Retroflexed dens in paediatric Chiari 1 patients and implications: Single centre retrospective study.

INTRODUCTION: Chiari 1 malformation and hind brain hernia can be associated with skull base and craniocervical anomalies. One of the more recently associated anomalies is a retroverted or retroflexed odontoid process or dens. We conducted a retrospective study of our operated symptomatic and conservatively managed asymptomatic Chiari cohort to assess the impact of dens retroflexion on rate of revision or cerebrospinal fluid diversion following primary foramen magnum decompression (FMD). METHODS: We undertook a retrospective study of all foramen magnum decompression (FMD) cases for Chiari type 1 malformation performed over a 15-year period in a single tertiary paediatric neurosurgical unit. For comparison, non-operated asymptomatic Chiari cases were considered as reference cohort. Information gathered included: demographics, age, sex, length of cerebellar tonsils below McRae's line, pB-C2 distance (a line drawn perpendicular to one drawn between the basion and the posterior aspect of the C2 body), angle of retroflexion (angle formed between a line drawn through the odontoid synchondrosis and its intersection with a line drawn from the tip of the odontoid process) and angle of retroversion (angle formed between the line drawn from the base of C2 and its intersection with a line drawn from the tip of the odontoid process). Grade of retroflexion was measured using pre-operative mid-sagittal MR images and classified as grade 0 (> 90°), grade 1 (85°-89°); grade 2 (80°-84°) and grade 3 (< 80°). The rates for redo surgery or need for cerebrospinal fluid (CSF) diversion were obtained from clinical records and compared in the operated and non-operated groups. RESULTS: One hundred twenty-six Chiari 1 patients were included in this study with adequate imaging. Sixty-five patients were in the non-operated asymptomatic cohort with 61 patients in the operated symptomatic cohort. Mean age of non-operated cohort was 10.2 years with M:F ratio (30:35). Mean cerebellar tonsillar length below McRae's line was 10.3 mm. 7.7% of this cohort had associated syrinx. Mean angles of retroversion and retroflexion were 76 and 78°, respectively. Retroflexion grades included (9.2% grade 1, 35% grade 2 and 52.3% grade 3). pB-C2 distance was 6.8 mm. Mean age of operated cohort was 11.3 years, with M:F ratio (21:40). Mean cerebellar tonsillar length below McRae's line was 15 mm. 45.9% of this cohort had associated syrinx. Mean angles of retroversion and retroflexion were 73 and 74.5°, respectively. Retroflexion grades included (4.9% grade 1, 16.5% grade 2 and 78.6% grade 3). pB-C2 distance was 6.9 mm. No association was identified between retroflexion grade and rate of revision or CSF diversion following primary foramen magnum decompression. CONCLUSION: The operated Chiari 1 cohort had more retroflexed dens, longer tonsils and associated syrinx compared to the non-operated asymptomatic cohort.

Transcallosal approach and post-operative subdural collections: 12-year paediatric neurosurgery tertiary centre experience.

