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Developmental epileptic encephalopathy with spike-wave activation in sleep (DEE-SWAS) is an epilepsy syndrome of childhood characterized by developmental delay or regression with significant abnormal epileptiform activity during sleep. In some cases, DEE-SWAS with an identified focal lesion is treated with surgical resection. The authors report an unusual case of focal DEE-SWAS that was successfully treated via transorbital resection with intraoperative electrocorticography (iECoG). The patient is an 11-year-old boy with a history of medication-responsive seizures who presented with cognitive and language decline. Electroencephalography demonstrated abnormal electrographic activity during sleep consistent with DEE-SWAS. Imaging and electrographic studies identified a probable epileptogenic zone anterior and adjacent to Broca's area. He underwent stereoelectroencephalography followed by focal resection with iECoG, which resulted in resolution of EEG abnormalities, improved word finding, and no further cognitive decline. While DEE-SWAS is not typically managed with surgical intervention, focal resection in carefully selected patients can achieve favorable outcomes., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Background Context: Intraoperative neurophysiological monitoring (IONM) is used to reduce the risk of spinal cord injury during pediatric spinal deformity surgery. Significant reduction and/or loss of IONM signals without immediate recovery may lead the surgeon to acutely abort the case. The timing of when monitorable signals return remains largely unknown., Purpose: The goal of this study was to investigate the correlation between IONM signal loss, clinical examination, and subsequent normalization of IONM signals after aborted pediatric spinal deformity surgery to help determine when it is safe to return to the operating room., Study Design/setting: This is a multicenter, multidisciplinary, retrospective study of pediatric patients (<18 years old) undergoing spinal deformity surgery whose surgery was aborted due to a significant reduction or loss of IONM potentials., Patient Sample: Sixty-six patients less than 18 years old who underwent spinal deformity surgery that was aborted due to IONM signal loss were enrolled into the study., Outcome Measures: IONM data, operative reports, and clinical examinations were investigated to determine the relationship between IONM loss, clinical examination, recovery of IONM signals, and clinical outcome., Methods: Information regarding patient demographics, deformity type, clinical history, neurologic and ambulation status, operative details, IONM information (eg, quality of loss [SSEPs, MEPs], laterality, any recovery of signals, etc.), intraoperative wake-up test, postoperative neurologic exam, postoperative imaging, and time to return to the operating were all collected. All factors were analyzed and compared with univariate and multivariate analysis using appropriate statistical analysis., Results: Sixty-six patients were enrolled with a median age of 13 years [IQR 11-14], and the most common sex was female (42/66, 63.6%). Most patients had idiopathic scoliosis (33/66, 50%). The most common causes of IONM loss were screw placement (27/66, 40.9%) followed by rod correction (19/66, 28.8%). All patients had either complete bilateral (39/66, 59.0%), partial bilateral (10/66, 15.2%) or unilateral (17/66, 25.8%) MEP loss leading to termination of the case. Overall, when patients were returned to the operating room 2 weeks postoperatively, nearly 75% (40/55) had monitorable IONM signals. Univariate analysis demonstrated that bilateral SSEP loss (p=.019), bilateral SSEP and MEP loss (p=.022) and delayed clinical neurologic recovery (p=.008) were significantly associated with having unmonitorable IONM signals at repeat surgery. Multivariate regression analysis demonstrated that delayed clinical neurologic recovery (> 72 hours) was significantly associated with unmonitorable IONM signals when returned to the operating room (p=.006). All patients ultimately made a full neurologic recovery., Conclusions: In children whose spinal deformity surgery was aborted due to intraoperative IONM loss, there was a strong correlation between combined intraoperative SSEP/MEP loss, the magnitude of IONM loss, the timing of clinical recovery, and the time of electrophysiological IONM recovery. The highest likelihood of having a prolonged postoperative neurological deficit and undetectable IONM signals upon return to the OR occurs with bilateral complete loss of SSEPs and MEPs., Competing Interests: Declaration of competing interest One or more of the authors declare financial or professional relationships on ICMJE-TSJ disclosure forms., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Non-hypothalamic glioneural hamartomas are rare entities known to cause medically refractory epilepsy. Olfactory bulb hamartomas, in particular, are exceptionally rare., Methods: We describe a case of an olfactory bulb hamartoma that was surgically resected at our institution. We also performed a literature review of all glioneural hamartomas and discuss the clinical presentation, diagnosis, and management of these lesions., Results: Herein, we present the unusual case of a typically developing 17-year-old boy with a near life-long history of drug-resistant epilepsy, found to have a 0.8 × 1.0 cm right olfactory bulb hamartoma. Endoscopic endonasal trans-cribriform resection of the lesion led to seizure freedom in the 6-month follow-up period (Engel class 1 outcome). Comprehensive literature review revealed only one other sporadic case, which was also successfully treated with total surgical resection., Conclusions: Our case of an olfactory bulb hamartoma adds to the limited literature currently available, illustrating key clinical characteristics of these exceedingly rare lesions and outlining an effective, minimally invasive, and low-morbidity treatment strategy., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests., (© 2024. The Author(s).)

