Pediatric Prostatic Alveolar Rhabdomyosarcoma Presenting with Metastatic Spinal Cord Compression in the Thoracic Spine: A Case Report and Review of the Literature

Rhabdomyosarcoma (RMS) is a pediatric malignancy with a variable prognosis depending on tumor stage and genotype. There has been a significant improvement in survival rates over the past decades. However, aggressive variants can metastasize to locations that are difficult to treat. We report a case of prostatic alveolar rhabdomyosarcoma with metastases to the bone marrow and thoracic spine in a child. The patient was treated with a multimodal approach that included surgical resection of the epidural mass; the administration of vincristine, dactinomycin, and cyclophosphamide; and radiotherapy. Unfortunately, after six months, the patient showed disease progression and was started on secondary-line treatment. This case illustrates the difficulties in managing end-stage metastatic rhabdomyosarcoma and is the first report of prostatic rhabdomyosarcoma presenting with spinal cord compression in a child.

Machine learning models for predicting seizure outcome after MR-guided laser interstitial thermal therapy in children

OBJECTIVE

MR-guided laser interstitial thermal therapy (MRgLITT) is associated with lower seizure-free outcome but better safety profile compared to open surgery. However, the predictors of seizure freedom following MRgLITT remain uncertain. This study aimed to use machine learning to predict seizure-free outcome following MRgLITT and to identify important predictors of seizure freedom in children with drug-resistant epilepsy.

METHODS

This multicenter study included children treated with MRgLITT for drug-resistant epilepsy at 13 epilepsy centers. The authors used clinical data, diagnostic investigations, and ablation features to predict seizure-free outcome at 1 year post-MRgLITT. Patients from 12 centers formed the training cohort, and patients in the remaining center formed the testing cohort. Five machine learning algorithms were developed on the training data by using 10-fold cross-validation, and model performance was measured on the testing cohort. The models were developed and tested on the complete feature set. Subsequently, 3 feature selection methods were used to identify important predictors. The authors then assessed performance of the parsimonious models based on these important variables.

RESULTS

This study included 268 patients who underwent MRgLITT, of whom 44.4% had achieved seizure freedom at 1 year post-MRgLITT. A gradient-boosting machine algorithm using the complete feature set yielded the highest area under the curve (AUC) on the testing set (AUC 0.67 [95% CI 0.50-0.82], sensitivity 0.71 [95% CI 0.47-0.88], and specificity 0.66 [95% CI 0.50-0.81]). Logistic regression, random forest, support vector machine, and neural network yielded lower AUCs (0.58-0.63) compared to the gradient-boosting machine but the findings were not statistically significant (all p > 0.05). The 3 feature selection methods identified video-EEG concordance, lesion size, preoperative seizure frequency, and number of antiseizure medications as good prognostic features for predicting seizure freedom. The parsimonious models based on important features identified by univariate feature selection slightly improved model performance compared to the complete feature set.

CONCLUSIONS

Understanding the predictors of seizure freedom after MRgLITT will assist with prognostication.

Seizure outcome of pediatric magnetic resonance-guided laser interstitial thermal therapy versus open surgery: A matched noninferiority cohort study

OBJECTIVE

Minimally invasive magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has been proposed as an alternative to open epilepsy surgery, to address concerns regarding the risk of open surgery. Our primary hypothesis was that seizure freedom at 1 year after MRgLITT is noninferior to open surgery in children with drug-resistant epilepsy (DRE). The secondary hypothesis was that MRgLITT has fewer complications and shorter hospitalization than surgery. The primary objective was to compare seizure outcome of MRgLITT to open surgery in children with DRE. The secondary objective was to compare complications and length of hospitalization of the two treatments.

METHODS

This retrospective multicenter cohort study included children with DRE treated with MRgLITT or open surgery with 1-year follow-up. Exclusion criteria were corpus callosotomy, neurostimulation, multilobar or hemispheric surgery, and lesion with maximal dimension > 60 mm. MRgLITT patients were propensity matched to open surgery patients. The primary outcome was seizure freedom at 1 year posttreatment. The difference in seizure freedom was compared using noninferiority test, with noninferiority margin of -10%. The secondary outcomes were complications and length of hospitalization.