INTRODUCTION: Following transcallosal surgery for tumour resection, the formation of convexity or interhemispheric subdural cerebrospinal fluid collections may lead to clinical deterioration and may influence decision-making with regards to additional interventions. The aim of this study was to determine the incidence, risk factors, and management of subdural collections following the transcallosal approach in a paediatric cohort. METHODS: A retrospective case note and radiological review of all children who underwent transcallosal surgery for intraventricular and thalamic tumours was carried out covering a 12-year period (2012-2023) in a single-centre tertiary paediatric neurosurgery unit. Parameters including demographics and clinical information including lesion location, pathology, extent of resection, need for and type of shunt required, as well as depth, laterality, and location of the collection were analysed prior to shunting, and at approximately 3 weeks, 3 months, and latest follow-up available post-operatively in order to further elucidate the natural history of these subdural collections and their clinical significance. RESULTS: Sixty-four cases satisfied the inclusion criteria of transcallosal surgery for tumour resection; 13 did not have adequate post-operative imaging and were excluded. Of the remaining 51 cases, there were 32 children (63%) with post-operative CSF subdural collections, of which 59% were ipsilateral, with the remainder showing bilateral distribution. The overall shunt insertion rate was 25.5% (12 ventriculoperitoneal and 1 subdural-peritoneal shunt) at 3 months, with a mean time to shunting of 19 days post-operatively. Children who developed post-operative subdural collections had a higher rate of shunting, at 37.5%, compared to 5.2% in those who did not. Pre- and post-operative hydrocephalus and subtotal resection were identified as risk factors for development of subdural collections post-operatively. Subdural collections showed a natural course of reduction and regression over follow-up, with the exception of 3 children where they persisted or increased over time; although none of these required shunting. Those children who underwent shunt insertion showed greater regression in the size of the subdural collection over time compared to the non-shunted group. CONCLUSION: In this paediatric cohort, 25.5 % of children required insertion of a shunt by 3 months following transcallosal surgery. Pre- and post-operative hydrocephalus and subtotal tumour resection were risk factors for development of subdural collections post-operatively.

Interpretation of telemetric intracranial pressure recordings in people with idiopathic intracranial hypertension after shunt implantation.

BACKGROUND: The M.scio telesensor (Aesculap-Miethke, Germany) is a device integrated within a ventriculoperitoneal (VP) shunt for non-invasive measurement of the intracranial pressure (ICP). The purpose of this study was to analyze the telemetric recordings with the M.scio system in shunted patients with idiopathic intracranial hypertension (IIH), in order to determine reference values and assist the interpretation of telemetric data. METHODS: This was a cohort study of consecutive patients with fulminant IIH who underwent primary VP shunt insertion between July 2019 and June 2022. The first telemetric measurements after surgery in the sitting and supine positions were analyzed. Telemetric ICP values, wave morphology, and pulse amplitude were determined for functioning and malfunctioning shunts. RESULTS: Fifty-seven out of 64 patients had available telemetric recordings. The mean ICP was - 3.8 mmHg (standard deviation (SD) = 5.9) in the sitting and 16.4 mmHg (SD = 6.3) in the supine position. The ICP curve demonstrated pulsatility in 49 (86%) patients. A pulsatile curve with mean ICP in the above ranges indicated a functioning shunt, whereas the lack of pulsatility was challenging to interpret. There was a significant positive correlation between ICP versus amplitude, ICP versus body mass index (BMI), and amplitude versus BMI. CONCLUSIONS: This clinical study defined ICP values and curves in IIH patients with a shunt. The results will assist the interpretation of telemetric ICP recordings in clinical decision making. More research is required to model longitudinal recordings and explore the link between telemetric measurements with clinical outcomes.

Molecular subgroup of medulloblastoma: evaluation of contribution to CSF diversion following tumour resection.

