Prophylactic removal of a migratory missile from the cerebral ventricles: case report

BACKGROUND AND IMPORTANCE

Nonpowder firearm injuries to the head pose major health risks, with retained fragments potentially causing harmful sequelae that require neurosurgical intervention.

CLINICAL PRESENTATION

We report the case of 2-year-old girl who sustained an accidental gunshot wound to the head. She sustained a penetrating ballistic intracranial injury caused by a BB shot from a rifle. At presentation, she was neurologically intact with a punctate laceration on her left forehead. Head CT demonstrated a small depressed left frontal skull fracture, a small intracerebral hematoma, and a 5-mm metallic bullet fragment in the deep left frontal lobe near the frontal horn of the left lateral ventricle. She was admitted to the hospital and managed nonoperatively with levetiracetam and intravenous antibiotics, and discharged home in good condition. Follow-up CT in 1 week showed slight migration of the metallic bullet fragment to the left, placing it at the anterior horn of the lateral ventricle. Six weeks later, follow-up CT showed migration of the bullet to the temporal horn of the left lateral ventricle. Intraventricular migration of the bullet raised concern that it could move further to obstruct the foramen of Monro or cerebral aqueduct. Therefore, we removed the bullet through a small left temporal craniotomy with image guidance using a microsurgical approach through a translucent tube.

CONCLUSION

The authors discuss the rationale and technique for removing a nonpowder firearm bullet that has migrated within the cerebral ventricles.

An unusual finding of an anaplastic meningioma in NF2-related schwannomatosis

NF2-related schwannomatosis (NF2) is a rare autosomal-dominant genetic disorder characterized by bilateral vestibular schwannomas and multiple meningiomas. This case report presents the extremely rare occurrence of an anaplastic meningioma in a 12-year-old male with previously undiagnosed NF2. The patient presented with a history of abdominal pain and episodic emesis, gait unsteadiness, right upper and lower extremity weakness, and facial weakness. He had sensorineural hearing loss and wore bilateral hearing aids. MR imaging revealed a sizable left frontoparietal, dural-based meningioma with heterogeneous enhancement with mass effect on the brain and midline shift. Multiple additional CNS lesions were noted including a homogenous lesion at the level of T5 indicative of compression of the spinal cord. The patient underwent a frontotemporoparietal craniotomy for the removal of his large dural-based meningioma, utilizing neuronavigation and transdural ultrasonography for precise en bloc resection of the mass. Histopathology revealed an anaplastic meningioma, WHO grade 3, characterized by brisk mitotic activity, small-cell changes, high Ki-67 proliferation rate, and significant loss of P16. We report an anaplastic meningioma associated with an underlying diagnosis of NF2 for which we describe clinical and histopathological features.

Risk of Subdural Hematoma Expansion in Patients With End-Stage Renal Disease: Continuous Venovenous Hemodialysis Versus Intermittent Hemodialysis

BACKGROUND AND OBJECTIVES

Subdural hematoma (SDH) patients with end-stage renal disease (ESRD) require renal replacement therapy in addition to neurological management. We sought to determine whether continuous venovenous hemodialysis (CVVHD) or intermittent hemodialysis (iHD) is associated with higher rates of SDH re-expansion as well as morbidity and mortality.

METHODS

Hemodialysis-dependent patients with ESRD who were discovered to have an SDH were retrospectively identified from 2016 to 2022. Rates of SDH expansion during CVVHD vs iHD were compared. Hemodialysis mode was included in a multivariate logistic regression model to test for independent association with SDH expansion and mortality.

RESULTS

A total of 123 hemodialysis-dependent patients with ESRD were discovered to have a concomitant SDH during the period of study. Patients who received CVVHD were on average 10.2 years younger ( P < .001), more likely to have traumatic SDH (47.7% vs 19.0%, P < .001), and more likely to have cirrhosis (25.0% vs 10.1%, P = .029). SDH expansion affecting neurological function occurred more frequently during iHD compared with CVVHD (29.7% vs 12.0%, P = .013). Multivariate logistic regression analysis found that CVVHD was independently associated with decreased risk of SDH affecting neurological function (odds ratio 0.25, 95% CI 0.08-0.65). Among patients who experienced in-hospital mortality or were discharged to hospice, 5% suffered a neurologically devastating SDH expansion while on CVVHD compared with 35% on iHD.

CONCLUSION

CVVHD was independently associated with decreased risk of neurologically significant SDH expansion. Therefore, receiving renal replacement therapy through a course of CVVHD may increase SDH stability in patients with ESRD.

Relative anemia and perioperative stroke in children with moyamoya

OBJECTIVES

Surgical revascularization for moyamoya arteriopathy decreases long-term stroke risk but carries a risk of perioperative ischemic complications. We aimed to evaluate modifiable stroke risk factors in children undergoing surgical revascularization for moyamoya.

MATERIALS AND METHODS

In this exploratory, single-center, retrospective cohort study, medical records of pediatric patients undergoing surgical revascularization for moyamoya arteriopathy at our center between 2003 and 2021 were reviewed. Candidate modifiable risk factors were analyzed for association with perioperative stroke, defined as ischemic stroke ≤7 days after surgery.

RESULTS

We analyzed 53 surgeries, consisting of 39 individual patients undergoing indirect surgical revascularization of 74 hemispheres. Perioperative ischemic stroke occurred following five surgeries (9.4%). There were no instances of hemorrhagic stroke. Larger pre-to-postoperative decreases in hemoglobin (OR 3.90, p=0.017), hematocrit (OR 1.69, p=0.012) and blood urea nitrogen (OR 1.83, p=0.010) were associated with increased risk of perioperative ischemic stroke. Weight-adjusted intraoperative blood loss was not associated with risk of perioperative ischemic stroke (OR 0.94, p=0.796). Among children with sickle cell disease, all of whom underwent exchange transfusion within one week prior to surgery, none experienced perioperative stroke.

