Management of cervical CSF-venous fistula causing acute cognitive impairment and coma.

CSF-venous fistulas (CVFs) are increasingly recognised as a cause of spontaneous intracranial hypotension. They may present atypically including with brain sagging pseudo-dementia. Cervical CVFs are rare and their management can be difficult due to associated eloquent nerve roots. We report the case of a 49-year-old woman who presented with cognitive decline progressing to coma. Brain imaging showed features of spontaneous intracranial hypotension and a right C7 CVF was identified at digital subtraction and CT myelography. Initial treatment with CT-guided injection of fibrin sealant produced temporary improvement in symptoms before surgical treatment resulted in total clinical remission and radiological resolution.

Bayesian networks for Risk Assessment and postoperative deficit prediction in intraoperative neurophysiology for brain surgery.

PURPOSE: To this day there is no consensus regarding evidence of usefulness of Intraoperative Neurophysiological Monitoring (IONM). Randomized controlled trials have not been performed in the past mainly because of difficulties in recruitment control subjects. In this study, we propose the use of Bayesian Networks to assess evidence in IONM. METHODS: Single center retrospective study from January 2020 to January 2022. Patients admitted for cranial neurosurgery with intraoperative neuromonitoring were enrolled. We built a Bayesian Network with utility calculation using expert domain knowledge based on logistic regression as potential causal inference between events in surgery that could lead to central nervous system injury and postoperative neurological function. RESULTS: A total of 267 patients were included in the study: 198 (73.9%) underwent neuro-oncology surgery and 69 (26.1%) neurovascular surgery. 50.7% of patients were female while 49.3% were male. Using the Bayesian Network´s original state probabilities, we found that among patients who presented with a reversible signal change that was acted upon, 59% of patients would wake up with no new neurological deficits, 33% with a transitory deficit and 8% with a permanent deficit. If the signal change was permanent, in 16% of the patients the deficit would be transitory and in 51% it would be permanent. 33% of patients would wake up with no new postoperative deficit. Our network also shows that utility increases when corrective actions are taken to revert a signal change. CONCLUSIONS: Bayesian Networks are an effective way to audit clinical practice within IONM. We have found that IONM warnings can serve to prevent neurological deficits in patients, especially when corrective surgical action is taken to attempt to revert signals changes back to baseline properties. We show that Bayesian Networks could be used as a mathematical tool to calculate the utility of conducting IONM, which could save costs in healthcare when performed.

Ventriculosubgaleal shunts in the management of neonatal post-haemorrhagic hydrocephalus: technical note.

INTRODUCTION: Germinal matrix / intraventricular haemorrhage (GMIVH) remains a significant complication of prematurity. The more severe grades are associated with parenchymal haemorrhagic infarction (PHI) and hydrocephalus. A temporising procedure is usually the first line in management of neonatal post-haemorrhagic hydrocephalus (nPHH) as the risk of failure of a permanent cerebrospinal fluid (CSF) diversion is higher in the early stage. Our choice of temporising procedure is a ventriculosubgaleal shunt (VSGS). In this technical note, we describe a modification in technique whereby the pocket of the VSGS is fashioned away from the surgical wound. This resulted in lower CSF leak and subsequent infection rates in our centre. METHODS: We conducted a retrospective analysis of all patients who underwent insertion of a VSGS between September 2014 and February 2023. RESULTS: Twenty children were included in our study with a mean gestational age of 31 weeks + 4 days. Post-operatively, 10% of patients did not need a tap, and 10%, 20%, 15%, 25% and 20% respectively had 1, 2, 3, 4 and 5 taps. Two patients experienced CSF leak from their wounds. In both these patients, the pocket was deemed too close to the wound. None of the patients without suspected pre-existing CNS infection at the time of insertion of VSGS had a subsequent VSGS-related infection. VSGS conversion to permanent ventriculoperitoneal shunts (VPS) was required in 15 (75%) of the patients with an average interval duration of 72 days. On reviewing the literature, the infection rate following VSGS is quoted up to 13.5%. In our own centre, 13 patients had undergone VSGS insertion between 2005 and 2013 with a 30.8% infection rate which seemed related to increased leak rates. CONCLUSION: Our modified surgical approach seems to be effective in reducing the risk of infection, which we postulate is a direct result of reduction in the risk of leak from the surgical wound.

H3 G34-mutant high-grade gliomas: integrated clinical, imaging and pathological characterisation of a single-centre case series.