RESULTS

One hundred eighty-five MRgLITT patients were matched to 185 open surgery patients. Seizure freedom at 1 year follow-up was observed in 89 of 185 (48.1%) MRgLITT and 114 of 185 (61.6%) open surgery patients (difference = -13.5%, one-sided 97.5% confidence interval = -23.8% to ∞, p_{Noninferiority}  = .79). The lower confidence interval boundary of -23.8% was below the prespecified noninferiority margin of -10%. Overall complications were lower in MRgLITT compared to open surgery (10.8% vs. 29.2%, respectively, p < .001). Hospitalization was shorter for MRgLITT than open surgery (3.1 ± 2.9 vs. 7.2 ± 6.1 days, p < .001).

SIGNIFICANCE

Seizure outcome of MRgLITT at 1 year posttreatment was inferior to open surgery. However, MRgLITT has the advantage of better safety profile and shorter hospitalization. The findings will help counsel children and parents on the benefits and risks of MRgLITT and contribute to informed decision-making on treatment options.

Endoscopic third ventriculostomy and choroid plexus cauterization (ETV/CPC) for hydrocephalus of infancy: a technical review

In the twenty-first century, choroid plexus cauterization (CPC) in combination with endoscopic third ventriculostomy (ETV) has emerged as an effective treatment for some infants with hydrocephalus, leading to the favourable condition of 'shunt independence'. Herein we provide a narrative technical review considering the indications, procedural aspects, morbidity and its avoidance, postoperative care and follow-up. The CP has been the target of hydrocephalus treatment for more than a century. Early eminent neurosurgeons including Dandy, Putnam and Scarff performed CPC achieving generally poor results, and so the procedure fell out of favour. In recent years, the addition of CPC to ETV was one of the reasons greater ETV success rates were observed in Africa, compared to developed nations, and its popularity worldwide has since increased. Initial results indicate that when ETV/CPC is performed successfully, shunt independence is more likely than when ETV is undertaken alone. CPC is commonly performed using a flexible endoscope via septostomy and aims to maximally cauterize the CP. Success is more likely in infants aged >1 month, those with hydrocephalus secondary to myelomeningocele and aqueductal obstruction and those with >90% cauterized CP. Failure is more likely in those with post-haemorrhagic hydrocephalus of prematurity (PHHP), particularly those <1 month of corrected age and those with prepontine scarring. High-quality evidence comparing the efficacy of ETV/CPC with shunting is emerging, with data from ongoing and future trials offering additional promise to enhance our understanding of the true utility of ETV/CPC.

Brain and Spinal Cord Tumors in Children

This article provides general principles of managing children with central nervous system tumors. The distribution, diagnostic work-up, and key principles of treatment are reviewed, and special circumstances that may be encountered by pediatricians in the community are discussed.

Management evaluation of metastasis in the brain (MEMBRAIN)-a United Kingdom and Ireland prospective, multicenter observational study

BACKGROUND

In recent years an increasing number of patients with cerebral metastasis (CM) have been referred to the neuro-oncology multidisciplinary team (NMDT). Our aim was to obtain a national picture of CM referrals to assess referral volume and quality and factors affecting NMDT decision making.

METHODS

A prospective multicenter cohort study including all adult patients referred to NMDT with 1 or more CM was conducted. Data were collected in neurosurgical units from November 2017 to February 2018. Demographics, primary disease, KPS, imaging, and treatment recommendation were entered into an online database.

RESULTS

A total of 1048 patients were analyzed from 24 neurosurgical units. Median age was 65 years (range, 21-93 years) with a median number of 3 referrals (range, 1-17 referrals) per NMDT. The most common primary malignancies were lung (36.5%, n = 383), breast (18.4%, n = 193), and melanoma (12.0%, n = 126). A total of 51.6% (n = 541) of the referrals were for a solitary metastasis and resulted in specialist intervention being offered in 67.5% (n = 365) of cases. A total of 38.2% (n = 186) of patients being referred with multiple CMs were offered specialist treatment. NMDT decision making was associated with number of CMs, age, KPS, primary disease status, and extent of extracranial disease (univariate logistic regression, P < .001) as well as sentinel location and tumor histology (P < .05). A delay in reaching an NMDT decision was identified in 18.6% (n = 195) of cases.