CONCLUSIONS

Decreases in hemoglobin, hematocrit, and blood urea nitrogen between the preoperative and postoperative periods are associated with increased risk of perioperative stroke. These novel findings suggest that dilutional anemia, possibly due to standardly administered hyperhydration, may increase the risk of perioperative stroke in some children with moyamoya. Further work optimizing both mean arterial pressure and oxygen-carrying capacity in these patients, including consideration of alternative blood transfusion thresholds, is necessary.

Sagittal Synostectomy With Tension Band Sutures for Correction of Sagittal Craniosynostosis

BACKGROUND AND OBJECTIVES

Premature fusion of the sagittal suture is the most common form of craniosynostosis and can be treated using a variety of open or endoscopic approaches. Existing approaches have varying degrees of effectiveness. Open approaches, whether performed early or late, can be associated with significant blood loss and the need for transfusion. Endoscope-assisted approaches are minimally invasive but require months of postoperative helmet therapy to help remodel the skull. Implantation of springs or distractors requires a second operation for removal of the devices. Here, we present an alternative technique for early correction of sagittal craniosynostosis combining sagittal synostectomy with tension band sutures to remodel the skull without need for transfusion or helmet therapy.

METHODS

We retrospectively reviewed the medical records of all patients treated for sagittal craniosynostosis using a synostectomy with tension band sutures at a single tertiary care institution. Data on patient demographics, operative factors, and postoperative course were collected.

RESULTS

Thirty-four patients underwent the novel procedure. The median preoperative cephalic index was 68 and improved to 76 immediately postoperatively. The median blood loss was 10 mL while the operative duration was 112 minutes. No blood transfusions were needed. One small dural laceration was encountered that was promptly repaired. There were no postoperative complications. Patients presenting for follow-up visits showed continued improvement in head shape and cephalic index.

CONCLUSION

A modified sagittal craniectomy with tension band sutures to remodel the skull is effective in achieving immediate correction of sagittal craniosynostosis. The correction remains durable over long-term follow-up. Importantly, the technique can be performed with minimal blood loss and reduces transfusion risk, operative time, and overall morbidity compared with traditional open approaches while avoiding the need for helmet therapy necessitated by endoscopic approaches.

William Macewen and the first documented successful resection of a brain tumor

William Macewen was a visionary fearless Scottish surgeon who performed the first documented successful resection of a brain tumor on July 27, 1879. The pioneering operation received little attention at the time, and even today Macewen is under-recognized for his historic accomplishment. In this vignette, the author discusses details of Macewen's landmark procedure and describes two other groundbreaking brain tumor operations, one performed by Rickman Godlee 5 years later and another performed by Zanobi Pecchioli almost half a century earlier.

Neuroendoscopy: How We Got Here

From its inception in ancient Egyptian rituals, neuroendoscopy always promised a minimally invasive route to the cerebrum. Early visionaries, however, hit the proverbial wall of technical development until the 20th century, when new technologies allowed for light to be transmitted across a tube for visualization of intracranial structures. Despite a hiccupping start, with surgical microscopy hampering initial excitement, the development and transformation of neuroendoscopy continued, and today it is a widespread and reliable surgical option for the treatment of numerous varied and complex pathologies.

Intracranial arachnoid cysts

PURPOSE

The purpose of this review article is to outline the natural history, pathogenesis, anatomic considerations and surgical decision-making in caring for patients with intracranial arachnoid cysts.

METHODS

A review of the literature for intracranial arachnoid cysts was performed using Embase, PubMed, and Web of Science databases, including review of the bibliographies of eligible articles and the author's own experience.

RESULTS

Among those reviewed, 59 relevant original articles were included as well as illustrative cases from the authors own experience.

CONCLUSIONS

Arachnoid cysts are congenital lesions characterized by split arachnoid membrane, thick collagen in the cyst wall, absent traversing trabecular processes within the cyst, and hyperplastic arachnoid cells in the cyst wall. The underlying etiology is not entirely known, and they occur in greater proportion in males and in greater incidence with various genetic conditions including Down syndrome, mucopolysaccharidosis, schizencephaly, neurofibromatosis, autosomal dominant polycystic kidney disease (ADPKD), acrocallosal syndrome, and Aicardi syndrome. Most intracranial arachnoid cysts are incidentally found and occur in the middle cranial fossa, with the remaining occurring in the cerebellopontine angle, suprasellar cistern, quadrigeminal cistern, convexity, and posterior fossa/cisterna magna. The current article outlines the natural history, prevalence, demographic factors, and treatment decisions in managing patients with intracranial arachnoid cysts.

Perioperative Management of Pediatric Patients with Moyamoya Arteriopathy

Pediatric patients with moyamoya arteriopathy are at high risk for developing new onset transient or permanent neurologic deficits secondary to cerebral hypoperfusion, particularly in the perioperative period. It is therefore essential to carefully manage these patients in a multidisciplinary, coordinated effort to reduce the risk of new permanent neurologic deficits. However, little has been published on perioperative management of pediatric patients with moyamoya, particularly in the early postoperative period during intensive care unit admission. Our pediatric neurocritical care team sought to create a multidisciplinary periprocedural evidence- and consensus-based care pathway for high-risk pediatric patients with moyamoya arteriopathy undergoing anesthesia for any reason to decrease the incidence of periprocedural stroke or transient ischemic attack (TIA). We reviewed the literature to identify risk factors associated with perioperative stroke or TIA among patients with moyamoya and to gather data supporting specific perioperative management strategies. A multidisciplinary team from pediatric anesthesia, neurocritical care, nursing, child life, neurosurgery, interventional neuroradiology, neurology, and hematology created a care pathway for children with moyamoya undergoing anesthesia, classifying them as either high or standard risk, and applying an individualized perioperative management plan to high-risk patients. The incidence of neurologic sequelae before and after pathway implementation will be compared in future studies.

Same-day versus staged revascularization of bilateral moyamoya arteriopathy in pediatric patients

PURPOSE

To compare the outcomes of conducting left and right hemisphere surgical revascularization on the same day versus different days for bilateral pediatric moyamoya arteriopathy patients.

