Challenges and patient outcomes in chronic subdural haematoma at the level of a regional care system A multi-centre, mixed-methods study from the East of England.

BACKGROUND: Chronic subdural haematoma (cSDH) is a common neurosurgical pathology affecting older patients with other health conditions. A significant proportion (up-to 90%) of referrals for surgery in neurosciences units (NSU) come from secondary care. However, the organisation of this care and the experience of patients repatriated to non-specialist centres are currently unclear. OBJECTIVES: This study aimed to clarify patient outcome in non-specialist centres following NSU discharge for cSDH surgery and to understand key system challenges. The study was set within a representative neurosurgical care system in the east of England. DESIGN AND METHODS: We performed a retrospective cohort analysis of patients referred for cSDH surgery. Alongside case record review, patient and staff experience were explored using surveys as well as an interactive c-design workshop. Challenges were identified from thematic analysis of survey responses and triangulated by focussed workshop discussions. RESULTS: Data on 381 patients referred for cSDH surgery from six centres was reviewed. One hundred and fifty-six (41%) patients were repatriated following surgery. Sixty-one (39%) of those repatriated suffered an inpatient complication (new infection, troponin rise or renal injury) following NSU discharge, with 58 requiring institutional discharge or new care. Surveys for staff (n = 42) and patients (n = 209) identified that resourcing, communication, and inter-hospital distance posed care challenges. This was corroborated through workshop discussions with stakeholders from two institutions. CONCLUSIONS: A significant amount of perioperative care for cSDH is delivered outside of specialist centres. Future improvement initiatives must recognise the system-wide nature of delivery and the challenges such an arrangement presents.

Consensus-Based Development of a Global Registry for Traumatic Brain Injury: Establishment, Protocol, and Implementation.

BACKGROUND AND OBJECTIVES: Global disparity exists in the demographics, pathology, management, and outcomes of surgically treated traumatic brain injury (TBI). However, the factors underlying these differences, including intervention effectiveness, remain unclear. Establishing a more accurate global picture of the burden of TBI represents a challenging task requiring systematic and ongoing data collection of patients with TBI across all management modalities. The objective of this study was to establish a global registry that would enable local service benchmarking against a global standard, identification of unmet need in TBI management, and its evidence-based prioritization in policymaking. METHODS: The registry was developed in an iterative consensus-based manner by a panel of neurotrauma professionals. Proposed registry objectives, structure, and data points were established in 2 international multidisciplinary neurotrauma meetings, after which a survey consisting of the same data points was circulated within the global neurotrauma community. The survey results were disseminated in a final meeting to reach a consensus on the most pertinent registry variables. RESULTS: A total of 156 professionals from 53 countries, including both high-income countries and low- and middle-income countries, responded to the survey. The final consensus-based registry includes patients with TBI who required neurosurgical admission, a neurosurgical procedure, or a critical care admission. The data set comprised clinically pertinent information on demographics, injury characteristics, imaging, treatments, and short-term outcomes. Based on the consensus, the Global Epidemiology and Outcomes following Traumatic Brain Injury (GEO-TBI) registry was established. CONCLUSION: The GEO-TBI registry will enable high-quality data collection, clinical auditing, and research activity, and it is supported by the World Federation of Neurosurgical Societies and the National Institute of Health Research Global Health Program. The GEO-TBI registry ( https://geotbi.org ) is now open for participant site recruitment. Any center involved in TBI management is welcome to join the collaboration to access the registry.

Technical considerations and long-term results of endovascular venous stenting to control venous hypertension from meningiomas invading intracranial venous sinuses.

