Microglia and macrophages in glioblastoma: landscapes and treatment directions

Glioblastoma is the most common primary malignant tumour of the central nervous system and remains uniformly and rapidly fatal. The tumour-associated macrophage (TAM) compartment comprises brain-resident microglia and bone marrow-derived macrophages (BMDMs) recruited from the periphery. Immune-suppressive and tumour-supportive TAM cell states predominate in glioblastoma, and immunotherapies, which have achieved striking success in other solid tumours have consistently failed to improve survival in this 'immune-cold' niche context. Hypoxic and necrotic regions in the tumour core are found to enrich, especially in anti-inflammatory and immune-suppressive TAM cell states. Microglia predominate at the invasive tumour margin and express pro-inflammatory and interferon TAM cell signatures. Depletion of TAMs, or repolarisation towards a pro-inflammatory state, are appealing therapeutic strategies and will depend on effective understanding and classification of TAM cell ontogeny and state based on new single-cell and spatial multi-omic in situ profiling. Here, we explore the application of these datasets to expand and refine TAM characterisation, to inform improved modelling approaches, and ultimately underpin the effective manipulation of function.

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 (IFNβ) promoted progenitor resistance to ZIKV, whereas inhibition of JAK1/2 signaling restored productive infection. Additionally, CD11b+ conditioned medium, and IFNβ 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.

Evidence of impaired macroautophagy in human degenerative cervical myelopathy

Degenerative cervical myelopathy (DCM) is a common progressive disease of the spinal cord which can cause tetraplegia. Despite its prevalence, few studies have investigated the pathophysiology of DCM. Macroautophagy is a cellular process which degrades intracellular contents and its disruption is thought to contribute to many neurodegenerative diseases. The present study tests the hypothesis that macroautophagy is impaired in DCM. To address this, we utilised a collection of post-mortem cervical spinal cord samples and investigated seven DCM cases and five human controls. Immunohistochemical staining was used to visualise proteins involved in autophagy. This demonstrated significantly reduced numbers of LC3 puncta in cases versus controls (p = 0.0424). Consistent with reduced autophagy, we identified large aggregates of p62 in four of seven cases and no controls. Tau was increased in two of five cases compared to controls. BCL-2 was significantly increased in cases versus controls (p = 0.0133) and may explain this reduction in autophagy. Increased BCL-2 (p = 0.0369) and p62 bodies (p = 0.055) were seen in more severe cases of DCM. This is the first evidence that autophagy is impaired in DCM; the impairment appears greater in more severe cases. Further research is necessary to investigate whether macroautophagy has potential as a therapeutic target in DCM.

Genome-wide meta-analysis, fine-mapping and integrative prioritization implicate new Alzheimer's disease risk genes

Genome-wide association studies have discovered numerous genomic loci associated with Alzheimer's disease (AD); yet the causal genes and variants are incompletely identified. We performed an updated genome-wide AD meta-analysis, which identified 37 risk loci, including new associations near CCDC6, TSPAN14, NCK2 and SPRED2. Using three SNP-level fine-mapping methods, we identified 21 SNPs with >50% probability each of being causally involved in AD risk and others strongly suggested by functional annotation. We followed this with colocalization analyses across 109 gene expression quantitative trait loci datasets and prioritization of genes by using protein interaction networks and tissue-specific expression. Combining this information into a quantitative score, we found that evidence converged on likely causal genes, including the above four genes, and those at previously discovered AD loci, including BIN1, APH1B, PTK2B, PILRA and CASS4.

Niacin-mediated rejuvenation of macrophage/microglia enhances remyelination of the aging central nervous system

Remyelination following CNS demyelination restores rapid signal propagation and protects axons; however, its efficiency declines with increasing age. Both intrinsic changes in the oligodendrocyte progenitor cell population and extrinsic factors in the lesion microenvironment of older subjects contribute to this decline. Microglia and monocyte-derived macrophages are critical for successful remyelination, releasing growth factors and clearing inhibitory myelin debris. Several studies have implicated delayed recruitment of macrophages/microglia into lesions as a key contributor to the decline in remyelination observed in older subjects. Here we show that the decreased expression of the scavenger receptor CD36 of aging mouse microglia and human microglia in culture underlies their reduced phagocytic activity. Overexpression of CD36 in cultured microglia rescues the deficit in phagocytosis of myelin debris. By screening for clinically approved agents that stimulate macrophages/microglia, we have found that niacin (vitamin B3) upregulates CD36 expression and enhances myelin phagocytosis by microglia in culture. This increase in myelin phagocytosis is mediated through the niacin receptor (hydroxycarboxylic acid receptor 2). Genetic fate mapping and multiphoton live imaging show that systemic treatment of 9-12-month-old demyelinated mice with therapeutically relevant doses of niacin promotes myelin debris clearance in lesions by both peripherally derived macrophages and microglia. This is accompanied by enhancement of oligodendrocyte progenitor cell numbers and by improved remyelination in the treated mice. Niacin represents a safe and translationally amenable regenerative therapy for chronic demyelinating diseases such as multiple sclerosis.

Astrocyte layers in the mammalian cerebral cortex revealed by a single-cell in situ transcriptomic map

Although the cerebral cortex is organized into six excitatory neuronal layers, it is unclear whether glial cells show distinct layering. In the present study, we developed a high-content pipeline, the large-area spatial transcriptomic (LaST) map, which can quantify single-cell gene expression in situ. Screening 46 candidate genes for astrocyte diversity across the mouse cortex, we identified superficial, mid and deep astrocyte identities in gradient layer patterns that were distinct from those of neurons. Astrocyte layer features, established in the early postnatal cortex, mostly persisted in adult mouse and human cortex. Single-cell RNA sequencing and spatial reconstruction analysis further confirmed the presence of astrocyte layers in the adult cortex. Satb2 and Reeler mutations that shifted neuronal post-mitotic development were sufficient to alter glial layering, indicating an instructive role for neuronal cues. Finally, astrocyte layer patterns diverged between mouse cortical regions. These findings indicate that excitatory neurons and astrocytes are organized into distinct lineage-associated laminae.