METHODS

We retrospectively analyzed mortality, stroke, and transient neurologic event (TNE) rates in North American bilateral pediatric moyamoya arteriopathy patients who underwent bilateral cerebral revascularization.

RESULTS

A total of 38 pediatric (≤ 18 years old) patients at our institution underwent bilateral cerebral revascularization for moyamoya arteriopathy. Of these patients, 24 (63.2%) had both operations on the same day and 14 (36.8%) had the two operations on different days. The average length of stay for patients who underwent same-day bilateral revascularization was 6.9 ± 2.0 days and the average length of stay for each operation for patients who underwent staged bilateral revascularization was 4.5 ± 1.4 days, p = 0.001. While there were 7 (14.6%) postoperative strokes in patients who had both hemispheres revascularized on the same day, 0 (0%) strokes occurred in hemispheres after they had been operated on in the staged cohort, p = 0.042. Additionally, the postoperative stroke-free survival time in the ipsilateral hemisphere and TNE-free survival time were significantly longer in patients in the staged revascularization cohort.

CONCLUSION

Same-day bilateral revascularization was associated with longer length of stay per operation, higher rate of ipsilateral stroke, and shorter postoperative TNE-free and stroke-free survival time in the revascularized hemisphere.

H3 K27-altered diffuse midline glioma presenting as massive cerebellopontine hemorrhage

We report the case of a 14-year-old boy who presented with extensive cerebellar and brainstem hemorrhage. Our presumptive diagnosis was a ruptured arteriovenous malformation (AVM), but two cerebral angiograms showed no significant vascular abnormalities. The patient underwent posterior fossa craniotomy and microsurgical evacuation of the hematoma. Pathological analysis of the hemorrhagic tissue made the diagnosis of diffuse midline glioma, H3 K27-altered (WHO grade 4), based on immunohistochemistry. He subsequently developed diffuse craniospinal leptomeningeal disease and progressed rapidly, with respiratory failure followed by severe neurologic decline without further hemorrhage. He was compassionately extubated at the request of the family and died before initiation of adjuvant therapy. This unusual case of a diffuse midline glioma presenting with massive hemorrhage underscores the importance of searching for an underlying etiology of hemorrhage in a child when a vascular lesion cannot be identified.

The Gordian knot of hydrocephalus: constrictive entanglement of distal ventriculoperitoneal shunt catheter

We recently cared for a patient with a distal ventriculoperitoneal shunt malfunction. The peritoneal catheter was coiled in a scarred pseudocyst, and we encountered strong resistance while attempting to remove the distal shunt catheter. The catheter was successfully removed under laparoscopic guidance and was found to be tightly coiled in a constrictive knot. We describe a technique for managing this unusual presentation to minimize the risk of complications.

Nephrogenic rest vs immature teratoma associated with lumbosacral lipomyelomeningocele: a case report and review of the literature

BACKGROUND

Lipomyelomeningoceles (LMMs) are subcutaneous lipomas with dural penetration that often present with spinal cord tethering and may lead to neurological deterioration if untreated. This report describes a rare case of an LMM associated with immature nephroblastic tissue, representing a nephrogenic rest (NR) or, less likely, an immature teratoma.

CLINICAL PRESENTATION

An 8-day-old infant girl presented to the clinic with a sacral dimple. Imaging demonstrated a tethered spinal cord with low-lying conus medullaris and an LMM. A firm mass was noted in the subcutaneous lipoma. Detethering surgery and removal of the lipoma and mass were performed at the age of 6 months. Pathological examination identified the mass as cartilage, fat, and immature nephroblastic tissue consistent with NR tissue or, less likely, a teratoma with renal differentiation.

CONCLUSION

This presentation of an LMM associated with an immature teratoma or NR poses a risk of malignant transformation in patients. As a result, careful surgical dissection, resection, and close clinical follow-up are recommended for these patients.

The neurosurgical management of Severe Hemophilia A and Moyamoya (SHAM): challenges, strategies, and literature review

INTRODUCTION

Severe Hemophilia A and Moyamoya arteriopathy (SHAM syndrome) is a rare genetic disorder caused by deletion of portions of the cytogenic band Xq28. A case of SHAM syndrome requiring bilateral cerebral revascularization is described with an emphasis on perioperative management.

CASE REPORT

A 5-year-old boy with severe hemophilia A complicated by factor VIII inhibition presented with right-sided weakness. Imaging revealed multiple strokes and vascular changes consistent with Moyamoya disease. The patient underwent two-staged indirect cerebral bypass revascularizations, first on the left side and several months later on the right. Perioperative management required balancing the administration of agents to prevent coagulopathy and perioperative hemorrhage while mitigating the risk of thromboembolic events associated with bypass surgery. Despite a multidisciplinary effort by the neurosurgery, hematology, critical care, and anesthesiology teams, the post-operative course after both surgeries was complicated by stroke. Fortunately, the patient recovered rapidly to his preoperative functional baseline.

CONCLUSION

We describe a rare case of SHAM syndrome in a pediatric patient who required bilateral revascularizations and discuss strategies for managing the perioperative risk of hemorrhage and stroke. We also review existing literature on SHAM syndrome.

Impact of international research fellows in neurosurgery: results from a single academic center

OBJECTIVE

International research fellows have been historically involved in academic neurosurgery in the United States (US). To date, the contribution of international research fellows has been underreported. Herein, the authors aimed to quantify the academic output of international research fellows in the Department of Neurosurgery at The Johns Hopkins University School of Medicine.

METHODS

Research fellows with Doctor of Medicine (MD), Doctor of Philosophy (PhD), or MD/PhD degrees from a non-US institution who worked in the Hopkins Department of Neurosurgery for at least 6 months over the past decade (2010-2020) were included in this study. Publications produced during fellowship, number of citations, and journal impact factors (IFs) were analyzed using ANOVA. A survey was sent to collect information on personal background, demographics, and academic activities.