BACKGROUND: Diffuse hemispheric glioma, H3 G34-mutant, is a novel paediatric tumour type in the fifth edition of the WHO classification of CNS tumours associated with an invariably poor outcome. We present a comprehensive clinical, imaging and pathological review of this entity. METHODS: Patients with confirmed H3 G34R-mutant high-grade glioma were included in a single-centre retrospective cohort study and examined for clinical, radiological and histo-molecular data. RESULTS: Twelve patients were enrolled in the study - 7 males/5 females; the mean age was 17.5 years (10-57 years). Most patients presented with signs of raised intracranial pressure (8/12). The frontal lobe (60%) was the prevalent location, with a mixed cystic-nodular appearance (10/12) and presence of vascular flow voids coursing through/being encased by the mass (8/12), and all tumours showed cortical invasion. Nine patients had subtotal resection limited by functional margins, two patients underwent supra-total resection, and one patient had biopsy only. 5-ALA was administered to 6 patients, all of whom showed positive fluorescence. Histologically, the tumours showed a marked heterogeneity and aggressive spread along pre-existing brain structures and leptomeninges. In addition to the diagnostic H3 G34R/V mutation, pathogenic variants in TP53 and ATRX genes were found in most cases. Potential targetable mutations in PDGFRA and PIK3CA genes were detected in five cases. The MGMT promoter was highly methylated in half of the samples. Methylation profiling was a useful diagnostic tool and highlighted recurrent structural chromosome abnormalities, such as PDGFRA amplification, CDKN2A/B deletion, PTEN loss and various copy number changes in the cyclin D-CDK4/Rb pathway. Radiochemotherapy was the most common adjuvant treatment (9/12), and the average survival was 19.3 months. CONCLUSIONS: H3 G34R-mutant hemispheric glioma is a distinct entity with characteristic imaging and pathological features. Genomic landscaping of individual tumours can offer an opportunity to adapt individual therapies and improve patient management.

Obstructive hydrocephalus due to an enlarged massa intermedia treated with endoscopic third ventriculostomy.

The massa intermedia (MI) or interthalamic adhesion (ITA) is a band of tissue connecting the medial surfaces of the thalami and is present in the majority of healthy individuals. Its enlargement as well as its absence have been associated with some pathological states.We describe the first case report of a 3-year-old child presenting with obstructive hydrocephalus in the context of an enlarged massa intermedia. The patient's symptoms abated following an endoscopic third ventriculostomy.

Neurosurgery and coronavirus: impact and challenges-lessons learnt from the first wave of a global pandemic.

INTRODUCTION AND OBJECTIVES: The novel severe acute respiratory syndrome coronavirus 2 (COVID-19) pandemic has had drastic effects on global healthcare with the UK amongst the countries most severely impacted. The aim of this study was to examine how COVID-19 challenged the neurosurgical delivery of care in a busy tertiary unit serving a socio-economically diverse population. METHODS: A prospective single-centre cohort study including all patients referred to the acute neurosurgical service or the subspecialty multidisciplinary teams (MDT) as well as all emergency and elective admissions during COVID-19 (18th March 2020-15th May 2020) compared to pre-COVID-19 (18th of January 2020-17th March 2020). Data on demographics, diagnosis, operation, and treatment recommendation/outcome were collected and analysed. RESULTS: Overall, there was a reduction in neurosurgical emergency referrals by 33.6% and operations by 55.6% during the course of COVID-19. There was a significant increase in the proportion of emergency operations performed during COVID-19 (75.2% of total, n=155) when compared to pre-COVID-19 (n = 198, 43.7% of total, p < 0.00001). In contrast to other published series, the 30-day perioperative mortality remained low (2.0%) with the majority of post-operative COVID-19-infected patients (n = 13) having underlying medical co-morbidities and/or suffering from post-operative complications. CONCLUSION: The capacity to safely treat patients requiring urgent or emergency neurosurgical care was maintained at all times. Strategies adopted to enable this included proactively approaching the referrers to maintain lines of communications, incorporating modern technology to run clinics and MDTs, restructuring patient pathways/facilities, and initiating the delivery of NHS care within private sector hospitals. Through this multi-modal approach we were able to minimize service disruptions, the complications, and mortality.

High grade gliomas in young children: The South Thames Neuro-Oncology unit experience and recent advances in molecular biology and targeted therapies.

High grade gliomas (HGG) have a dismal prognosis with survival rates of 15-35%. Approximately 10-12% of pediatric HGG occur in young children and their molecular biology and clinical outcomes differ from those arising at older ages. We report on four children aged <5 years newly diagnosed with non-brainstem HGG between 2011 and 2018 who were treated with surgery and BBSFOP chemotherapy. Two died of tumor progression. The other two are still alive without radiotherapy at 3.8 and 3.9 years from diagnosis: one of whom remains disease-free off treatment; and the other one, whose tumor harbored a KCTD16:NTRK2 fusion, went on to receive larotrectinib. Additionally we review the general management, outcomes and latest updates in molecular biology and targeted therapies for young children with HGG. Infant gliomas can be stratified in molecular subgroups with clinically actionable oncogenic drivers. Chemotherapy-based strategies can avoid or delay the need for radiotherapy in young children with HGG. Harnessing the potential of NTRK, ALK, ROS1 and MET inhibitors offers the opportunity to optimize the therapeutic armamentarium to improve current outcomes for these children.