OBJECTIVE: Meningiomas invading the intracranial venous sinuses may cause intracranial venous hypertension, papilledema, and visual compromise. Sinus resection and graft reconstructions, however, add significant complexity to tumor surgery, with the potential for increased morbidity. In this study, the authors explored whether venous sinus stenting might provide an alternative means of controlling venous hypertension that would be sustainable over the long term. METHODS: The authors performed a retrospective review of all 16 patients with intracranial meningiomas who underwent stenting at their institution for venous sinus compromise. At presentation, all had headache and 9 had papilledema. Thirteen patients had 1 meningioma and 3 had 2 or more. Three patients had had previous tumor resection and radiotherapy. One patient had been treated with a lumboperitoneal shunt and radiotherapy. The median length of clinical follow-up was 8 years (range 4 months-18 years). RESULTS: Venous sinus narrowing was often not confined to the site of meningioma, and bilateral transverse sinus narrowing, reminiscent of that seen in idiopathic intracranial hypertension, was present in 7 patients with sagittal sinus meningiomas. Eleven patients had stents placed solely across sinus narrowing caused by meningioma. Five patients had additional stents placed at other sites of venous narrowing at the same time: in one of these patients, a stent was placed across a defect in the sagittal sinus caused by previous surgery, and in the 4 other patients, stents were placed across nontumor narrowings of the transverse sinuses. In 1 patient, the jugular vein was also stented. Nine patients developed symptomatic in-stent restenosis at the meningioma site. Eight had further stenting procedures with variable success in restoring the in-stent lumen. The remaining patient, with a late partial relapse, is being reinvestigated. Papilledema resolved in all patients after stenting. Six patients experienced prolonged and very substantial relief of all symptoms. Five patients had persistent headache despite restoration of the sinus lumen. Five had persistent symptoms associated with resistant in-stent stenosis. There were no significant complications from any of the diagnostic or therapeutic procedures. CONCLUSIONS: In patients who are symptomatic with meningiomas obstructing the venous sinuses, successful stenting of the affected segment can give a good outcome, especially in terms of relieving papilledema. However, further procedures are often necessary to maintain stent patency, other areas of venous compromise frequently coexist, and some patients remain symptomatic despite apparently successful treatment of the index lesion. Long-term surveillance is a requirement.

An international, prospective observational study on traumatic brain injury epidemiology study protocol: GEO-TBI: Incidence.

Background: The epidemiology of traumatic brain injury (TBI) is unclear - it is estimated to affect 27-69 million individuals yearly with the bulk of the TBI burden in low-to-middle income countries (LMICs). Research has highlighted significant between-hospital variability in TBI outcomes following emergency surgery, but the overall incidence and epidemiology of TBI remains unclear. To address this need, we established the Global Epidemiology and Outcomes following Traumatic Brain Injury (GEO-TBI) registry, enabling recording of all TBI cases requiring admission irrespective of surgical treatment. Objective: The GEO-TBI: Incidence study aims to describe TBI epidemiology and outcomes according to development indices, and to highlight best practices to facilitate further comparative research. Design: Multi-centre, international, registry-based, prospective cohort study. Subjects: Any unit managing TBI and participating in the GEO-TBI registry will be eligible to join the study. Each unit will select a 90-day study period. All TBI patients meeting the registry inclusion criteria (neurosurgical/ICU admission or neurosurgical operation) during the selected study period will be included in the GEO-TBI: Incidence. Methods: All units will form a study team, that will gain local approval, identify eligible patients and input data. Data will be collected via the secure registry platform and validated after collection. Identifiers may be collected if required for local utility in accordance with the GEO-TBI protocol. Data: Data related to initial presentation, interventions and short-term outcomes will be collected in line with the GEO-TBI core dataset, developed following consensus from an iterative survey and feedback process. Patient demographics, injury details, timing and nature of interventions and post-injury care will be collected alongside associated complications. The primary outcome measures for the study will be the Glasgow Outcome at Discharge Scale (GODS) and 14-day mortality. Secondary outcome measures will be mortality and extended Glasgow Outcome Scale (GOSE) at the most recent follow-up timepoint.