INTRODUCTION: Medulloblastoma is the commonest malignant brain tumour in children. Pre-operative hydrocephalus is present in up to 90% of these patients at presentation. Following posterior fossa surgery, despite resolution of fourth ventricular obstruction, a proportion of these children will still require cerebrospinal fluid (CSF) diversion for management of persistent or new hydrocephalus. Various scoring systems have been developed to predict the risk for CSF diversion following posterior fossa surgery. However, no accurate tool exists regarding which pathological subset or group of medulloblastoma patients will require a shunt post-operatively. In this study we investigated the impact of molecular subgroup of medulloblastoma on shunt dependency post-operatively in paediatric patients. METHODS: We undertook a retrospective multi-centre study of children with medulloblastoma who underwent tumour resection. Those with available molecular subgroup were identified. Demographic data and clinical parameters including age, sex, presence of pre-operative hydrocephalus, extent of surgical resection, evidence of metastasis/leptomeningeal disease and need for CSF diversion post-operatively were further analysed. RESULTS: Sixty-nine children with medulloblastoma with available molecular data were identified during the study period with male to female ratio of 1.5:1 (42M:27F). Twelve patients (17.4%) belonged to SHH, 10 (14.5%) Wnt, 19 (27.5%) Group 3 and 15 (21.7%) Group 4; 13 (18.8%) were non-specified Group 3 or 4. A total of 18 (26%) patients had evidence of leptomeningeal disease at presentation (20% of Wnt, 42% of Group 3, 33% of group 4, 23% of group 3/4, and 0% of SHH). Fifteen patients (22%) underwent post-operative ventriculoperitoneal (VP) shunt insertion. No patient in the Wnt group required ventriculoperitoneal (VP) shunt post-operatively in this cohort. Need for shunt was associated with pre-operative hydrocephalus, leptomeningeal disease, with molecular group 3 or 4 demonstrating higher rate of leptomeningeal disease, and pre-operative hydrocephalus. Age, extent of resection and pre-operative EVD were not associated with need for shunt in this cohort. Regression analysis identified only pre-operative hydrocephalus and leptomeningeal disease as independent predictors of need for shunt post-resection in this cohort. CONCLUSION: All patients requiring permanent post-operative VP shunt belonged to non-Wnt groups, particularly group 3 and 4. Although medulloblastoma subgroup does not independently predict need for post-operative shunt, presence of leptomeningeal disease and pre-operative hydrocephalus, and their higher prevalence in group 3 and 4, likely account for observed higher rate of shunting in these groups.

Spinal canal stenosis in children with achondroplasia: the role of augmentation laminoplasty-a 15-year single institution experience.

PURPOSE: Achondroplasia typically results in compressive spinal canal stenosis in one-third of children, but rare under the age of 15 years. Laminectomy is the mainstay of treatment but this leads to instability and progressive deformity requiring complex fixation. In order to reduce that risk, we developed a novel modified augmented laminoplasty that increases spinal canal diameter while preserving the posterior column stability. METHODS: All laminoplasty cases for spinal compressive achondroplasia from 2006 to 2020 were included. Ten augmentation laminoplasty procedures were performed in 7 children with regular clinical and radiological post-operative follow-up. Kyphotic deformity and clinical outcomes (neurological and urological) were evaluated. RESULTS: At presentation, clinical features included radiculopathy, neurogenic claudication or acute cauda equina compression with sphincter dysfunction. The average age at initial surgery was 11.2 (range 5-16) with a mean follow-up of 5 (range 2-8) years. All patients demonstrated improvement in neurogenic claudication symptoms after surgery; however, bladder dysfunction persisted in some children. In one child, cervical and lumbar augmentation laminoplasties were performed for concomitant disease. Augmentation laminoplasty effectively prevented deformity progression over time in all cases except one where a further revision laminoplasty with extension was required for screw loosening. Despite this, progressive symptomatic kyphotic deformity led to a 360° fixation. Minor complications included one dural breach (repaired intraoperatively) and one superficial wound infection. CONCLUSION: Augmentation laminoplasty is a viable surgical option following laminectomy in achondroplasia patients as an alternative to surgical fixation. Fixation can be reserved for cases where there is progressive deformity and kyphosis.

ERF-related craniosynostosis and surgical management in the paediatric cohort.

