A tailored approach to the management of post-haemorrhagic hydrocephalus.

PURPOSE: Neuro-endoscopic lavage (NEL) is an increasingly popular intervention for intraventricular haemorrhage (IVH) and post-haemorrhagic hydrocephalus (PHH), with considerable variation in technique dependent on clinician and clinical circumstances. Whilst efforts to standardise the technique are ongoing, this work describes a tertiary centre experience utilising NEL, highlighting potential caveats to standardisation. METHODS: A retrospective review of electronic case notes for patients undergoing temporising surgical intervention for IVH between 2012 and 2021 at our centre was performed. Data collected included (i) gestational age, (ii) aetiology of hydrocephalus, (iii) age at time of intervention, (iv) intervention performed, (v) need for permanent CSF diversion, (vi) 'surgical burden', i.e. number of procedures following primary intervention, and (vii) wound failure and infection rate. Data was handled in Microsoft Excel and statistical analysis SPSS v27.0 RESULTS: 49 neonates (n = 25 males) were included. Overall mean gestational age was 27 weeks and at intervention 35 + 3 weeks. IVH was the predominant cause of hydrocephalus (93.8%) and primary surgical interventions included insertion of a ventriculosubgaleal shunt (VSGS) in n = 41 (83.6%) patients, NEL in n = 6 (12.2%) patients and insertion of an EVD in n = 2 (4.1%). N = 9 (18.4%) patients underwent NEL at some point during the time interval reviewed; n = 4 (8.2%) received NEL monotherapy and n = 5 (10.2%) also received a VSGS. Rate of conversion to definitive CSF diversion between NEL (n = 8, 88.9%) and VSGS cohorts (n = 37, 92.5%) was not significantly different (p = 0.57), nor between NEL alone (n = 3, 75%) and NEL + VSGS (n = 5, 100%) (p = 0.44). None of the patients that underwent NEL monotherapy had any wound issues or CNS infection as a result of the initial intervention, compared to n = 3 (60%) of those that underwent NEL and implantation of VSGS (p = 0.1). CONCLUSION: Both NEL and VSGS are effective in temporising hydrocephalus in neonates, occasionally offering a definitive solution in and of themselves. The benefit of dual therapy however remains to be seen, with the addition of VSGS potentially increasing the risk of wound failure in an already vulnerable cohort.

Hydrocephalus in prematurity: does valve choice make a difference?

PURPOSE: Extremely premature neonates diagnosed with post-haemorrhagic hydrocephalus (PHH) are recognised to have particularly poor outcomes. This study assessed the impact of a number of variables on outcomes in this cohort, in particular the choice of shunt valve mechanism. METHODS: Electronic case notes were retrospectively reviewed of all premature neonates admitted to our centre for management of hydrocephalus between 2012 and 2021. Data included (i) gestational age, (ii) birth weight, (iii) hydrocephalus aetiology, (iv) surgical intervention, (v) shunt system, (vi) 'surgical burden' and (vii) wound failure and infection rate. Data was handled in Microsoft Excel and statistical analysis performed in SPSS v27.0 RESULTS: N = 53 premature hydrocephalic patients were identified (n = 28 (52.8%) female). Median gestational age at birth was 27 weeks (range: 23-36 + 6 weeks), with n = 35 extremely preterm patients and median birth weight of 1.9 kg (range: 0.8-3.6 kg). Total n = 99 programmable valves were implanted (n = 28 (28.3%) de novo, n = 71 (71.2%) revisions); n = 28 (28.3%) underwent n ≥ 1 pressure alterations, after which n = 21 (75%) patients had symptoms improve. In n = 8 patients exchanged from fixed to programmable valves, a mean reduction of 1.9 revisions per patient after exchange was observed (95%CI: 0.36-3.39, p = 0.02). Mean overall shunt survival was 39.5 weeks (95%CI: 30.6-48.5); 33.2 weeks (95%CI: 25.2-41.1) in programmable valves and 35.1 weeks (95%CI: 19.5-50.6) in fixed pressure (p = 0.22) with 12-month survival rates of 25.7% and 24.7%, respectively (p = 0.22). Shorter de novo shunt survival was associated with higher operation count overall (Pearson's R: - 0.54, 95%CI: - 0.72 to - 0.29, p < 0.01). Wound failure, gestational age and birth weight were significantly associated with shorter de novo shunt survival in a Cox regression proportional hazards model; gestational age had the greatest impact on shunt survival (Exp(B): 0.71, 95%CI: 0.63-0.81, p < 0.01). CONCLUSION: Hydrocephalus is especially challenging in extreme prematurity, with a shorter de novo shunt survival associated with higher number of future revisions. Programmable valves provide flexibility with regard to pressure setting, with the potential for fewer shunt revisions in this complex cohort.

