Evaluation of severe traumatic brain injury referrals to the National Tertiary Neurosurgical Centre in the Republic of Ireland.

BACKGROUND: Transfer of all severe TBI patients to a neurosurgical unit (NSU) has been advocated irrespective of levels of complexity and prognostic factors. Previous publications have suggested that only 50% of severe TBI patients in Ireland were managed in NSUs. AIMS: This study aims to audit severe TBI referrals to the National Neurosurgical Centre, to evaluate reasons for nonacceptance, assess for differences in the transferred and not transferred cohorts and to analyse observed and expected mortality rates. METHODS: Data on all patients with TBI referred in 2021 were prospectively collected using an electronic referral system. Patients with severe TBI (GCS ≤ 8 and AIS ≥ 3) were included and dichotomised into transferred and not transferred cohorts. RESULTS: Of 118 patients referred with severe TBI, 45 patients (38.1%) were transferred to the neurosurgical centre. Patients in the transferred cohort were significantly younger (p < 0.001), had a higher GCS score (p < 0.001) and a lower proportion of bilaterally unreactive pupils (p < 0.001) compared to the not transferred cohort. 93% (68/73) of those not transferred were either >65 years old, or had bilaterally unreactive pupils, or both. Based on the IMPACT model, the observed to expected mortality ratios in the transferred and not transferred cohorts were 0.65 (95% CI 0.25-1.05) and 0.88 (95% CI 0.65-1.11) respectively. CONCLUSION: The observed mortality rate for severe TBI in Ireland was similar to or better than expected mortality rates when adjusted for important prognostic factors. 93% of severe TBI patients not transferred to a neurosurgical centre were either elderly or had bilaterally unreactive pupils or both. These patients have an extremely poor prognosis and recommendation for transfer cannot be made based on current available evidence.

Risk factor synergism in aneurysmal subarachnoid hemorrhage: a cross-sectional study.

BACKGROUND: Spontaneous subarachnoid hemorrhage (SAH) accounts for 5-10% of strokes but a disproportionately large amount of stroke-related morbidity. Several risk factors have been described, including smoking, hypertension, increasing age, and female sex. METHODS: This cross-sectional study examined all patients with aSAH within a nationally representative catchment from 01/01/2017 to 31/12/2020. Patients with aneurysmal SAH were identified from multiple sources, including a prospective database and death records. The population was estimated from projections from a door-to-door census and risk factors from stratified random sampled surveys conducted on a yearly basis. Poisson regression models were used to estimate the incidence and incidence rate ratios (IRRs) for risk factors with 95% confidence intervals (95% CIs). RESULTS: We identified 875 cases of aSAH in 11,666,807 patient-years of follow-up, which corresponded to a crude incidence of 7.5 per 100,000 patient-years (95% CI 7-8) and a standardized incidence of 6.1/100,000 (95% CI 5.6-6.5). Smoking was the strongest individual risk factor, with a standardized incidence of 24/100,000 (95% CI 20-27) in smokers compared with 2.6/100,000 (2.1-3.2) in non-smokers (age-adjusted IRR 9.2, 95% CI 6.3-13.6). Hypertension (age-adjusted IRR 3.1, 95% CI 2.2-4.3) and female sex (age-adjusted IRR 1.8, 95% CI 1.4-2.3) were also associated with increased incidence. The highest incidence was observed in hypertensive smokers (standardized incidence 63/100,000, 95% CI 41-84), who had a lifetime risk of aSAH of 6.7% (95% CI 5.4-8.1) after age 35. Compared with participants who were non-smokers without hypertension, the age-adjusted IRR in hypertensive smokers was 27.9 (95% CI 15.9-48.8). CONCLUSION: Smoking is the most prominent individual risk factor for aSAH. Smoking and hypertension appear to interact to increase the risk of aSAH synergistically.

Meningioma in the elderly.

Meningiomas are the most common primary intracranial neoplasm, accounting for approximately 40% of all primary brain tumors. The incidence of meningioma increases with age to 50 per 100,000 in patients older than 85. As the population ages, an increasing proportion of meningioma patients are elderly. Much of this increase is accounted for by an increase in incidental, asymptomatic diagnoses, which have a low risk of progression in the elderly. The first-line treatment of symptomatic disease is resection. Fractionated radiotherapy (RT) or stereotactic radiosurgery (SRS) can be considered as primary treatment where surgery is not feasible, or as adjuvant therapy in cases of subtotal resection or high grade histopathology. The role of RT/SRS, particularly following gross total resection of atypical meningioma, is unclear and requires further evaluation. There is an increased risk of perioperative and postoperative morbidity in the elderly and therefore management decisions must be tailored to individual circumstances. Good functional outcomes can be achieved in selected patients and age alone is not a contraindication to intervention. The immediate postoperative course is an important determinant of prognosis. Therefore, careful preoperative evaluation and avoidance of complications are necessary to optimize outcomes.