INTRODUCTION: ERF mutation is one of the most recently identified genetic aberrations associated with syndromic craniosynostosis. Data on the pattern of craniosynostosis, surgical management of ERF-related craniosynostosis and outcomes is limited. We report on our single-centre experience in paediatric cohort of patients with syndromic craniosynostosis secondary to ERF mutation. METHODS: A retrospective review of all paediatric craniofacial cases was performed over an 8-year period (2014-2022). All patients with genetically confirm ERF-related craniosynostosis were identified, and clinical parameters including, age, sex, pattern of craniosynostosis, associated tonsillar herniation and follow-up period were further analysed from electronic clinical and imaging systems. All patients were selected and discussed in multidisciplinary craniofacial meeting (composed of neurosurgical, maxillofacial, plastics and genetics teams) prior to any surgical intervention. RESULTS: Overall, 10 patients with ERF-related craniosynostosis were identified with a male-to-female ratio of 4:1 with mean age at the time of surgery of 21.6 months with a mean follow-up period of 5.2 years. ERF-confirmed cases led to variable craniosynostosis pattern with multi-sutural synostosis with concurrent sagittal and bilateral lambdoid involvement as the most common pattern (7/10). No patient pre-operatively had evidence of papilloedema on ophthalmological assessment. Eight out of 10 patients had associated low-lying tonsils/hind brain hernia pre-operatively. Eight out of 10 patients required surgery which included 2 fronto-orbital advancement, 3 calvarial remodelling, 2 posterior calvarial remodelling/release and 1 insertion of ventriculoperitoneal shunt. CONCLUSION: Involvement of sagittal and lambdoid sutures is the most common pattern of craniosynostosis. ERF-related craniosynostosis can have variable pattern of suture fusion, and management of each patient requires unique surgical planning and execution based on clinical needs for the optimal outcomes.

Myasthenia gravis complicating the surgical management of achondroplasia: a case-based update.

BACKGROUND: Achondroplasia is the commonest skeletal dysplasia of autosomal dominant inheritance caused by "gain of function" mutations in the fibroblast growth factor receptor 3 (FGFR3) gene. Foramen magnum compression due to accelerated ossification and spinal canal stenosis secondary to reduced interpedicular distance is a hallmark of achondroplasia, driven by G380R nucleotide pair substitution. In severe cases, limb weakness and neurogenic claudication will require surgical decompression. Rarely, a neurological condition may mimic the compressive spinal dysfunction and therefore, non-surgical causes must also be considered in cases of acute neurological deterioration in children with achondroplasia. Myasthenia gravis (MG) is an autoimmune condition resulting in fatigable muscle weakness. There are no reported cases of myasthenia gravis in achondroplasia in the literature. RESULTS: We report a child with achondroplasia scheduled for decompressive surgery for severe lumbar canal stenosis presenting with neurological claudication and knee weakness. While waiting for surgery during the COVID-19 pandemic, she developed generalized fatigability and severe weakness raising concerns of acute worsening of cord compression. Urgent investigations ruled out spinal cord compression but identified an unexpected concurrent myasthenia gravis with positive antibodies to acetylcholine receptors. The surgical intervention was postponed averting the potential risk of life-threatening anaesthetic complications. She was successfully managed with a combination of pyridostigmine, steroids, azathioprine, and plasma exchange. CONCLUSION: We report the first case of myasthenia gravis in achondroplasia and review implications in the management.

Tectal Plate Gliomas Masquerading as Idiopathic Aqueduct Stenosis.

Aqueduct stenosis is a recognized cause of obstructive hydrocephalus in children and can be treated effectively with endoscopic third ventriculostomy. Preoperative magnetic resonance imaging is often diagnostic of the cause of aqueduct stenosis. We describe 2 pediatric cases with obstructive hydrocephalus secondary to a working diagnosis of idiopathic aqueduct stenosis. Following successful endoscopic third ventriculostomy, repeat magnetic resonance brain imaging revealed tectal plate glioma as the primary cause of obstruction. We believe these 2 reported cases demonstrate a previously unreported phenomenon whereby concealed tectal gliomas presenting with hydrocephalus are only unmasked following relief of hydrocephalus and decompression and normalization of the ventricular system. We aim to raise awareness about this unusual phenomenon and recommend routine postoperative interval imaging following endoscopic third ventriculostomy to avoid missing underlying pathology masquerading as aqueduct stenosis.

Posterior Calvarial Distraction in older paediatric population: single centre paediatric neurosurgery craniofacial unit outcomes.