Safety and effectiveness of Evicel® fibrin sealant as an adjunct to sutured dural repair in children undergoing cranial neurosurgery.

PURPOSE: Cerebrospinal fluid (CSF) leakage is a challenging complication of intradural cranial surgery, and children are particularly at risk. The use of dural sealants confers protection in adults, but pediatric studies are scarce. We evaluated the safety and efficacy of Evicel® fibrin sealant as an adjunct to primary dural suturing in children undergoing cranial surgery. METHODS: A multicenter trial prospectively enrolled pediatric subjects (< 18 years) undergoing cranial neurosurgery who, upon completion of primary sutured dural repair, experienced CSF leakage. As agreed by the EMA Evicel® Pediatric Investigation Plan, 40 subjects were intra-operatively randomized 2:1 to Evicel® or additional sutures ('Sutures'). Data analysis was descriptive. The efficacy endpoint was treatment success rate, with success defined as intra-operative watertight closure after provocative Valsalva maneuver (primary endpoint). Safety endpoints were postoperative CSF leakage (incisional CSF leakage, pseudomeningocele or both) and surgical site complications (secondary endpoints). RESULTS: Forty subjects (0.6-17 years) were randomized to Evicel® (N = 25) or Sutures (N = 15) (intention-to-treat). Intracranial tumor was the most common indication and procedures were mostly supratentorial craniotomies. Success rates were 92.0% for Evicel® and 33.3% for Sutures, with a 2.76 estimated ratio of success rates (Farrington-Manning 95% CI [1.53, 6.16]). Sensitivity analyses in per-protocol and safety sets showed similar results. Despite a higher rescue treatment rate, the frequencies of postoperative CSF leakage and wound complications were higher for Sutures than for Evicel®. CONCLUSION: This small-scale prospective study shows Evicel® treatment to be safe and effective as an adjunct to primary sutured dura mater closure in a pediatric population. Compared to additional sutures, Evicel® was associated with reduced postoperative CSF leakage and surgical site complications. (Trial registration: The trial was registered as NCT02309645 and EudraCT 2013-003558-26).

Selective dorsal rhizotomy in non-ambulant children with cerebral palsy: a multi-center prospective study.

PURPOSE: Assess the effects of selective dorsal rhizotomy (SDR) on motor function and quality of life in children with a Gross Motor Function Classification System (GMFCS) level of IV or V (non-ambulatory). METHODS: This is a prospective, observational study in three tertiary neurosurgery units in England, UK, performing SDR on children aged 3-18 with spastic diplegic cerebral palsy, and a GMFCS level of IV or V, between 2012 and 2019. The primary outcome measure was the change in the 66-item Gross Motor Function Measure (GMFM-66) from baseline to 24 months after SDR, using a linear mixed effects model. Secondary outcomes included spasticity, bladder function, quality of life, and pain scores. RESULTS: Between 2012 and 2019, 144 children who satisfied these inclusion criteria underwent SDR. The mean age was 8.2 years. Fifty-two percent were female. Mean GMFM-66 score was available in 77 patients (53.5%) and in 39 patients (27.1%) at 24 months after SDR. The mean increase between baseline and 24 months post-SDR was 2.4 units (95% CI 1.7-3.1, p < 0.001, annual change 1.2 units). Of the 67 patients with a GMFM-66 measurement available, a documented increase in gross motor function was seen in 77.6% (n = 52). Of 101 patients with spasticity data available, mean Ashworth scale decreased after surgery (2.74 to 0.30). Of patients' pain scores, 60.7% (n = 34) improved, and 96.4% (n = 56) of patients' pain scores remained the same or improved. Bladder function improved in 30.9% of patients. CONCLUSIONS: SDR improved gross motor function and reduced pain in most patients at 24 months after surgery, although the improvement is less pronounced than in children with GMFCS levels II and III. SDR should be considered in non-ambulant patients.

