The prepontine block and its relevance for the development and treatment of hydrocephalus.

OBJECTIVE: Pulsatile CSF flow patterns include flow through the ventricles to the subarachnoid space and cisterns and from the infra- to the supratentorial subarachnoid space. In this study, we demonstrate how an obstruction at the level of the prepontine space may lead to obstructive hydrocephalus with specific radiological characteristics, as well as the implications for treatment options. METHODS: We retrospectively collected data of patients who underwent surgery between February 2010 and December 2022 for hydrocephalus secondary to a suspected prepontine block. One additional patient diagnosed with prepontine block who did not undergo surgery was also included. We excluded patients with a background of previous unrelated neurosurgical procedures or CNS infections. RESULTS: Six children and two adults were included. Three presented with hydrocephalus on imaging, without any other underlying pathology. Five had a suprasellar arachnoid cyst, with its lower border abating the pons and occluding the spinal subarachnoid space (SAS). All cases had an open aqueduct on T2 sagittal sequences, as well as an infracerebellar or retrocerebellar CSF collection. In most cases, a horizontal web was identified in the prepontine region. Seven cases were treated with an endoscopic fenestration. One patient subsequently underwent a shunt surgery. All the operated children reached normal developmental milestones after surgery. CONCLUSIONS: This paper describes a rather small series of cases where clear obstruction was observed at the level of the prepontine subarachnoid space. We believe this anatomical subtlety adds to a better understanding of CSF pathways and the role of ETV in treating hydrocephalus, focusing on a small subgroup of patients without a clear obstruction.

Positional shunt assist for slit ventricle syndrome.

PURPOSE: Hydrocephalus is one of the most common pathologies in pediatric neurosurgery. One of the causes of recurring events of headaches among shunted children is "slit ventricle syndrome" (SVS). Several potential treatments have been proposed, yet SVS often represents a treatment challenge. The goal of the current series is to present our experience with adding a positional shunt-assist (SA) (Miethke, Aesculap) for the treatment of SVS. METHODS: Clinical data was retrospectively collected from all consecutive children with SVS that were treated with SA (Miethke, Aesculap) at our center. Surgical and clinical outcomes as expressed by hospital visits, or need for additional surgery, were evaluated. RESULTS: Nine cases were included. Hydrocephalus etiology included IVH (6), postinfectious (1), and congenital syndromes (2). Average age at first shunt was 4 months. Primary shunt type was differential-pressure-valve in all. Average age at SVS onset was 4 years. Average age at SA placement was 5.5 years. There were no perioperative complications besides a single stich abscess. A 6-month follow-up period after SA was compared to a 6-month period prior to the SA: average hospital visits decreased from 2.4 to 0.6 per patient (p < 0.0002). 4/9 patients needed an LP or shunt revision before the SA surgery, while no procedure was indicated during the immediate 6-month follow-up. At the last follow-up, there was a significant reduction in the rate of ER visits compared to prior to surgery; however, the number of neurosurgical procedures did not significantly differ. CONCLUSION: Using a SA for SVS was associated with a short-term improvement of symptoms in the majority of cases, reduction in hospital visits, and reduced need for SVS-related procedures.

The Pediatric Epilepsy Surgery Interest Group (PESIG) under the auspice of the ISPN Research Committee: Availability of relevant technology and geographical distribution.