WITHDRAWN: Middle Meningeal Artery Embolization for Chronic Subdural Hematoma-A New Treatment Paradigm?

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.wneu.2023.01.069. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/policies/article-withdrawal.

LITTing up Gliomas-Is the Future Bright?

Background: Laser interstitial thermal therapy (LITT) represents an attractive therapeutic strategy for several intracranial pathologies; however, there is a paucity of literature regarding its efficacy for the treatment of gliomas. Methods: MEDLINE, EMBASE, Scopus, and Web of Science were searched from inception until March 19, 2021. Studies specifically relating to the use of LITT in treatment of glioma were eligible for inclusion. A meta-analysis of means was performed to assess the progression-free survival (PFS) and overall survival (OS) following LITT and descriptive statistics relating to patients undergoing LITT were collated and a meta-analysis of proportions was also performed to assess the rate of complications. Results: In total, 17 studies were included for the meta-analysis, comprising 401 patients with 408 gliomas of which 88 of 306 (28.8%) were grade 1 or 2 and 218 of 306 (71.2%) were grade 3 or 4. Of these, 256 of 408 (62.8%) were primary presentation and 152 of 408 (37.2%) were recurrent. The pooled mean OS was 13.58 months (95% confidence interval [CI] 9.77-17.39) and the PFS was 4.96 months (95% CI 4.19-5.72). The OS and PFS of recurrent glioblastoma were 12.4 months (95% CI 9.61-16.18) and 4.84 months (95% CI 0.23-9.45), respectively. Complications occurred in 114 of 411 (24%; 95% CI 14-41), of which 44 (11%) were transient deficits. Conclusions: There is an increasing body of evidence demonstrating the use of LITT in the surgical management of deep-seated gliomas in patients of poor performance status. However, further studies are required to interrogate the clinical effectiveness of LITT in the setting of gliomas as well as assessing the survival benefit versus standard treatment alone.

The shrinking vestibular schwannoma.

We present a case of spontaneous 79% regression in the size of a vestibular schwannoma (VS). A 41-year-old lady with a large (36 mm) vestibular schwannoma underwent serial follow-up MRI scans which demonstrated the shrinkage over 9 years; the highest relative spontaneous regression recorded in the literature for vestibular schwannoma of this size.

Management of Chronic Subdural Hematoma: A Systematic Review and Component Network Meta-analysis of 455 Studies With 103 645 Cases.

BACKGROUND: Chronic subdural hematoma (CSDH) is a common neurosurgical condition with a high risk of recurrence after treatment. OBJECTIVE: To assess and compare the risk of recurrence, morbidity, and mortality across various treatments for CSDH. METHODS: A systematic review and meta-analysis was performed. PubMed/MEDLINE, EMBASE, SCOPUS, and Web of Science were searched from January 01, 2000, to July 07, 2021. The primary outcome was recurrence, and secondary outcomes were morbidity and mortality. Component network meta-analyses (CNMAs) were performed for surgical and medical treatments, assessing recurrence and morbidity. Incremental risk ratios (iRRs) with 95% CIs were estimated for each component. RESULTS: In total, 12 526 citations were identified, and 455 studies with 103 645 cases were included. Recurrence occurred in 11 491/93 525 (10.8%, 95% CI 10.2-11.5, 418 studies) cases after surgery. The use of a postoperative drain (iRR 0.53, 95% CI 0.44-0.63) and middle meningeal artery embolization (iRR 0.19, 95% CI 0.05-0.83) reduced recurrence in the surgical CNMA. In the pharmacological CNMA, corticosteroids (iRR 0.47, 95% CI 0.36-0.61) and surgical intervention (iRR 0.11, 95% CI 0.07-0.15) were associated with lower risk. Corticosteroids were associated with increased morbidity (iRR 1.34, 95% CI 1.05-1.70). The risk of morbidity was equivalent across surgical treatments. CONCLUSION: Recurrence after evacuation occurs in approximately 10% of cSDHs, and the various surgical interventions are approximately equivalent. Corticosteroids are associated with reduced recurrence but also increased morbidity. Drains reduce the risk of recurrence, but the position of drain (subdural vs subgaleal) did not influence recurrence. Middle meningeal artery embolization is a promising treatment warranting further evaluation in randomized trials.