Communicating hydrocephalus and raised intracranial pressure in association with multi-systemic smooth muscle dysfunction syndrome (MSMDS).

Multi-systemic smooth muscle dysfunction syndrome (MSMDS) is extremely rare and can manifest in multiple ways. Associated hydrocephalus has not yet been reported. Here, we report a three-year-old girl with communicating hydrocephalus and raised intracranial pressure secondary to MSMDS. Pathological mechanisms are proposed, as is the need to investigate patients diagnosed with MSMDS for ventriculomegaly and raised pressure.

Secure windows for child safety: a retrospective study of window falls in children, aiming to raise prevention awareness.

PURPOSE: The aim of the study is to enhance understanding, raise awareness and inform prevention programmes regarding potential factors that lead to severe paediatric injuries caused by unintentional falls from windows. METHODS: This is a retrospective review from a major Trauma Centre, covering the majority of North West England and North Wales and included children under the age of 16 that had sustained falls from windows and were hospitalised between April 2015 and June 2020. RESULTS: Overall, 825 patients' records have been reviewed, 39% of which exhibited neurosurgical injuries (322 admissions). The most common cause of injury was falls (42%), out of which 19% was identified as falls from windows which was eventually the core focus of this review (25 patients). The records showed that 72% of the falls were not witnessed by another individual, suggesting that children were being left unattended. Average GCS recorded at presentation was 11.2 and 56% of cases were identified as severe major traumas. With a mean stay of 2.2 days in ICU, 1.6 days in HDU and 6 days in the neurosurgical clinic, average treatment costs per patient were £4,493, £651 and £4,156 respectively. Finally, 52% of patients were identified to require long-term physiotherapy/occupational therapy due to permanent disabilities, 20% long-term antiepileptic treatment for seizures and 44% long-term psychological services input. CONCLUSION: This study presents our experience at a major tertiary trauma centre in the UK over a 5-year period, from a paediatric neurosurgical injuries perspective due to fall from windows. We aim to raise awareness and highlight the importance of establishing prevention programmes which would hopefully decrease the incidence of paediatric window falls.

Intracranial Empyemas in the COVID-19 Era: A New Phenomenon? A Paediatric Case Series and Review of the Literature.

INTRODUCTION: We present the largest series of paediatric intracranial empyemas occurring after COVID-19 infection to date, and discuss the potential implications of the pandemic on this neurosurgical pathology. METHODS: Patients admitted to our centre between January 2016 and December 2021 with a confirmed radiological diagnosis of intracranial empyema were retrospectively reviewed, excluding non-otorhinological source cases. Patients were grouped according to onset before or after onset of the COVID-19 pandemic and COVID-19 status. A literature review of all post-COVID-19 intracranial empyemas was performed. SPSS v27 was used for statistical analysis. RESULTS: Sixteen patients were diagnosed with intracranial empyema: n = 5 prior to 2020 and n = 11 after, resulting in an average annual incidence of 0.3% prior to onset of the pandemic and 1.2% thereafter. Of those diagnosed since the pandemic, 4 (25%) were confirmed to have COVID-19 on recent PCR test. Time from COVID-19 infection until empyema diagnosis ranged from 15 days to 8 weeks. Mean age for post-COVID-19 cases was 8.5 years (range: 7-10 years) compared to 11 years in non-COVID cases (range: 3-14 years). Streptococcus intermedius was grown in all cases of post-COVID-19 empyema, and 3 of 4 (75%) post-COVID-19 cases developed cerebral sinus thromboses, compared to 3 of 12 (25%) non-COVID-19 cases. All cases were discharged home with no residual deficit. CONCLUSION: Our post-COVID-19 intracranial empyema series demonstrates a greater proportion of cerebral sinus thromboses than non-COVID-19 cases, potentially reflecting the thrombogenic effects of COVID-19. Incidence of intracranial empyema at our centre has increased since the start of the pandemic, causes of which require further investigation and multicentre collaboration.