PURPOSE: Epilepsy surgery for pediatric drug-resistant epilepsy has been shown to improve seizure control, enhance patient and family QoL, and reduce mortality. However, diagnostic tools and surgical capacity are less accessible worldwide. The International Society Pediatric Neurosurgery (ISPN) has established a Pediatric Epilepsy Surgery Interest Group (PESIG), aiming to enhance global collaboration in research and educational aspects. The goals of this manuscript are to introduce PESIG and analyze geographical differences of epilepsy surgery and technology availability. METHODS: PESIG was established (2022) following an ISPN executive board decision. Using a standardized form, we surveyed the PESIG members, collecting and analyzing data regarding geographical distribution, and availability of various epilepsy treatment-related technologies. RESULTS: Two hundred eighty-two members registered in PESIG from 70 countries, over 6 continents, were included. We categorized the countries by GDP as follows: low, lower-medium, upper-medium, and high income. The most commonly available technology was vagus nerve stimulation 68%. Stereoelectroencephalography was available for 58%. North America had statistically significant greater availability compared to other continents. Europe had greater availability compared to Africa, Asia, and South (Latin) America. Asia had greater availability compared to Africa. High-income countries had statistically significant greater availability compared to other income groups; there was no significant difference between the other income-level subgroups. CONCLUSION: There is a clear discrepancy between countries and continents regarding access to epilepsy surgery technologies. This strengthens the need for collaboration between neurologists and neurosurgeons from around the world, to enhance medical education and training, as well as to increase technological availability.

Shifting Strategies in the Treatment of Pediatric Craniopharyngioma.

PURPOSE OF REVIEW: Craniopharyngiomas represent one of the most challenging diseases to treat. Despite their benign histology, and after many decades of surgical experience and technological advancements, there is still no clear consensus regarding the most effective management for this tumor. Due to their location and aggressive local characteristics, purely surgical approaches all too often result in unacceptable morbidity. RECENT FINDINGS: Partial resection combined with radiation therapy results in similar control rates when compared to aggressive surgery, while also minimalizing the neuro-endocrinological morbidity. In this manuscript, we describe the historical progression of the shifting strategies in the management of pediatric craniopharyngioma. Time has also altered our expectations for outcomes, evolving from purely morbidity and mortality to simple Glasgow Outcomes Scales, now to formal neuro-psychometric and quality of life data.

Chiari Type 1 Malformation and Syringomyelia in Children: Classification and Treatment Options.

Chiari type 1 malformation (CIM) is defined as tonsillar ectopia of >5 mm, while syringomyelia (SM) is defined as a cerebrospinal fluid (CSF)-filled cavity larger than 3 mm dissecting the spinal cord. Over the last decades, our understanding of these pathologies has grown; however, many controversies still exist almost in every aspect of CIM and SM, including etiology, indication for treatment, timing of treatment, surgical technique, follow-up regime, and outcome. This chapter provides a comprehensive overview on different aspects of CIM and SM and on the still existing controversies, based on the evidence presently available. Future directions for clinical research concerning CIM and SM treatment and outcome are elaborated and discussed as well.

[EPILEPSY SURGERY IN CHILDREN: A SUMMARY OF A DECADE AT THE SOURASKY TEL AVIV MEDICAL CENTER].

INTRODUCTION: Drug-resistant epilepsy in children is associated with morbidity, developmental regression and mortality. Over recent years, there is an increase in awareness regarding the role of surgery in the treatment of refractory epilepsy, both in the diagnostic phase and for treatment, reducing the number and magnitude of seizures. Technological advancements have enabled a minimalization of surgery, with reduction in surgical associated morbidity. METHODS: In this retrospective study, we review our experience with cranial surgery for epilepsy between the years 2011-2020. Collected data included information regarding the epileptic disorder, surgery, surgical-related complications and epilepsy outcome. RESULTS: A total of 93 children underwent 110 cranial surgeries over a decade. The main etiologies included cortical dysplasia (29), Rasmussen encephalitis (10), genetic disorders (9), tumors (7) and tuberous sclerosis (7). The main surgeries included lobectomies (32), focal resections (26), hemispherotomies (25), and callosotomies (16). Two children underwent MRI-guided laser interstitial thermal treatment (LITT). The most significant improvements following surgery were following hemispherotomy or tumor resection (100% of children, each). Following resections for cortical dysplasia led to a significant improvement in 70%. In 83% of children undergoing callosotomy, there were no additional drop seizures; 14% of the entire group underwent additional epilepsy surgery; 23% of children had an unexpected complication, in the vast majority with no permanent sequela. There was not mortality. CONCLUSIONS: Epilepsy surgery may lead to significant improvement and even cure of epilepsy. There is a wide span of epilepsy surgical procedures. Ealy referral of children with refractory epilepsy for surgical evaluation may significantly reduce the developmental injury, and improve functional outcomes.