Study Design: Modified Delphi consensus study., Objective: To develop consensus-based best practices for the care of pediatric patients who have implanted programmable devices (IPDs) and require spinal deformity surgery., Summary of Background Data: Implanted programmable devices (IPDs) are often present in patients with neuromuscular or syndromic scoliosis who require spine surgery. Guidelines for monitoring and interrogating these devices during the perioperative period are not available., Methods: A panel was assembled consisting of 25 experts (i.e., spinal deformity surgeons, neurosurgeons, neuroelectrophysiologists, cardiologists, and otolaryngologists). Initial postulates were based on a literature review and results from a prior survey. Postulates addressed the following IPDs: vagal nerve stimulators (VNS), programmable ventriculoperitoneal shunts (VPS), intrathecal baclofen pumps (ITBP), cardiac pacemakers and implantable cardioverter-defibrillators (ICD), deep brain stimulators (DBS), and cochlear implants. Cardiologist and otolaryngologist participants responded only to postulates on cardiac pacemakers or cochlear implants, respectively. Consensus was defined as ≥80% agreement, items that did not reach consensus were revised and included in subsequent rounds. A total of 3 survey rounds and 1 virtual meeting were conducted., Results: Consensus was reached on 39 total postulates across 6 IPD types. Postulates addressed general spine surgery considerations, the use of intraoperative monitoring and cautery, the use of magnetically controlled growing rods (MCGRs), and the use of an external remote controller to lengthen MCGRs. Across IPD types, consensus for the final postulates ranged from 94.4% to 100%. Overall, experts agreed that MCGRs can be surgically inserted and lengthened in patients with a variety of IPDs and provided guidance for the use of intraoperative monitoring and cautery, which varied between IPD types., Conclusion: Spinal deformity correction surgery often benefits from the use of intraoperative monitoring, monopolar and bipolar cautery, and MCGRs. The final postulates from this study can inform the perioperative and postoperative practices of spinal deformity surgeons who treat patients with both scoliosis and IPDs., Level of Evidence: V-Expert opinion., Competing Interests: J.T.B. has consulted for Orthopediatrics Corporation, Medtronic, Inc., and Medical Devices Business Services, Inc. T.J.G. has consulted for NuVasive. L.M.A. has consulted/served as a speaker for Medtronic, Inc. and NuVasive. R.E.F. has consulted for Medical Devices Business Services, Inc. L.Y. has consulted for Medtronic, Inc. L.C.B. has consulted for Stryker Corp., Medtronic, Inc., and SeaSpine Orthopedics Corp. C.K.H. has consulted/served as a speaker for Medtronic, Inc. V.V.D. is a proctor and consultant for the following companies: Medtronic, Inc., Edwards Lifesciences, B. Braun and Abbott Vascular. J.H.P. received royalties/license fees and is a consultant for Medtronic, Inc. D.W.P. received royalties/license fees and has consulted for SI-BONE. He has also consulted for Globus Medical, Inc. J.R.S. has consulted for Orthopediatrics and Medtronic, Inc. P.D.S. received royalties/license fees from Globus Medical and has served as a consultant for the following companies: Medical Devices Business Services, Inc., Orthopediatrics, and NuVasive. P.F.S. has consulted for NuVasive. B.Y. received royalties/license fees from NuVasive, Stryker Corp, and Globus Medical. He has also consulted for Stryker, Pacira Pharmaceuticals Inc., Medical Device Business Services, Inc., and Orthopediatrics Corp. The remaining authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Tonic and atonic "drop attack" seizures are a classic and morbid semiology in Lennox-Gastaut syndrome, resulting in frequent injuries and emergency room visits, in addition to neurocognitive sequelae. Recent years have seen a growing interest in less invasive techniques for performing the classic surgical treatment for drop attacks in Lennox-Gastaut syndrome, that is, corpus callosotomy., Observations: A 5-year-old boy with Lennox-Gastaut syndrome presented for surgical evaluation. He experienced up to 20 daily tonic seizures despite multiple antiseizure medications. Preoperative imaging revealed highly abnormal anatomy with severe ventriculomegaly and thinning of the cortex and corpus callosum. Open microsurgery or an interhemispheric bimanual endoscopic approach to corpus callosotomy posed a risk for ventricular collapse and subdural hematoma, and the corpus callosum was too thin for laser ablation. A fully endoscopic transventricular "inside-out" complete corpus callosotomy was performed through a 7-mm burr hole via a single working channel without intraoperative complications. The patient continues to experience daily seizures but with a reduced frequency and intensity and a family-reported increased quality of life., Lessons: In cases of drug-resistant tonic and atonic seizures associated with ventriculomegaly, a fully endoscopic transventricular complete corpus callosotomy can be performed safely, potentially limiting the risk of ventricular collapse and subdural bleeding. https://thejns.org/doi/10.3171/CASE24160.

Objective: Intracranial complications of acute bacterial sinusitis are rare pathologies that occur in children, and are associated with significant neurological morbidity and mortality. There is a subjective concern among neurosurgeons that the incidence of this rare disease has increased since the onset of the novel COVID-19 pandemic. The primary objective of this study was to review the presentation and management of patients admitted at the authors' institution with intracranial extension of sinusitis, to better understand the local disease burden relative to the COVID-19 pandemic., Methods: This is a single-center retrospective observational cohort study. The patients underwent neurosurgical intervention for intracranial extension of sinusitis between January 1, 2007, and March 1, 2023. The historical cohort was defined as those patients who presented prior to March 2020. Clinical covariates such as surgical and microbiological data were collected and analyzed., Results: A total of 78 patients (55 historical, 23 new) were included; they had a median age of 11.7 years and a male predominance of 69.2%. There was a significant increase in the annual rate of neurosurgical intervention for suppurative intracranial extension of acute bacterial sinusitis after the onset of the COVID-19 pandemic, with an average of 4.2 cases per year prior to March 2020 compared to 7.7 cases per year after that date (p = 0.013). This increase was largely driven by the unprecedented case volume of 13 cases in 2022. Patients in the new cohort were older (p = 0.009) and more likely to have Pott's puffy tumor/frontal bone osteomyelitis (p = 0.003) at the time of presentation than patients in the historical cohort. Patients in the new cohort had lower rates of readmission within 30 days of discharge than those in the historical cohort (p = 0.047). In both cohorts, patients with seizure on presentation were more likely to have neurological sequelae at last follow-up (p = 0.004), which occurred at a median of 2.9 months after discharge., Conclusions: Clinicians encountering pediatric patients presenting with persistent symptoms of acute bacterial sinusitis must have a high index of suspicion for suppurative intracranial extension. Prompt neuroimaging and subsequent neurosurgical intervention are critical to ensure timely diagnosis and treatment. The results in this study show a significant increase in the number of neurosurgical interventions for suppurative intracranial extension of sinusitis per year after the onset of the COVID-19 pandemic. Further research is needed to understand the underlying pathophysiology of this clinical phenomenon.

The transpalpebral approach provides a minimally invasive corridor to the anterior skull base and temporal lobe. It has been described for anterior circulation aneurysms and skull base tumors as well as more recently for resection of epileptogenic pathology in the adult population. We describe our experience using this approach in a 13-year-old adolescent boy suffering from epilepsy secondary to concomitant left temporal focal cortical dysplasia and pleomorphic xanthoastrocytoma extending throughout the amygdala with excellent results.1-5 To the best of our knowledge, this is the first published case using the transpalpebral approach for this pathology, as well for epilepsy in the pediatric population. The patient consented to the procedure and to the publication of his image., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

While recent technological advancements are reshaping the landscape of surgical epilepsy management, the established techniques of resective and disconnective surgeries guided by electrographic monitoring remain the workhorse interventions for the management of refractory seizures and have the highest likelihood of achieving complete seizure resolution. Here we discuss examples of recent developments in surgical approaches and techniques for resective and disconnective surgeries with discussion of their indications and potential advantages., Competing Interests: Declaration of competing interest The authors report no conflicts of interest., (Copyright © 2024. Published by Elsevier Inc.)