CONCLUSIONS

This study demonstrates a changing landscape of metastasis management in the United Kingdom and Ireland, including a trend away from adjuvant whole-brain radiotherapy and specialist intervention being offered to a significant proportion of patients with multiple CMs. Poor quality or incomplete referrals cause delay in NMDT decision making.

Selective dorsal rhizotomy: an illustrated review of operative techniques

OBJECTIVE

Selective dorsal rhizotomy (SDR) is a procedure primarily performed to improve function in a subset of children with limitations related to spasticity. There is substantial variability in operative techniques among centers and surgeons. Here, the authors provide a technical review of operative approaches for SDR.

METHODS

Ovid MEDLINE, Embase, and PubMed databases were queried in accordance with PRISMA guidelines. All studies included described a novel surgical technique. The technical nuances of each approach were extracted, including extent of exposure, bone removal, and selection of appropriate nerve roots. The operative approach preferred at the authors' institution (the "2 × 3 exposure") is also detailed.

RESULTS

Five full-text papers were identified from a total of 380 articles. Operative approaches to SDR varied significantly with regard to level of exposure, extent of laminectomy, and identification of nerve roots. The largest exposure involved a multilevel laminectomy, while the smallest exposure involved a keyhole interlaminar approach. At the Hospital for Sick Children, the authors utilize a two-level laminoplasty at the level of the conus medullaris. The benefits and disadvantages of the spectrum of techniques are discussed, and illustrative figures are provided.

CONCLUSIONS

Surgical approaches to SDR vary considerably and are detailed and illustrated in this review as a guide for neurosurgeons. Future studies should address the long-term impact of these techniques on functional outcomes and complications such as spinal deformity.

Humanized Stem Cell Models of Pediatric Medulloblastoma Reveal an Oct4/mTOR Axis that Promotes Malignancy

Medulloblastoma (MB), the most frequent malignant childhood brain tumor, can arise from cellular malfunctions during hindbrain development. Here we generate humanized models for Sonic Hedgehog (SHH)-subgroup MB via MYCN overexpression in primary human hindbrain-derived neuroepithelial stem (hbNES) cells or iPSC-derived NES cells, which display a range of aggressive phenotypes upon xenografting. iPSC-derived NES tumors develop quickly with leptomeningeal dissemination, whereas hbNES-derived cells exhibit delayed tumor formation with less dissemination. Methylation and expression profiling show that tumors from both origins recapitulate hallmarks of infant SHH MB and reveal that mTOR activation, as a result of increased Oct4, promotes aggressiveness of human SHH tumors. Targeting mTOR decreases cell viability and prolongs survival, showing the utility of these varied models for dissecting mechanisms mediating tumor aggression and demonstrating the value of humanized models for a better understanding of pediatric cancers.

•

Human iPSC-derived or primary neuroepithelial stem cells can be transformed by MYCN

•

MYCN drives infant SHH medulloblastoma with clinically relevant features

•

Epigenetically regulated Oct4 promotes mTOR hyperactivation in infant SHH tumors

•

mTOR inhibition efficiently targets metastatic SHH medulloblastoma models and PDXs

Engineering Genetic Predisposition in Human Neuroepithelial Stem Cells Recapitulates Medulloblastoma Tumorigenesis

Human neural stem cell cultures provide progenitor cells that are potential cells of origin for brain cancers. However, the extent to which genetic predisposition to tumor formation can be faithfully captured in stem cell lines is uncertain. Here, we evaluated neuroepithelial stem (NES) cells, representative of cerebellar progenitors. We transduced NES cells with MYCN, observing medulloblastoma upon orthotopic implantation in mice. Significantly, transcriptomes and patterns of DNA methylation from xenograft tumors were globally more representative of human medulloblastoma compared to a MYCN-driven genetically engineered mouse model. Orthotopic transplantation of NES cells generated from Gorlin syndrome patients, who are predisposed to medulloblastoma due to germline-mutated PTCH1, also generated medulloblastoma. We engineered candidate cooperating mutations in Gorlin NES cells, with mutation of DDX3X or loss of GSE1 both accelerating tumorigenesis. These findings demonstrate that human NES cells provide a potent experimental resource for dissecting genetic causation in medulloblastoma.