Comparison of intraoperative and post-operative 3-T MRI performed at 24-72 h following brain tumour resection in children.

PURPOSE: Intraoperative MRI (ioMRI) is a valuable tool aiding paediatric brain tumour resection. There is no published evidence comparing the effectiveness of the final intraoperative MRI and early post-operative (24-72 h) MRI as baseline scans following brain tumour resection. We aimed to evaluate whether the final ioMRI scan could serve as the post-operative baseline scan after paediatric brain tumour resections. METHODS: This prospective study compared the final ioMRI scan with the immediate post-operative MRI scan performed 24-72 h post-surgery. We included 20 patients aged 6.6-21 years undergoing brain tumour resection using ioMRI and were suitable for MRI scan without general anaesthesia. The scans were independently evaluated by experienced local and external paediatric neuroradiologists. Identical sequences in the final ioMRI and the 24-72-h MRI were compared to assess the extent of resection, imaging characteristics of residual tumour, the surgical field, extent of surgically induced contrast enhancement, and diffusion abnormalities. RESULTS: In 20 patients undergoing intraoperative and early post-operative MRI, there was no difference between ioMRI and 24-72-h post-op scans in identifying residual tumour. Surgically induced contrast enhancement was similar in both groups. There were more abnormalities on diffusion imaging and a greater degree of oedema around the surgical cavity on the 24-72-h scan. CONCLUSION: The final 3-T ioMRI scan may be used as a baseline post-operative scan provided standard imaging guidelines are followed and is evaluated jointly by the operating neurosurgeon and neuroradiologist. Advantages of final ioMRI as a baseline scan are identified.

Evolution of surgical attitudes to paediatric thalamic tumours: the alder hey experience.

PURPOSE: Attitudes to surgery for paediatric thalamic tumours have evolved due to improved preoperative imaging modalities and the advent of intraoperative MRI (iMRI) as well as enhanced understanding of tumour biology. We review the developments in our local practice over the last three decades with particular attention to the impact of iMRI. METHODS: We identified all paediatric patients from a prospectively maintained neuro-oncology database who received surgery for a thalamic tumour (n = 30). All children were treated in a single UK tertiary paediatric neurosurgery centre between January 1991 and June 2020. Twenty patients underwent surgical resection, the remainder (10) undergoing biopsy only. Pre-operative surgical intent (biopsy versus debulking, near-total resection, or complete resection) as well as the use of iMRI were prospectively recorded. Complications recorded in clinical documentation between postoperative days 0 and 30 were retrospectively graded using a modified version of the Clavien Dindo scale. The extent of resection with respect to the pre-determined surgical aim was also recorded. Data on patient survival and disease progression status were obtained retrospectively. RESULTS: In our series, there were 42 procedures (25 craniotomies, 17 biopsies) performed on 30 patients (17 male, with a median age of 8 at surgery). Of the 25 surgical resections performed, complete resection was achieved in 9 (36%), near-total resection in 10 (40%), and limited debulking in 6 (24%). The predetermined surgical aim was achieved or exceeded in 91.3% of cases. The proportion of craniotomies for which substantial resection was achieved, increased from 37.5 to 94.2% with use of iMRI (p = 0.014). Surgical morbidity was not associated with greater extent of surgical resection. High-grade histology is identified as the only independent significant factor influencing overall survival as calculated by Cox proportional hazards model (p = 0.006). CONCLUSION: We note a significant change in the rate and extent of attempted resection of paediatric thalamic tumours that has developed over the last 3 decades. Use of iMRI is associated with a significant increase in substantial tumour resection surgeries. This is not associated with any significant level of surgical morbidity. Improvements in pre- and intra-operative imaging alongside better understanding of tumour biology facilitate patient selection and a surgically more aggressive approach in selected cases whilst maintaining safety and avoiding operative morbidity.

Efficacy and safety of the Miethke programmable differential pressure valve (proGAV®2.0): a single-centre retrospective analysis.