Preclinical tumor models have advanced our understanding of the tumor microenvironment. However, the temporal dynamics of cellular recruitment and retention within these models is poorly understood. Here, we present a protocol using transcutaneous labeling of the tumor compartment using subcutaneous and orthotopic tumors. We describe the process of cell line implantation and photoconversion of tumors to differentiate newly recruited cells from those retained within tumors. Photoconversion enables tracking of both immune cell recruitment to tumors and egress to the lymphatics. For complete details on the use and execution of this protocol, please refer to Li et al. 1 and Molostvov et al. 2 ., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: Polymorphous low-grade neuroepithelial tumors of the young (PLNTY) represent a rare pediatric-type tumor that most commonly presents as medically refractory epilepsy. PLNTY has only recently been recognized as a distinct clinical entity, having been first described in 2016 and added to the World Health Organization classification of CNS tumors in 2021. Molecular studies have determined that PLNTY is uniformly driven by aberrant MAPK pathway activation, with most tumors carrying either a BRAF V600E mutation or activating FGFR2 or FGFR3 fusion protein. Although it is known that these driver mutations are mutually exclusive, little is known about differences in clinical presentation or treatment outcomes between PLNTY cases driven by these distinct mutations., Methods: We performed a systematic review and cumulative analysis of PLNTY cases to assess whether or not PLNTY tumors carrying the BRAF V600E mutation exhibit different clinical behaviors. By searching the literature for all cases of PLNTY wherein BRAF V600E status was characterized, we compiled a dataset of 62 unique patient instances. Using a logistic regression-based approach, we assessed a primary outcome of what factors of a clinical presentation were associated with BRAF V600E mutations and a secondary outcome of what factors predicted total seizure freedom post-surgical resection., Results: PLNTY cases carrying BRAF V600E mutations in the literature were strongly positively associated with adult patients (p = 0.0055, OR = 6.556; 95% Conf. Int. = 1.737-24.742). BRAF V600E status was also positively associated with tumor involvement of the temporal lobe (p = 0.0046, OR = 11.036; 95% Conf. Int. = 2.100-58.006). Male sex was also positively associated with BRAF V600E status, but the result did not quite achieve statistical significance (p = 0.0731). BRAF V600E status was not found to be associated with post-operative seizure freedom., Conclusions: These findings indicate that BRAF V600E-positive PLNTY exhibit characteristic clinical presentations but are not necessarily different in treatment responsiveness. Non-BRAF V600E tumors are more commonly associated with young patients., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Trans-sylvian peri-insular hemispherotomy represents a functional hemispherectomy with minimal brain removal used for treatment of refractory hemispheric epilepsy.1 Exposure for this procedure is achieved by craniotomy. Refinement in the hemispherotomy technique, including trends toward minimizing cortical resection, has contributed to a substantial drop in complication rates.2 We present a refinement of this technique, allowing for complete hemispheric disconnection through a single burr hole. In this instance, this technique was applied in the case of a 4-year-old girl who presented with medically refractory epilepsy, which had developed on the first day of life due to a perinatal incomplete left middle cerebral artery stroke. Postoperatively, the patient experienced no worsening of her preexisting right-sided hemiparesis and remains seizure-free 18 months postoperatively, now off medication. While the trans-sylvian peri-insular hemispherotomy represents an established surgical technique, this is the first report of this procedure performed in a minimally invasive fashion through a single burr hole. Beyond the minimal incision and small aperture in the skull, seldom appreciated nuances of hemispheric disconnection are described and demonstrated, including amygdala disconnection, hippocampal tail disconnection directly into splenium disconnection, concomitant intermediate disconnection and callosotomy, and frontobasal disconnection landmarks. Consent was obtained from the patient's parents for the surgical procedure, use of outcome videos, and for publication of this video and associated materials. The participants and patient's parents consented to publication of their images and that of the patient., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Immune cell dysfunction within the tumor microenvironment (TME) undermines the control of cancer progression. Established tumors contain phenotypically distinct, tumor-specific natural killer (NK) cells; however, the temporal dynamics, mechanistic underpinning and functional significance of the NK cell compartment remains incompletely understood. Here, we use photo-labeling, combined with longitudinal transcriptomic and cellular analyses, to interrogate the fate of intratumoral NK cells. We reveal that NK cells rapidly lose effector functions and adopt a distinct phenotypic state with features associated with tissue residency. NK cell depletion from established tumors did not alter tumor growth, indicating that intratumoral NK cells cease to actively contribute to anti-tumor responses. IL-15 administration prevented loss of function and improved tumor control, generating intratumoral NK cells with both tissue-residency characteristics and enhanced effector function. Collectively, our data reveals the fate of NK cells after recruitment into tumors and provides insight into how their function may be revived., (© 2024. The Author(s).)

Tumour dendritic cells (DCs) internalise antigen and upregulate CCR7, which directs their migration to tumour-draining lymph nodes (dLN). CCR7 expression is coupled to an activation programme enriched in regulatory molecule expression, including PD-L1. However, the spatio-temporal dynamics of CCR7 + DCs in anti-tumour immune responses remain unclear. Here, we use photoconvertible mice to precisely track DC migration. We report that CCR7 + DCs are the dominant DC population that migrate to the dLN, but a subset remains tumour-resident despite CCR7 expression. These tumour-retained CCR7 + DCs are phenotypically and transcriptionally distinct from their dLN counterparts and heterogeneous. Moreover, they progressively downregulate the expression of antigen presentation and pro-inflammatory transcripts with more prolonged tumour dwell-time. Tumour-residing CCR7 + DCs co-localise with PD-1 + CD8 + T cells in human and murine solid tumours, and following anti-PD-L1 treatment, upregulate stimulatory molecules including OX40L, thereby augmenting anti-tumour cytolytic activity. Altogether, these data uncover previously unappreciated heterogeneity in CCR7 + DCs that may underpin a variable capacity to support intratumoural cytotoxic T cells., (© 2024. The Author(s).)

Middle meningeal artery (MMA) embolization has gained acceptance as a treatment for chronic subdural hematoma (cSDH) in adult patients but has not been well described in pediatric patients. Standard cSDH treatment has historically consisted of burr hole drainage with or without subdural drain placement. However, due to the high rate of recurrence and frequency of comorbidities within this population, as both pediatric and adult patients with cSDH frequently have concurrent cardiac disease and a need for anticoagulant therapies, MMA embolization has increasingly demonstrated its value as both an adjunctive and primary treatment. In this report, the authors present 3 cases of successful MMA embolization in medically complex children at a single institution. MMA embolization was used as a primary treatment modality and as an adjunctive therapy in the acute setting following surgical hematoma evacuation. Two patients were receiving anticoagulation treatment requiring reversal. Technical considerations specific to the pediatric population as well as those common to both the pediatric and adult populations are addressed. Further work is needed to define the optimal indications and outcomes for MMA embolization in children with cSDH.

Objective: The authors of this study evaluated the safety and efficacy of stereotactic laser ablation (SLA) for the treatment of drug-resistant epilepsy (DRE) in children., Methods: Seventeen North American centers were enrolled in the study. Data for pediatric patients with DRE who had been treated with SLA between 2008 and 2018 were retrospectively reviewed., Results: A total of 225 patients, mean age 12.8 ± 5.8 years, were identified. Target-of-interest (TOI) locations included extratemporal (44.4%), temporal neocortical (8.4%), mesiotemporal (23.1%), hypothalamic (14.2%), and callosal (9.8%). Visualase and NeuroBlate SLA systems were used in 199 and 26 cases, respectively. Procedure goals included ablation (149 cases), disconnection (63), or both (13). The mean follow-up was 27 ± 20.4 months. Improvement in targeted seizure type (TST) was seen in 179 (84.0%) patients. Engel classification was reported for 167 (74.2%) patients; excluding the palliative cases, 74 (49.7%), 35 (23.5%), 10 (6.7%), and 30 (20.1%) patients had Engel class I, II, III, and IV outcomes, respectively. For patients with a follow-up ≥ 12 months, 25 (51.0%), 18 (36.7%), 3 (6.1%), and 3 (6.1%) had Engel class I, II, III, and IV outcomes, respectively. Patients with a history of pre-SLA surgery related to the TOI, a pathology of malformation of cortical development, and 2+ trajectories per TOI were more likely to experience no improvement in seizure frequency and/or to have an unfavorable outcome. A greater number of smaller thermal lesions was associated with greater improvement in TST. Thirty (13.3%) patients experienced 51 short-term complications including malpositioned catheter (3 cases), intracranial hemorrhage (2), transient neurological deficit (19), permanent neurological deficit (3), symptomatic perilesional edema (6), hydrocephalus (1), CSF leakage (1), wound infection (2), unplanned ICU stay (5), and unplanned 30-day readmission (9). The relative incidence of complications was higher in the hypothalamic target location. Target volume, number of laser trajectories, number or size of thermal lesions, or use of perioperative steroids did not have a significant effect on short-term complications., Conclusions: SLA appears to be an effective and well-tolerated treatment option for children with DRE. Large-volume prospective studies are needed to better understand the indications for treatment and demonstrate the long-term efficacy of SLA in this population.