In Vitro Recapitulation of Developmental Transitions in Human Neural Stem Cells

During nervous system development, early neuroepithelial stem (NES) cells with a highly polarized morphology and responsiveness to regionalizing morphogens give rise to radial glia (RG) cells, which generate region-specific neurons. Recently, stable neural cell populations reminiscent of NES cells have been obtained from pluripotent stem cells and the fetal human hindbrain. Here, we explore whether these cell populations, similar to their in vivo counterparts, can give rise to neural stem (NS) cells with RG-like properties and whether region-specific NS cells can be generated from NES cells with different regional identities. In vivo RG cells are thought to form from NES cells with the onset of neurogenesis. Therefore, we cultured NES cells temporarily in differentiating conditions. Upon reinitiation of growth factor treatment, cells were found to enter a developmental stage reflecting major characteristics of RG-like NS cells. These NES cell-derived NS cells exhibited a very similar morphology and marker expression as primary NS cells generated from human fetal tissue, indicating that conversion of NES cells into NS cells recapitulates the developmental progression of early NES cells into RG cells observed in vivo. Importantly, NS cells generated from NES cells with different regional identities exhibited stable region-specific transcription factor expression and generated neurons appropriate for their positional identity. Stem Cells 2019;37:1429-1440.

Using Virtual Reality to investigate multitasking ability in individuals with frontal lobe lesions

Individuals with lesions in the prefrontal cortex often show impairments with the organisation of their behaviour in everyday life. These difficulties can be hard to detect using structured formal tests. The objective of this study was to use Virtual Reality (VR) to explore the multitasking performance of individuals with focal frontal lobe lesions, specifically using the Jansari assessment of Executive Functions (JEF^©). Nineteen individuals with frontal lobe lesions were compared with 19 matched controls on the test and a group of commonly used clinical measures of neuropsychological functioning, as well as questionnaire measures of everyday activity, anxiety and depression. There was a significant difference between groups on the overall JEF^© score and on five of the eight individual constructs, namely the planning, creative thinking, adaptive thinking, event-based Prospective Memory (PM) and time-based PM constructs. There were no differences between groups on the non-VR EF individual measures apart from on one EF control measure, Trail Making A. These results demonstrate the potential clinical utility of the JEF^© and highlight the value of ecologically valid VR measures in detecting impairments in EF in individuals with frontal lobe lesions.

Clinical audit effectively bridges the evidence-practice gap in chronic subdural haematoma management

BACKGROUND

Placement of a subdural drain after drainage of chronic subdural haematoma (CSDH) has been shown to reduce the rate of recurrence in several randomised controlled trials (RCT). The most recently published RCT was from Cambridge, UK, in 2009. Despite class I evidence for the use of subdural drains, it is unclear whether these results have been translated into clinical practice. In this clinical audit we review the use of subdural drains in our institution before and after the publication of the 2009 RCT results.

METHODS

A longitudinal retrospective study was performed on all adults having burr holes for CSDH between January 2009 and January 2014. Case notes were analysed to determine subdural drain use, re-operation for CSDH recurrence and post-operative complications. The audit loop was closed with data collected from August 2015 to January 2016.

RESULTS

Thirty-one per cent of patients had subdural drains placed at operation. Drain placement was associated with lower reoperation rates (8% vs. 17%, p = 0.021) without increasing complication rates. Drain usage doubled after publication of the Santarius et al. (2009) trial but we observed persisting and significant variability in drain utilisation by supervising consultants. The use of drains in the department increased from 35% to 75% of all cases after presentation of these results.

CONCLUSIONS

The use of subdural drains in our unit reduced recurrence rates following drainage of CSDH and reproduced the results of a 2009 clinical trial. Although the use of subdural drains doubled in the post-trial epoch, significant variability remains in practice. Clinical audit provided an effective tool necessary to drive the implementation of subdural drain placement in our unit.