Radiological pseudoprogression post-radiotherapy in a child with pineal germ cell tumour.

Little is known about pseudoprogression in brain tumours other than gliomas. A 9-year-old male child with a pineal teratoma/germinoma underwent surgical resection followed by adjuvant chemo-radiotherapy. The magnetic resonance imaging scan 4 months post-radiotherapy showed a contrast-enhancing lesion within the surgical cavity suspicious of recurrence. These radiological findings subsequently resolved without any specific intervention. The child continues in remission 2 years post-treatment. This case illustrates the occurrence of pseudoprogression post-radiotherapy in intracranial GCT and highlights an unmet need for greater implementation of functional imaging techniques in paediatric neuro-oncology to avoid undue discontinuation of effective treatments or inappropriate enrolment in clinical trials.

Undergraduate neurosurgical conferences - what role do they play?

INTRODUCTION: Undergraduate student conferences provide networking opportunities for students interested in exploring a speciality. The ability to meet with like-minded students, engage with senior clinicians and experience the practical side of a speciality are valuable in shaping the career trajectory of undergraduates. We report our experience of developing a national undergraduate neurosurgery conference - a combined project between the medical students of King's College London School of Medicine and the neurosurgery department at King's College Hospital NHS Foundation Trust. DESIGN: Evaluation of conference design and student feedback. METHODS: The conference was organised by medical students with support from a neurosurgical unit. Senior clinicians and trainees helped design practical workshops and a focused programme. Questionnaires were distributed before and after the conference to assess the quality of content and impact of the conference on students. RESULTS: Prior to the conference, 80.7% of respondents stated they were interested in a career in neurosurgery. After the conference the figure rose to 88.9%. The percentage of students who felt they understood what a career in neurosurgery involves increased from 38.6% to 92.1% of respondents. 39.0% of participants had no neurosurgery exposure prior to the conference. 91.9% of participants agreed or strongly agreed they would be more confident engaging with a neurosurgical department following the conference. All participants agreed (29.0%) or strongly agreed (71.0%) that they would recommend this conference to a colleague. CONCLUSIONS: Student conferences are a valuable method of increasing exposure to a career in neurosurgery. They serve a great purpose in demystifying the specialty and guiding those with an interest through the steps required to enter and progress.

Posterior fossa arachnoid cyst causing torticollis and gastro-oesophageal reflux in an infant.

INTRODUCTION: Arachnoid cysts (ACs) account for a small proportion of all intracranial lesions. They are often incidental but can become symptomatic and even cause a threat to life. Symptoms are usually due to direct compression of neural elements and/or raised intracranial pressure. CASE REPORT: We report the case of an infant with an enlarging posterior fossa arachnoid cyst (PFAC) causing torticollis and gastro-oesophageal reflux (GOR), the combination of which had been previously unreported in this context. Endoscopic fenestration and cyst decompression were followed by complete resolution of the symptoms. We discuss the possible mechanisms of torticollis and GOR in this context.

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.

Intraoperative indocyanine green video-angiography as an aid to the microsurgical treatment of spinal vascular malformations.

AIMS AND OBJECTIVES. Intra-operative Indocyanine Green (ICG) video-angiography (ICG-VA) has become an established aid to cerebrovascular surgery. We describe our experience using this technique to define angio-architecture intraoperatively in a range of spinal vascular malformations. METHODS. A retrospective review of notes and imaging was carried out from a prospectively maintained database. Our series comprises 27 patients who underwent surgical treatment between September 2007 and August 2012. We carried out a retrospective review of data from a prospectively maintained database. RESULTS. For slow-flow Type 1 fistulae the ICG videoangiogram demonstrated conclusively that the arteriovenous shunt was obliterated. This is a consideration on the rare occasions where a second fistula is present, an example of which is included in this series. ICG-VA also helps to demonstrate normal vascular anatomy and distinguish these vessels from pathology. For Type II lesions it allowed orientation to the vascular anatomy as demonstrated by the pre-operative angiogram. In one of two cases in this series it ensured to the complete extirpation of a large arteriovenous malformation (AVM). However a second Type II case demonstrated its limitations, as a diffuse intramedullary component could not be identified. Two cases were explored where digital subtraction spinal angiography was not possible and incomplete understanding of the angio-architectures of the lesions were available from Time Resolved dynamic magnetic resonance angiography and/or multi-detector CT angiography. ICG-VA provided invaluable information on alterations in arterio-venous flow that allowed diagnosis and obliteration of the arteriovenous shunts in each case. DISCUSSION. ICG video-angiography is a time-efficient and safe alternative to intra-operative spinal angiography. It provided useful information on haemodynamic changes intraoperatively and completeness of treatment. We discuss its limitations and role in the management of these lesions.