Traumatic brain injury (TBI) is a significant global health problem, which affects 27­69 million people every year. After-effects of TBI commonly affect the injured individuals for years. Most patients who sustain a TBI are from developing countries. Research has shown that there are differences in patients' recovery after TBI between countries and hospitals. The causes of these differences are unclear and tackling them could improve TBI treatment worldwide. To address this need, we have recently established the Global Epidemiology and Outcomes Following Traumatic Brain Injury (GEO-TBI) registry. The international collaborative registry aims to collect data related to the causes, treatments and outcomes related to TBI patients. This data will hopefully enable future research to elucidate the causes of the recovery differences between hospitals, which could lead to improved patient outcomes. The GEO-TBI: Incidence study collects data from all TBI patients that are admitted to participating hospitals or undergo a neurosurgical operation due to TBI during a 90-day period. This study looks at the patient's recovery at discharge using the Glasgow Outcome at Discharge Scale (GODS), and at the 2-week mortality. In addition, the study also evaluates recovery at the most recent follow-up timepoint. We hope that this information will enhance our understanding on the causes, treatments, and commonness of TBI. The study results will also help local hospitals compare their treatment results to an international standard.

Incidence and presentation of vestibular schwannoma: a 3-year cohort registry study.

BACKGROUND: Vestibular schwannoma (VS) is the most common benign tumour arising in the lateral skull base. Reported incidence rates of VS vary across geographical locations and over time. There is scarce updated evidence over the past decade on the epidemiology and mode of presentation of VS. OBJECTIVE: To describe the epidemiology and mode of presentation of VS in the East of England between 2013 and 2016. METHODS: A retrospective epidemiological analysis of data from a national VS registry and electronic patient records was conducted, including all newly diagnosed adult patients in a UK tertiary referral centre, between April 1st, 2013, and March 31st, 2016. RESULTS: There were 391 new cases identified resulting in an overall mean incidence of 2.2 VS cases per 100,000 person-year. The incidence rate for all patients in the <40 age group ranged between 0.3 and 0.7 per 100,000 person-year, increasing to a range of 5.7 to 6.1 per 100,000 person-year in the 60-69 age group. The top three combinations of symptoms on presentation per patient were hearing loss and tinnitus (97, 24.8%), hearing loss alone (79, 20.2%) and hearing loss, tinnitus, and balance symptoms (61, 15.6%). The median duration of symptoms was 12 months, with a wide range from 1.4 to 300 months. Age was negatively correlated with tumour size (r = -0.14 [-0.24 to -0.04], p=0.01) and positively correlated with symptom duration (r = 0.16 [0.03-0.29], p=0.02). CONCLUSIONS: The incidence of vestibular schwannoma has increased compared to previous studies in the UK and is similar to incidence rates reported in other countries during the past decade. It peaks in the seventh decade of life, mainly because of an increase in the diagnosis of small tumours with a long duration of audio-vestibular symptoms in older patients, compared to earlier studies.

Assessing the accuracy of the International Classification of Disease (ICD) framework in the identification of patients with chronic subdural haematoma from hospital records.

BACKGROUND: Chronic subdural hematoma (CSDH) is one of the commonest neurosurgical pathologies with an increasing incidence. Observational studies of routine care have demonstrated high perioperative morbidity and approximately 10% mortality at one year. The development, implementation, and evaluation of a potential care framework relies on an accurate and reproducible method of case identification and case ascertainment. With this manuscript, we report on the accuracy of diagnostic ICD codes for identifying patients with CSDH from retrospective electronic data and explore whether basic demographic data could improve the identification of CSDH. METHODS: Data were collected retrospectively from the hospital administrative system between 2014 and 2018 of all patients coded with either S065 or I620. Analysis of the ICD codes in identifying patients with CSDH diagnosis was calculated using the caretR package in RStudioR,.and stepwise logistic regression analysis was performed to evaluate the best predictive model for CSDH. RESULTS: A total of 1861 patients were identified. Of these, 189 (10.2%) had a diagnosis of non-traumatic SDH (I620) and 1672 (89.8%) traumatic subdural haematomas (S065). Variables that identified CSDH as a diagnosis on univariate logistic regression included male sex (Odds Ratios (OR) - 1.606 (1.197-2.161), elderly age (OR) - 1.023 (1.015-1.032) per year for age (p < 0.001) and shorter length of hospital stay. Using stepwise regression against AIC the best model to predict CSDH included male sex, older age, and shorter LOS. The calculated sensitivity for identifying CSDH with the model is 88.4% with a specificity of 84.5% and PPV of 87.9%. CONCLUSION: CSDH is a common neurosurgical pathology with increasing incidence and ongoing unmet clinical need. We demonstrate that case ascertainment for research purposes can be improved with the incorporation of additional demographic data but at the expense of significant case exclusion.