Cytosine-5 RNA Methylation Regulates Neural Stem Cell Differentiation and Motility

Loss-of-function mutations in the cytosine-5 RNA methylase NSUN2 cause neurodevelopmental disorders in humans, yet the underlying cellular processes leading to the symptoms that include microcephaly remain unclear. Here, we show that NSUN2 is expressed in early neuroepithelial progenitors of the developing human brain, and its expression is gradually reduced during differentiation of human neuroepithelial stem (NES) cells in vitro. In the developing Nsun2-/- mouse cerebral cortex, intermediate progenitors accumulate and upper-layer neurons decrease. Loss of NSUN2-mediated methylation of tRNA increases their endonucleolytic cleavage by angiogenin, and 5' tRNA fragments accumulate in Nsun2-/- brains. Neural differentiation of NES cells is impaired by both NSUN2 depletion and the presence of angiogenin. Since repression of NSUN2 also inhibited neural cell migration toward the chemoattractant fibroblast growth factor 2, we conclude that the impaired differentiation capacity in the absence of NSUN2 may be driven by the inability to efficiently respond to growth factors.

Supratentorial ependymoma presenting as a cortical cyst with a mural nodule in an adult

Supratentorial ependymoma is a rare tumour in the adult central nervous system. We present an unusual case of supratentorial ependymoma in a young adult that presented as a pure cortical cyst with a mural nodule and discuss the differential diagnosis of such lesions in the brain.

Capture of neuroepithelial-like stem cells from pluripotent stem cells provides a versatile system for in vitro production of human neurons

Human embryonic stem cells (hESC) and induced pluripotent stem cells (iPSC) provide new prospects for studying human neurodevelopment and modeling neurological disease. In particular, iPSC-derived neural cells permit a direct comparison of disease-relevant molecular pathways in neurons and glia derived from patients and healthy individuals. A prerequisite for such comparative studies are robust protocols that efficiently yield standardized populations of neural cell types. Here we show that long-term self-renewing neuroepithelial-like stem cells (lt-NES cells) derived from 3 hESC and 6 iPSC lines in two independent laboratories exhibit consistent characteristics including i) continuous expandability in the presence of FGF2 and EGF; ii) stable neuronal and glial differentiation competence; iii) characteristic transcription factor profile; iv) hindbrain specification amenable to regional patterning; v) capacity to generate functionally mature human neurons. We further show that lt-NES cells are developmentally distinct from fetal tissue-derived radial glia-like stem cells. We propose that lt-NES cells provide an interesting tool for studying human neurodevelopment and may serve as a standard system to facilitate comparative analyses of hESC and hiPSC-derived neural cells from control and diseased genetic backgrounds.

Hemangiopericytoma: long-term outcome revisited. Clinical article

OBJECT

Hemangiopericytomas are rare tumors that behave aggressively with a high rate of local recurrence and distant metastases. With the aim of determining the outcome and response to various treatment modalities, a series of 39 patients who underwent microsurgical resection for primary meningeal hemangiopericytoma over a 24-year period is presented.

METHODS

Patients with hemangiopericytoma were identified from histopathology records and their medical records were analyzed retrospectively by 2 independent reviewers to collect data on surgical treatment, adjuvant therapy, postoperative course, local or distant recurrence, and follow-up.

RESULTS

Of the 39 patients, 19 were male and 20 were female. Mean patient age was 44.1 years. Thirty-four tumors were intracranial and 5 were spinal. The mean follow-up period was 123 months. Twenty-eight patients developed local recurrence. The recurrence rate at 1, 5, and 15 years was 3.5%, 46%, and 92%, respectively. Extraneural metastasis occurred in 8 patients (26%) at an average of 123 months after initial surgery. Recurrences and metastases were treated by surgical excision, external beam radiation therapy (EBRT), chemotherapy, and/or stereotactic radiosurgery. Adjuvant EBRT following initial surgery was found to extend the disease-free interval from 154 months to 254 months, although it did not prevent the development of metastasis. In those patients with EBRT and complete resection, the mean recurrence-free interval was found to be 126.3 months longer (p = 0.04) and overall survival 126 months longer than without EBRT. Furthermore, adjusting for resection, patients undergoing EBRT had 0.33 times increased risk of recurrence compared with those who did not (p = 0.03). A majority of patients remained able to live independently despite revision surgery for recurrence.