Free Flap Selection and Outcomes of Soft Tissue Reconstruction Following Resection of Intra-oral Malignancy

Introduction: Surgery to resect intra-oral malignancy is a well-established mode of primary treatment. The tissue requirement in this area is for a thin, pliable flap with minimal bulk and this has historically been provided by free tissue transfer with a radial forearm free flap (RFFF). More recently, a role for the anterolateral thigh free flap (ALTFF) has been described, although in populations with a westernized diet, body habitus may preclude use of an ALTFF due to flap thickness, relative to a radial forearm free flap.

Methods: An analysis of data was performed retrospectively for 90 consecutive patients with intra-oral malignancy, requiring immediate soft tissue reconstruction by the senior author, at Addenbrooke's Hospital between July 2008 and April 2016. Cases requiring bony reconstruction were excluded. Data on patient age, sex, indication for surgery, tumor location and defect type, complications, success rates, and length of stay were recorded.

Results: The majority of patients received an ALTFF (n = 56) with 38% receiving a RFFF (n = 34). Surgical resection took place in the floor of the mouth most frequently. These were closed with ALTFF and RFFF in 41 and 28 occasions, respectively. A success rate of 97% was observed in the RFFF group; 1 flap developed partial necrosis and required complete revision. In the ALTFF group, there was a 100% flap success rate. ALTFF usage resulted in a reduction in the number of intraoperative (p = 0.021) in addition a reduction in the number of days in ITU (p = 0.01) and post-operative clinic visits (p = 0.025).

Conclusion: We present a series that used predominately the ALTFF to reconstruct intra-oral defects following resection of squamous cell carcinoma in a Western population. The results demonstrate that this treatment can produce at least as comparable results as to the use of a RFFF repair in this population, whilst avoiding the donor site morbidity and aesthetic compromise of a RFFF.

Correction: Modelling outcomes after paediatric brain injury with admission laboratory values: a machine-learning approach

A correction to this paper has been published and can be accessed via a link at the top of the paper.

Probable Catastrophic Antiphospholipid Syndrome with Intracerebral Hemorrhage Secondary to Epstein-Barr Viral Infection

BACKGROUND

Catastrophic antiphospholipid syndrome (CAPS) is a rare, severe variant of antiphospholipid syndrome with a high mortality rate. We report a unique case of CAPS secondary to Epstein-Barr viral (EBV) infection complicated by pulmonary and intracerebral hemorrhage. A review of the CAPS literature relevant to intensive care practice is used to outline a rational approach to diagnosis and management.

METHODS

All data are from a single patient admitted to the Neurosciences Critical Care Unit in Addenbrooke's Hospital, Cambridge, in March 2016. Medline, Web of Science, PubMed, and the Cochrane Library were searched through September 2016 without restrictions for cases of CAPS, management of CAPS in the intensive care unit, and hemorrhage complicating CAPS. The patient gave express written consent to access and publish these data.

RESULTS

This is only the second reported case of probable CAPS secondary to EBV infection. Furthermore, pulmonary and intracerebral hemorrhage is rare manifestations of this multisystem prothrombotic state which provided unique challenges to the management.

CONCLUSIONS

While rare, CAPS should be considered in any patient presenting with rapidly progressive multiorgan failure, evidence of thrombotic microangiopathy, and antiphospholipid antibodies. A high index of suspicion is required as early, aggressive, multimodal treatment with anticoagulation, and immunosuppression improves outcomes.

An integrated genomic analysis of anaplastic meningioma identifies prognostic molecular signatures

Anaplastic meningioma is a rare and aggressive brain tumor characterised by intractable recurrences and dismal outcomes. Here, we present an integrated analysis of the whole genome, transcriptome and methylation profiles of primary and recurrent anaplastic meningioma. A key finding was the delineation of distinct molecular subgroups that were associated with diametrically opposed survival outcomes. Relative to lower grade meningiomas, anaplastic tumors harbored frequent driver mutations in SWI/SNF complex genes, which were confined to the poor prognosis subgroup. Aggressive disease was further characterised by transcriptional evidence of increased PRC2 activity, stemness and epithelial-to-mesenchymal transition. Our analyses discern biologically distinct variants of anaplastic meningioma with prognostic and therapeutic significance.

Predictors of early progression of surgically treated atypical meningiomas

Background

Clinical behaviour of atypical meningiomas is not uniform. While, as a group, they exhibit a high recurrence rate, some pursue a more benign course, whereas others progress early. We aim to investigate the imaging and pathological factors that predict risk of early tumour progression and to determine whether early progression is related to outcome.

Methods

Adult patients with WHO grade II meningioma treated in three regional referral centres between 2007 and 2014 were included. MRI and pathology characteristics were assessed. Gross total resection (GTR) was defined as Simpson 1–3. Recurrence was classified into early and late (≤ 24 vs. > 24 months).