The clinical success of immune checkpoint blockade in some patients has transformed treatment approaches in cancer and offers the hope of durable curative responses. Building from studies of chronic infection, the composition of tumour infiltrating lymphocytes and in particular, the spectrum of exhausted CD8 T cells has now been characterized in detail, profiling the phenotype, function, transcriptional regulation and even the epigenetic changes. However, what remains less clear is how intratumoural immune cells interface with populations in the periphery, both in terms of sustaining the response in cancer, but also in establishing systemic memory responses that can provide long-term protection. Here we will succinctly review the current understanding of the anti-tumour response, consider the tissue microenvironments that support key cellular subsets and the extent to which cellular migration between these sites impacts the response., Competing Interests: The authors declare no conflicts of interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Society for Immunology.)

Heterozygous pathogenic variants in DNM1 cause developmental and epileptic encephalopathy (DEE) as a result of a dominant-negative mechanism impeding vesicular fission. Thus far, pathogenic variants in DNM1 have been studied with a canonical transcript that includes the alternatively spliced exon 10b. However, after performing RNA sequencing in 39 pediatric brain samples, we find the primary transcript expressed in the brain includes the downstream exon 10a instead. Using this information, we evaluated genotype-phenotype correlations of variants affecting exon 10a and identified a cohort of eleven previously unreported individuals. Eight individuals harbor a recurrent de novo splice site variant, c.1197-8G>A (GenBank: NM&#95;001288739.1), which affects exon 10a and leads to DEE consistent with the classical DNM1 phenotype. We find this splice site variant leads to disease through an unexpected dominant-negative mechanism. Functional testing reveals an in-frame upstream splice acceptor causing insertion of two amino acids predicted to impair oligomerization-dependent activity. This is supported by neuropathological samples showing accumulation of enlarged synaptic vesicles adherent to the plasma membrane consistent with impaired vesicular fission. Two additional individuals with missense variants affecting exon 10a, p.Arg399Trp and p.Gly401Asp, had a similar DEE phenotype. In contrast, one individual with a missense variant affecting exon 10b, p.Pro405Leu, which is less expressed in the brain, had a correspondingly less severe presentation. Thus, we implicate variants affecting exon 10a as causing the severe DEE typically associated with DNM1-related disorders. We highlight the importance of considering relevant isoforms for disease-causing variants as well as the possibility of splice site variants acting through a dominant-negative mechanism., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

The molecular diversity of glia in the human hippocampus and their temporal dynamics over the lifespan remain largely unknown. Here, we performed single-nucleus RNA sequencing to generate a transcriptome atlas of the human hippocampus across the postnatal lifespan. Detailed analyses of astrocytes, oligodendrocyte lineages, and microglia identified subpopulations with distinct molecular signatures and revealed their association with specific physiological functions, age-dependent changes in abundance, and disease relevance. We further characterized spatiotemporal heterogeneity of GFAP-enriched astrocyte subpopulations in the hippocampal formation using immunohistology. Leveraging glial subpopulation classifications as a reference map, we revealed the diversity of glia differentiated from human pluripotent stem cells and identified dysregulated genes and pathological processes in specific glial subpopulations in Alzheimer's disease (AD). Together, our study significantly extends our understanding of human glial diversity, population dynamics across the postnatal lifespan, and dysregulation in AD and provides a reference atlas for stem-cell-based glial differentiation., Competing Interests: Declaration of interests G.-l.M. is a member of the Advisory Board for Cell Stem Cell., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: Ventriculoperitoneal (VP) shunt placement is a common neurosurgical procedure performed in patients with early onset scoliosis (EOS). To provide insight into the risks of spine lengthening operations, we investigate the rate of VP shunt complications in patients with EOS undergoing spinal deformity correction interventions., Methods: A retrospective review was performed of all patients with EOS at a single institution undergoing spinal deformity correction procedures from 2007 to 2018. Patients having undergone VP shunt implantation prior to deformity correction were included. A minimum of 2-year follow-up was required for inclusion. Clinical records and imaging studies were reviewed., Results: Nineteen patients with VP shunts underwent Vertical Expandable Prosthetic Titanium Rib (VEPTR) implantation for treatment of early onset spinal deformity. The mean age at shunt placement and spine instrumentation surgery was 13.7 months (1 day to 13 years) and 6.1 years (0.5-15.1) respectively. The diagnoses associated with shunt implantation were: 12 spina bifida, 3 structural defects or obstructions, 2 intraventricular hemorrhage, 1 cerebral palsy, and 1 campomelic dwarfism. During the first 2 years following rib-based insertion, there was a mean of 2.5 expansion/revision procedures (0-5) with no shunt-related complications. The mean length of follow-up in this series was 7.0 years (2.6-13.2). A total of three (16%) patients required shunt revision following their rib-based device insertion, two patients with proximal shunt malfunctions and one with a mid-catheter breakage, at 2.4, 2.6, and 5.6 years, respectively, after rod implantation (Fig. 2). Each of these shunt revisions occurred more than 50 days following an expansion procedure (1.9, 2.9, and 5.7 months, respectively)., Conclusion: Growing instrumentation procedures in EOS are associated with low risk for post-operative shunt complications in patients with ventriculoperitoneal shunts. There were no shunt revision procedures performed in the first 2 years following rib-based device insertion. Sixteen percent of patients went on to require a shunt revision at some point during their follow-up, which is comparable to the baseline rate of shunt revision in non-EOS patients., Level of Evidence: IV, Case series., (© 2022. The Author(s), under exclusive licence to Scoliosis Research Society.)

Objective: Stereoelectroencephalography (SEEG) is a widely used technique for localizing seizure onset zones prior to resection. However, its use has traditionally been avoided in children under 2 years of age because of concerns regarding pin fixation in the immature skull, intraoperative and postoperative electrode bolt security, and stereotactic registration accuracy. In this retrospective study, the authors describe their experience using SEEG in patients younger than 2 years of age, with a focus on the procedure's safety, feasibility, and accuracy as well as surgical outcomes., Methods: A retrospective review of children under 2 years of age who had undergone SEEG while at Children's Hospital of Philadelphia between November 2017 and July 2021 was performed. Data on clinical characteristics, surgical procedure, imaging results, electrode accuracy measurements, and postoperative outcomes were examined., Results: Five patients younger than 2 years of age underwent SEEG during the study period (median age 20 months, range 17-23 months). The mean age at seizure onset was 9 months. Developmental delay was present in all patients, and epilepsy-associated genetic diagnoses included tuberous sclerosis (n = 1), KAT6B (n = 1), and NPRL3 (n = 1). Cortical lesions included tubers from tuberous sclerosis (n = 1), mesial temporal sclerosis (n = 1), and cortical dysplasia (n = 3). The mean number of placed electrodes was 11 (range 6-20 electrodes). Bilateral electrodes were placed in 1 patient. Seizure onset zones were identified in all cases. There were no SEEG-related complications, including skull fracture, electrode misplacement, hemorrhage, infection, cerebrospinal fluid leakage, electrode pullout, neurological deficit, or death. The mean target point error for all electrodes was 1.0 mm. All patients proceeded to resective surgery, with a mean follow-up of 21 months (range 8-53 months). All patients attained a favorable epilepsy outcome, including Engel class IA (n = 2), IC (n = 1), ID (n = 1), and IIA (n = 1)., Conclusions: SEEG can be safely, accurately, and effectively utilized in children under age 2 with good postoperative outcomes using standard SEEG equipment. With minimal modification, this procedure is feasible in those with immature skulls and guides the epilepsy team's decision-making for early and optimal treatment of refractory epilepsy through effective localization of seizure onset zones.