A Prospective Study of Longitudinal Risks of Cognitive Deficit for People Undergoing Glioblastoma Surgery Using a Tablet Computer Cognition Testing Battery: Towards Personalized Understanding of Risks to Cognitive Function.

Glioblastoma and the surgery to remove it pose high risks to the cognitive function of patients. Little reliable data exist about these risks, especially postoperatively before radiotherapy. We hypothesized that cognitive deficit risks detected before surgery will be exacerbated by surgery in patients with glioblastoma undergoing maximal treatment regimens. We used longitudinal electronic cognitive testing perioperatively to perform a prospective, longitudinal, observational study of 49 participants with glioblastoma undergoing surgery. Before surgery (A1), the participant risk of deficit in 5/6 cognitive domains was increased compared to normative data. Of these, the risks to Attention (OR = 31.19), Memory (OR = 97.38), and Perception (OR = 213.75) were markedly increased. These risks significantly increased in the early period after surgery (A2) when patients were discharged home or seen in the clinic to discuss histology results. For participants tested at 4-6 weeks after surgery (A3) before starting radiotherapy, there was evidence of risk reduction towards A1. The observed risks of cognitive deficit were independent of patient-specific, tumour-specific, and surgery-specific co-variates. These results reveal a timeframe of natural recovery in the first 4-6 weeks after surgery based on personalized deficit profiles for each participant. Future research in this period could investigate personalized rehabilitation tools to aid the recovery process found.

Protocol for the development of a multidisciplinary clinical practice guideline for the care of patients with chronic subdural haematoma.

Introduction: A common neurosurgical condition, chronic subdural haematoma (cSDH) typically affects older people with other underlying health conditions. The care of this potentially vulnerable cohort is often, however, fragmented and suboptimal. In other complex conditions, multidisciplinary guidelines have transformed patient experience and outcomes, but no such framework exists for cSDH. This paper outlines a protocol to develop the first comprehensive multidisciplinary guideline from diagnosis to long-term recovery with cSDH. Methods: The project will be guided by a steering group of key stakeholders and professional organisations and will feature patient and public involvement. Multidisciplinary thematic working groups will examine key aspects of care to formulate appropriate, patient-centered research questions, targeted with evidence review using the GRADE framework. The working groups will then formulate draft clinical recommendations to be used in a modified Delphi process to build consensus on guideline contents. Conclusions: We present a protocol for the development of a multidisciplinary guideline to inform the care of patients with a cSDH, developed by cross-disciplinary working groups and arrived at through a consensus-building process, including a modified online Delphi.

Myeloid cell interferon secretion restricts Zika flavivirus infection of developing and malignant human neural progenitor cells.

Zika virus (ZIKV) can infect human developing brain (HDB) progenitors resulting in epidemic microcephaly, whereas analogous cellular tropism offers treatment potential for the adult brain cancer, glioblastoma (GBM). We compared productive ZIKV infection in HDB and GBM primary tissue explants that both contain SOX2+ neural progenitors. Strikingly, although the HDB proved uniformly vulnerable to ZIKV infection, GBM was more refractory, and this correlated with an innate immune expression signature. Indeed, GBM-derived CD11b+ microglia/macrophages were necessary and sufficient to protect progenitors against ZIKV infection in a non-cell autonomous manner. Using SOX2+ GBM cell lines, we found that CD11b+-conditioned medium containing type 1 interferon beta (IFNß) promoted progenitor resistance to ZIKV, whereas inhibition of JAK1/2 signaling restored productive infection. Additionally, CD11b+ conditioned medium, and IFNß treatment rendered HDB progenitor lines and explants refractory to ZIKV. These findings provide insight into neuroprotection for HDB progenitors as well as enhanced GBM oncolytic therapies.

