The safety of early pharmacological venous thromboembolism prophylaxis in patients with traumatic intracranial haemorrhage: a systematic review and meta-analysis.

INTRODUCTION: In patients with traumatic intracranial haemorrhage (tICH) there is significant risk of both venous thromboembolism (VTE) and haemorrhage progression. There is a paucity of literature to inform the timing of pharmacological thromboprophylaxis (PTP) initiation. AIM: This meta-analysis aims to summarise the current literature on the timing of PTP initiation in tICH. METHODS: This meta-analysis followed the Methodological Expectations of Cochrane Intervention Reviews checklist and the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Following the literature search, studies were matched against the criteria for inclusion. Data from included studies was pooled, analysed using random-effect analysis and presented as forest plots of risk ratios, except one result reported as difference of means. The ROBINS-I tool was used to assess the risk of bias in the studies. The GRADE approach was taken to assess the quality of included studies. Heterogeneity of studies was assessed using Tau∧2. Funnel plots were generated and used in conjunction with Harbord's test and Rucker's arcsine to assess for small-study effect including publication bias. RESULTS: A total of 9927 ICH patients who received PTP were included from 15 retrospective observational cohort studies, 4807 patients received early PTP, the remaining 5120 received late PTP. The definition of early was dependent on the study but no more than 72-hours after admission. The mean age of the included cohort was 45.3 (std dev ±9.5) years, and the proportion of males was 71%. Meta-analysis indicated that there was a significant difference between early and late groups for the rate of VTE (RR, 0.544; p = 0.000), pulmonary embolus (RR, 0.538; p = 0.004), deep vein thrombosis (RR, 0.484; p = 0.000) and the intensive care unit length of stay (difference of means, -2.021; 95% CI, -2.250, -1.792; p = 0.000; Tau∧2 = 0.000), favouring the early group. However, the meta-analysis showed no significant difference between the groups for the rate of mortality (RR, 1.008; p = 0.936), tICH progression (RR, 0.853; p = 0.157), and neurosurgical intervention (RR, 0.870; p = 0.480). CONCLUSION: These findings indicated that early PTP appears to be safe and effective in patients with tICH.

Surgical recovery from the COVID-19 pandemic in English adult neurosurgical centres.

OBJECTIVES: The COVID-19 pandemic required a change in resource priority from Neurosurgical care in order to treat medically unwell patients suffering from the complications of COVID-19 infections. We demonstrate the impact of COVID-19 on total bed days in 24 Neurosurgical centres in England offering adult Neurosurgery as well as the total spells (single inpatient episodes) for operative Neurosurgical patients between 2020 and 2022 when compared with 2019. METHODS: We used Capse Healthcare Knowledge System software iCompare in order to show the change in total spells for patients undergoing a primary or secondary Neurosurgical procedure as defined using the National Neurosurgical Audit Programme (NNAP) OPCS-4 coding framework between 2019 and 2022. RESULTS: The overall mortality rate of COVID-19 patients was 12.3% and the percentage of total bed days taken up by COVID-19 patients in hospitals at large was on average 7.7%. The total number of spells for all procedures over the 24 centres in 2022 was 39,019 compared with 45,742 in 2019. There was a cumulative deficit of 24,904 spells. The loss of spells was not equally distributed across regions and hospital Trusts. The average number of referral to treatment pathways completed within 18 weeks has declined from 76% to 57% over the study period and the referral to treatment clearance time has risen from 17 to 24 weeks. CONCLUSIONS: The mean elective cranial output in 2022 compared with 2019 is at 88% with spinal output lagging at 69%. If the rate of change year on year were to remain at current levels then we would reach pre-pandemic levels of output by 2026.

Trial of Dexamethasone for Chronic Subdural Hematoma.