Results

Among the 220 cases, 37 (16.8%) patients progressed within 24 months of operation. Independent predictors of early progression were subtotal resection (STR) (p = 0.005), parafalcine/parasagittal location (p = 0.015), peritumoural oedema (p = 0.027) and mitotic index (MI) > 7 (p = 0.007). Adjuvant radiotherapy was negatively associated with early recurrence (p = 0.046). Thirty-two per cent of patients with residual tumour and 26% after GTR received adjuvant radiotherapy. There was a significantly lower proportion of favourable outcomes at last follow-up (mRS 0–1) in patients with early recurrence (p = 0.001).

Conclusions

Atypical meningiomas are a heterogeneous group of tumours with 16.8% patients having recurrence within 24 months of surgery. Residual tumour, parafalcine/parasagittal location, peritumoural oedema and a MI > 7 were all independently associated with early recurrence. As administration of adjuvant radiotherapy was not protocolised in this cohort, any conclusions about benefits of irradiation of WHO grade II meningiomas should be viewed with caution. Patients with early recurrence had worse neurological outcome. While histological and imaging characteristics provide some prognostic value, further molecular characterisation of atypical meningiomas is warranted to aid clinical decision making.

Radiological Correlates of Raised Intracranial Pressure in Children: A Review

Radiological assessment of the head is a routine part of the management of traumatic brain injury. This assessment can help to determine the requirement for invasive intracranial pressure (ICP) monitoring. The radiological correlates of elevated ICP have been widely studied in adults but far fewer specific pediatric studies have been conducted. There is, however, growing evidence that there are important differences in the radiological presentations of elevated ICP between children and adults; a reflection of the anatomical and physiological differences, as well as a difference in the pathophysiology of brain injury in children. Here in, we review the radiological parameters that correspond with increased ICP in children that have been described in the literature. We then describe the future directions of this work and our recommendations in order to develop non-invasive and radiological markers of raised ICP in children.

Prognostic value of peripheral leukocyte counts and plasma glucose in intracerebral haemorrhage

INTRODUCTION

The value of routine blood markers as prognostic indicators is increasingly established in acute ischaemic stroke. The relationship is less well defined in haemorrhagic stroke. In this study, we examined routine admission blood markers and applied a logistic regression model to predict outcome in haemorrhagic stroke.

METHOD

A retrospective study was performed between September 2009-2011 in a general admission stroke unit in the UK. 1400 patients were admitted with stroke during this period, of which 117 were haemorrhagic. Admission systolic and diastolic blood pressure, venous blood samples and pre- and post-morbid (i.e. at discharge or death) modified Rankin scores were also recorded. Patients were controlled for age, sex, smoking status, hypertension status and co-morbidities (using Charleson Comorbidity Index scores). Logistic regression models were generated using SPSS.

RESULTS

113 patients were analysed (58 male/55 female). Lower admission blood glucose (p=0.009), lower total leukocyte count (p=0.001) and lower neutrophil count (p=0.021) were found to be significantly associated with survival vs. death. 90 patients with complete glucose, leukocyte count, sex (forced) and pre-morbid Rankin score (forced) data were entered into a logistic regression model. This predicted correct group membership (survived/deceased) in 72.2% of cases (83.9% survivors/52.9% deceased correctly predicted). In females with normal leukocyte count and glucose, survival was predicted with 68% accuracy.

CONCLUSION

These results suggest that a logistic regression model using low admission glucose and low total leukocyte count may be markers of better prognosis in acute haemorrhagic stroke with a differential effect between sexes.

Correlating optic nerve sheath diameter with opening intracranial pressure in pediatric traumatic brain injury

INTRODUCTION

The use of clinical markers to predict intracranial pressure (ICP) is desirable as a first-line measure to assist in decision making as to whether invasive monitoring is required. Correlations between ICP and optic nerve sheath diameter (ONSD) using CT and MRI have been observed in adult populations. However, data on this modality in children is less well documented.

METHODS

ONSD was measured by independent observers and correlated with opening ICP at insertion of invasive monitoring probes in pediatric traumatic brain injury patients admitted to Addenbrookes Hospital between January 2009 and December 2013.

RESULTS

Thirty-six patients with a mean age of 8.2 y were admitted to the Pediatric Intensive Care Unit (PICU) with a traumatic head injury and required invasive neurosurgical monitoring. The median ICP was 18 ± 10 mmHg (median ± IQR), the median right ONSD was 5.6 ± 2.5 mm and the left was 5.9 ± 3.2 mm. The Intraclass correlation between observers was 0.91 (P < 0.0001). The correlation of mean ONSD and max ONSD with ICP was 0.712 (P < 0.0001) and 0.713 (P < 0.0001), respectively. Area under ROC curve for both mean and max ONSD is 0.85 (95% CI: 0.73-0.98).

CONCLUSION

Where pediatric patients present with an ONSD of over 6.1 mm following a traumatic brain injury (TBI), ICP monitoring should be implemented.

Minimising costs in spinal surgery: is group & save testing justified in lumbar decompression surgery?

BACKGROUND

Lumbar microdiscectomy and laminectomy are two of the most common neurosurgical procedures performed worldwide. Current practice still sees pre-operative group and save testing prior to this surgery. The aim of this study was to determine the need for pre-operative group and save and post-operative blood checks.

METHODS

Patient archives were reviewed to identify those undergoing primary elective lumbar decompression surgery at the Institute of Neurological Sciences, Queen Elizabeth University Hospital, Glasgow, UK. Hematology results before and after surgery, whether group and save was carried out, and blood transfusion requirements, if any, were collected.

RESULTS

A total of 200 patients in total were included. Ninety-one percent of microdiscectomy patients and 95% of laminectomy patients underwent group and save testing prior to surgery. No patients received a transfusion as a result of their procedure. The mean hemoglobin drop after surgery was 11 g/L for the microdiscectomy group and 17 g/L for the laminectomy group.