Facial Nerve Function Outcome and Risk Factors in Resection of Large Cystic Vestibular Schwannomas.

Objective Cystic vestibular schwannomas (VS) in contrast to solid VS tend to have accelerated growth, larger volume, rapid/atypical presentation, lobulated/adherent surface, and unpredictable course of the cranial nerves. Cystic VS are surgically challenging, with worse clinical outcomes and higher rate of subtotal resection (STR). Methods We retrospectively analyzed postoperative outcomes of 125 patients with cystic VS, operated between years 2005 and 2019 in our center. We confronted the extent of the resection and House-Brackmann (HB) grade of facial palsy with the results of comparable cohort of patients with solid VS operated in our center and literature review by Thakur et al. 1 Results Translabyrinthine approach was preferred for resection of large, cystic VS (97.6%). Gross-total resection (GTR) was achieved in 78 patients (62.4%), near-total resection (NTR) with remnant (<4 × 4 × 2 mm) in 43 patients (34.4%), and STR in 4 patients (3.2%). NTR/STR were significantly associated with higher age, tumor volume >5 cm 3 , retrosigmoid approach, high-riding jugular bulb, tumor adherence to the brain stem, and facial nerve ( p = 0.016; 0.003; 0.005; 0.025; 0.001; and <0.00001, respectively). One year after the surgery, 76% of patients had HB grades 1 to 2, 16% had HB grades 3 to 4, and 8% had HB grades 5 to 6 palsy. Worse outcome (HB grades 3 to 6) was associated with preoperative facial palsy, tumor volume >25 cm 3 , and cyst over the brain stem ( p = 0.045; 0.014; and 0.05, respectively). Comparable solid VS operated in our center had significantly higher HB grades 1 to 2 rate than our cystic VS (94% versus 76%; p = 0.03). Comparing our results with literature review, our HB grades 1 to 2 rate was significantly higher (76% versus 39%; p = 0.0001). Tumor control rate 5 years after surgery was 95.8%. Conclusion Our study confirmed that microsurgery of cystic VS has worse outcomes of facial nerve preservation and extent of resection compared with solid VS. Greater attention should be paid to the above-mentioned risk factors.

Casemix, management, and mortality of patients rreseceiving emergency neurosurgery for traumatic brain injury in the Global Neurotrauma Outcomes Study: a prospective observational cohort study.

BACKGROUND: Traumatic brain injury (TBI) is increasingly recognised as being responsible for a substantial proportion of the global burden of disease. Neurosurgical interventions are an important aspect of care for patients with TBI, but there is little epidemiological data available on this patient population. We aimed to characterise differences in casemix, management, and mortality of patients receiving emergency neurosurgery for TBI across different levels of human development. METHODS: We did a prospective observational cohort study of consecutive patients with TBI undergoing emergency neurosurgery, in a convenience sample of hospitals identified by open invitation, through international and regional scientific societies and meetings, individual contacts, and social media. Patients receiving emergency neurosurgery for TBI in each hospital's 30-day study period were all eligible for inclusion, with the exception of patients undergoing insertion of an intracranial pressure monitor only, ventriculostomy placement only, or a procedure for drainage of a chronic subdural haematoma. The primary outcome was mortality at 14 days postoperatively (or last point of observation if the patient was discharged before this time point). Countries were stratified according to their Human Development Index (HDI)-a composite of life expectancy, education, and income measures-into very high HDI, high HDI, medium HDI, and low HDI tiers. Mixed effects logistic regression was used to examine the effect of HDI on mortality while accounting for and quantifying between-hospital and between-country variation. FINDINGS: Our study included 1635 records from 159 hospitals in 57 countries, collected between Nov 1, 2018, and Jan 31, 2020. 328 (20%) records were from countries in the very high HDI tier, 539 (33%) from countries in the high HDI tier, 614 (38%) from countries in the medium HDI tier, and 154 (9%) from countries in the low HDI tier. The median age was 35 years (IQR 24-51), with the oldest patients in the very high HDI tier (median 54 years, IQR 34-69) and the youngest in the low HDI tier (median 28 years, IQR 20-38). The most common procedures were elevation of a depressed skull fracture in the low HDI tier (69 [45%]), evacuation of a supratentorial extradural haematoma in the medium HDI tier (189 [31%]) and high HDI tier (173 [32%]), and evacuation of a supratentorial acute subdural haematoma in the very high HDI tier (155 [47%]). Median time from injury to surgery was 13 h (IQR 6-32). Overall mortality was 18% (299 of 1635). After adjustment for casemix, the odds of mortality were greater in the medium HDI tier (odds ratio [OR] 2·84, 95% CI 1·55-5·2) and high HDI tier (2·26, 1·23-4·15), but not the low HDI tier (1·66, 0·61-4·46), relative to the very high HDI tier. There was significant between-hospital variation in mortality (median OR 2·04, 95% CI 1·17-2·49). INTERPRETATION: Patients receiving emergency neurosurgery for TBI differed considerably in their admission characteristics and management across human development settings. Level of human development was associated with mortality. Substantial opportunities to improve care globally were identified, including reducing delays to surgery. Between-hospital variation in mortality suggests changes at an institutional level could influence outcome and comparative effectiveness research could identify best practices. FUNDING: National Institute for Health Research Global Health Research Group.