BACKGROUND: Chronic subdural hematoma is a common neurologic disorder that is especially prevalent among older people. The effect of dexamethasone on outcomes in patients with chronic subdural hematoma has not been well studied. METHODS: We conducted a multicenter, randomized trial in the United Kingdom that enrolled adult patients with symptomatic chronic subdural hematoma. The patients were assigned in a 1:1 ratio to receive a 2-week tapering course of oral dexamethasone, starting at 8 mg twice daily, or placebo. The decision to surgically evacuate the hematoma was made by the treating clinician. The primary outcome was a score of 0 to 3, representing a favorable outcome, on the modified Rankin scale at 6 months after randomization; scores range from 0 (no symptoms) to 6 (death). RESULTS: From August 2015 through November 2019, a total of 748 patients were included in the trial after randomization - 375 were assigned to the dexamethasone group and 373 to the placebo group. The mean age of the patients was 74 years, and 94% underwent surgery to evacuate their hematomas during the index admission; 60% in both groups had a score of 1 to 3 on the modified Rankin scale at admission. In a modified intention-to-treat analysis that excluded the patients who withdrew consent for participation in the trial or who were lost to follow-up, leaving a total of 680 patients, a favorable outcome was reported in 286 of 341 patients (83.9%) in the dexamethasone group and in 306 of 339 patients (90.3%) in the placebo group (difference, -6.4 percentage points [95% confidence interval, -11.4 to -1.4] in favor of the placebo group; P = 0.01). Among the patients with available data, repeat surgery for recurrence of the hematoma was performed in 6 of 349 patients (1.7%) in the dexamethasone group and in 25 of 350 patients (7.1%) in the placebo group. More adverse events occurred in the dexamethasone group than in the placebo group. CONCLUSIONS: Among adults with symptomatic chronic subdural hematoma, most of whom had undergone surgery to remove their hematomas during the index admission, treatment with dexamethasone resulted in fewer favorable outcomes and more adverse events than placebo at 6 months, but fewer repeat operations were performed in the dexamethasone group. (Funded by the National Institute for Health Research Health Technology Assessment Programme; Dex-CSDH ISRCTN number, ISRCTN80782810.).

Systematic review on traumatic intracranial haemorrhage in patients on anti-thrombotic medications; haemorrhage progression, thrombosis, and anti-thrombotic recommencement.

A large number of patients who sustain a traumatic intracranial haemorrhage (tICH) are taking anti-thrombotic (AT) medications at the time of injury. These are stopped acutely, but there is uncertainty about safe timing for recommencement. This review aimed to understand the rate of new/progressive haemorrhage, thrombosis, and death in tICH patients on ATs and the rate and timing of AT recommencement. A systematic review of OVID Medline and EMBASE from 2000 to 2021 including adult patients with tICH on ATs with reported outcomes was performed. A total of 59 observational studies (20,421 patients) were included. Most patients were elderly (mean age 74), suffering falls (78%), and had a mild head injury. The mean new/progressive haemorrhage rate during admission was 26%, mostly diagnosed on routine imaging performed within 72 h of injury, with only 8% clinically significant. Thrombotic events were reported in 17 studies; mean rate of 3% during admission, 4-9% at 30 days and 3-11% at 6 months. AT recommencement rate and timing were only reported in six studies and varied widely, with some studies demonstrating reduced thrombotic events and mortality with earlier AT recommencement. Current data is observational and sparse in relation to haemorrhage, thrombosis, and AT recommencement. There is some suggestion that early recommencement, within 7-14 days, may be beneficial but higher quality studies with more consistent data are urgently required.

Radiological follow-up of endovascularly treated intracranial aneurysms: a survey of current practice in the UK and Ireland.

PURPOSE: Due to the risk of intracranial aneurysm (IA) recurrence and the potential requirement for re-treatment following endovascular treatment (EVT), radiological follow-up of these aneurysms is necessary. There is little evidence to guide the duration and frequency of this follow-up. The aim of this study was to establish the current practice in neurosurgical units in the UK and Ireland. METHODS: A survey was designed with input from interventional neuroradiologists and neurosurgeons. Neurovascular consultants in each of the 30 neurosurgical units providing a neurovascular service in the UK and Ireland were contacted and asked to respond to questions regarding the follow-up practice for IA treated with EVT in their department. RESULTS: Responses were obtained from 28/30 (94%) of departments. There was evidence of wide variations in the duration and frequency of follow-up, with a minimum follow-up duration for ruptured IA that varied from 18 months in 5/28 (18%) units to 5 years in 11/28 (39%) of units. Young patient age, previous subarachnoid haemorrhage and incomplete IA occlusion were cited as factors that would prompt more intensive surveillance, although larger and broad-necked IA were not followed-up more closely in the majority of departments. CONCLUSIONS: There is a wide variation in the radiological follow-up of IA treated with EVT in the UK and Ireland. Further standardisation of this aspect of patient care is likely to be beneficial, but further evidence on the behaviour of IA following EVT is required in order to inform this process.

A survey of the radiological follow-up of unruptured intracranial aneurysms in the United Kingdom.