CONCLUSIONS

Our findings strongly suggest that pre-operative group and save is unnecessary in lumbar microdiscectomy and laminectomy. As such, we support the abandonment of routine pre-operative group and save and post-operative blood checks, with significant cost saving effects. However, O negative blood should always be available in case of major peri-operative bleeding.

Corrigendum: Glycemia Is Related to Impaired Cerebrovascular Autoregulation after Severe Pediatric Traumatic Brain Injury: A Retrospective Observational Study

[This corrects the article on p. 205 in vol. 5, PMID: 28993802.].

Decompressive craniectomy for traumatic intracranial hypertension: application in children

Traumatic brain injury remains prevalent in children, particularly within the adolescent age group. In severe injury, the priority of treatment is to stabilise the patient initially and prevent the evolution of brain swelling and secondary ischaemia using tiers of medical therapy. The final stage of intervention for such patients is a decompressive craniectomy. Here in, we identify the current evidence for performing decompressive crainectomy in children including the results from the RESCUEicp study.

Glycemia Is Related to Impaired Cerebrovascular Autoregulation after Severe Pediatric Traumatic Brain Injury: A Retrospective Observational Study

INTRODUCTION

A strong association exists between hyperglycemia and outcome in pediatric traumatic brain injury (TBI). Herein, we describe observations of serum markers of glucose metabolism in a cohort of pediatric TBI patients and how these variables are related to parameters of intracranial pathophysiology.

METHODS

A retrospective analysis was performed on pediatric severe TBI patients admitted to Addenbrookes Hospital Paediatric Intensive Care Unit (PICU) between January 2001 and December 2013. Demographic, outcome, systemic physiological, and cerebral autoregulatory data were extracted for patients who had received continuous invasive monitoring (ICM+, Cambridge Enterprise, Cambridge, UK). Data were analyzed using a mixed linear model.

RESULTS

Forty-four patients with an average age of 12.2 years were admitted to the PICU with a TBI requiring invasive neurosurgical monitoring. Thirty-two patients (73%) survived, with favorable outcomes in 62%. The mean (SD) intracranial pressure (ICP) was 17.6 + 9.0 mmHg, MAP was 89.7 + 9.0 mmHg, and pressure-reactivity index (PRx) was -0.01 + 0.23 a.u. The mean (SD) serum lactate was 2.2 (3.3) mmol/L. and the mean (SD) serum glucose was 6.1 (1.6) mmol/L. Early hyperglycemia was strongly associated with both PRx (Pearson correlation 0.351, p < 0.001) and ICP (Pearson correlation 0.240, p = 0.002) death (p = 0.021) and impaired cerebral autoregulation (p = 0.02). There was a strong association between ICP and serum lactate (p = 0.001).

CONCLUSION

Increases in systemic glucose are associated with impaired cerebrovasular autoregulation after severe pediatric TBI. Moreover, deranged blood glucose is a marker of poor prognosis. Further studies are required to delineate putative mechanisms of hyperglycemia induced cerebral harm.

The application of adult traumatic brain injury models in a pediatric cohort

OBJECTIVE There is increasing interest in the use of predictive models of outcome in adult head injury. Two international models have been identified to be reliable modalities for predicting outcome: the Corticosteroid Randomisation After Significant Head Injury (CRASH) model, and the International Mission on Prognosis and Analysis of randomized Controlled Trials in TBI (IMPACT) model. However, these models are designed only to identify outcomes in adult populations. METHODS A retrospective analysis was performed on pediatric patients with severe traumatic brain injury (TBI) admitted to the pediatric intensive care unit (PICU) of Addenbrooke's Hospital between January 2009 and December 2013. The individual risk of 14-day mortality was calculated using the CRASH-Basic and -CT models, and the risk of 6-month mortality calculated using the IMPACT-Core and -Extended (including CT findings) models. Model accuracy was determined by standardized mortality ratio (SMtR; observed/expected deaths), discrimination was evaluated as the area under the receiver operating curve (AUROC), and calibration assessed using the Hosmer-Lemeshow χ² test. RESULTS Ninety-four patients with an average age of 7.3 years were admitted to the PICU with a TBI. The mortality rate was 12.7% at 14 days and at 6 months. For the CRASH-Basic model, the SMtR was 1.42 and both calibration (χ² = 6.1, p = 0.64) and discrimination (AUROC = 0.92) were good. For the IMPACT-Core model, the SMtR was 1.03 and the model was also well calibrated (χ² = 8.99, p = 0.34) and had good discrimination (AUROC = 0.85). Poor outcome was observed in 17% of the cohort and identified with the CRASH-Basic and IMPACT-Core models to varying degrees: standardized morbidity ratio = 0.89 vs 0.67, respectively; calibration = 6.5 (χ²) and 0.59 (p value) versus 8.52 (χ²) and 0.38 (p value), respectively; and discrimination (AUROC) = 0.92 versus 0.83, respectively. CONCLUSIONS Adult head injury models may be applied with sufficient accuracy to identify predictors of morbidity and mortality in pediatric TBI.