Can compliment and complaint data inform the care of individuals with chronic subdural haematoma (cSDH)?

OBJECTIVES: To explore the frequency and nature of complaints and compliments reported to Patient Advice and Liaison (PALS) in individuals undergoing surgery for a chronic subdural haematoma (cSDH). DESIGN: A retrospective study of PALS user interactions. SUBJECTS: Individuals undergoing treatment for cSDH between 2014 and 2019. METHODS: PALS referrals from patients with cSDH between 2014 and 2019 were identified. Case records were reviewed and data on the frequency, nature and factors leading up to the complaint were extracted and coded according to Healthcare Complaints Analysis Tool (HCAT). RESULTS: Out of 531 patients identified, 25 (5%) had a PALS interaction, of which 15 (3%) were complaints and 10 (2%) were compliments. HCAT coding showed 8/15 (53%) of complaints were relationship problems, 6/15 (33%) a management problem and 1/15 (7%) other. Of the relationship problems, 6 (75%) were classed as problems with communication and 2 (25%) as a problem with listening. Of the compliments, 9/10 (90%) related to good clinical quality and 1/10 (10%) to staff-patient relationship. Patients were more likely to register a compliment than family members, who in turn were more likely to register a complaint (p<0.005). Complaints coded as a relationship problem had 2/8 (25%) submitted by a patient and 6/8 (75%) submitted by a relative. CONCLUSIONS: Using the HCAT, routinely collected PALS data can easily be coded to quantify and provide unique perspective on tertiary care, such as communication. It is readily suited to quality improvement and audit initiatives.

Integrated care pathways in neurosurgery: A systematic review.

INTRODUCTION: Integrated care pathways (ICPs) are a pre-defined framework of evidence based, multidisciplinary practice for specific patients. They have the potential to enhance continuity of care, patient safety, patient satisfaction, efficiency gains, teamwork and staff education. In order to inform the development of neurosurgical ICPs in the future, we performed a systematic review to aggregate examples of neurosurgical ICP, to consider their impact and design features that may be associated with their success. METHODS: Electronic databases MEDLINE, EMBASE, and CENTRAL were searched for relevant literature published from date of inception to July 2020. Primary studies reporting details of neurosurgical ICPs, across all pathologies and age groups were eligible for inclusion. Patient outcomes in each case were also recorded. RESULTS: Twenty-four studies were included in our final dataset, from the United States, United Kingdom, Italy, China, Korea, France, Netherlands and Switzerland, and a number of sub-specialties. 3 for cerebrospinal fluid diversion, 1 functional, 2 neurovascular, 1 neuro-oncology, 2 paediatric, 2 skull base, 10 spine, 1 for trauma, 2 miscellaneous (other craniotomies). All were single centre studies with no regional or national examples. Thirteen were cohort studies while 11 were case series which lacked a control group. Effectiveness was typically evaluated using hospital or professional performance metrics, such as length of stay (n = 11, 45.8%) or adverse events (n = 17, 70.8%) including readmission, surgical complications and mortality. Patient reported outcomes, including satisfaction, were evaluated infrequently (n = 3, 12.5%). All studies reported a positive impact. No study reported how the design of the ICP was informed by published literature or other methods. CONCLUSIONS: ICPs have been successfully developed across numerous neurosurgical sub-specialities. However, there is often a lack of clarity over their design and weaknesses in their evaluation, including an underrepresentation of the patient's perspective.