OBJECTIVE: Unruptured intracranial aneurysms (UIA) are common. For many the treatment risks outweigh their risk of subarachnoid haemorrhage and patients undergo surveillance imaging. There is little data to inform if and how to monitor UIAs resulting in widely varying practices. This study aimed to determine the current practice of unruptured UIA surveillance in the United Kingdom. METHODS: A questionnaire was designed to address the themes of surveillance protocols for UIA including when surveillance is initiated, how frequently it is performed, and when it is terminated. Additionally, how aneurysm growth is managed and how clinically meaningful growth is defined were explored. The questionnaire was distributed to members of the British Neurovascular Group using probability-based cluster and non-probability purposive sampling methods. RESULTS: Responses were received from 30 of the 30 (100.0%) adult neurosurgical units in the United Kingdom of which 27 (90.0%) routinely perform surveillance for aneurysm growth. Only four units had a unit policy. The mean patient age up to which a unit would initiate follow-up of a low-risk UIA was 65.4 ± 9.0 years. The time points at which imaging is performed varied widely. There was an even split between whether units use a fixed duration of follow-up or an age threshold for terminating surveillance. Forty percent of units will follow-up patients more than 5 years from diagnosis. The magnitude in the change in size that was felt to constitute growth ranged from 1 to 3mm. No units routinely used vessel wall imaging although 27 had access to 3T MRI capable of performing it. CONCLUSIONS: There is marked heterogeneity in surveillance practices between units in the United Kingdom. This study will help units better understand their practice relative to their peers and provide a framework forplanning further research on aneurysm growth.

Biomarkers for differentiating grade II meningiomas from grade I: a systematic review.

INTRODUCTION: There are a number of prognostic markers (methylation, CDKN2A/B) described to be useful for the stratification of meningiomas. However, there are currently no clinically validated biomarkers for the preoperative prediction of meningioma grade, which is determined by the histological analysis of tissue obtained from surgery. Accurate preoperative biomarkers would inform the pre-surgical assessment of these tumours, their grade and prognosis and refine the decision-making process for treatment. This review is focused on the more controversial grade II tumours, where debate still surrounds the need for adjuvant therapy, repeat surgery and frequency of follow up. METHODS: We evaluated current literature for potential grade II meningioma clinical biomarkers, focusing on radiological, biochemical (blood assays) and immunohistochemical markers for diagnosis and prognosis, and how they can be used to differentiate them from grade I meningiomas using the post-2016 WHO classification. To do this, we conducted a PUBMED, SCOPUS, OVID SP, SciELO, and INFORMA search using the keywords; 'biomarker', 'diagnosis', 'atypical', 'meningioma', 'prognosis', 'grade I', 'grade 1', 'grade II' and 'grade 2'. RESULTS: We identified 1779 papers, 20 of which were eligible for systematic review according to the defined inclusion and exclusion criteria. From the review, we identified radiological characteristics (irregular tumour shape, tumour growth rate faster than 3cm3/year, high peri-tumoural blood flow), blood markers (low serum TIMP1/2, high serum HER2, high plasma Fibulin-2) and histological markers (low H3K27me3, low SMARCE1, low AKAP12, high ARIDB4) that may aid in differentiating grade II from grade I meningiomas. CONCLUSION: Being able to predict meningioma grade at presentation using the radiological and blood markers described may influence management as the likely grade II tumours will be followed up or treated more aggressively, while the histological markers may prognosticate progression or post-treatment recurrence. This to an extent offers a more personalised treatment approach for patients.

Fibulin-2: A Novel Biomarker for Differentiating Grade II from Grade I Meningiomas.

There is an unmet need for the identification of biomarkers to aid in the diagnosis, clinical management, prognosis and follow-up of meningiomas. There is currently no consensus on the optimum management of WHO grade II meningiomas. In this study, we identified the calcium binding extracellular matrix glycoprotein, Fibulin-2, via mass-spectrometry-based proteomics, assessed its expression in grade I and II meningiomas and explored its potential as a grade II biomarker. A total of 87 grade I and 91 grade II different meningioma cells, tissue and plasma samples were used for the various experimental techniques employed to assess Fibulin-2 expression. The tumours were reviewed and classified according to the 2016 edition of the Classification of the Tumours of the central nervous system (CNS). Mass spectrometry proteomic analysis identified Fibulin-2 as a differentially expressed protein between grade I and II meningioma cell cultures. Fibulin-2 levels were further evaluated in meningioma cells using Western blotting and Real-time Quantitative Polymerase Chain Reaction (RT-qPCR); in meningioma tissues via immunohistochemistry and RT-qPCR; and in plasma via Enzyme-Linked Immunosorbent Assay (ELISA). Proteomic analyses (p < 0.05), Western blotting (p < 0.05) and RT-qPCR (p < 0.01) confirmed significantly higher Fibulin-2 (FBLN2) expression levels in grade II meningiomas compared to grade I. Fibulin-2 blood plasma levels were also significantly higher in grade II meningioma patients compared to grade I patients. This study suggests that elevated Fibulin-2 might be a novel grade II meningioma biomarker, when differentiating them from the grade I tumours. The trend of Fibulin-2 expression observed in plasma may serve as a useful non-invasive biomarker.