PURPOSE: Posterior calvarial distraction (PCD) is a safe and effective technique used to increase cranial vault volume and therefore reduce intracranial pressure in children with complex craniosynostosis. Optimal timing and method used for PCD is controversial. This procedure is usually performed in children younger than 2 years. Literature regarding calvarial distraction in older children is sparse and limited. We report our single-centre experience with PCD in children aged 6 and above to outline the applications, benefits and challenges of employing this technique in an older paediatric population. METHODS: A retrospective analysis of a database on craniofacial cases from 2006 to 2021 was performed. Patients undergoing PCD were identified and children aged 6 and above at the time of operation were included. Data on demographics and clinical outcomes were obtained from electronic records and relevant imaging was reviewed. All cases were reviewed prior to a decision for surgery by the multidisciplinary craniofacial team (composed of neurosurgery, maxillofacial and plastics teams) and underwent surgery in our paediatric craniofacial centre. RESULTS: Overall, 98 PCD cases were identified during the study period, of which 20 cases were identified as having undergone PCD at age 6 or above with mean age of 8.8 years (range 6-18). The most common indication was pansynostosis associated with raised intracranial pressure. Four cases had calvarial remodelling previously and represented with symptoms of raised intracranial pressure sometime after their initial surgery requiring PCD as rescue procedure. Average duration of inpatient stay was 5.85 days. The average duration of follow-up was 3.5 years (0.3 to 11 years). Mean distraction distance achieved was 22.5 mm (18-29 mm). Five patients experienced complications related to wound infection or distractor. Follow-up assessment in all patients demonstrated evidence of vault expansion and symptomatic improvement and resolution of intracranial pressure signs. Comparison with younger cohort did not reveal any difference in any parameters except lower rate of transfusion in the older cohort compared to young cohort (5% vs 38%). CONCLUSION: Posterior calvarial distraction in older children is safe and effective for vault expansion and treatment of raised intracranial pressure in selected cases. A multidisciplinary craniofacial team approach is crucial for appropriate case selection and management in order to optimise outcomes.

UK Chiari 1 Study: protocol for a prospective, observational, multicentre study.

INTRODUCTION: Chiari 1 malformation (CM1) is a structural abnormality of the hindbrain characterised by the descent of the cerebellar tonsils through the foramen magnum. The management of patients with CM1 remains contentious since there are currently no UK or international guidelines for clinicians. We therefore propose a collaborative, prospective, multicentre study on the investigation, management and outcome of CM1 in the UK: the UK Chiari 1 Study (UKC1S). Our primary objective is to determine the health-related quality of life (HRQoL) in patients with a new diagnosis of CM1 managed either conservatively or surgically at 12 months of follow-up. We also aim to: (A) determine HRQoL 12 months following surgery; (B) measure complications 12 months following surgery; (C) determine the natural history of patients with CM1 treated conservatively without surgery; (D) determine the radiological correlates of presenting symptoms, signs and outcomes; and (E) determine the scope and variation within UK practice in referral patterns, patient pathways, investigations and surgical decisions. METHODS AND ANALYSIS: The UKC1S will be a prospective, multicentre and observational study that will follow the British Neurosurgical Trainee Research Collaborative model of collaborative research. Patients will be recruited after attending their first neurosurgical outpatient clinic appointment. Follow-up data will be collected from all patients at 12 months from baseline regardless of whether they are treated surgically or not. A further 12-month postoperative follow-up timepoint will be added for patients treated with decompressive surgery. The study is expected to last three years. ETHICS AND DISSEMINATION: The UKC1S received a favourable ethical opinion from the East Midlands Leicester South Research Ethics Committee (REC reference: 20/EM/0053; IRAS 269739) and the Health Research Authority. The results of the study will be published in peer-reviewed medical journals, presented at scientific conferences, shared with collaborating sites and shared with participant patients if they so wish.

Utility of Arterial Spin Labeling Magnetic Resonance Imaging in Differentiating Sellar Region Meningiomas from Pituitary Adenomas.