Immature dentate granule cells (imGCs) arising from adult hippocampal neurogenesis contribute to plasticity and unique brain functions in rodents 1,2 and are dysregulated in multiple human neurological disorders 3-5 . Little is known about the molecular characteristics of adult human hippocampal imGCs, and even their existence is under debate 1,6-8 . Here we performed single-nucleus RNA sequencing aided by a validated machine learning-based analytic approach to identify imGCs and quantify their abundance in the human hippocampus at different stages across the lifespan. We identified common molecular hallmarks of human imGCs across the lifespan and observed age-dependent transcriptional dynamics in human imGCs that suggest changes in cellular functionality, niche interactions and disease relevance, that differ from those in mice 9 . We also found a decreased number of imGCs with altered gene expression in Alzheimer's disease. Finally, we demonstrated the capacity for neurogenesis in the adult human hippocampus with the presence of rare dentate granule cell fate-specific proliferating neural progenitors and with cultured surgical specimens. Together, our findings suggest the presence of a substantial number of imGCs in the adult human hippocampus via low-frequency de novo generation and protracted maturation, and our study reveals their molecular properties across the lifespan and in Alzheimer's disease., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Objective: To demonstrate that a novel noninvasive index of intracranial pressure (ICP) derived from diffuse optics-based techniques is associated with intracranial hypertension., Study Design: We compared noninvasive and invasive ICP measurements in infants with hydrocephalus. Infants born term and preterm were eligible for inclusion if clinically determined to require cerebrospinal fluid (CSF) diversion. Ventricular size was assessed preoperatively via ultrasound measurement of the fronto-occipital (FOR) and frontotemporal (FTHR) horn ratios. Invasive ICP was obtained at the time of surgical intervention with a manometer. Intracranial hypertension was defined as invasive ICP ≥15 mmHg. Diffuse optical measurements of cerebral perfusion, oxygen extraction, and noninvasive ICP were performed preoperatively, intraoperatively, and postoperatively. Optical and ultrasound measures were compared with invasive ICP measurements, and their change in values after CSF diversion were obtained., Results: We included 39 infants, 23 with intracranial hypertension. No group difference in ventricular size was found by FOR (P = .93) or FTHR (P = .76). Infants with intracranial hypertension had significantly higher noninvasive ICP (P = .02) and oxygen extraction fraction (OEF) (P = .01) compared with infants without intracranial hypertension. Increased cerebral blood flow (P = .005) and improved OEF (P < .001) after CSF diversion were observed only in infants with intracranial hypertension., Conclusions: Noninvasive diffuse optical measures (including a noninvasive ICP index) were associated with intracranial hypertension. The findings suggest that impaired perfusion from intracranial hypertension was independent of ventricular size. Hemodynamic evidence of the benefits of CSF diversion was seen in infants with intracranial hypertension. Noninvasive optical techniques hold promise for aiding the assessment of CSF diversion timing., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Pharmaceuticals and personal care products (PPCPs) can enter agricultural fields through wastewater irrigation, biosolid amendments, or urine fertilization. Numerous studies have assessed the risk of PPCP contamination, however there are no standardized methodologies for sample treatment, making the interpretation of results challenging. Various time periods between sampling and analysis have been reported (shipping, storage, etc.), but literature is lacking in the evaluation of PPCP degradation amidst this process. This study assessed the stability of 20 pharmaceuticals (200 μg L -1 ) in soil and crops stored at -40 °C for 7, 30, and 310 days. After 310 days, caffeine, meprobamate, trimethoprim, primidone, carbamazepine, anhydro-erythromycin and dilantin were found to be stable (≥75% recovery) in all matrices. On the other hand, acetaminophen, amitriptyline, bupropion, lamotrigine, sulfamethoxazole, naproxen, ibuprofen, and paroxetine were unstable after 30 days in at least one of the matrices investigated. Due to variations in analyte stability, fortification with isotopically-labelled surrogates at the point of sample collection was evaluated in comparison to fortification after shipment and storage, immediately prior to extraction. Chromatographic peak areas of stable analytes were found to be reproducible (±15%) in field-fortified samples, indicating that no additional error occurred during sample handling under field conditions despite having a less controlled environment. Unstable analytes revealed notable differences in peak areas between fortification times, suggesting that fortification immediately after sample collection is crucial to account for analyte losses during shipping and storage, resulting in accurate quantification of PPCPs.

Objective: Single-ventricle congenital heart disease (CHD) in pediatric patients with Glenn and Fontan physiology represents a unique physiology requiring the surgical diversion of the systemic venous return from the superior vena cava (Glenn) and then the inferior vena cava (Fontan) directly to the pulmonary arteries. Because many of these patients are on chronic anticoagulation therapy and may have right-to-left shunts, arrhythmias, or lymphatic disorders that predispose them to bleeding and/or clotting, they are at risk of experiencing neurological injury requiring intubation and positive pressure ventilation, which can significantly hamper pulmonary blood flow and cardiac output. The aim of this study was to describe the complex neurological and cardiopulmonary interactions of these pediatric patients after acute central nervous system (CNS) injury., Methods: The authors retrospectively analyzed the records of pediatric patients who had been admitted to a quaternary children's hospital with CHD palliated to bidirectional Glenn (BDG) or Fontan circulation and acute CNS injury and who had undergone intubation and mechanical ventilation. Patients who had been admitted from 2005 to 2019 were included in the study. Clinical characteristics, surgical outcomes, cardiovascular and pulmonary data, and intracranial pressure data were collected and analyzed., Results: Nine pediatric single-ventricle patients met the study inclusion criteria. All had undergone the BDG procedure, and the majority (78%) were status post Fontan palliation. The mean age was 7.4 years (range 1.3-17.3 years). At the time of acute CNS injury, which included traumatic brain injury, intracranial hemorrhage, and cerebral infarct, the median time interval from the most recent cardiac surgical procedure was 3 years (range 2 weeks-11 years). Maintaining normocarbia to mild hypercarbia for most patients during intubation periods did not cause neurological deterioration, and hemodynamic profiles were more favorable as compared to periods of hypocarbia. Hypocarbia was associated with unfavorable hemodynamics but was necessary to decrease intracranial hypertension. Most patients were managed using low mean airway pressure (MAWP) in order to minimize the impact on preload and cardiac output., Conclusions: The authors highlight the complex neurological and cardiopulmonary interactions with respect to partial pressure of arterial CO2 (PaCO2) and MAWP when pediatric CHD patients with single-ventricle physiology require mechanical ventilation. The study data demonstrated that tight control of PaCO2 and minimizing MAWP with the goal of early extubation may be beneficial in this population. A multidisciplinary team of pediatric critical care intensivists, cardiac intensivists and anesthesiologists, and pediatric neurosurgeons and neurologists are recommended to ensure the best possible outcomes.