PURPOSE: Achieving decompression without CSF over-drainage remains a challenge in hydrocephalus. Differential pressure valves are a popular treatment modality, with evidence suggesting that incorporation of gravitational units helps minimise over-drainage. This study seeks to describe the utility of the proGAV®2.0 programmable valve in a paediatric population. METHODS: Clinical records and imaging of all patients fitted with proGAV®2.0 valves and Miethke fixed-pressure valves between 2014 and 2019 at our tertiary centre were analysed. Patient demographics, indication for shunt and valve insertion/revision and time to shunt/valve revision were collected. Ventricular linear metrics (fronto-occipital horn ratio (FOHR) and fronto-occipital horn width ratio (FOHWR)) were collected pre- and post-valve insertion. Microsoft Excel and SPSS v24 were used for data collection and statistical analysis. RESULTS: Eighty-eight proGAV®2.0 valves were inserted in a population of 77 patients (n = 45 males (58%), mean age 5.1 years (IQR: 0.4-11.0 years)). A total of 102 Miethke fixed-pressure valves were inserted over the same time period. Median follow-up was 17.5 months (1.0-47.3). One (1.1%) proGAV®2.0 was revised due to over-drainage, compared to 2 (1.9%) fixed-pressure valves (p > 0.05). ProGAV®2.0 insertion resulted in a significant decrease in the mean number of revisions per patient per year (1.77 vs 0.25; p = 0.01). Overall shunt system survival with the proGAV®2.0 was 80.4% at 12 months, and mean time to revision was 37.1 months, compared to 31.0 months (95%CI: 25.7-36.3) and 58.3% in fixed-pressure valves (p < 0.01). Significant decreases were seen following proGAV®2.0 insertion in both FOHR and FOHWR, by 0.014 (95%CI: 0.006-0.023, p = 0.002) and 0.037 (95%CI: 0.005-0.069, p = 0.024) respectively. CONCLUSION: The proGAV®2.0 provides effective decompression of hydrocephalic patients, significantly reduces the number of valve revisions per patient and had a significantly greater mean time to revision than fixed-pressure valves.

Infant hydrocephalus: what valve first?

PURPOSE: To review the use of different valve types in infants with hydrocephalus, in doing so, determining whether an optimal valve choice exists for this patient cohort. METHODS: We conducted (1) a literature review for all studies describing valve types used (programmable vs. non-programmable, valve size, pressure) in infants (≤ 2 years) with hydrocephalus, (2) a review of data from the pivotal BASICS trial for infant patients and (3) a separate, institutional cohort study from Alder Hey Children's Hospital NHS Foundation Trust. The primary outcome was any revision not due to infection. RESULTS: The search identified 19 studies that were included in the review. Most did not identify a superior valve choice between programmable and non-programmable, small compared to ultra-small, and differential pressure compared to flow-regulating valves. Five studies investigated a single-valve type without a comparator group. The BASICS data identified 391 infants, with no statistically significant difference between gravitational and programmable subgroups. The institutional data from our tertiary referral centre did not reveal any significant difference in failure rate between valve subtypes. CONCLUSION: Our review highlights the challenges of valve selection in infant hydrocephalus, reiterating that the concept of an optimal valve choice in this group remains a controversial one. While the infant-hydrocephalic population is at high risk of valve failure, heterogeneity and a lack of direct comparison between valves in the literature limit our ability to draw meaningful conclusions. Data that does exist suggests at present that there is no difference in non-infective failure rate are increasing in number, with the British valve subtypes in infant hydrocephalus, supported by both the randomised trial and institutional data in this study.

The effect of GMFCS level, age, sex, and dystonia on multi-dimensional outcomes after selective dorsal rhizotomy: prospective observational study.