Workforce planning in neurosurgery.

Purpose: Since the introduction of run-through training in UK Neurosurgery in 2007, there has been no limit on the number of posts deaneries may apply for. The rationale for run-through training was based on the premise that the number of trainees recruited would match the number of consultant posts eight years later. There has been no formal survey of the number of consultant neurosurgeons in the UK for several years. A survey was undertaken to measure the current Neurosurgical workforce.Methods: The Specialist Advisory Committee undertook a survey to establish the current workforce and estimate how best to ensure that the correct number of trainees are being recruited. Data was also obtained from public bodies including the GMC, NHS Jobs and JCST.Results: Since 1993 the number of Neurosurgeons in UK and Ireland has increased from 132.5 to 389 whole time equivalents (4.4% curvilinear annual increase). The number of registered neurosurgical trainees fell 9% from 278 in 2012 to 248 in 2017. The number of UK graduates in Neurosurgical training has remained constant. The number of trainees failing to complete training has increased from 1.25 per annum in 2009-2012 to 5-6 in 2014-2017. The number of ST1 level trainees recruited has risen, which a fall in the number of trainees entering at the ST3 level has partially offset. The number of doctors with a CCT in Neurosurgery but no substantive consultant post has risen from 26 to 43 between 2015 and 2018.Conclusions: Neurosurgical workforce data should be collected regularly and a workforce planning process should be implemented. Consultant expansion is required to reduce the number of CCT holders without consultant jobs. The specialty should prevent any further increase in the number of trainees recruited and we should consider a marginal reduction in recruitment.

Giant vertebrobasilar aneurysm: a rare cause of central sleep apnoea.

We report a case of central sleep apnoea (CSA) due to a giant vertebrobasilar aneurysm with brainstem compression. A flow diverter stent was deployed with coil embolization of the right vertebral artery distal to the posterior inferior cerebellar artery (PICA) to occlude the aneurysm. The patient's symptoms improved following therapy.

The evolution of British neurosurgical selection and training over the past decade.

Selection of junior doctors into the British neurosurgical training program and subsequent speciality training have undergone several key changes over the past decade. Shift patterns in the era of the European Working Time Directive (EWTD) have had a major impact on surgical training. We discuss the national selection process, formalization of surgical simulation training and the need to encompass generic professional capabilities within the neurosurgical curriculum in order to create the "well-rounded surgeon". Future directions including hybrid cerebrovascular training, training in stereotactic radiosurgery, and dedicated training opportunities in spinal surgery.

Pathophysiology of chronic subdural haematoma: inflammation, angiogenesis and implications for pharmacotherapy.

Chronic subdural haematoma (CSDH) is an encapsulated collection of blood and fluid on the surface of the brain. Historically considered a result of head trauma, recent evidence suggests there are more complex processes involved. Trauma may be absent or very minor and does not explain the progressive, chronic course of the condition. This review focuses on several key processes involved in CSDH development: angiogenesis, fibrinolysis and inflammation. The characteristic membrane surrounding the CSDH has been identified as a source of fluid exudation and haemorrhage. Angiogenic stimuli lead to the creation of fragile blood vessels within membrane walls, whilst fibrinolytic processes prevent clot formation resulting in continued haemorrhage. An abundance of inflammatory cells and markers have been identified within the membranes and subdural fluid and are likely to contribute to propagating an inflammatory response which stimulates ongoing membrane growth and fluid accumulation. Currently, the mainstay of treatment for CSDH is surgical drainage, which has associated risks of recurrence requiring repeat surgery. Understanding of the underlying pathophysiological processes has been applied to developing potential drug treatments. Ongoing research is needed to identify if these therapies are successful in controlling the inflammatory and angiogenic disease processes leading to control and resolution of CSDH.

Generation of functionally distinct isoforms of PTBP3 by alternative splicing and translation initiation.