Purpose: Several variations of functional disconnection surgery have been described for the treatment of lateralized, hemispheric, drug-resistant epilepsy in children. The purpose of this study is to investigate the existing literature regarding patient selection, approach, and outcomes after hemispherotomy., Methods: A systematic review of the English literature through February 2019 was performed in accordance with the PRISMA statement. The articles were classified by level of evidence and summarized in an evidentiary table. Seizure outcomes, functional outcomes, surgical techniques, complications, and patient selection were critically analyzed., Results: A total of 173 papers were reviewed, of which 37 met criteria of inclusion and exclusion. Thirteen studies were classified as level III evidence, the remaining reached level IV. Vertical and lateral hemispherotomy achieve similar rates of seizure freedom and functional outcomes, though parasagittal and interhemispheric approaches may have shorter operative times and less blood loss. Etiology, bilateral MRI abnormalities, and nonlateralizing EEG did not predict worse seizure or functional outcomes., Conclusions: Both vertical and lateral hemispherotomy approaches result in durable, reproducible benefits to epilepsy severity and functional status in appropriately selected pediatric patients.

Objective: Stereoelectroencephalography (SEEG) has become widespread in the United States during the past decade. Many pediatric neurosurgeons practicing SEEG may not have had experience with this technique during their formal training, and the literature is mostly limited to single-center series. As a result, implementation of this relatively new technique may vary at different institutions. The authors hypothesized that aspects of SEEG experience, techniques, and outcomes would vary widely among programs across the country., Methods: An electronic survey with 35 questions addressing the categories of training and experience, technique, electrode locations, and outcomes was sent to 128 pediatric epilepsy surgeons who were potential SEEG users., Results: Sixty-one pediatric fellowship-trained epilepsy surgeons in the United States responded to the survey. Eighty-nine percent were actively using SEEG in their practice. Seventy-two percent of SEEG programs were in existence for less than 5 years, and 68% were using SEEG for > 70% of their invasive monitoring. Surgeons at higher-volume centers operated on younger patients (p < 0.001). Most surgeons (70%) spent 1-3 hours per case planning electrode trajectories. Two-thirds of respondents reported a median implant duration of 5-7 days, but 16% reported never having an implant duration > 5 days, and 16% reported having had implants stay in place for > 4 weeks. The median response for the median number of electrodes initially implanted was 12 electrodes, although 19% of respondents reported median implants of 5-8 electrodes and 17% reported median implants of 15-18 electrodes. Having a higher volume of SEEG cases per year was associated with a higher median number of electrodes implanted (p < 0.001). Most surgeons found SEEG helpful in defining an epileptic network and reported that most of their SEEG patients undergo focal surgical treatment., Conclusions: SEEG has been embraced by the pediatric epilepsy surgery community. Higher case volume is correlated with a tendency to place more electrodes and operate on younger patients. For most parameters addressed in the survey, responses from surgeons clustered around a norm, though additional findings of substantial variations highlight differences in implementation and philosophy among pediatric epilepsy programs.

Spring-mediated cranioplasty is a useful treatment modality for correcting scaphocephalic head shape in sagittal craniosynostosis because it is less invasive than whole-vault cranioplasty and offers durable morphologic outcomes. Herein, the authors provide a multimedia demonstration of alternative operative approaches for spring-mediated cranioplasty for sagittal craniosynostosis. The video can be found here: https://vimeo.com/511256259., Competing Interests: Disclosures Dr. Swanson reports receiving non–study-related educational grants from and providing educational content development for KLS Martin and Synthes., (© 2021, The Authors.)

Cranial spring hardware is generally removed 3 months after placement for spring-mediated cranioplasty. Spring removal is performed as an outpatient procedure under general anesthesia in approximately 15 minutes through the incision locations of the index procedure. Herein, the authors provide a multimedia demonstration of cranial spring hardware removal after spring-mediated cranioplasty for sagittal craniosynostosis. The video can be found here: https://vimeo.com/511179695., Competing Interests: Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this publication., (© 2021, The Authors.)

ALK (Anaplastic lymphoma kinase) fusion proteins are oncogenic and have been seen in various tumors. PPP1CB-ALK fusions are rare but have been reported in a few patients with low- or high-grade gliomas. However, little is known regarding the mechanism of fusion formation and genomic break points of this fusion. We performed genomic characterization of a PPP1CB-ALK fusion with fusion gene amplification in a congenital glioblastoma. The PPP1CB-ALK consists of exons 1-5 of PPP1CB and exons 20-29 of ALK. The genomic translocation breakpoints were determined by real-time quantitative PCR (RT-qPCR) and Sanger sequencing of genomic DNA. Next generation sequencing, RT-qPCR and fluorescence in situ hybridization analyses demonstrated PPP1CB-ALK amplification. Copy number analyses of genes between PPP1CB and ALK using RT-qPCR suggest that the PPP1CB-ALK is likely the result of local chromothripsis followed by episomal amplification. Transcriptome sequencing demonstrated high-level SOX2 expression and predicted WNT/β-catenin pathway activation, suggesting possible therapeutic approaches., Competing Interests: Declaration of Competing Interest None declared., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Hemispheric disconnection in the form of hemispherectomy or hemispherotomy is the most effective way of treating intractable hemispheric epilepsy. Anatomical hemispherectomy approaches have largely been abandoned in most cases due to a higher risk of superficial hemosiderosis, intraoperative blood loss, hydrocephalus, prolonged hospital stay, and mortality compared to the variety of tissue-sparing hemispherotomy techniques. Disconnective hemispherotomy approaches utilize the lateral ventricle as a key component of the surgical corridor. Without a lateral ventricle, disconnective surgery becomes significantly challenging, typically leading to a hemispherectomy. The authors present the case of a patient with severe hemispheric dysplasia without a lateral ventricle on the pathologic side and detail a novel surgical technique for a prone, occipital interhemispheric, tissue-sparing, purely disconnective aventricular hemispherotomy with an excellent surgical outcome.

Monkeys can learn the implied ranking of pairs of images drawn from an ordered set, despite never seeing all of the images simultaneously and without explicit spatial or temporal cues. We recorded the activity of posterior parietal cortex (including lateral intraparietal area LIP) neurons while monkeys learned 7-item transitive inference (TI) lists with 2 items presented on each trial. Behavior and neuronal activity were significantly influenced by the ordinal relationship of the stimulus pairs, specifically symbolic distance (the difference in rank) and joint rank (the sum of the ranks). Symbolic distance strongly predicted decision accuracy and learning rate. An effect of joint rank on performance was found nested within the symbolic distance effect. Across the population of neurons, there was significant modulation of firing correlated with the relative ranks of the two stimuli presented on each trial. Neurons exhibited selectivity for stimulus rank during learning, but not before or after. The observed behavior is poorly explained by associative or reward mechanisms, and appears more consistent with a mental workspace model in which implied serial order is mapped within a spatial framework. The neural data suggest that posterior parietal cortex supports serial learning by representing information about the ordinal relationship of the stimuli presented during a given trial.