BACKGROUND: Differentiating sellar region meningiomas from pituitary adenomas on standard magnetic resonance imaging (MRI) sequences can be difficult. Arterial spin labeling (ASL) is a noninvasive technique of magnetic resonance perfusion imaging. The range of applications of ASL in neurosurgery has increased, and the information provided can be unique and complementary to other MRI sequences. Here we investigate the utility of ASL MRI in differentiating between sellar region meningiomas and pituitary adenomas. METHODS: This was a retrospective comparison of quantitative assessments on absolute and normalized tumor blood flow in histologically proven meningiomas versus pituitary adenomas. RESULTS: A total of 15 patients with sellar region lesions were identified, including 9 meningiomas and 6 pituitary adenomas. Mean absolute tumor blood flow and normalized tumor blood flow were significantly higher in meningiomas (131 mL/100 g/min and 2.22) than adenomas (47 mL/100 g/min and 0.92; P < 0.05). CONCLUSIONS: ASL MRI is a useful adjunct sequence in differentiating sellar region meningiomas, which exhibit high perfusion, from pituitary adenomas, which exhibit relatively low perfusion.

The 'transverse guard' wound dressing technique to reduce faecal contamination after spinal surgery in neonates and infants.

Wound care following lower spinal surgery in infants, especially open lumbosacral myelomeningocele (MMC) repair is challenging for a number of reasons: the babies' small size, uneven contour of the natal cleft, proximity of the wound to the perianal area, continuous soiling by loose/poorly-formed stool, and fragile skin. Faecal contamination of the wound can lead to infection, ascending meningitis and further morbidity. A single adhesive dressing does not reliably obliterate the space in the natal cleft and, therefore, does not prevent faecal material tracking rostrally underneath the dressing. This increases the risk of contamination and necessitates frequent wound dressing changes. The authors describe the use of the 'transverse guard', a simple technique routinely used in their unit that help overcome these problems. They also report on the wound infection rates of neonates undergoing open MMC repair who had the new dressings versus those who had conventional dressings.

Posterior Calvarial Augmentation for Chiari Malformation Type 1 Refractory to Foramen Magnum Decompression.

BACKGROUND: Chiari 1 malformation is a structural abnormality of the hindbrain and posterior fossa characterized by herniation of the cerebellar tonsils through the foramen magnum. Although asymptomatic in some cases, hindbrain herniation can be associated with disruption of cerebrospinal fluid flow dynamics at the craniovertebral junction and syrinx formation, leading to symptoms. Foramen magnum decompression with or without duraplasty has been the most commonly performed surgical procedure in the management of this condition. The management of syringomyelia associated with Chiari malformation is more challenging and controversial. Although the associated syrinx can significantly improve after craniovertebral decompression and restoration of cerebrospinal fluid flow, in some cases, it will persist despite decompressive surgery and could even continue to enlarge. CASE DESCRIPTION: We have described the case of a 4-year-old boy with non-craniosynostotic Chiari malformation and extensive cervical syrinx who, despite foramen magnum decompression and further revision, continued to deteriorate clinically and radiologically. Posterior calvarial augmentation was performed as a salvage procedure, with resolution of the tonsillar herniation and syrinx. CONCLUSIONS: Posterior calvarial augmentation is a viable option for patients with Chiari malformation refractory to foramen magnum decompression.

Paediatric spondylodiscitis: a 10-year single institution experience in management and clinical outcomes.