PURPOSE: Investigate the effect of age category (1-9 years vs 10-18 years), sex, Gross Motor Function Classification System (GMFCS) level, and presence of dystonia on changes in eight function test parameters 24 months after selective dorsal rhizotomy (SDR). METHODS: Prospective, single-center study of all children aged 3-18 years with bilateral cerebral palsy with spasticity who underwent SDR at a tertiary pediatric neurosurgery center between 2012 and 2019. A linear mixed effects model was used to assess longitudinal changes. RESULTS: From 2012 to 2019, 42 children had follow-up available at 24 months. Mean GMFM-66 scores increased after SDR (mean difference 5.1 units: 95% CI 3.05-7.13, p < 0.001). Statistically significant improvements were observed in CPQoL, PEDI Self-care and Mobility, 6MWT, Gillette, and MAS scores. There was no significant difference in the improvements seen for age category, sex, GMFCS level, and presence of dystonia for most of the parameters tested (5/8, 6/8, 5/8, and 6/8 respectively). CONCLUSION: SDR may improve gross and fine motor function, mobility and self-care, quality of life, and overall outcome based on extensive scoring parameter testing at 24 months. Atypical patient populations may benefit from SDR if appropriately selected. Multi-center, prospective registries investigating the effect of SDR are required.

Management of paediatric hydrocephalous with Miethke fixed pressure gravitational valves. The Alder Hey Children's Hospital experience.

OBJECTIVE: The management of paediatric hydrocephalous remains challenging with the complication and revision rates being consistent in the literature. We hypothesise that the use of a fixed pressure gravitational valve for all de novo shunt insertions decreases the rate of functional revisions and that by implementing the routine use of gravitational valves in children, we would see a reduction in over-drainage and slit ventricle syndrome. METHODS: Retrospective data collection in a single centre, between February 2010 and August 2018. All patients undergoing fixed pressure gravitational Miethke valve insertion were included. We collected data on patients' demographics, reason for shunt insertion, type of valve and time to and reason for first revision. Data analysis was done with SPSS. RESULTS: A total of 235 patients were included in our study (124 males, 111 females), aged from 0 to 18.6 years (median 0.28). A total of 99 shunt revisions were documented, 30 of which secondary to ventricular catheter malfunction and 28 secondary to infection. The overall mechanical valve survival rates were 88.5%, 86.4% and 85.5% at 1, 2 and 5 years, respectively. Shunt revision due to over-drainage was documented in only 3 cases (1.3%). CONCLUSION: Our results are in agreement with existing literature regarding shunt failures secondary to all extrinsic factors to the valve (infection and mechanical failure). We have shown that the use of a Miethke fixed pressure valve for all de novo shunt insertions in paediatric hydrocephalus decreases the need for functional revisions with valve survival rates being superior to the ones described for other types.

Biopsy in diffuse pontine gliomas: expert neurosurgeon opinion-a survey from the SIOPE brain tumor group.

INTRODUCTION: The prognosis of diffuse intrinsic pontine glioma (DIPG) is poor. The role of biopsy in DIPG remains controversial since the diagnosis may be established with imaging alone. Recent advances in understanding molecular biology and targeting of brain tumors have created a renewed interest in biopsy for DIPG. The Neurosurgery Working Group (NWG) of the SIOP-Europe Brain Tumor Group (BTG) undertook a survey among international pediatric neurosurgeons to define their current perceptions and practice regarding DIPG biopsy. METHODS: The NWG developed a 20-question survey which was emailed to neurosurgeons in the International Society for Pediatric Neurosurgery (ISPN). The questionnaire included questions on diagnosis, indications, and techniques for biopsy, clinical trials, and healthcare infrastructure. RESULTS: The survey was sent to 202 neurosurgeons and 73 (36%) responded. Consensus of > 75% agreement was reached for 12/20 questions, which included (1) radiological diagnosis of DIPG is sufficient outside a trial, (2) clinical trial-based DIPG biopsy is justified if molecular targets are investigated and may be used for treatment, and (3) morbidity/mortality data must be collected to define the risk:benefit ratio. The remaining 8/20 questions proved controversial and failed to reach consensus. CONCLUSIONS: Routine DIPG biopsy continues to be debated. Most neurosurgeons agreed that DIPG biopsy within a clinical trial should be supported, with the aims of defining the procedure risks, improving understanding of tumor biology, and evaluating new treatment targets. Careful family counseling and consent remain important.

Complex Cervicomedullary Junction Malformation and Hypoplastic Cerebellar Tonsils following Fetal Repair of Myelomeningocele: Case Report and Literature Review.