Neurosurgical aspects of Noonan syndrome.

PURPOSE: Noonan syndrome (NS) is a rare neurodevelopmental syndrome characterized by dysmorphic features, congenital heart defects, neurodevelopmental delay, and bleeding diathesis. Though rare, several neurosurgical manifestations have been associated with NS, such as Chiari malformation (CM-I), syringomyelia, brain tumors, moyamoya, and craniosynostosis. We describe our experience in treating children with NS and various neurosurgical conditions, and review the current literature on neurosurgical aspects of NS. METHODS: Data were retrospectively collected from the medical records of children with NS who were operated at a tertiary pediatric neurosurgery department, between 2014 and 2021. Inclusion criteria were clinical or genetic diagnosis of NS, age < 18 years at treatment, and need for a neurosurgical intervention of any kind. RESULTS: Five cases fulfilled the inclusion criteria. Two had tumors, one underwent surgical resection. Three had CM-I, syringomyelia, and hydrocephalus, of whom one also had craniosynostosis. Comorbidities included pulmonary stenosis in two patients and hypertrophic cardiomyopathy in one. Three patients had bleeding diathesis, two of them with abnormal coagulation tests. Four patients were treated preoperatively with tranexamic acid, and two with Von Willebrand factor or platelets (1 each). One patient with a clinical bleeding predisposition developed hematomyelia following a syringe-subarachnoid shunt revision. CONCLUSIONS: NS is associated with a spectrum of central nervous system abnormalities, some of which with known etiology, while in others a pathophysiological mechanism has been suggested in the literature. When operating on a child with NS, a meticulous anesthetic, hematologic, and cardiac evaluation should be conducted. Neurosurgical interventions should then be planned accordingly.

Ventriculosinus shunts: their role in selected patients.

OBJECTIVE: Ventriculoperitoneal shunt placement is the most common treatment for hydrocephalus. However, most patients will require multiple shunt revisions over time. In cases of peritoneal shunt failure, the pleura and heart are alternative distal sites. Sinus shunts have been described but are not commonly used. The potential vascular complications, as well as inexperience with these shunts, make these tools less attractive. The goal of this study was to share the authors' experience with ventriculosinus shunts (VSSs) in selected patients. METHODS: Between December 2018 and February 2022, a total of 7 patients (1 adult, 6 children) underwent 11 surgeries for the placement of a VSS at the authors' institution. Data regarding complications and shunt function were retrospectively collected and assessed, and a review of the literature was conducted. RESULTS: The mean (± standard deviation) age at surgery was 11.9 ± 12.8 years (range 1.3-38.2 years). All patients had had previous shunt systems that failed and systemic conditions that made other distal sites less desirable. In all cases, a low-pressure differential valve was installed. Over a mean follow-up of 18 ± 9.8 months (range 9-39 months), 4 of the 7 patients underwent additional shunt revisions, 2 of whom had shunts placed at other sites. One patient had symptomatic partial sinus thrombosis, managed conservatively. During follow-up, 5 patients showed improvement in their symptoms of high intracranial pressure using the VSS. There were no severe complications of air embolism, bleeding, or infection. CONCLUSIONS: VSSs may have a role to play in selected patients in whom more commonly used distal shunt locations have failed. Significant complications with these shunts are rare. Additional experience is needed to better understand the ideal catheter and placement locations.

Postoperative coagulopathy among otherwise healthy pediatric patients undergoing open craniosynostosis repair: a retrospective study.