PURPOSE: Discitis in the paediatric population poses diagnostic challenges due to non-specific presenting symptoms and difficulty with expressing pain in non-communicating children. Discitis remains a relatively rare condition in the paediatric population and previous reports are limited to small cohorts. In this article, we report our experience in management of discitis over a 10-year period and review the literature on this topic. METHODS: We retrospectively reviewed cases of paediatric discitis/spondylodiscitis over a 10-year period between 2008 and 2018 managed in our regional paediatric neurosurgery unit. Relevant demographic information, microbiological data, blood investigation profile, antibiotic treatment duration and clinical outcomes were interrogated from clinical notes and electronic databases and further analysed. RESULTS: Overall, 21 cases of paediatric discitis were identified from year 2008 to 2018 with a female to male ratio of 1.3:1. The mean age at presentation was 4.3 years (range 1 to 15 years). Overall, there were 19 cases of lumbosacral/lumbar, 1 thoracic and 1 cervical discitis. The mean duration of follow-up was 20 months (range 6 to 69 months). The most common presenting features were back pain and refusal to walk/sit or weight bear. Erythrocyte sedimentation rate (ESR) was found to be more sensitive than C-reactive protein (CRP) (sensitivity 78% versus 38%) in our cohort. Computer tomography (CT)-guided biopsy was performed in five cases and only one of these was positive (20%). All patients were treated with intravenous antibiotics with resolution of discitis. CONCLUSIONS: Presentation of discitis in children can be non-specific and requires high index of suspicion. CT-guided biopsy in our cohort revealed a low rate of positive cultures. Despite negative blood cultures and CT-guided biopsy results, empirical intravenous antibiotics were effective in treating discitis successfully. In our cohort, low yield of CT-guided biopsy does not support its use on each case and this may be reserved for cases resistant to antimicrobial therapy or concerns regarding other pathology mimicking infection. Better understanding and awareness of this condition and its pathophysiology can lead to timely imaging, diagnosis and treatment.

Endoscopic endonasal surgery for Clival Chordomas - a single institution experience and short term outcomes.

Purpose: Clival Chordomas are locally aggressive tumours which pose a significant treatment challenge. Endoscopic endonasal approach for clival chordomas is correlated with higher resection rates and lower morbidity rates in comparison to open approaches. We present our initial single institution experience and short-term patient outcomes following endoscopic endonasal approach for resection of clival chordomas. Materials and methods: This is a retrospective analysis of ten patients undergoing endoscopic endonasal approach for clival chordomas in our neurosurgical unit over a 6 year period between August 2010 and September 2016. The procedures were performed using two surgeons, four hands, binostril endoscopic endonasal approach with a Karl Storz® endoscope and intraoperative BrainLab® image guidance. Results: Overall 15 endoscopic endonasal approach resections of clival chordoma were performed in 10 patients with median follow up period of 39.5 months (range 9-76). Gross total resection was achieved in 4 cases (40%), near total resection in 4 cases (40%) and subtotal resection in 2 cases (20%). 5 cases (50%) required revision resections. Cerebrospinal fluid leak occurred in 2 patients. 1 case of meningitis occurred in a patient with revision surgery. There were no new neurological deficits post operatively with 3 patients demonstrating resolution of diplopia post operatively. No recurrence occurred following gross total resection. 1 out of 4 cases of near total resection showed evidence of progression during the follow up period. Both cases of subtotal resection demonstrated evidence of progression with one dying of unrelated cause during the follow up period. Conclusion: Endoscopic endonasal approach represents a safe technique for debulking and resection of clival chordomas. Due to the rarity of clival chordomas, it is important that patients with this pathology are managed in high volume skull base centres where a multi-disciplinary team approach is available.

Salvage of cervical motor radiculopathy using peripheral nerve transfer reconstruction.

Purpose: Motor nerve transfer surgery involves re-innervation of important distal muscles using either an expendable motor branch or a fascicle from an adjacent functioning nerve. This technique is established as part of the reconstructive algorithm for traumatic brachial plexus injuries. The reproducible outcomes of motor nerve transfer surgery have resulted in exploration of the application of this technique to other paralysing conditions. The objective of this study is to report feasibility and increase awareness about nerve transfer as a method of improving upper limb function in patients with cervical motor radiculopathy of different aetiology. Results: In this case series we report 3 cases with different modes of injury to the spinal nerve roots with significant and residual motor radiculopathy that have been successfully treated with nerve transfer surgery with good functional outcomes. The cases involved iatrogenic nerve root injury, tumour related root compression and degenerative root compression. Conclusion: Nerve transfer surgery may offer reliable reconstruction for paralysis when there has been no recovery following a period of conservative management. However the optimum timing of nerve transfer intervention is not yet identified for patients with motor radiculopathy.