BACKGROUND: Following the publication of the Management of Myelomeningocele study (MOMS), fetal repair of myelomeningocele (MMC) has become increasingly prevalent worldwide. However, limited case presentations exist illustrating the potential mechanical and embryological effects of fetal repair. We present a unique case report of a complex embryological cervicomedullary junction (CMJ) malformation and cerebellar hypoplasia following fetal repair of MMC. CASE DESCRIPTION: A 1-day-old female was referred to the paediatric neurosurgical team after having successful surgical intrauterine closure of MMC abroad at 25 weeks gestation. The patient was born by emergency caesarean section at 33 weeks gestation and had a ventricular-peritoneal shunt inserted at 25 days old due to resulting hydrocephalus. Neonatal MRI scans revealed a complex number of malformations that included a split cord located at the CMJ, hypoplasia of the cerebellum and vermis, and a Chiari type II malformation. CONCLUSION: It is possible that the clefting of the upper cervical spinal cord was undetected at preoperative MRI; however, this is unlikely given the antenatal images. It is our hypothesis that the malformation may have exhibited mechanical change after the repair, as the preoperative MRI showed only a Chiari II malformation without any of the complex abnormalities being present and the split cord was already there but not obvious. There are no existing reports of such a complex malformation following antenatal surgery in the literature. This should be further explored as more cases and trials become available.

The benefit of surveillance imaging for paediatric cerebellar pilocytic astrocytoma.

OBJECTIVES: Paediatric cerebellar pilocytic astrocytomas (PA) (WHO grade 1) are amongst the most common of childhood brain tumours and are generally amenable to resection, with surgery alone being curative in the majority of cases. There is, however, a lack of consensus regarding the frequency and duration of post-treatment MRI surveillance for these tumours. This is important, as follow-up imaging is a significant use of resources and often associated with patient and family anxiety. We have assessed the utility of MRI surveillance in the detection of cerebellar PA recurrence at our regional paediatric neurosurgical centre. MATERIALS AND METHODS: The tumour register at Alder Hey Children's Hospital was searched to identify all patients diagnosed between 2007 and 2017, with a confirmed histopathological diagnosis of cerebellar PA. Patient demographics, surgical outcome, number of MRI scans and length of follow-up were recorded for each patient. RESULTS: Forty patients met the inclusion criteria. The mean age at diagnosis was 7.8 years (range 2 to 17 years). Complete surgical resection (CR), confirmed by post-operative MRI, was achieved in 36 of the 40 patients, including all 31 cases from 2009 and later for which intraoperative MRI (iMRI) was utilised. There was one case of recurrence after CR (at 2.2 years) out of the 36 cases, whereas all 4 patients with initial partial resections had progressive growth of their tumours and required second surgical interventions. CONCLUSION: This series confirms the very low likelihood of recurrence for completely resected cerebellar PAs and suggests that in such cases the duration and frequency of surveillance imaging could be limited to a maximum of 2.5 to 3 years of follow-up imaging. This report also indicates improved complete resection rates over time, probably associated with technical advances including the routine in-house use of iMRI in 2009.

Tumour compartment transcriptomics demonstrates the activation of inflammatory and odontogenic programmes in human adamantinomatous craniopharyngioma and identifies the MAPK/ERK pathway as a novel therapeutic target.

Adamantinomatous craniopharyngiomas (ACPs) are clinically challenging tumours, the majority of which have activating mutations in CTNNB1. They are histologically complex, showing cystic and solid components, the latter comprised of different morphological cell types (e.g. ß-catenin-accumulating cluster cells and palisading epithelium), surrounded by a florid glial reaction with immune cells. Here, we have carried out RNA sequencing on 18 ACP samples and integrated these data with an existing ACP transcriptomic dataset. No studies so far have examined the patterns of gene expression within the different cellular compartments of the tumour. To achieve this goal, we have combined laser capture microdissection with computational analyses to reveal groups of genes that are associated with either epithelial tumour cells (clusters and palisading epithelium), glial tissue or immune infiltrate. We use these human ACP molecular signatures and RNA-Seq data from two ACP mouse models to reveal that cell clusters are molecularly analogous to the enamel knot, a critical signalling centre controlling normal tooth morphogenesis. Supporting this finding, we show that human cluster cells express high levels of several members of the FGF, TGFB and BMP families of secreted factors, which signal to neighbouring cells as evidenced by immunostaining against the phosphorylated proteins pERK1/2, pSMAD3 and pSMAD1/5/9 in both human and mouse ACP. We reveal that inhibiting the MAPK/ERK pathway with trametinib, a clinically approved MEK inhibitor, results in reduced proliferation and increased apoptosis in explant cultures of human and mouse ACP. Finally, we analyse a prominent molecular signature in the glial reactive tissue to characterise the inflammatory microenvironment and uncover the activation of inflammasomes in human ACP. We validate these results by immunostaining against immune cell markers, cytokine ELISA and proteome analysis in both solid tumour and cystic fluid from ACP patients. Our data support a new molecular paradigm for understanding ACP tumorigenesis as an aberrant mimic of natural tooth development and opens new therapeutic opportunities by revealing the activation of the MAPK/ERK and inflammasome pathways in human ACP.