On the brain structure heterogeneity of autism: Parsing out acquisition site effects with significance-weighted principal component analysis

Neuroimaging studies have reported structural and physiological differences that could help understand the causes and development of Autism Spectrum Disorder (ASD). Many of them rely on multisite designs, with the recruitment of larger samples increasing statistical power. However, recent large-scale studies have put some findings into question, considering the results to be strongly dependent on the database used, and demonstrating the substantial heterogeneity within this clinically defined category. One major source of variance may be the acquisition of the data in multiple centres. In this work we analysed the differences found in the multisite, multi-modal neuroimaging database from the UK Medical Research Council Autism Imaging Multicentre Study (MRC AIMS) in terms of both diagnosis and acquisition sites. Since the dissimilarities between sites were higher than between diagnostic groups, we developed a technique called Significance Weighted Principal Component Analysis (SWPCA) to reduce the undesired intensity variance due to acquisition site and to increase the statistical power in detecting group differences. After eliminating site-related variance, statistically significant group differences were found, including Broca's area and the temporo-parietal junction. However, discriminative power was not sufficient to classify diagnostic groups, yielding accuracies results close to random. Our work supports recent claims that ASD is a highly heterogeneous condition that is difficult to globally characterize by neuroimaging, and therefore different (and more homogenous) subgroups should be defined to obtain a deeper understanding of ASD. Hum Brain Mapp 38:1208-1223, 2017. © 2016 Wiley Periodicals, Inc.

Medical student perceptions of research and research-orientated careers: An international questionnaire study

BACKGROUND

Engaging and inspiring the next generation of physician-scientists at an early stage is recognised as key to ensure the future of medical research. However, little is known about medical student perceptions of research.

OBJECTIVES

We attempted to ascertain perceptions of research and research-orientated careers from medical students studying in different countries.

METHODS

An online questionnaire was developed, piloted, and promoted to medical students in various countries.

RESULTS

1625 responses were collected from 38 countries. Analysis was restricted to data collected from countries with >100 responses (n = 890). Less than half the respondents felt their medical school provided adequate research training. Key perceived barriers to research participation as a student included lack of time and difficulty finding mentors or projects. A significant gender disparity existed in research ambitions of students with females desiring less research involvement. The importance of barriers and satisfaction with research training differed significantly between countries.

CONCLUSIONS

Students perceive a number of key barriers to research involvement and pursuit of research-orientated careers. Programmes designed to engage students with research should focus on overcoming identified barriers. Greater effort is needed to engage female students who report more significant barriers and less desire to follow research-orientated careers.

Increased trends in the use of treatment-limiting decisions in a regional neurosurgical unit

INTRODUCTION

Treatment-limiting decisions (TLDs) are employed to actively withhold treatment from patients whom clinicians feel would derive no benefit or suffer detrimental effects from further intervention. The use of such decisions has been heavily discussed in the media and clinicians in the past have been reluctant to institute them, even though it is in the best interests of the patients. Their use is influenced by several ethical, religious and social factors all of which have changed significantly over time. This study reports the trends in use of TLDs in a regional neurosurgical unit over 23 years.

METHODS

Patient archives were reviewed to identify the number of admissions and procedures performed at the Institute of Neurological Sciences, Glasgow, in the years 1988, 1997 and 2011. Death certificate records were used to identify mortality in the unit in the year 2011. Patient records were used to obtain details of diagnosis, time from admission to death, and the presence and timing of a TLD.

RESULTS

The results show an increase in the use of TLDs, with decisions made for 89% of those who died in 2011, compared to 68% in 1997 and 51% in 1988. The number of admissions has increased substantially since 1988 as has the percentage of patients undergoing surgery (46, 67 and 72% in 1988, 1997 and 2011, respectively).

CONCLUSION

There is a trending increase in the number of patients who have a TLD in our regional neurosurgical unit. This demonstrates an increased willingness of clinicians to recognise poor prognosis and to withdraw or withhold treatment in these cases. Continued appropriate use of the TLD is recommended but it is to only ever reflect the best interests of the patient.

Comparative surgical outcome associated with the management of brain arteriovenous malformation in a regional neurosurgical centre

OBJECTIVES

Microsurgical resection of brain arteriovenous malformation (AVMs) is challenging, however, expert surgical series from large volume centres, have reported over 95% occlusion rates with 2 to 8% risk of morbidity & mortality. Data from a regional neurosurgical unit was analysed and compared with published series for the purposes of quality control. We also compared our surgical result with other treatment modalities from the whole AVM cohort managed over the same study period.

DESIGN

Retrospective analysis of a locally held AVM database.

SUBJECTS

Of the 141 AVM patients, 54 (35M, 19F, age range 9-68 years) underwent microsurgical removal of AVM by the senior author, from 2006 to 2012. 27 (19%), 18 (13%), 20 (14%), 22 (16%) had endovascular therapy only, radiosurgery only, combination therapy (endovascular and radiosurgery) and conservative management, respectively.

METHODS

Case notes were reviewed to determine clinical and radiological outcomes. Statistical analysis performed using SPSS with p < 0.05 defined as statistical significance.

RESULTS

In the surgical series, the Spetzler-Martin (SM) grade distribution was as follows: 17 grade I (32%), 31 grade II (57%), and 6 grade III (11%). 31 patients (57%) presented with intracranial haemorrhage, 12 patients (22%) with seizures. Of the 54 patients, 51 (94%) had angiographically confirmed obliteration of their AVM. Median follow-up for the entire cohort was 7 years. 83% of surgical patients have mRS 0-1, compared to 78%, 67%, 45%, 18% of patients managed by endovascular therapy, radiosurgery, combination therapy, conservative surveillance, respectively (p < 0.0001). However, the groups were not comparable in terms of SM grade or clinical presentation and the numbers in each group were relatively small. Seizure presentations were encountered in 23% (32/141) of the overall patients, and all the surviving patients were on anticonvulsants, except in the surgical arm, 7/12 (58%) patients were off their antiepileptic medications at last follow-up.