A practical guide to the use of anti-epileptic drugs by neurosurgeons.

Initiation of anti-epileptic drugs is increasingly relevant to daily neurosurgical practice. Intracranial pathologies ranging from brain tumours to subarachnoid haemorrhage and traumatic brain injury are commonly associated with the subsequent development of seizures. The scope and range of anti-epileptic drugs available has increased dramatically in recent years and understanding the evidence base behind this class of drugs in addition to their interaction/side effect profiles is essential. In this review we aim to generate a practical guide for neurosurgeons regarding the use of different anti-epileptic medications in common neurosurgical conditions, including considerations for their use in pregnancy.

Proposal for establishment of the UK Cranial Reconstruction Registry (UKCRR).

BACKGROUND: The increasing utilisation of decompressive craniectomy for traumatic brain injury and stroke has led to an increase in the number of cranioplasties undertaken. Cranioplasty is also undertaken following excision of tumours originating from or invading the skull vault, removal of bone flaps due to post-operative infection, and decompressive craniectomy for the management of rarer causes of brain oedema and/or refractory intracranial hypertension. The existing literature which mainly consists of single-centre, retrospective studies, shows a significant variation in practice patterns and a wide range of morbidity. There also exists a need to measure the outcome as perceived by the patients themselves with patient reported outcome measures (PROMs; functional outcome, quality of life, satisfaction with cosmesis). In the UK, the concept of long-term surveillance of neurosurgical implants is well established with the UK shunt registry. Based on this background, we propose to establish the UK Cranial Reconstruction Registry (UKCRR). AIM: The overarching aim of the UKCRR is to collect high-quality data about cranioplasties undertaken across the UK and Ireland in order to improve outcomes for patients. METHODS: Any patient undergoing reconstruction of the skull vault with autologous bone, titanium, or synthetic material in participating units will be eligible for inclusion. Data will be submitted directly by participating units to the Outcome Registry Intervention and Operation Network secure platform. A Steering Committee will be responsible for overseeing the strategic direction and running of the UKCRR. OUTCOME MEASURES: These will include re-operation due to a cranioplasty-related issue, surgical site infection, re-admission due to a cranioplasty-related issue, unplanned post-operative escalation of care, adverse events, length of stay in admitting unit, destination at discharge from admitting unit, mortality at discharge from admitting unit, neurological status and PROMs during routine follow-up. CONCLUSION: The UKCRR will be an important pillar in the ongoing efforts to optimise the outcomes of patients undergoing cranioplasty.

Diffuse cerebral vasospasm following resection of a hypoglossal schwannoma in a child.

Diffuse cerebral vasospasm is a rare complication following tumour resection. This phenomenon seems to be even rarer in the paediatric population and more so following resections of posterior fossa tumours. Here we report diffuse cerebral vasospasm in a child with hypoglossal nerve Schwannoma eight days following resection of the tumour.

Isolated hypoglossal schwannoma in a 9-year-old child.

The authors report a case of an isolated schwannoma of left hypoglossal nerve in a 9-year-old girl. To the authors' knowledge, this is the first case report of hypoglossal nerve schwannoma in the pediatric population in the absence of neurofibromatosis Type 2. The patient presented with a 2-month history of morning nausea and vomiting with occasional daytime headaches. Magnetic resonance imaging and subsequent CT scanning revealed a dumbbell tumor with a belly in the lower third of the posterior fossa and head underneath the left jugular foramen. Its neck protruded through an expanded hypoglossal canal. Although the lesion bore radiological characteristics of a hypoglossal schwannoma, the absence of hypoglossal palsy and the apparent lack of such tumors in the pediatric population the preoperative diagnosis was not certain. The tumor was approached via a midline suboccipital craniotomy, and gross-total resection was achieved. Pathological examination confirmed the diagnosis of schwannoma. Blood and tumor tests for mutations in the NF2 gene were negative. Postoperative mild hypoglossal palsy recovered by the 3-month follow-up, and an MRI study obtained at 1 year did not show recurrence.