any patient with a shunt.

Multifocal primary central nervous system Ewing sarcoma presenting with intracranial hemorrhage and leptomeningeal dissemination: illustrative case.

BACKGROUND: Ewing sarcoma is a neoplasm within the family of small round blue cell tumors and most frequently arises from skeletal bone. Primary involvement of the central nervous system in these lesions is extremely rare, with an incidence of 1%. OBSERVATIONS: A case is presented of a 34-year-old man who presented with left facial numbness, multiple intracranial lesions, a lumbar intradural lesion, and diffuse spinal leptomeningeal involvement. A lumbar laminectomy and biopsy were performed, which revealed the diagnosis of extraskeletal Ewing sarcoma/primitive neuroectodermal tumor. The patient had a rapidly progressive clinical decline despite total neuroaxis radiation and multiple lines of chemotherapeutic treatments, eventually dying from his disease and its sequelae 6 months after diagnosis. LESSONS: The authors' review of 40 cases in the literature revealed only 2 patients with isolated intraaxial cranial lesions, 4 patients with cranial and spine involvement, and an additional 34 patients with spine lesions. The unique characteristics of this patient's case, including his presentation with diffuse disease and pathology that included a rare V600E BRAF mutation, are discussed in the context of the available literature.