Polypyrimidine tract binding protein (PTBP1) is a widely expressed RNA binding protein that acts as a regulator of alternative splicing and of cytoplasmic mRNA functions. Vertebrates contain two closely-related paralogs with >75% amino acid sequence identity. Early replacement of PTBP1 by PTBP2 during neuronal differentiation causes a concerted set of splicing changes. By comparison, very little is known about the molecular functions or physiological roles of PTBP3, although its expression and conservation throughout the vertebrates suggest a role in haematopoietic cells. To begin to understand its functions we have characterized the mRNA and protein isoform repertoire of PTBP3. Combinatorial alternative splicing events at the 5' end of the gene allow for the generation of eight mRNA and three major protein isoforms. Individual mRNAs generate up to three protein isoforms via alternative translation initiation by re-initiation and leaky scanning using downstream AUG codons. The N-terminally truncated PTBP3 isoforms lack nuclear localization signals and/or most of the RRM1 domain and vary in their RNA binding properties and nuclear/cytoplasmic distribution, suggesting that PTBP3 may have major post-transcriptional cytoplasmic roles. Our findings set the stage for understanding the non-redundant physiological roles of PTBP3.

A case of spontaneous haematoma from vertebral artery arterio-venous fistula in a patient with neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is an autosomal dominant condition caused by a mutation on chromosome 17. Vascular abnormalities are recognised complications of NF1. These include aneurysms, stenoses, arteriovenous malformations, fistulae, etc. We report the case of a young gentleman with NF1 with a spontaneous cervical bleed from an arteriovenous fistula arising from the left vertebral artery, and illustrate the various management options and difficulties arising from rapid fistula formation.

Simulation in neurosurgical training: a blueprint and national approach to implementation for initial years trainees.

Simulation has played an increasing role in surgical training in recent years, this follows from various reports such as the Chief Medical Officer annual report and Sir John Temple's 'Time for Training' and also from other factors such as increasing focus on efficiency and transparency within the healthcare system. Evidence has shown that simulation can develop and improve technical, clinical, communication and management skills. With technological advances, the quality of simulation has also improved with more realistic models and environment. We have undertaken a review of recent drivers for simulation training in the UK, current techniques and have focused on the application of simulation training within the current UK Neurosurgical curriculum for newly appointed trainees.

Early versus late readmission of subarachnoid haemorrhage patients into neurocritical care.

INTRODUCTION: Subarachnoid haemorrhage (SAH) patients will typically require monitoring in a specialised Neurocritical Care Unit (NCCU) regardless of the primary treatment modality. Once discharged from NCCU, readmission within 48 h is regarded as a "failed" discharge. The aims of this study are to (1) Evaluate the readmission rate of SAH patients into NCCU, (2) Identify the indications for readmission, (3) Analyse clinical parameters on discharge between patients readmitted early and late. MATERIALS AND METHODS: Retrospective observational study of the Intensive Care National Audit and Research Centre (ICNARC) database of patients from our unit diagnosed with SAH from January 2009-December 2014, who were readmitted into NCCU. Demographic data, World Federation of Neurosurgical Societies (WFNS) grade, Fisher grade, length of initial and subsequent NCCU stay, time of readmission, indication for readmission, and mortality rate data were collected. Patients were categorised by early (<48 h) and late (>48 h) readmission, and their clinical parameters on NCCU discharge were statistically analysed. RESULTS: Five hundred and seventy-five SAH patients were admitted into NCCU, of which 49 patients (9%) were readmitted after discharge to ward-level care. The mean age of readmitted patients was 64.1 ± 11.6 years old. The most common indications were delayed cerebral ischaemia (DCI) (50%) and infection (19%). Readmitted SAH patients were typically WFNS grade I-II (n = 22) and Fisher grade III-IV (n = 44). 17 (35%) patients were readmitted early, and were older (p = 0.0049) with a lower GCS (p = 0.0077) compared to patients readmitted later. White cell count and C-reactive protein were higher in patients readmitted early, but did not reach statistical significance (p = 0.09, p = 0.07). CONCLUSION: DCI and infection were the most common indications for NCCU readmission in SAH patients. "Failed" discharged patients from NCCU are typically older with a lower GCS than patients readmitted after 48 h, and therefore clinicians should be more cautious in discharging these patients prematurely.

Management of CSF leak in base of skull fractures in adults.