Significant blood loss and resultant transfusion may lead to coagulopathy. The need for routine transfusion of non-RBC blood products in healthy pediatric patients suffering significant, yet controlled, intra-operative blood loss is controversial. Open craniosynostosis surgery is often associated with significant intra-operative blood loss and transfusion, and routinely preformed on otherwise healthy pediatric patients. Therefore, we found it as a useful model for our study, which aimed to assess the need for routine transfusion of non-RBC blood products in healthy pediatric patients suffering significant intra-operative blood loss. We conducted a retrospective cohort study of otherwise healthy pediatric patients, undergoing open craniosynostosis surgery and transfused solely with packed red blood cells (pRBCs) in a single large-volume tertiary surgical center, between January 2010 and December 2021. Among 457 eligible patients, 34 (7.4%) developed significant postoperative coagulopathy. Median [IQR] intra-operative pRBC transfusion volume was 17.4 ml kg-1 [13.3, 23.1]. Patients who developed coagulopathy did not have higher postoperative pRBC transfusion rate (8.8% vs 3.8%, P = 0.16) or volume (median [IQR], 0 [0, 0] vs 0 [0, 0] ml, P = 0.15), nor higher hospital LOS (5 [4, 5] vs 5 [4, 5] days, P = 0.66). ICU LOS was 0.8 [0.7, 1] vs 0.7 [0.6, 0.8] days (P = 0.02), a difference of no clinical significance.  Conclusions: The incidence of significant coagulopathy after craniosynostosis surgery was low, and not associated with clinically important complications. In otherwise healthy pediatric patients, even significant intra-operative blood loss can be safely managed solely with intravenous fluids and pRBC transfusion. What is Known: • Significant intra-operative blood loss and resultant transfusion may lead to postoperative coagulopathy. • There are potential deleterious effects from both coagulopathy and administration of blood products. What is New: • Open craniosynostosis corrective surgery is a useful model for studying coagulopathy after significant intra-operative blood loss and transfusion in otherwise healthy children. • Under certain conditions, in otherwise healthy pediatric patients, even significant intra-operative blood loss can be safely treated with intravenous fluids and pRBC transfusion alone, with no clinically significant postoperative coagulopathy or its complications.

The role of messaging services in day-to-day practice in pediatric neurosurgery, advantages of a bubble network, and an international survey.

INTRODUCTION: Messaging services (MS) are used widely worldwide. The implications of MS usage in daily hospital patient care have not been investigated. In this study, we discuss the extensive usage of MS in our Pediatric Neurosurgical Department, introduce our bubble algorithm, and provide additional input from an international survey. METHODS: WhatsApp activity in the department of pediatric neurosurgery at Dana Children's Hospital, Tel Aviv, Israel, was analyzed. We designed a graphic representation of the content of the different conversation bubbles and how they interact. We also described a survey evaluating MS use in daily neurosurgical practice was sent to 25 neurosurgeons around the world. Collected data included details on the usage of MS, the type of information being transferred, and the participants' opinion of the potential risks and benefits of these systems. We began collecting messaging data November 2018, before the COVID pandemic era. We continued to collect data over the course of almost 3 years. RESULTS: We identified a bubble network structure that reflects a logical method of communication between different segments of pediatric neurosurgical care in our institution. Additionally, we analyzed 22 survey responses, received from 14 different countries. The vast majority of centers with "department groups" use messaging services to transfer multimedia files of patient-related data. Nineteen responders believe that MS significantly improve overall patient care. CONCLUSION: MS has revolutionized and improved the patterns of communication in our department. The great benefits of quick, simple access to information strongly outweigh formality and the potential for medicolegal disadvantages (e.g., HIPAA).

Fetal cerebral ventriculomegaly: What do we tell the prospective parents?