First Report of a Multicenter Prospective Registry of Cranioplasty in the United Kingdom and Ireland.

BACKGROUND: There are many questions that remain unanswered regarding outcomes following cranioplasty including the timing of cranioplasty following craniectomy as well as the material used. OBJECTIVE: To establish and evaluate 30-d outcomes for all cranial reconstruction procedures in the United Kingdom (UK) and Ireland through a prospective multicenter cohort study. METHODS: Patients undergoing cranioplasty insertion or revision between June 1, 2019 and November 30, 2019 in 25 neurosurgical units were included. Data collected include demographics, craniectomy date and indication, cranioplasty material and date, and 30-d outcome. RESULTS: In total, 313 operations were included, consisting of 255 new cranioplasty insertions and 58 revisions. Of the new insertions, the most common indications for craniectomy were traumatic brain injury (n = 110, 43%), cerebral infarct (n = 38, 15%), and aneurysmal subarachnoid hemorrhage (n = 30, 12%). The most common material was titanium (n = 163, 64%). Median time to cranioplasty was 244 d (interquartile range 144-385), with 37 new insertions (15%) within or equal to 90 d. In 30-d follow-up, there were no mortalities. There were 14 readmissions, with 10 patients sustaining a wound infection within 30 d (4%). Of the 58 revisions, the most common reason was due to infection (n = 33, 59%) and skin breakdown (n = 13, 23%). In 41 (71%) cases, the plate was removed during the revision surgery. CONCLUSION: This study is the largest prospective study of cranioplasty representing the first results from the UK Cranial Reconstruction Registry, a first national registry focused on cranioplasty with the potential to address outstanding research questions for this procedure.

A map of transcriptional heterogeneity and regulatory variation in human microglia.

Microglia, the tissue-resident macrophages of the central nervous system (CNS), play critical roles in immune defense, development and homeostasis. However, isolating microglia from humans in large numbers is challenging. Here, we profiled gene expression variation in primary human microglia isolated from 141 patients undergoing neurosurgery. Using single-cell and bulk RNA sequencing, we identify how age, sex and clinical pathology influence microglia gene expression and which genetic variants have microglia-specific functions using expression quantitative trait loci (eQTL) mapping. We follow up one of our findings using a human induced pluripotent stem cell-based macrophage model to fine-map a candidate causal variant for Alzheimer's disease at the BIN1 locus. Our study provides a population-scale transcriptional map of a critically important cell for human CNS development and disease.

Prevention of road traffic collisions and associated neurotrauma in Colombia: An exploratory qualitative study.