The impact of intraoperative magnetic resonance in routine pediatric neurosurgical practice-a 6-year appraisal.

BACKGROUND: The intraoperative magnetic resonance scanner (ioMR) was introduced in our unit in 2009, and has been used routinely since then. OBJECTIVE: This study aims to describe indications, radiological features, and clinical outcomes of the patients operated on with ioMRI and analyze our experience. METHODS: A retrospective analysis of a prospective surgical database has been performed, including surgical procedure, intent, radiological reports, need for second-look surgery, and complications, supplemented by further review of the clinical notes and the scans. RESULTS: From 2009 to 2015, 255 surgical procedures with ioMR were performed: 175 were craniotomies for tumor excision, 65 were epilepsy related, and 15 were biopsies or cyst drainages. The mean age was 9.4 years. One ioMR was performed in 79.5% patients; the mean duration of the MR was 41 min. In 172 cases (67.4%), no actions followed the ioMR. When the aim of the surgery was debulking of the tumor, the percentage of patients in which the ioMR was followed by resection was higher than when complete resection was the aim (56 vs 27.5%). The complication rate was not increased when compared with our previous results (infection 1%, neurological deficits 12%). CONCLUSION: This is the largest published series of ioMRI-aided pediatric neurosurgery to date. We have demonstrated that it can be used safely and routinely in pediatric neurosurgical procedures at any age, assisting the surgeon in achieving the best extent of resection and aiding in intra-operative decision-making for tumor- and non-tumor-related intracranial pathology.

Neonatal post-haemorrhagic hydrocephalus in the UK: a survey of current practice.

OBJECTIVES: The management of neonatal post-haemorrhagic hydrocephalus (nPHH) varies considerably between centres and even between neurosurgeons in the same centre. We performed a nationwide survey to evaluate current practice in the UK and reviewed the evidence for each intervention. METHODS: An online semi-structured questionnaire was emailed to all units registered on the British Paediatric Neurosurgery Group Mailing List. The survey consisted of 18 questions designed to establish the status quo in the management of nPHH, including preferred temporising procedure, factors guiding the timing of intervention and willingness to participate in a prospective study. RESULTS: A total of 24 consultants responded to the survey. Ventricular access device (VAD), trans-fontanelle tap, ventriculosubgaleal shunt (VSGS) and lumbar puncture (LP) were used by 33, 25, 17 and 17%, respectively, as the first temporising measure. Almost all reported that the timing of this intervention was guided by increasing head circumference and tense fontanelle. If the first temporising procedure fails, VAD, external ventricular drainage (EVD), trans-fontanelle tap, VSGS and other procedures (including ventriculoperitoneal (VP) shunting and endoscopic third ventriculostomy (ETV)) were performed by 42, 17, 13, 8 and 21%, respectively. Almost all respondents reported that VP shunting would be their preferred method of definitive cerebrospinal fluid (CSF) diversion. Almost all responded that they would be willing to participate in a prospective study in the future to determine best practice. CONCLUSION: As expected there was a significant heterogeneity between respondents in the initial management of nPHH in the UK. VAD was the most popular first and second choice temporising measure. On reviewing the literature, it is clear that more work still needs to be done to establish which temporising measure is best. There is willingness in the UK to participate in a study to help determine this.