Fetal cerebral ventriculomegaly is a relatively common finding, observed during approximately 1% of obstetric ultrasounds. In the second and third trimester, mild (≥10 mm) and severe ventriculomegaly (≥15 mm) are defined according to the measurement of distal lateral ventricles that is included in the routine sonographic examination of central nervous system. A detailed neurosonography and anatomy ultrasound should be performed to detect other associated anomalies in the central nervous system and in other systems, respectively. Fetal MRI might be useful when neurosonography is unavailable or suboptimal. The risk of chromosomal and non-chromosomal genetic disorders associated with ventriculomegaly is high, therefore invasive genetic testing, including microarray, is recommended. Screening for prenatal infections, in particular cytomegalovirus and toxoplasmosis, should also be carried out at diagnosis. The prognosis is determined by the severity of ventriculomegaly and/or by the presence of co-existing abnormalities. Fetal ventriculoamniotic shunting in progressive isolated severe ventriculomegaly is an experimental procedure. After delivery, ventricular-peritoneal shunting or ventriculostomy are the two available options to treat hydrocephalus in specific conditions with similar long-term outcomes. A multidisciplinary fetal neurology team, including perinatologists, geneticists, pediatric neurologists, neuroradiologists and neurosurgeons, can provide parents with the most thorough prenatal counseling. This review outlines the latest evidence on diagnosis and management of pregnancies complicated by fetal cerebral ventriculomegaly.

Pediatric colloid cysts: a multinational, multicenter study. An IFNE-ISPN-ESPN collaboration.

OBJECTIVE: Colloid cysts (CCs) are rare at all ages, and particularly among children. The current literature on pediatric CC is limited, and often included in mixed adult/pediatric series. The goal of this multinational, multicenter study was to combine forces among centers and investigate the clinical course of pediatric CCs. METHODS: A multinational, multicenter retrospective study was performed to attain a large sample size, focusing on CC diagnosis in patients younger than 18 years of age. Collected data included clinical presentation, radiological characteristics, treatment, and outcome. RESULTS: One hundred thirty-four children with CCs were included. Patient age at diagnosis ranged from 2.4 to 18 years (mean 12.8 ± 3.4 years, median 13.2 years, interquartile range 10.3-15.4 years; 22% were < 10 years of age). Twenty-two cases (16%) were diagnosed incidentally, including 48% of those younger than 10 years of age. Most of the other patients had symptoms related to increased intracranial pressure and hydrocephalus. The average follow-up duration for the entire group was 49.5 ± 45.8 months. Fifty-nine patients were initially followed, of whom 28 were eventually operated on at a mean of 19 ± 32 months later due to cyst growth, increasing hydrocephalus, and/or new symptoms. There was a clear correlation between larger cysts and symptomatology, acuteness of symptoms, hydrocephalus, and need for surgery. Older age was also associated with the need for surgery. One hundred three children (77%) underwent cyst resection, 60% using a purely endoscopic approach. There was 1 death related to acute hydrocephalus at presentation. Ten percent of operated patients had some form of complication, and 7.7% of operated cases required a shunt at some point during follow-up. Functional outcome was good; however, the need for immediate surgery was associated with educational limitations. Twenty operated cases (20%) experienced a recurrence of their CC at a mean of 38 ± 46 months after the primary surgery. The CC recurrence rate was 24% following endoscopic resection and 15% following open resections (p = 0.28). CONCLUSIONS: CCs may present in all pediatric age groups, although most that are symptomatic present after the age of 10 years. Incidentally discovered cysts should be closely followed, as many may grow, leading to hydrocephalus and other new symptoms. Presentation of CC may be acute and may cause life-threatening conditions related to hydrocephalus, necessitating urgent treatment. The outcome of treated children with CCs is favorable.

Genomic predictors of response to PD-1 inhibition in children with germline DNA replication repair deficiency.