INTRODUCTION: Neurotrauma is an important but preventable cause of death and disability worldwide, with the majority being associated with road traffic collisions (RTCs). The greatest burden is seen in low -and middle- income countries (LMICs) where variations in the environment, infrastructure, population and habits can challenge the success of conventional preventative approaches. It is therefore necessary to understand local perspectives to allow for the development and implementation of context-specific strategies which are effective and sustainable. METHODS: This study took place in Colombia where qualitative data collection was carried out with ten key informants between October and November 2019. Semi-structured interviews were conducted and explored perceptions on RTCs and neurotrauma, preventative strategies and interventions, and the role of research in prevention. Interview transcripts were analysed by thematic analysis using a framework approach. RESULTS: Participants' confirmed that RTCs are a significant problem in Colombia with neurotrauma as an important outcome. Human and organisational factors were identified as key causes of the high rates of RTCs. Participants described the current local preventative strategies, but were quick to discuss limitations and challenges to their success. Key barriers reported were poor attitudes and knowledge, particularly in the community. Suggestions were provided on ways to improve prevention through better education and awareness, stricter enforcement and new policies on prevention, proper budgeting and resource allocation, as well as through collaboration and changes in attitudes and leadership. Participants identified four key research areas they felt would influence prevention of RTCs and associated neurotrauma: causes of RTCs; consequences and impact of RTCs; public involvement in research; improving prevention. CONCLUSION: RTCs are a major problem in Colombia despite the current preventative strategies and interventions. Findings from this study have a potential to influence policy, practice and research by illustrating different solutions to the challenges surrounding prevention and by highlighting areas for further research.

Determinants of Vestibular Schwannoma Growth.

OBJECTIVE: Management of vestibular schwannomas (VS) involves surgery, radiotherapy, or surveillance, based on patient and tumor factors. We recently described conditional probability as a more accurate method for stratifying VS growth risk. Building on this, we now describe determinants of VS growth, allowing clinicians to move toward a more personalized approach to growth-risk profiling. METHODS: Retrospective analysis of a prospectively collected database in a tertiary referral skull base unit between 2005 and 2014. Inclusion of patients with unilateral VS managed on surveillance protocol for a minimum of 5 years. Analysis of patient age, sex, tumor location, tumor size, and symptomology using conditional probability. RESULTS: A total of 340 patients met inclusion criteria. The conditional probability of growth of extracanalicular VS was significantly higher versus intracanalicular (IC) VS (30% versus 13%, p < 0.001) as was small-sized VS versus IC VS (28 versus 13%, p = 0.002), but only in the first year after diagnosis. Sex, age, and presenting symptoms did not significantly affect VS growth. CONCLUSION: In our series, extracanalicular VS were more likely to grow than IC VS and small-sized VS more likely to grow than IC VS, but only in the first year after diagnosis. Conversely, sex, age, and presenting symptoms did not affect the conditional probability of VS growth.

Impact of COVID-19 pandemic on surgical neuro-oncology multi-disciplinary team decision making: a national survey (COVID-CNSMDT Study).

OBJECTIVES: Pressures on healthcare systems due to COVID-19 has impacted patients without COVID-19 with surgery disproportionally affected. This study aims to understand the impact on the initial management of patients with brain tumours by measuring changes to normal multidisciplinary team (MDT) decision making. DESIGN: A prospective survey performed in UK neurosurgical units performed from 23 March 2020 until 24 April 2020. SETTING: Regional neurosurgical units outside London (as the pandemic was more advanced at time of study). PARTICIPANTS: Representatives from all units were invited to collect data on new patients discussed at their MDT meetings during the study period. Each unit decided if management decision for each patient had changed due to COVID-19. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome measures included number of patients where the decision to undergo surgery changed compared with standard management usually offered by that MDT. Secondary outcome measures included changes in surgical extent, numbers referred to MDT, number of patients denied surgery not receiving any treatment and reasons for any variation across the UK. RESULTS: 18 units (75%) provided information from 80 MDT meetings that discussed 1221 patients. 10.7% of patients had their management changed-the majority (68%) did not undergo surgery and more than half of this group not undergoing surgery had no active treatment. There was marked variation across the UK (0%-28% change in management). Units that did not change management could maintain capacity with dedicated oncology lists. Low volume units were less affected. CONCLUSION: COVID-19 has had an impact on patients requiring surgery for malignant brain tumours, with patients receiving different treatments-most commonly not receiving surgery or any treatment at all. The variations show dedicated cancer operating lists may mitigate these pressures. STUDY REGISTRATION: This study was registered with the Royal College of Surgeons of England's COVID-19 Research Group (https://www.rcseng.ac.uk/coronavirus/rcs-covid-research-group/).