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.

Impact of Preoperative Mapping and Intraoperative Neuromonitoring in Minimally Invasive Parafascicular Surgery for Deep-Seated Lesions.

BACKGROUND: Transsulcal tubular retractor-assisted minimally invasive parafascicular surgery changes the surgical strategy for deep-seated lesions by promoting a deficit-sparing approach. When integrated with preoperative brain mapping and intraoperative neuromonitoring (IONM), this approach may potentially improve patient outcomes. In this study, we assessed the impact of preoperative brain mapping and IONM in tubular retractor-assisted neuro-oncological surgery. METHODS: This retrospective single-center cohort study included patients who underwent transsulcal tubular retractor-assisted minimally invasive parafascicular surgery for resection of deep-seated brain tumors from 2016 to 2022. The cohort was divided into 3 groups: group 1, no preoperative mapping or IONM (17 patients); group 2, IONM only (25 patients); group 3, both preoperative mapping and IONM (38 patients). RESULTS: We analyzed 80 patients (33 males and 47 females) with a median age of 46.5 years (range: 1-81 years). There was no significant difference in mean tumor volume (26.2 cm3 [range 1.07-97.4 cm3]; P = 0.740) and mean preoperative depth of the tumor (31 mm [range 3-65 mm], P = 0.449) between the groups. A higher proportion of high-grade gliomas and metastases was present within group 3 (P = 0.003). IONM was related to fewer motor (P = 0.041) and language (P = 0.032) deficits at hospital discharge. Preoperative mapping and IONM were also related to shorter length of stay (P = 0.008). CONCLUSIONS: Preoperative and intraoperative brain mapping and monitoring enhance transsulcal tubular retractor-assisted minimally invasive parafascicular surgery in neuro-oncology. Patients had a reduced length of stay and prolonged overall survival. IONM alone reduces postoperative neurological deficit.

Prevalence of recurrence and retreatment of ruptured intracranial aneurysms treated with endovascular coil occlusion.

OBJECT: Endovascular coiling is a common treatment for ruptured intracranial aneurysms. However, concerns have been raised over the durability of this treatment. The aim of this study was to establish the rate of recurrence and retreatment of coiled aneurysms treated in our unit. METHODS: We performed a retrospective analysis of 264 surviving patients with ruptured aneurysms treated by endovascular coiling between November 2003 and April 2007. Data was collected on patient age, location of aneurysm, angiogram results and any subsequent retreatment. RESULTS: Follow-up angiography performed at 6 months was available in 239 cases (91%) and revealed 158 (66%) aneurysms completely occluded, 51 (21%) had neck recurrence and 31 (13%) had significant recurrence. Thirty (12.6%) aneurysms required retreatment over a mean follow-up period of 46 (range 24-66) months. Younger age predisposed to a higher risk of recurrence and retreatment. Aneurysms of the anterior communicating and anterior cerebral arteries were less likely to recur or require retreatment (relative risk 0.42 and 0.29, respectively); aneurysms of the posterior communicating arteries were more likely to recur (relative risk 2.22). Aneurysms of the basilar and carotid arteries were more likely to undergo retreatment (relative risk 2.84 and 2.46, respectively). CONCLUSION: Long-term follow-up is required for ruptured aneurysms treated by coiling. Certain subgroups may require closer follow-up due to the increased risk of recurrence or retreatment, such as younger patients and those with aneurysms of the posterior communicating, basilar or carotid arteries.

Novel therapeutic approaches for pediatric diencephalic tumors: improving functional outcomes.

Pediatric diencephalic tumors represent a histopathologically and molecularly diverse group of neoplasms arising in the central part of the brain and involving eloquent structures, including the hypothalamic-pituitary axis (HPA), optic pathway, thalamus, and pineal gland. Presenting symptoms can include significant neurological, endocrine, or visual manifestations which may be exacerbated by injudicious intervention. Upfront multidisciplinary assessment and coordinated management is crucial from the outset to ensure best short- and long-term functional outcomes. In this review we discuss the clinical and pathological features of the neoplastic entities arising in this location, and their management. We emphasize a clear move towards 'function preserving' diagnostic and therapeutic approaches with novel toxicity-sparing strategies, including targeted therapies.