RESULTS

Sixty-four international research fellows were included, with 42 (65.6%) having MD degrees, 17 (26.6%) having PhD degrees, and 5 (7.8%) having MD/PhD degrees. During an average 27.9 months of fellowship, 460 publications were produced in 136 unique journals, with 8628 citations and a cumulative journal IF of 1665.73. There was no significant difference in total number of publications, first-author publications, and total citations per person among the different degree holders. Persons holding MD/PhDs had a higher number of citations per publication per person (p = 0.027), whereas those with MDs had higher total IFs per person (p = 0.048). Among the 43 (67.2%) survey responders, 34 (79.1%) had nonimmigrant visas at the start of the fellowship, 16 (37.2%) were self-paid or funded by their country of origin, and 35 (81.4%) had mentored at least one US medical student, nonmedical graduate student, or undergraduate student.

CONCLUSIONS

International research fellows at the authors' institution have contributed significantly to academic neurosurgery. Although they have faced major challenges like maintaining nonimmigrant visas, negotiating cultural/language differences, and managing self-sustainability, their scientific productivity has been substantial. Additionally, the majority of fellows have provided reciprocal mentorship to US students.

Rhomboencephalosynapsis: Review of the literature

Rhombencephalosynapsis is a rare congenital anomaly, characterized by partial or total agenesis of the cerebellar vermis with midline fusion of the cerebellar hemispheres, dentate nuclei, and the superior cerebellar peduncles, creating the distinctive Keyhole appearance of the fourth ventricle. Rhombencephalosynapsis can be isolated or can occur in association with other congenital anomalies and syndromes such as Gómez-López-Hernández Syndrome (GLHS) or VACTERL; vertebral anomalies (V), anal atresia (A), cardiovascular defects (C), esophageal atresia and/or tracheo-esophageal fistula (TE), renal (R) and limb/radial (L) anomalies. Recent advances in prenatal imaging have resulted in an increasing rate of prenatal diagnosis of abnormalities of the posterior fossa including Rhombencephalosynapsis. Patients with rhombencephalosynapsis may present with motor developmental delay, ataxia, swallowing difficulties, muscular hypotonia, spastic quadriparesis, abnormal eye movements and a characteristic "figure-of-eight" head shaking. Cognitive outcome varies from severe intellectual disability to normal intellectual function. Rhombencephalosynapsis with VACTERL is often associated with severe cognitive disabilities, whereas patients with GLHS may have better cognitive function. The most common associated findings with rhombencephalosynapsis include hydrocephalus, mesencephalosynapsis, holoprosencephaly, pontocerebellar hypoplasia, corpus callosum dysgenesis and absence of septum pellucidum. Patients can be categorized into four groups: (1) Rhombencephalosynapsis associated with Gómez-López-Hernández syndrome; (2) Rhombencephalosynapsis with VACTERL; (3) Rhombencephalosynapsis with atypical holoprosencephaly, and (4) isolated rhomboencephalosynapsis. The etiology of rhombencephalosynapsis is unknown. Here, we discuss several hypotheses about its etiology.

An update on the US adult thalassaemia population: a report from the CDC thalassaemia treatment centres

Thalassaemia is caused by genetic globin defects leading to anaemia, transfusion-dependence and comorbidities. Reduced survival and systemic organ disease affect transfusion-dependent thalassaemia major and thalassaemia intermedia. Recent improvements in clinical management have reduced thalassaemia mortality. The therapeutic landscape of thalassaemia may soon include gene therapies as functional cures. An analysis of the adult US thalassaemia population has not been performed since the Thalassemia Clinical Research Network cohort study from 2000 to 2006. The Centers for Disease Control and Prevention supported US thalassaemia treatment centres (TTCs) to compile longitudinal information on individuals with thalassaemia. This dataset provided an opportunity to evaluate iron balance, chelation, comorbidities and demographics of adults with thalassaemia receiving care at TTCs. Two adult cohorts were compared: those over 40 years old (n = 75) and younger adults ages 18-39 (n = 201). The older adult cohort was characterized by higher numbers of iron-related comorbidities and transfusion-related complications. By contrast, younger adults had excess hepatic and cardiac iron and were receiving combination chelation therapy. The ethnic composition of the younger cohort was predominantly of Asian origin, reflecting the demographics of immigration. These findings demonstrate that comprehensive care and periodic surveys are needed to ensure optimal health and access to emerging therapies.

Endoscope-assisted microsurgical retrosigmoid approach to the lateral posterior fossa: Cadaveric model and a review of literature

Background:

The advancement of endoscopic techniques in the past decade has improved the surgical management of cerebellopontine angle (CPA) tumors. Endoscope-assisted microsurgery improves the ability to evaluate the extent of resection, achieve safe tumor resection and reduce the risk of surgery-related morbidity.

Methods:

In this study, we used a cadaveric model to demonstrate a step by step endoscope-assisted microsurgery of the retrosigmoid approach to the lateral posterior fossa.

Results:

Retrosigmoid craniotomies were performed on four latex-injected cadaver heads (eight CPAs). Microsurgical exposures were performed to identify neurovascular structures in each segment. 0° and 30° rigid endoscope lenses were subsequently introduced into each corridor and views were compared in this manner. The endoscopic images were compared with the standard microscopic views to determine the degree of visualization with each technique. In each case, better visualization was provided by both the 0° and 30° endoscope lenses. Endoscopic views frequently clarified neurovascular relationships in obscured anatomic regions.

Conclusion:

Endoscope-assisted microsurgery could allow better visualization of various regions of the posterior fossa. Surgical planning for posterior fossa lesions should include consideration of this combined approach.

Epidemiology and outcomes of pediatric intracranial aneurysms: comparison with an adult population in a 30-year, prospective database

OBJECTIVE

Pediatric intracranial aneurysms are rare. Most large series in the last 15 years reported on an average of only 39 patients. The authors sought to report their institutional experience with pediatric intracranial aneurysms from 1991 to 2021 and to compare pediatric patient and aneurysm characteristics with those of a contemporaneous adult cohort.

METHODS

Pediatric (≤ 18 years of age) and adult patients with one or more intracranial aneurysms were identified in a prospective database. Standard epidemiological features and outcomes of each pediatric patient were retrospectively recorded. These results were compared with those of adult aneurysm patients managed at a single institution over the same time period.