Corpus callosotomy is a palliative surgical option for patients with refractory epilepsy and frequent drop attacks, decreasing seizure frequency and severity by disconnecting the cerebral hemispheres. Though often successful, open surgery is not without risk. Corpus callosotomy by MRI-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive alternative to the standard open procedure. This report aims to present an illustrative case and systematically review the current literature on the surgical technique. A systematic review of the English literature through January 2019 was performed. Articles were searched by title utilizing the following key word combinations: "laser" and "callosotomy", "callosotomy" and "ablation", "laser" and "corpus", "callosotomy" and "thermal", and "stereotactic" and callosotomy". The articles recovered were then classified by level of evidence and summarized. Fifteen papers were reviewed, of which 6 met inclusion and exclusion criteria. All included studies were classified as level IV evidence. There was a total of 13 patients ranging from 13 months to 44 years old (mean 23.5 years old). The number of laser fibers utilized ranged from 1 to 3. Engel class I was achieved in 5 patients, II in 4, III in 2, IV in 1. Reported patient follow up was 4-39.7 months (mean 15.43). Corpus callosotomy utilizing MRI-guided laser interstitial thermal therapy results in improvement in seizure frequency and severity with minimal complications. Prospective trials are needed to compare its seizure control and long-term outcomes to that of standard open callosotomy., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Purpose: Children with myelomeningocele (MMC) are at increased risk of developing neuromuscular scoliosis and spinal cord re-tethering (Childs Nerv Syst 12:748-754, 1996; Neurosurg Focus 16:2, 2004; Neurosurg Focus 29:1, 2010). Some centers perform prophylactic untethering on asymptomatic MMC patients prior to scoliosis surgery because of concern that additional traction on the cord may place the patient at greater risk of neurologic deterioration peri-operatively. However, prophylactic untethering may not be justified if it carries increased surgical risks. The purpose of this study was to determine if prophylactic untethering is necessary in asymptomatic children with MMC undergoing scoliosis surgery., Methods: A multidisciplinary, retrospective cohort study from seven children's hospitals was performed including asymptomatic children with MMC < 21 years old, managed with or without prophylactic untethering prior to scoliosis surgery. Patients were divided into three groups for analysis: (1) untethering at the time of scoliosis surgery (concomitant untethering), (2) untethering within 3 months of scoliosis surgery (prior untethering), and (3) no prophylactic untethering. Baseline data, intra-operative reports, and 90-day post-operative outcomes were analyzed to assess for differences in neurologic outcomes, surgical complications, and overall length of stay., Results: A total of 208 patients were included for analysis (mean age 9.4 years, 52% girls). No patient in any of the groups exhibited worsened motor or sensory function at 90 days post-operatively. However, comparing the prophylactic untethering groups with the group that was not untethered, there was an increased risk of surgical site infection (SSI) (31.3% concomitant, 28.6% prior untethering vs. 12.3% no untethering; p = 0.0104), return to the OR (43.8% concomitant, 23.8% prior untethering vs. 17.4% no untethering; p = 0.0047), need for blood transfusion (51.6% concomitant, 57.1% prior untethering vs. 33.8% no untethering; p = 0.04), and increased mean length of stay (LOS) (13.4 days concomitant, 10.6 days prior untethering vs. 6.8 days no untethering; p < 0.0001). In multivariable logistic regression analysis, prophylactic untethering was independently associated with increased adjusted relative risks of surgical site infection (aRR = 2.65, 95% CI 1.17-5.02), unplanned re-operation (aRR = 2.17, 95% CI 1.02-4.65), and any complication (aRR = 2.25, 95% CI 1.07-4.74)., Conclusion: In this study, asymptomatic children with myelomeningocele who underwent scoliosis surgery developed no neurologic injuries regardless of prophylactic untethering. However, those who underwent prophylactic untethering were more likely to experience SSIs, return to the OR, need a blood transfusion, and have increased LOS than children not undergoing untethering. Based on these data, prophylactic untethering in asymptomatic MMC patients prior to scoliosis surgery does not provide any neurological benefit and is associated with increased surgical risks.

Objective: Intracerebral convection-enhanced delivery (CED) has been limited to short durations due to a reliance on externalized catheters. Preclinical studies investigating topotecan (TPT) CED for glioma have suggested that prolonged infusion improves survival. Internalized pump-catheter systems may facilitate chronic infusion. The authors describe the safety and utility of long-term TPT CED in a porcine model and correlation of drug distribution through coinfusion of gadolinium., Methods: Fully internalized CED pump-catheter systems were implanted in 12 pigs. Infusion algorithms featuring variable infusion schedules, flow rates, and concentrations of a mixture of TPT and gadolinium were characterized over increasing intervals from 4 to 32 days. Therapy distribution was measured using gadolinium signal on MRI as a surrogate. A 9-point neurobehavioral scale (NBS) was used to identify side effects., Results: All animals tolerated infusion without serious adverse events. The average NBS score was 8.99. The average maximum volume of distribution (Vdmax) in chronically infused animals was 11.30 mL and represented 32.73% of the ipsilateral cerebral hemispheric volume. Vdmax was achieved early during infusions and remained relatively stable despite a slight decline as the infusion reached steady state. Novel tissue TPT concentrations measured by liquid chromatography mass spectroscopy correlated with gadolinium signal intensity on MRI (p = 0.0078)., Conclusions: Prolonged TPT-gadolinium CED via an internalized system is safe and well tolerated and can achieve a large Vdmax, as well as maintain a stable Vd for up to 32 days. Gadolinium provides an identifiable surrogate for measuring drug distribution. Extended CED is potentially a broadly applicable and safe therapeutic option in select patients.

Objective: Craniopharyngioma represents up to 10% of pediatric brain tumors. Although these lesions are benign, attempts at gross-total resection (GTR) can lead to serious complications. More conservative approaches have emerged but require adjuvant radiation. Endoscopic endonasal surgery (EES) aimed at GTR has the potential to result in fewer complications, but there has been limited comparison to open surgery. The authors performed a review of these two approaches within their institution to elucidate potential benefits and complication differences., Methods: The authors performed a retrospective review of pediatric patients undergoing resection of craniopharyngioma at their institution between 2001 and 2017. Volumetric analysis of tumor size and postoperative ischemic injury was performed. Charts were reviewed for a number of outcome measures., Results: A total of 43 patients with an average age of 8.2 years were identified. Open surgery was the initial intervention in 15 and EES in 28. EES was performed in patients 3-17 years of age. EES has been the only approach used since 2011. In the entire cohort, GTR was more common in the EES group (85.7% vs 53.3%, p = 0.03). Recurrence rate (40% vs 14.2%, p = 0.13) and need for adjuvant radiation (20.0% vs 10.7%, p = 0.71) were higher in the open surgical group, although not statistically significant. Pseudoaneurysm development was only observed in the open surgical group. Volumetric imaging analysis showed a trend toward larger preoperative tumor volumes in the open surgical group, so a matched cohort analysis was performed with the largest tumors from the EES group. This revealed no difference in residual tumor volume (p = 0.28), but the volume of postoperative ischemia was still significantly larger in the open group (p = 0.004). Postoperative weight gain was more common in the open surgical group, a statistically significant finding in the complete patient group that trended toward significance in the matched cohort groups. Body mass index at follow-up correlated with volume of ischemic injury in regression analysis of the complete patient cohort (p = 0.05)., Conclusions: EES was associated with similar, if not better, extent of resection and significantly less ischemic injury than open surgery. Pseudoaneurysms were only seen in the open surgical group. Weight gain was also less prevalent in the EES cohort and appears be correlated with extent of ischemic injury at time of surgery.