CONCLUSIONS

The results demonstrate a 94% surgical obliteration rate and 11% long-term neurological deficits for brain AVM patients managed surgically and were comparable to expert series. Achieving acceptable results is possible in lower volume settings, however, patient selection is important and the role of an experienced neurovascular team cannot be overstated.

Continuous Multimodality Monitoring in Children after Traumatic Brain Injury-Preliminary Experience

Introduction

Multimodality monitoring is regularly employed in adult traumatic brain injury (TBI) patients where it provides physiologic and therapeutic insight into this heterogeneous condition. Pediatric studies are less frequent.

Methods

An analysis of data collected prospectively from 12 pediatric TBI patients admitted to Addenbrooke’s Hospital, Pediatric Intensive Care Unit (PICU) between August 2012 and December 2014 was performed. Patients’ intracranial pressure (ICP), mean arterial pressure (MAP), and cerebral perfusion pressure (CPP) were monitored continuously using brain monitoring software ICM+^®,) Pressure reactivity index (PRx) and ‘Optimal CPP’ (CPPopt) were calculated. Patient outcome was dichotomized into survivors and non-survivors.

Results

At 6 months 8/12 (66%) of the cohort survived the TBI. The median (±IQR) ICP was significantly lower in survivors 13.1±3.2 mm Hg compared to non-survivors 21.6±42.9 mm Hg (p = 0.003). The median time spent with ICP over 20 mm Hg was lower in survivors (9.7+9.8% vs 60.5+67.4% in non-survivors; p = 0.003). Although there was no evidence that CPP was different between survival groups, the time spent with a CPP close (within 10 mm Hg) to the optimal CPP was significantly longer in survivors (90.7±12.6%) compared with non-survivors (70.6±21.8%; p = 0.02). PRx provided significant outcome separation with median PRx in survivors being 0.02±0.19 compared to 0.39±0.62 in non-survivors (p = 0.02).

Conclusion

Our observations provide evidence that multi-modality monitoring may be useful in pediatric TBI with ICP, deviation of CPP from CPPopt, and PRx correlating with patient outcome.

Multimodal MRI can identify perfusion and metabolic changes in the invasive margin of glioblastomas

PURPOSE

To use perfusion and magnetic resonance (MR) spectroscopy to compare the diffusion tensor imaging (DTI)-defined invasive and noninvasive regions. Invasion of normal brain is a cardinal feature of glioblastomas (GBM) and a major cause of treatment failure. DTI can identify invasive regions.

MATERIALS AND METHODS

In all, 50 GBM patients were imaged preoperatively at 3T with anatomic sequences, DTI, dynamic susceptibility perfusion MR (DSCI), and multivoxel spectroscopy. The DTI and DSCI data were coregistered to the spectroscopy data and regions of interest (ROIs) were made in the invasive (determined by DTI), noninvasive regions, and normal brain. Values of relative cerebral blood volume (rCBV), N-acetyl aspartate (NAA), myoinositol (mI), total choline (Cho), and glutamate + glutamine (Glx) normalized to creatine (Cr) and Cho/NAA were measured at each ROI.

RESULTS

Invasive regions showed significant increases in rCBV, suggesting angiogenesis (invasive rCBV 1.64 [95% confidence interval, CI: 1.5-1.76] vs. noninvasive 1.14 [1.09-1.18]; P < 0.001), Cho/Cr (invasive 0.42 [0.38-0.46] vs. noninvasive 0.35 [0.31-0.38]; P = 0.02) and Cho/NAA (invasive 0.54 [0.41-0.68] vs. noninvasive 0.37 [0.29-0.45]; P = < 0.03), suggesting proliferation, and Glx/Cr (invasive 1.54 [1.27-1.82] vs. noninvasive 1.3 [1.13-1.47]; P = 0.028), suggesting glutamate release; and a significantly reduced NAA/Cr (invasive 0.95 [0.85-1.05] vs. noninvasive 1.19 [1.06-1.31]; P = 0.008). The mI/Cr was not different between the three ROIs (invasive 1.2 [0.99-1.41] vs. noninvasive 1.3 [1.14-1.46]; P = 0.68). In the noninvasive regions, the values were not different from normal brain.

CONCLUSION

Combining DTI to identify the invasive region with perfusion and spectroscopy, we can identify changes in invasive regions not seen in noninvasive regions.

From molecules to neural morphology: understanding neuroinflammation in autism spectrum condition

Growing evidence points toward a critical role for early (prenatal) atypical neurodevelopmental processes in the aetiology of autism spectrum condition (ASC). One such process that could impact early neural development is inflammation. We review the evidence for atypical expression of molecular markers in the amniotic fluid, serum, cerebrospinal fluid (CSF), and the brain parenchyma that suggest a role for inflammation in the emergence of ASC. This is complemented with a number of neuroimaging and neuropathological studies describing microglial activation. Implications for treatment are discussed.

Defending a traditional practice in the modern era: The use of lumbar puncture in the investigation of subarachnoid haemorrhage

INTRODUCTION

Acute severe headache is a common medical presentation, and a common area of diagnostic uncertainty. Subarachnoid haemorrhage (SAH) is the cause in a minority of patients and has a high rate of morbidity and mortality. Therefore, its conclusive diagnosis with computed tomography (CT) or lumbar puncture (LP) is paramount. With advancement in imaging technology, emerging evidence now suggests that LP is no longer required for a subset of patients as CT has 100% sensitivity in detecting SAH, when performed under specific conditions.

OBJECTIVES

To assess the proportion of patients with conclusive CSF xanthochromia results following a negative CT scan in suspected SAH to determine the diagnostic efficacy of LP.