AIMS: CSF leaks are not uncommon after a base of skull fracture. Currently there is no standardised algorithm for the investigation and management of post-traumatic CSF leaks. In this paper we aim to provide an evidence-based framework for managing post-traumatic CSF leaks. METHODS: We searched the English literature over the past 45 years using CINAHL, EMBASE and MEDLINE for the terms (1) post-traumatic CSF leaks or fistulas, and (2) basilar or base of skull fractures, but excluded papers on post-operative and non-traumatic CSF leaks, and papers on paediatric post- traumatic CSF leaks. RESULTS: The diagnosis of a base of skull fracture and any resultant CSF leak can be challenging. Therefore a combination of biochemical and radiological studies are needed to optimise the diagnosis of this condition. Post-traumatic CSF leaks are generally treated conservatively, and a majority of them resolve without further surgical management. However for patients who are refractory to such treatments, surgical closure of the CSF fistula is necessary. Surgical obliteration of CSF leaks can be challenging and requires the involvement of multiple surgical specialties such as neurosurgery, otolaryngology, and maxillofacial surgery. CONCLUSION: Although we have formulated a simple algorithm to aid the investigation and management of post-traumatic CSF leaks, there are still many important unresolved questions requiring further well powered studies to answer.

Seven years of cranioplasty in a regional neurosurgical centre.

INTRODUCTION: In recent years craniectomy has been widely used in the management of traumatic brain injury and ischaemic stroke. The objective of this study was to evaluate the indications, techniques and outcomes for patients undergoing cranioplasty over a recent 7-year period in a geographically distinct population. MATERIALS AND METHODS: An observational study was performed retrospectively, with review of case records from 2004 to 2011. Demographic, clinical and outcome data were collected, and complications were classified as major and minor. A multi-variant analysis was performed to identify patient and management factors that influenced outcome. RESULTS: Data were collected on a total of 87 cranioplasty patients with a median age of 42 and a mean follow-up time of 3 years and 10 months. The main indications for craniectomy were trauma (46%), infection (19%) intracranial haemorrhage (15%), tumour (13%) and ischaemic stroke (6%). Eight percent of patients had a synchronous craniectomy and cranioplasty, 14% had cranioplasty within 3 months of craniectomy, 21% within 3-6 months, 35% within 6-12 months, 14% over 1 year and 8% over 2 years later. The most frequently implanted cranioplasty material was titanium (53%), followed by autologous bone (26%) and acrylic (15%). Administration of prophylactic antibiotics was recorded in 97% of cases. Major complications occurred in 20% of patients, including 2 deaths (2%), 5 extradural haemorrhages (6%) and 9 infections (10%). A further 10% of cases experienced minor or cosmetic complications. CONCLUSIONS: Cranioplasty is often considered as a low-risk procedure following craniectomy. In our cohort, a 20% risk of major complications, including death, was identified. These findings contribute to the literature, emphasising that cranioplasty is a high-risk procedure. Whilst compelling reasons may guide the undertaking of craniectomy, it is essential that consideration is given to the significant subsequent risks of cranioplasty.

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.

Can AI pass the written European Board Examination in Neurological Surgery? - Ethical and practical issues.

Introduction: Artificial intelligence (AI) based large language models (LLM) contain enormous potential in education and training. Recent publications demonstrated that they are able to outperform participants in written medical exams. Research question: We aimed to explore the accuracy of AI in the written part of the EANS board exam. Material and methods: Eighty-six representative single best answer (SBA) questions, included at least ten times in prior EANS board exams, were selected by the current EANS board exam committee. The questions' content was classified as 75 text-based (TB) and 11 image-based (IB) and their structure as 50 interpretation-weighted, 30 theory-based and 6 true-or-false. Questions were tested with Chat GPT 3.5, Bing and Bard. The AI and participant results were statistically analyzed through ANOVA tests with Stata SE 15 (StataCorp, College Station, TX). P-values of <0.05 were considered as statistically significant. Results: The Bard LLM achieved the highest accuracy with 62% correct questions overall and 69% excluding IB, outperforming human exam participants 59% (p = 0.67) and 59% (p = 0.42), respectively. All LLMs scored highest in theory-based questions, excluding IB questions (Chat-GPT: 79%; Bing: 83%; Bard: 86%) and significantly better than the human exam participants (60%; p = 0.03). AI could not answer any IB question correctly. Discussion and conclusion: AI passed the written EANS board exam based on representative SBA questions and achieved results close to or even better than the human exam participants. Our results raise several ethical and practical implications, which may impact the current concept for the written EANS board exam.