Stereoelectroencephalography (SEEG) is an invasive technique used during the surgical management of medically refractory epilepsy. The utility of SEEG rests in its ability to survey the three-dimensional organization of the epileptogenic zone as well as nearby eloquent cortices. Once concentrated to specialized centers in Europe and Canada, the SEEG methodology has gained worldwide popularity due to its favorable morbidity profile, superior coverage of deep structures, and ability to perform multilobar explorations without the need for craniotomy. This rapid shift in practice represents both a challenge and an opportunity for pediatric neurosurgeons familiar with the subdural grid approach. The purpose of this review is to discuss the indications, technique, and safety of long-term SEEG monitoring in children. In addition to reviewing the conceptual and technical points of the diagnostic evaluation, attention will also be given to SEEG-based interventions (e.g., radiofrequency thermo-coagulation).

Objective: Interictal spikes are a characteristic feature of invasive electroencephalography (EEG) recordings in children with refractory epilepsy. Spikes frequently co-occur across multiple brain regions with discernable latencies, suggesting that spikes can propagate through distributed neural networks. The purpose of this study was to examine the long-term reproducibility of spike propagation patterns over hours to days of interictal recording., Methods: Twelve children (mean age 13.1 years) were retrospectively studied. A mean ± standard deviation (SD) of 47.2 ± 40.1 hours of interictal EEG recordings were examined per patient (range 17.5-166.5 hours). Interictal recordings were divided into 30-minute segments. Networks were extracted based on the frequency of spike coactivation between pairs of electrodes. For each 30-minute segment, electrodes were assigned a "Degree Preference (DP)" based on the tendency to appear upstream or downstream within propagation sequences. The consistency of DPs across segments ("DP-Stability") was quantified using the Spearman rank correlation., Results: Regions exhibited highly stable preferences to appear upstream, intermediate, or downstream in spike propagation sequences. Across networks, the mean ± SD DP-Stability was 0.88 ± 0.07, indicating that propagation patterns observed in 30-minute segments were representative of the patterns observed in the full interictal window. At the group level, regions involved in seizure generation appeared more upstream in spike propagation sequences., Significance: Interictal spike propagation is a highly reproducible output of epileptic networks. These findings shed new light on the spatiotemporal dynamics that may constrain the network mechanisms of refractory epilepsy., (Wiley Periodicals, Inc. © 2019 International League Against Epilepsy.)

Single-cell gene expression analyses of mammalian tissues have uncovered profound stage-specific molecular regulatory phenomena that have changed the understanding of unique cell types and signaling pathways critical for lineage determination, morphogenesis, and growth. We discuss here the case for a Pediatric Cell Atlas as part of the Human Cell Atlas consortium to provide single-cell profiles and spatial characterization of gene expression across human tissues and organs. Such data will complement adult and developmentally focused HCA projects to provide a rich cytogenomic framework for understanding not only pediatric health and disease but also environmental and genetic impacts across the human lifespan., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Conjoined twins who are classified as craniopagus (joined at the cranium) have a rare congenital anomaly. Despite advances in surgical techniques and critical care, the rate of complications and death is still high among twins with total fusion in which the superior sagittal sinus is shared. Here, we describe total-fusion craniopagus twins who at 10 months of age underwent successful surgical separation performed by a multidisciplinary team. Computer-aided design and modeling with a three-dimensional printer, custom-designed cranial distraction and constriction devices, and intraoperative navigation techniques were used. These techniques allowed for separation of the twins at an early age and harnessed the regenerative capacity of their young brains.

Early-life iron deficiency is a common nutrient condition worldwide and can result in cognitive impairment in adulthood despite iron treatment. In rodents, prenatal choline supplementation can diminish long-term hippocampal gene dysregulation and neurocognitive deficits caused by iron deficiency. Since fetal iron status is generally unknown in humans, we determined whether postnatal choline supplementation exerts similar beneficial effects. Male rat pups were made iron deficient (ID) by providing pregnant and nursing dams an ID diet (3-6ppm Fe) from gestational day (G) 3 through postnatal day (P) 7, and an iron-sufficient (IS) diet (200ppm Fe) thereafter. Control pups were provided IS diet throughout. Choline (5ppm) was given to half the nursing dams and weanlings in each group from P11-P30. P65 rat cognitive performance was assessed by novel object recognition (NOR). Real-time PCR was performed to validate expression levels of synaptic plasticity genes known to be dysregulated by early-life iron deficiency. Postnatal choline supplementation prevented impairment of NOR memory in formerly iron-deficient (FID) adult rats but impaired NOR memory in IS controls. Gene expression analysis revealed a recovery of 4 out of 10 dysregulated genes compared to 8 of the same 10 genes that we previously demonstrated to recover following prenatal choline supplementation. Recognition memory deficits induced by early-life iron deficiency can be prevented by postnatal choline supplementation and disrupted expression of a subset of synaptic plasticity genes can be ameliorated. The positive response to postnatal choline represents a potential adjunctive therapeutic supplement to treat iron-deficient anemic children in order to spare long-term neurodevelopmental deficits., (Copyright © 2017. Published by Elsevier B.V.)

Competing Interests: Conflict of interest: Authors are staff members or unpaid volunteers of the Accreditation Council for Graduate Medical Education (ACGME). All aspects of the development of the new work hour standards, including travel to meetings of the Task Force, was fully funded by the ACGME. All authors, with the exception of Drs Brigham and Philibert, were members of the ACGME Task Force. Dr Brigham provided staff facilitation to the Task Force; Dr Philibert conducted a comprehensive review of the literature on resident work hours and presented the findings at a Task Force meeting.

Pavlovian conditioned approach behavior can be directed as much toward discrete cues as it is toward the environmental contexts in which those cues are encountered. The current experiments characterized a tendency of rats to approach object cues whose prior exposure had been paired with reward (conditioned object preference, COP). To demonstrate the phenomenon, rats were conditioned to associate cocaine or saline with two different objects. Rats acquired a preference, assessed using investigation times directed toward each object, for the cocaine-paired object following conditioning. Furthermore, high levels of object investigation during cocaine conditioning predicted stronger preferences for the cocaine-paired object in the test phase. Conditioned approach diminished across extinction but was reinstated through a priming injection of cocaine. To determine whether preferences are affected by reward value, rats were conditioned using three objects paired with 0, 5, or 20 mg/kg of cocaine. This produced object preferences in the post-test that scaled with cocaine dose used for conditioning. Finally, we explored whether contextual cues modulate expression of COP by testing rats for renewal of cocaine seeking. When conditioning was conducted in one context and extinction training in a second context, COP was renewed when the rats were retested in the original context. Thus, conditioned object preferences are readily acquired, easily measured, and amenable to a number of standard Pavlovian conditioning manipulations. This task promises to become a valuable addition to the panoply of behavioral tools available to test mechanisms underlying adaptive and maladaptive reward processing., (© 2016 Kennedy et al.; Published by Cold Spring Harbor Laboratory Press.)