RESULTS

From a total of 4500 patients with 5150 intracranial aneurysms admitted over 30 years, there were 47 children with 53 aneurysms and 4453 adults with 5097 aneurysms; 53.2% of children and 36.4% of adults presented with a subarachnoid hemorrhage (SAH). Pediatric aneurysms were significantly more common in males, more likely giant (≥ 25 mm), and most frequently located in the middle cerebral artery. Overall, 85.1% of the pediatric patients had a modified Rankin Scale score ≤ 2 at the last follow-up (with a mean follow-up of 65.9 months), and the pediatric mortality rate was 10.6%; all 5 patients who died had an SAH. The recurrence rate of treated aneurysms was 6.7% (1/15) in the endovascular group but 0% (0/31) in the microsurgical group. No de novo aneurysms occurred in children (mean follow-up 5.5 years).

CONCLUSIONS

Pediatric intracranial aneurysms are significantly different from adult aneurysms in terms of sex, presentation, location, size, and outcomes. Future prospective studies will better characterize long-term aneurysm recurrence, rebleeds, and de novo aneurysm occurrences. The authors currently favor microsurgical over endovascular treatment for pediatric aneurysms.

Repair of Giant Anterior Skull Base Encephalocele Containing Intralesional Eloquent Brain: Technical Note

BACKGROUND

Encephaloceles are herniations of intracranial neural tissue and meninges through defects in the skull. Basal encephaloceles are rare anterior skull base defects incident in 1 in 35,000 live births. Sphenoethmoidal encephaloceles are even more uncommon, with an incidence of 1 in 700,000 live births. Anterior skull base encephaloceles may be life-threatening in infants, presenting as airway obstruction and respiratory compromise. They can also present with cerebrospinal fluid (CSF) rhinorrhea, purulent nasal drainage, or meningitis.

OBJECTIVE

To report a novel technique for repairing a giant sphenoethmoidal encephalocele containing eloquent neural tissue.

METHODS

A 16-mo-old girl presented with progressive airway obstruction from a giant sphenoethmoidal encephalocele that filled her oral cavity. She had multiple congenital anomalies including agenesis of the corpus callosum and cleft lip and palate. Computed tomography showed complete absence of the bony anterior cranial base, and magnetic resonance imaging demonstrated the presence of the pituitary gland and hypothalamus in the hernia sac.

RESULTS

We repaired the encephalocele using a combined microsurgical and endoscopic multidisciplinary approach working through transcranial, transnasal, and transpalatal corridors. The procedure was completed in a single stage, during which the midline cleft lip was also repaired. The child made an excellent neurological and aesthetic recovery with preservation of pituitary and hypothalamic function, without evidence of CSF fistula.

CONCLUSION

The authors describe a novel multidisciplinary technique for treating a giant sphenoethmoidal encephalocele containing eloquent brain. The cleft lip was also repaired at the same time. The ability to work through multiple corridors can enhance the safety and efficacy of an often-treacherous operative endeavor.

Posterior ischemic optic neuropathy following supine craniotomy for epidural abscess in a child

Post-operative vision loss (POVL) can be a devastating complication of neurosurgical procedures and is unusual in the pediatric population. Mechanisms of POVL include direct optic nerve injury, vascular occlusion, or indirect malperfusion resultant from surgeries with substantial blood loss or fluid shifts, with prone positioning being a major risk factor for these events. Posterior ischemic optic neuropathy (PION) is a rare cause of POVL and is associated with a poor prognosis for recovery of visual function. We present a case of PION following a supine bifrontal craniotomy for a frontal epidural abscess secondary to pan-sinusitis in a pediatric patient. This is an unusual reported case in that no additional traditional risk factors were identified. We present clinical and radiographic findings, diagnostic considerations, treatment strategies, and a literature review. The patient was managed medically and recovered substantial vision in the affected eye.

Predictors of Academic Neurosurgical Career Trajectory among International Medical Graduates Training Within the United States

BACKGROUND

Within the literature, there has been limited research tracking the career trajectories of international medical graduates (IMGs) following residency training.

OBJECTIVE

To compare the characteristics of IMG and US medical school graduate (USMG) neurosurgeons holding academic positions in the United States and also analyze factors that influence IMG career trajectories following US-based residency training.

METHODS

We collected data on 243 IMGs and 2506 USMGs who graduated from Accreditation Council for Graduate Medical Education (ACGME)-accredited neurosurgery residency programs. We assessed for significant differences between cohorts, and a logistic regression model was used for the outcome of academic career trajectory.

RESULTS

Among the 2749 neurosurgeons in our study, IMGs were more likely to pursue academic neurosurgery careers relative to USMGs (59.7% vs 51.1%; P = .011) and were also more likely to complete a research fellowship before beginning residency (odds ratio [OR] = 9.19; P < .0001). Among current US academic neurosurgeons, USMGs had significantly higher pre-residency h-indices relative to IMGs (1.23 vs 1.01; P < .0001) with no significant differences between cohorts when comparing h-indices during (USMG = 5.02, IMG = 4.80; P = .67) or after (USMG = 14.05, IMG = 13.90; P = .72) residency. Completion of a post-residency clinical fellowship was the only factor independently associated with an academic career trajectory among IMGs (OR = 1.73, P = .046).

CONCLUSION

Our study suggests that while IMGs begin their US residency training with different research backgrounds and achievements relative to USMG counterparts, they attain similar levels of academic productivity following residency. Furthermore, IMGs are more likely to pursue academic careers relative to USMGs. Our work may be useful for better understanding IMG career trajectories following US-based neurosurgery residency training.

Unexpected Binding of Tozuleristide "Tumor Paint" to Cerebral Vascular Malformations: A Potentially Novel Application of Fluorescence-Guided Surgery

BACKGROUND

Fluorescence-guided surgery (FGS) is under investigation as a means to improve the extent of resection for primary central nervous system (CNS) tumors. Tozuleristide, known also as "Tumor Paint," is an investigational tumor-targeting agent covalently conjugated to a derivative of the fluorescent dye indocyanine green.