METHODS

CSF bilirubin and oxyhaemoglobin spectrophotometric absorbance data from all centres in a regional health board were identified for consecutive patients over a 6-month period. Results were stratified as conclusive (positive or negative), or inconclusive according to national guidelines.

RESULTS

239 of 255 (93.7%) results were conclusive: 89.0% were negative (227 of 255). 4.7% of results were positive (12 of 255), revealing 4 cerebral aneurysms requiring treatment. 16 out of 255 (6.3%) samples were inconclusive, yielding 1 aneurysm requiring treatment. In the same period, there were 27 CT-positive cases of SAH.

CONCLUSIONS

LP has a high diagnostic yield, eliminating the need for neurosurgical opinion or investigation in almost 90% of cases. The test is both cost and time efficient and subjects only a small number of patients to the radiation and contrast risks of angiography.

Intracranial aneurysm in a patient with glucocorticoid-remediable aldosteronism

Glucocorticoid-remediable aldosteronism (GRA) is an autosomal dominant disorder in which the increase in aldosterone secretion produced by Adrenocorticotropic hormone (ACTH) is no longer transient. Here we present a case of a 32-year-old man with GRA who was found to have an intracranial aneurysm following screening. His blood pressure had been well controlled and closely monitored since diagnosis and the institution of treatment at age 13 years. This is a rarely reported example of this manifestation in GRA, and both the treatment and rationale for therapy are discussed below.

Pharmacologic Management of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) remains a condition with suboptimal functional outcomes, especially in the young population. Pharmacotherapy has an accepted role in several aspects of the disease and an emerging role in several others. No preventive pharmacologic interventions for SAH currently exist. Antiplatelet medications as well as anticoagulation have been used to prevent thromboembolic events after endovascular coiling. However, the main focus of pharmacologic treatment of SAH is the prevention of delayed cerebral ischemia (DCI). Currently the only evidence-based medical intervention is nimodipine. Other calcium channel blockers have been evaluated without convincing efficacy. Anti-inflammatory drugs such as statins have demonstrated early potential; however, they failed to provide significant evidence for the use in preventing DCI. Similar findings have been reported for magnesium, which showed potential in experimental studies and a phase 2 trial. Clazosentane, a potent endothelin receptor antagonist, did not translate to improve functional outcomes. Various other neuroprotective agents have been used to prevent DCI; however, the results have been, at best inconclusive. The prevention of DCI and improvement in functional outcome remain the goals of pharmacotherapy after the culprit lesion has been treated in aneurysmal SAH. Therefore, further research to elucidate the exact mechanisms by which DCI is propagated is clearly needed. In this article, we review the current pharmacologic approaches that have been evaluated in SAH and highlight the areas in which further research is needed.

Trends in the mortality of non-traumatic subarachnoid hemorrhage in Colombia: a 10-year analysis of a nationwide registry

OBJECTIVE

To assess trends in mortality from 1999 to 2008 resulting from non-traumatic subarachnoid hemorrhage (SAH) in the Colombian population.

METHOD

This population-based study analyzed all deaths by assuming a Poisson model.

RESULTS

Subarachnoid hemorrhage-related deaths showed a statistically significant increase of 1.6% per year (p<0.001). The age-standardized analysis demonstrated an increased mortality trend of 3.3% per year (p<0.001) in people older than 70 years, but a decreased mortality trend in people younger than 50. It remained stable in patients 50-69 years old.

CONCLUSION

The overall SAH-related mortality rate in Colombia has increased because increased mortality among the elderly has been counterbalanced by reduced mortality rates in younger age groups. These disparities may reflect epidemiologic transition, treatment inequities, or a less favorable comorbid profile.

Is there a role for treating inflammation in moyamoya disease?: a review of histopathology, genetics, and signaling cascades

Moyamoya disease is a slowly progressing steno-occlusive condition affecting the cerebrovasculature. Affecting the terminal internal carotid arteries (ICA) and there branches, bilaterally, a resulting in a fine vascular network in the base of the brain to allow for compensation of the stenosed vessels. While there is obvious evidence of the involvement of inflammatory proteins in the condition, this has historically not been acknowledged as a causal factor. Here we describe the fundamental histopathology, genetics, and signaling cascades involved in moyamoya and debate whether these factors can be linked as causal factor for the condition or whether they are simply a secondary result of the ischemia described in the condition. A particular focus has been placed on the multitude of signaling cascades linked to the condition as these are viewed as having the greatest therapeutic potential. As such we hope to draw some novel insight into potential diagnostic and therapeutic inflammatory targets in the condition.

Non-steroidal anti-inflammatory drugs used as a treatment modality in subarachnoid hemorrhage

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most frequently prescribed therapies worldwide. Meta-analysis data indicate the potential for myocardial infarction, cerebrovascular incident, heart failure, renal failure and arterial hypertension. Here we review the mechanisms of their actions and the potential for therapeutic use in subarachnoid hemorrhage. Searches were performed using PubMed with the search terms "subarachnoid hemorrhage", "NSAID", "treatment", "management", "cerebral aneurysm", and "vasospasm" from 1970 to February, 2012. Articles were also identified through searches of the Cochrane library and searches of the authors' own files. Only papers published in English were reviewed.There are considerably mixed views on the potential impact of NSAIDs on the treatment and prevention of SAH. Whilst theoretically, the potential for positive intervention in the condition is huge, little effect appears to be measurable in clinical practice.