CONCLUSIONS

The mean follow-up of this patient series represents the longest follow-up duration published to date and demonstrates extended survival in a significant number of patients with hemangiopericytoma. Gross-total resection followed by adjuvant EBRT provides patients with the highest probability of an increased recurrence-free interval and overall survival. Prolonged survival justifies long-term follow-up and aggressive treatment of initial, recurrent, and metastatic disease.

Hugh Cairns and the origin of British neurosurgery

Sir Hugh Cairns, the first Nuffield Professor of Surgery in Oxford and consultant neurosurgeon to the Royal Army Medical Corps during World War II, was a leader in helping to establish neurosurgery as a speciality in Britain. After learning the craft from Dr Harvey Cushing in Boston, Cairns fought against the general surgical orthodoxy in London to establish the first specialised neurosurgical unit in a teaching hospital. We review his early life, training with Cushing, his inspiring character and administrative prowess which not only helped to win the battle for neurosurgery in London but also helped to establish the Oxford Clinical School and to save thousands of lives during the Second World War.

Triorchidism at orchidopexy: a case report

Introduction

Polyorchidism is defined as the presence of more than two testes. The management of this rare condition is still debatable, particularly when it is an incidental finding at surgery.

Case presentation

We present the case of an 8-year-old boy with triorchidism found incidentally during an elective orchidopexy. This supernumerary, ectopic and atrophic testis was removed to avoid an increased risk of malignancy.

Conclusion

Risk of malignancy justifies the removal of an atrophic and ectopic testis in triorchidism. However, it would appear safe to preserve a viable intrascrotal supernumerary testis found incidentally at surgery provided that the patient is followed up in the long term.

Primary pleural synovial sarcoma presenting as a multiloculated cyst in an adolescent

Primary pleural synovial sarcoma (PPSS) is a rare pleural malignancy with a grave prognosis. Most cases present as a well-circumscribed mass with foci of haemorrhage and necrosis. We present an unusual case in a Nepalese boy that presented as a multiloculated cyst mimicking hydatid disease. The diagnosis was confirmed by histology and cytogenetic analysis.

Conservative treatment of spontaneous spinal epidural hematoma associated with oral anticoagulant therapy in a child

OBJECTIVE

Spontaneous spinal epidural hematoma (SSEH) is rare in the pediatric population. This case report reviews the indications and strategies for nonoperative management in selected patients.

METHODS

An eight-year-old boy presented with back pain. There was no antecedent trauma, but the patient was anticoagulated for a mechanical heart valve. MRI revealed an epidural mass from T12 to L2 consistent with SSEH. The absence of focal neurologic deficits, combined with the high stroke risk with anticoagulation reversal, prompted a nonoperative approach. Clinical symptoms resolved over several weeks while maintaining therapeutic anticoagulation. Follow-up MRI demonstrated resolution of the hematoma.

CONCLUSION

SSEH can present in the setting of poorly controlled therapeutic anticoagulation in the pediatric population. This case supports the premise that patients who present with SSEH without focal neurologic deficit can be successfully managed while maintaining therapeutic levels of anticoagulation. Close follow-up with frequent neurologic examinations, imaging and monitoring of the prothrombin time is mandatory.

Reversal of hypertonic co-contraction after bilateral pallidal stimulation in generalised dystonia: a clinical and electromyogram case study

In a patient of generalised dystonia treated with bilateral pallidal stimulation, serial surface EMGs recorded from the neck muscles during alternating head movements revealed progressive reduction in hypertonic activity and reversal of co-contraction to reciprocal contraction, which preceded clinical improvement.

N,N-Diethanolaminomethyl Polystyrene: An Efficient Solid Support to Immobilize Boronic Acids

The key to the efficiency of N,N-diethanolaminomethyl polystyrene (DEAM-PS), the first solid support capable of coupling to boronic acids, is the formation of a stable, resin-bound boronic ester ate adduct (see scheme). With this resin it is now possible to efficiently immobilize a wide variety of boronic acids including functionalized ones that can be derivatized by solid-phase combinatorial synthesis.