OBJECTIVE

To report the finding of avid intraoperative fluorescence of tozuleristide on cerebral vascular malformations.

METHODS

Our institution is participating in a phase 2/3 study of intraoperative near-infrared fluorescence detection of pediatric primary CNS tumors in patients receiving intravenous tozuleristide and imaged with the Canvas system. Our site enrolled 2 patients with intracranial lesions, suspected preoperatively of possibly being gliomas that proved to be cavernous vascular malformations after resection.

RESULTS

Each lesion had a dark blue mulberry appearance and each fluoresced avidly with tozuleristide. Each was completely resected, and the patients recovered without deficit. Pathological assessment showed cavernous angioma for both cases. Tozuleristide fluorescence is postulated to result from binding to matrix metalloproteinase-2 and annexin A2, and literature review demonstrates expression of both these ligands on multiple cerebrovascular lesions, including cavernous malformations.

CONCLUSION

This finding deserves further investigation to determine if tozuleristide "Tumor Paint" may have a wider role in the identification of non-neoplastic intracranial pathologies.

Minimally invasive therapeutic ultrasound: Ultrasound-guided ultrasound ablation in neuro-oncology

INTRODUCTION

To improve patient outcomes (eg, reducing blood loss and infection), practitioners have gravitated toward noninvasive and minimally invasive surgeries (MIS), which demand specialized toolkits. Focused ultrasound, for example, facilitates thermal ablation from a distance, thereby reducing injury to surrounding tissue. Focused ultrasound can often be performed noninvasively; however, it is more difficult to carry out in neuro-oncological tumors, as ultrasound is dramatically attenuated while propagating through the skull. This shortcoming has prompted exploration of MIS options for intracranial placement of focused ultrasound probes, such as within the BrainPath™ (NICO Corporation, Indianapolis, IN). Herein, we present the design, development, and in vitro testing of an image-guided, focused ultrasound prototype designed for use in MIS procedures. This probe can ablate neuro-oncological lesions despite its small size.

MATERIALS & METHODS

Preliminary prototypes were iteratively designed, built, and tested. The final prototype consisted of three 8-mm-diameter therapeutic elements guided by an imaging probe. Probe functionality was validated on a series of tissue-mimicking phantoms.

RESULTS

Lesions were created in tissue-mimicking phantoms with average dimensions of 2.5 × 1.2 × 6.5 mm and 3.4 × 3.25 × 9.36 mm after 10- and 30-second sonification, respectively. 30 s sonification with 118 W power at 50% duty cycle generated a peak temperature of 68 °C. Each ablation was visualized in real time by the built-in imaging probe.

CONCLUSION

We developed and validated an ultrasound-guided focused ultrasound probe for use in MIS procedures. The dimensional constraints of the prototype were designed to reflect those of BrainPath trocars, which are MIS tools used to create atraumatic access to deep-seated brain pathologies.

Endoscope-assisted microsurgical resection of intrinsic brainstem epidermoid: technical note and review of the literature

Intrinsic epidermoid tumors of the brainstem are rare, histologically benign lesions associated with high surgical morbidity and mortality due to their eloquent location. The authors report a child with progressive severe neurological deterioration from a large midline intrinsic brainstem epidermoid at the pontomedullary junction. The mass was removed through a posterior fossa craniotomy and midline endoscope-assisted microsurgical corridor through the floor of the fourth ventricle, using neurophysiological monitoring. Postoperatively, there was dramatic improvement in the patient's symptoms. Early recurrence of the mass necessitated reoperation with more aggressive resection of the cyst capsule, which led to complete radiographic reconstitution of the brainstem. The patient remains well with a durable recovery 7 years after presentation. The authors review the literature on brainstem epidermoids and discuss the differential diagnosis and management strategies for approaching these lesions, advocating for conservative surgery with resection of as much of the tumor capsule as is safely possible.

Educational Program Rankings Are Independently Associated With Residents' Academic Career Trajectory in Neurological Surgery

OBJECTIVE

Many studies have sought to determine predictors of academic career placement in surgical subspecialities. However, previous research has yet to establish whether the ranking of a surgeon's undergraduate institution or medical school is significantly associated with pursuit of an academic career. The purpose of this study was to investigate these novel factors' predictive impact on an academic career in the surgical subspeciality of neurosurgery. Factors investigated included undergraduate university rankings, medical school rankings, and residency program rankings.

DESIGN

Data were retrospectively collected for 884 alumni of Accreditation Council for Graduate Medical Education neurological surgery residency programs. Bivariate analyses were conducted to determine covariates for a logistic regression model, and multivariate analysis was performed with 13 covariates to determine which factors were independently associated with academic career trajectory.

RESULTS

In multivariate analysis, factors that were independently associated with an academic career in neurological surgery included having 1 year or more of protected research time during residency (odds ratio [OR] =1.96, p = 0.020), attending a "top" undergraduate university (OR =1.88, p = 0.00033), attending a "top" research medical school (OR = 1.53, p = 0.031) attending a residency program affiliated with a "top" research medical school (OR = 1.78, p = 0.012), possessing a Master of Science (OR = 3.46, p = 0.00097), or Doctor of Philosophy (OR = 2.05, p = 0.0019) degree, and completing a clinical fellowship (OR = 2.56, p = 1.90 × 10^-8).

CONCLUSIONS

Our study establishes 3 novel factors for predicting residents' choice of pursuing an academic career in neurological surgery, namely undergraduate university rank, medical school rank, and completing residency at a program affiliated with a "top" research medical school. Such findings reinforce the notion that educational and training environments are key in shaping the career trajectory of future academic surgical subspecialists.

Impact of COVID-19 on an Academic Neurosurgery Department: The Johns Hopkins Experience

OBJECTIVE

Coronavirus disease 2019 (COVID-19) is a disruptive pandemic that has continued to test the limits of health care system capacities. It is important to highlight the specific challenges facing US neurosurgery during these difficult circumstances. In the present study, we have described our neurosurgery department's unique experience during the COVID-19 pandemic.