Exploring the use of estrogen & progesterone replacement therapy in subarachnoid hemorrhage

The hypothesis that alterations in hormone levels can impact on subarachnoid hemorrhage (SAH) is rapidly gaining momentum. Specifically, the concept that post-menopausal women are more susceptible to the condition has convinced many of the protective roles of estrogen and progesterone. Here we review the mechanisms of their actions and the potential for estrogen and progesterone replacement therapy in subarachnoid hemorrhage. Searches were performed using PubMed with the search terms "subarachnoid hemorrhage", "estrogen", "progesterone "treatment", "management", "cerebral aneurysm", and "vasospasm" from 1970 to February, 2012. Articles were also identified through searches of the Cochrane library and searches of the authors' own files. Only papers published in English were reviewed. In conclusion, there is significant theoretical evidence for the potential role of estrogen and progesterone use in altering the pathogenesis of SAH. Nevertheless, this has received mixed reviews in both case controlled studies and cohort analysis within the literature.

Biomarkers of pediatric brain tumors

Background and Need for Novel Biomarkers: Brain tumors are the leading cause of death by solid tumors in children. Although improvements have been made in their radiological detection and treatment, our capacity to promptly diagnose pediatric brain tumors in their early stages remains limited. This contrasts several other cancers where serum biomarkers such as cancer antigen (CA) 19-9 and CA 125 facilitate early diagnosis and treatment.

AIM

The aim of this article is to review the latest literature and highlight biomarkers which may be of clinical use in the common types of primary pediatric brain tumor.

METHODS

A PubMed search was performed to identify studies reporting biomarkers in the bodily fluids of pediatric patients with brain tumors. Details regarding the sample type [serum, cerebrospinal fluid (CSF), or urine], biomarkers analyzed, methodology, tumor type, and statistical significance were recorded.

RESULTS

A total of 12 manuscripts reporting 19 biomarkers in 367 patients vs. 397 controls were identified in the literature. Of the 19 biomarkers identified, 12 were isolated from CSF, 2 from serum, 3 from urine, and 2 from multiple bodily fluids. All but one study reported statistically significant differences in biomarker expression between patient and control groups.

CONCLUSION

This review identifies a panel of novel biomarkers for pediatric brain tumors. It provides a platform for the further studies necessary to validate these biomarkers and, in addition, highlights several techniques through which new biomarkers can be discovered.

Regional susceptibility to TNF-α induction of murine brain inflammation via classical IKK/NF-κB signalling

It is becoming clear that inflammation plays a significant role in a number of neurological and psychiatric conditions. Post mortem brain samples in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, schizophrenia and most recently autism spectrum condition, all exhibit neuroglial activation and inflammatory markers within the CSF. Many questions remain about the underlying molecular mechanisms. By adding the pro-inflammatory cytokine, TNF-α, to mouse brain tissue we demonstrated that the frontal lobes and temporal region, areas involved in higher functions such as memory and learning, are most susceptible to cytokine-induced inflammation via the NF-κB signalling pathway. We observed direct correlations between the volumetric increase and molecular expression indicating that therapeutic targets in these lobes may require different approaches when treating conditions with a central neuroinflammatory component.

Audio-induced psychogenic non-epileptic seizures

A 45-year-old woman presented with vague attacks, which consisted of headaches, confusion and sleepiness. An electroencephalograph was normal, but subsequent scans revealed the presence of a right-sided convexity meningioma. This was excised and complications led to the removal of an infected bone flap in a separate procedure the following year. Various types of 'seizures' resulted from the operation. These were described to involve both tonic-clonic and absence seizures. This continued for 18 years, unaffected by medication, until a specialist diagnosed pseudo-epilepsy, by fortune of a hospital fire alarm. The patient began a psychological intervention programme including cognitive-behavioural therapy, which has significantly reduced episodes. In conclusion, psychogenic non-epileptic seizures may develop after intracranial neurosurgery undertaken for indications other than the control of refractory epileptic seizures. A diagnosis of psychogenic non-epileptic seizures should be considered in patients who develop refractory seizures after neurosurgery and managed appropriately.

Aberrant NF-kappaB expression in autism spectrum condition: a mechanism for neuroinflammation

Autism spectrum condition (ASC) is recognized as having an inflammatory component. Post-mortem brain samples from patients with ASC display neuroglial activation and inflammatory markers in cerebrospinal fluid, although little is known about the underlying molecular mechanisms. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a protein found in almost all cell types and mediates regulation of immune response by inducing the expression of inflammatory cytokines and chemokines, establishing a feedback mechanism that can produce chronic or excessive inflammation. This article describes immunodetection and immunofluorescence measurements of NF-κB in human post-mortem samples of orbitofrontal cortex tissue donated to two independent centers: London Brain Bank, Kings College London, UK (ASC: n = 3, controls: n = 4) and Autism Tissue Program, Harvard Brain Bank, USA (ASC: n = 6, controls: n = 5). The hypothesis was that concentrations of NF-κB would be elevated, especially in activated microglia in ASC, and pH would be concomitantly reduced (i.e., acidification). Neurons, astrocytes, and microglia all demonstrated increased extranuclear and nuclear translocated NF-κB p65 expression in brain tissue from ASC donors relative to samples from matched controls. These between-groups differences were increased in astrocytes and microglia relative to neurons, but particularly pronounced for highly mature microglia. Measurement of pH in homogenized samples demonstrated a 0.98-unit difference in means and a strong (F = 98.3; p = 0.00018) linear relationship to the expression of nuclear translocated NF-κB in mature microglia. Acridine orange staining localized pH reductions to lysosomal compartments. In summary, NF-κB is aberrantly expressed in orbitofrontal cortex in patients with ASC, as part of a putative molecular cascade leading to inflammation, especially of resident immune cells in brain regions associated with the behavioral and clinical symptoms of ASC.