Cancers arising from germline DNA mismatch repair deficiency or polymerase proofreading deficiency (MMRD and PPD) in children harbour the highest mutational and microsatellite insertion-deletion (MS-indel) burden in humans. MMRD and PPD cancers are commonly lethal due to the inherent resistance to chemo-irradiation. Although immune checkpoint inhibitors (ICIs) have failed to benefit children in previous studies, we hypothesized that hypermutation caused by MMRD and PPD will improve outcomes following ICI treatment in these patients. Using an international consortium registry study, we report on the ICI treatment of 45 progressive or recurrent tumors from 38 patients. Durable objective responses were observed in most patients, culminating in a 3 year survival of 41.4%. High mutation burden predicted response for ultra-hypermutant cancers (>100 mutations per Mb) enriched for combined MMRD + PPD, while MS-indels predicted response in MMRD tumors with lower mutation burden (10-100 mutations per Mb). Furthermore, both mechanisms were associated with increased immune infiltration even in 'immunologically cold' tumors such as gliomas, contributing to the favorable response. Pseudo-progression (flare) was common and was associated with immune activation in the tumor microenvironment and systemically. Furthermore, patients with flare who continued ICI treatment achieved durable responses. This study demonstrates improved survival for patients with tumors not previously known to respond to ICI treatment, including central nervous system and synchronous cancers, and identifies the dual roles of mutation burden and MS-indels in predicting sustained response to immunotherapy.

Factors That Influence Intraoperative Decision-Making among Pediatric Neurosurgeons: A Grounded Theory Study.

INTRODUCTION: Pediatric neurosurgery is a subspecialty of medicine that is responsible for diagnosing, managing, and treating neurological disease in children with the use of surgery. Good intraoperative decision-making is critical to ensuring patient safety, yet almost nothing is known about what factors play a role in intraoperative decisions. As such, the purpose of this paper was to explore the factors that influence intraoperative decisions when pediatric neurosurgeons encounter something unexpected or uncertain during surgery. METHODS: The study utilized the grounded theory method of data collection and analysis. Twenty-six pediatric neurosurgeons from 12 countries around the world were interviewed between June and October 2020 about the factors that go into making intraoperative decisions. Data were analyzed line by line and constant comparison was used to examine relationships within and across codes and categories. RESULTS: Pediatric neurosurgeons reflected on 6 factors while operating in order to come to a decision about how to proceed when they encountered an uncertainty or complication. The study findings resulted in a conceptual model that describes how concrete data including biological and technological factors and contextual data including emotional/relational factors, surgeon factors, and cultural factors influence risk assessment when making an intraoperative decision during surgery. CONCLUSIONS: The findings from this research can be used for training and educating surgeons about intraoperative decision-making processes. Pedagogical modules can be developed that include training sessions on factors that may implicitly and explicitly influence thinking processes during an operation. Surgeons may also benefit from having open discussions with surgical colleagues about the rich, emotional, intellectual scope of the work that they do with all the challenges that these relationships can bring into decision-making in the operating room.

Pediatric thalamic incidentalomas: an international retrospective multicenter study.

OBJECTIVE: Widespread use of modern neuroimaging has led to a surge in diagnosing pediatric brain incidentalomas. Thalamic lesions have unique characteristics such as deep location, surgical complexity, and proximity to eloquent neuronal structures. Currently, the natural course of incidental thalamic lesions is unknown. Therefore, the authors present their experience in treating such lesions. METHODS: A retrospective, international multicenter study was carried out in 8 tertiary pediatric centers from 5 countries. Patients were included if they had an incidental thalamic lesion suspected of being a tumor and were diagnosed before the age of 20 years. Treatment strategy, imaging characteristics, pathology, and the outcome of operated and unoperated cases were analyzed. RESULTS: Overall, 58 children (23 females and 35 males) with a mean age of 10.8 ± 4.0 years were included. The two most common indications for imaging were nonspecific reasons (n = 19; e.g., research and developmental delay) and headache unrelated to small thalamic lesions (n = 14). Eleven patients (19%) underwent early surgery and 47 were followed, of whom 10 underwent surgery due to radiological changes at a mean of 11.4 ± 9.5 months after diagnosis. Of the 21 patients who underwent surgery, 9 patients underwent resection and 12 underwent biopsy. The two most frequent pathologies were pilocytic astrocytoma and WHO grade II astrocytoma (n = 6 and n = 5, respectively). Three lesions were high-grade gliomas. CONCLUSIONS: The results of this study indicate that pediatric incidental thalamic lesions include both low- and high-grade tumors. Close and long-term radiological follow-up is warranted in patients who do not undergo immediate surgery, as tumor progression may occur.