METHODS

We analyzed the following data points both before and during the first months of the COVID-19 pandemic: the number of patients infected with COVID-19 at our institution, changes in neurosurgical operative workflow, changes in neurosurgical outpatient and inpatient clinic workflows, resident redeployment statistics and changes in call schedules, and changes in neurosurgical education.

RESULTS

At our institution, the adult surgery numbers decreased from 120 during the week of March 4-11, 2020 (before the World Health Organization had classified the COVID-19 outbreak as a pandemic) to 17 during the week of April 13-17, 2020. The number of pediatric surgeries decreased from 15 to 3 during the same period. Significantly more surgeries were cancelled than were delayed (P < 0.0001). A drastic decline occurred in the number of in-person neurosurgery clinic visits (97.12%) between March and April 2020 (P = 0.0020). The inpatient census declined from mid-March to mid-April 2020 by 44.68% compared with a 4.26% decline during the same period in 2019 (P < 0.0001). Finally, neurosurgery education has largely shifted toward video-conferencing sessions rather than in-person sessions.

CONCLUSION

By detailing our experience during the COVID-19 pandemic, we hope to have provided a detailed picture of the challenges facing neurosurgery within an academic medical center.

A phase II/III randomized, blinded study of tozuleristide for fluorescence imaging detection during neurosurgical resection of pediatric primary central nervous system (CNS) tumors: PNOC012 (Pacific Pediatric Neuro-oncology Consortium)

TPS2575

Background: Tozuleristide (also known as BLZ-100 or Tumor Paint) is a fluorescent imaging drug designed to specifically label and accumulate in tumor tissue, thus enabling more precise surgical tumor resection intraoperatively. Tozuleristide achieves tumor targeting through the peptide portion of the molecule, a modified chlorotoxin peptide, and its imaging properties from a coupled near-infrared fluorescent dye, an indocyanine green. Tozuleristide has been studied in 4 Phase 1 studies, including a trial in pediatric brain cancer subjects. No tozuleristide SAEs or dose limiting toxicity were observed in the 97 subjects treated in the Phase 1 program at doses up to 30 mg in adults or 17.3 mg/m2 in pediatrics (Hansen S et al, WMIC 2018, P196). Eighty percent of pediatric subjects receiving tozuleristide had tumors considered fluorescence positive, including high and low grade glioma, ependymoma, and medulloblastoma. Methods: This study randomizes subjects in a 1:10 ratio to standard of care or tozuleristide arms. The primary efficacy objectives and endpoints are based on equivocal regions of tissue encountered in surgery. Prior to fluorescence assessment, the surgeon assesses the suspected nature of the tissue (more likely tumor/less likely tumor). Tissue specimens of equivocal regions are collected for blinded central pathology assessment. Sensitivity and specificity of the surgeon’s designation, fluorescence assessment, and ratios of surgeon to fluorescence assessments comprise the primary efficacy analyses. Tozuleristide is given as an IV bolus dose of 15 mg/m2 to pediatric subjects 1 to 36 hours prior to surgery. Subjects must have a MRI documented lesion consistent with a CNS tumor for which resection is planned. Measures of safety include adverse events, laboratory measures of hematology, liver and kidney function and changes in vital signs and ECGs. Pharmacokinetic blood samples are collected up to 3 hr post dose. Fluorescence imaging is assessed during surgery using an investigational “Canvas System” imaging device attached to a surgical microscope. Collected pathology specimens will also be subjected to further genetic, molecular and pathology studies, including fluorescence assessment of frozen tissue sections. SAEs and patient reported outcomes are collected for 3 months. The SMC for the study last reviewed the data for this study in July 2019 and recommended the trial continue as planned. Clinical trial information: NCT03579602 .

Occurrence of spinal extradural arachnoid cysts in a child with concomitant intracranial midline abnormalities: case report

Spinal extradural arachnoid cysts (SEACs) are uncommon spinal lesions that may cause myelopathy, most frequently in the 2nd decade of life. There are multiple theories of their pathogenesis, and associated entities include spinal trauma, spina bifida, and the lymphedema-distichiasis syndrome. The authors report the case of an otherwise healthy, developmentally normal 13-year-old boy who presented with multiple SEACs. Upon further neuroimaging workup, he was found to have an asymptomatic retrocerebellar arachnoid cyst, cavum septi pellucidi, and cavum vergae. Three contiguous but separate spinal cysts were identified intraoperatively, and they were completely excised with closure of the dural defects. The patient recovered motor and sensory function of the lower extremities. This collection of uncommon neuroimaging findings provides important clues to the pathogenesis of the disease and guides the optimal management of patients with SEACs. The unusual presentation of SEACs, together with uncommon midline abnormalities, provides further evidence of their congenital, midline origin. Therefore, it is reasonable to pursue imaging of the brain in atypical cases of SEACs.

Meet in the middle: a technique for resecting nasocranial dermoids-technical note and review of the literature

INTRODUCTION

Nasal dermoids with intracranial extension are benign lesions that can have life-threatening consequences, as a nasal punctum may serve as a portal of entry for infection into the central nervous system. The surgical management of these lesions can be challenging, as the extracranial and intracranial cysts and sinus tract must be resected to prevent recurrence, and the surgery must be carried out with an acceptable esthetic result.

TECHNIQUE

The authors present a technique for the resection of nasocranial dermoids that eliminates the need to remove and replace the frontonasal segment. Working through a small frontal craniotomy enables the surgeon to drill out the sinus tract through the foramen cecum and inferiorly into the nose. This exposure eliminates the need to enter the frontal sinus, if it is present.

CONCLUSION

The extracranial punctum and tract are resected from below in a minimally invasive fashion that permits removal of the lesion without a disfiguring scar.

The great neurosurgical masquerader: 3 cases of desmoplastic infantile ganglioglioma

Desmoplastic infantile ganglioglioma (DIG) is a rare, distinctive, supratentorial neoplasm with a generally favorable prognosis. Clinical, radiographic, and pathologic features can sometimes mimic those of a malignant tumor and other serious intracranial disorders. The author describes his experience with 3 cases of DIG, each of which initially masqueraded as another neurological disease with a very different prognosis. Case 1 was an infant boy referred for evaluation of a hemorrhagic infarction at birth. Case 2 was an infant girl referred for evaluation of a holohemispheric malignant neoplasm. Case 3 was an infant girl referred for evaluation of an intracranial mass believed to be a subdural empyema or possible sarcoma. In each case the lesion was resected and found to be a WHO grade I DIG. Each child has had a benign postoperative course. DIG can be mistaken for other serious neurological conditions including malignant neoplasm, cerebral infarction, and infection. It is prudent to consider this rare, low-grade resectable tumor in the differential diagnosis of atypical intracranial masses of childhood, as the impact on prognosis can be profound. The author discusses management strategies for DIG, including a role for molecular sequencing.

Treatment-refractory Escherichia coli subdural empyema caused by infection of a chronic subdural hematoma in an infant

INTRODUCTION

Subdural empyema (SDE) is a neurosurgical emergency that is typically treated with surgical drainage, either by burr hole or by craniotomy. Escherichia coli is an uncommon cause of SDE and is associated with infection of a pre-existing subdural hematoma.

CASE REPORT

We report the case of an otherwise healthy, immunocompetent 4-month-old infant girl with an E. coli-infected subdural hematoma. The infection persisted despite aggressive neurosurgical treatment that included drainage of the subdural space through burr holes and, subsequently, a wide craniotomy was performed. Ultimately, after 30 days, the SDE resolved with good neurological outcome. A review of prior literature indicates that infected subdural hematomas (including those caused by E. coli) are typically less aggressive and respond to burr hole drainage.

CONCLUSION

We illustrate the fulminant progression of the SDE in the face of neurosurgical treatment. Our experience suggests lowering the threshold for wide craniotomy in these incompletely understood cases.

Pipeline-assisted coil embolization of a large middle cerebral artery pseudoaneurysm in a 9-month-old infant: experience from the youngest flow diversion case

Intracranial aneurysms in the pediatric population are rare entities. The authors recently treated a 9-month-old infant with a 19-mm recurrent, previously ruptured, and coil-embolized left middle cerebral artery (MCA) pseudoaneurysm, which was treated definitively with single-stage Pipeline-assisted coil embolization. The patient was 5 months old when she underwent resection of a left temporal Grade 1 desmoplastic infantile ganglioglioma at an outside institution, which was complicated by left MCA injury with a resultant 9-mm left M1 pseudoaneurysm. Within a month, the patient had two aneurysmal rupture events and underwent emergency craniectomy for decompression and evacuation of subdural hematoma. The pseudoaneurysm initially underwent coil embolization; however, follow-up MR angiography (MRA) revealed aneurysm recanalization with saccular enlargement to 19 mm. The patient underwent successful flow diversion-assisted coil embolization at 9 months of age. At 7 months after the procedure, follow-up MRA showed complete aneurysm occlusion without evidence of in-stent thrombosis or stenosis. Experience with flow diverters in the pediatric population is still in its early phases, with the youngest reported patient being 22 months old. In this paper the authors report the first case of such a technique in an infant, whom they believe to be the youngest patient to undergo cerebral flow diversion treatment.

Iliopsoas hematoma in a patient with sickle cell disease

Although musculoskeletal pain in patients with sickle cell disease (SCD) is most frequently the result of vaso-occlusive episodes, clinicians often consider other etiologies including osteomyelitis, avascular necrosis, and trauma. In this study, we report the case of a young female with SCD with hip and back pain secondary to a nontraumatic iliopsoas periosteal hematoma with evidence of adjacent bone infarction. The pathophysiology, diagnostic considerations, and management of periosteal hematomas in SCD are reviewed. This case highlights the need for recognition of unusual causes of musculoskeletal pain in SCD.

Bullough's bump: unusual protuberant fibro-osseous tumor of the temporal bone. Case report

Scalp and calvarial masses are common in children and the differential diagnosis is broad. The authors recently cared for a child with an unusual fibro-osseous lesion of the temporal bone that has previously not been described in the pediatric neurosurgery literature. A 10-year-old girl presented with a firm, slowly enlarging protuberant mass arising from the squamous suture of the temporal bone without intracranial extension. The mass was removed en bloc through a temporal craniectomy and cranioplasty was performed. The patient had a smooth postoperative course. Histological examination showed multiple oval osseous islands dispersed throughout a bland fibrous stroma. The pathological diagnosis was "Bullough's bump," a rare, benign fibro-osseous neoplasm first described in 1999, and only 8 reported cases appear in the literature. Here the authors report the first case of Bullough's bump in a child.

Safety and pharmacokinetics of the oral iron chelator SP-420 in β-thalassemia

Our phase I, open-label, multi-center, dose-escalation study evaluated the pharmacokinetics (PK) of SP-420, a tridentate oral iron chelating agent of the desferrithiocin class, in patients with transfusion dependent β-thalassemia. SP-420 was administered as a single dose of 1.5 (n = 3), 3 (n = 3), 6 (n = 3), 12 (n = 3), and 24 (n = 6) mg/kg or as a twice-daily dose of 9 mg/kg (n = 6) over 14-28 days. There was a near dose-linear increase in the mean plasma SP-420 concentrations and in the mean values for C_max and AUC_0-τ over the dose range evaluated. The median t_max ranged from 0.5 to 2.25 h and was not dose dependent. The study was prematurely terminated by the sponsor due to renal adverse events (AE) including proteinuria, increase in serum creatinine, and one case of Fanconi syndrome. Other adverse effects included hypersensitivity reactions and gastrointestinal disturbances. Based on current dose administration, the renal AE observed outweighed the possible benefits from chelation therapy. However, additional studies assessing efficacy and safety of lower doses or less frequent dosing of SP-420 over longer durations with close monitoring would be necessary to better explain the findings of our study and characterize the safety of the study drug.