Prevalence of incidental intracranial findings on magnetic resonance imaging: a systematic review and meta-analysis.

BACKGROUND: As the volume and fidelity of magnetic resonance imaging (MRI) of the brain increase, observation of incidental findings may also increase. We performed a systematic review and meta-analysis to determine the prevalence of various incidental findings. METHODS: PubMed/MEDLINE, EMBASE and SCOPUS were searched from inception to May 24, 2021. We identified 6536 citations and included 35 reports of 34 studies, comprising 40,777 participants. A meta-analysis of proportions was performed, and age-stratified estimates for each finding were derived from age-adjusted non-linear models. RESULTS: Vascular abnormalities were observed in 423/35,706 participants (9.1/1000 scans, 95%CI 5.2-14.2), ranging from 2/1000 scans (95%CI 0-7) in 1-year-olds to 16/1000 scans (95%CI 1-43) in 80-year-olds. Of these, 204/34,306 were aneurysms (3.1/1000 scans, 95%CI 1-6.3), which ranged from 0/1000 scans (95%CI 0-5) at 1 year of age to 6/1000 scans (95%CI 3-9) at 60 years. Neoplastic abnormalities were observed in 456/39,040 participants (11.9/1000 scans, 95%CI 7.5-17.2), ranging from 0.2/1000 scans (95%CI 0-10) in 1-year-olds to 34/1000 scans (95%CI 12-66) in 80-year-olds. Meningiomas were the most common, in 246/38,076 participants (5.3/1000 scans, 95%CI 2.3-9.5), ranging from 0/1000 scans (95%CI 0-2) in 1-year-olds to 17/1000 scans (95%CI 4-37) in 80-year-olds. Chiari malformations were observed in 109/27,408 participants (3.7/1000 scans, 95%CI 1.8-6.3), pineal cysts in 1176/32,170 (9/1000 scans, 95%CI 1.8-21.4) and arachnoid cysts in 414/36,367 (8.5/1000 scans, 95%CI 5.8-11.8). CONCLUSION: Incidental findings are common on brain MRI and may result in substantial resource expenditure and patient anxiety but are often of little clinical significance.

Preoperative embolisation of brain arteriovenous malformations: a systematic review and meta-analysis.

Preoperative embolisation is a commonly performed adjunct to microsurgical excision of brain arteriovenous malformations (bAVMs), with aims such as lessening the technical difficulty of the microsurgical procedure, reducing operative time, decreasing blood loss, and improving patient functional outcomes. We aim to perform a systematic review of randomised trials and cohort studies evaluating preoperative embolisation of bAVMs published between 01 January 2000 and 31 March 2021 and appraise its role in clinical practice. A MEDLINE search was performed, and articles reporting on outcomes following preoperative embolisation, as an adjunct to microsurgery, were eligible for inclusion. PRISMA reporting and Cochrane Handbook guidelines were followed. The primary outcome measure was the risk of complications associated with preoperative embolisation. The study was registered with PROSPERO (CRD42021244231). Of the 1661 citations, 8 studies with 588 patients met predefined inclusion criteria. No studies specifically compared outcomes of surgical excision of bAVMs between those with and without preoperative embolisation. Spetzler Martin (SM) grading was available in 301 cases. 123 of 298 (41⋅28%) patients presented with haemorrhage. Complications related to embolisation occurred in 175/588 patients (29.4%, 95% CI 19.6-40.2). Permanent neurological deficits occurred in 36/541 (6%, 95% CI 3.9-8.5) and mortality in 6/588 (0.41%, 95% CI 0-1.4). This is the first systematic review evaluating preoperative embolisation of bAVMs. Existing studies assessing this intervention are of poor quality. Associated complication rates are significant. Based on published literature, there is currently insufficient evidence to recommend preoperative embolisation of AVMs. Further studies are required to ascertain if there are benefits of this procedure and if so, in which cases.

Sinonasal outcomes associated with the use of BioGlue® in endoscopic transsphenoidal pituitary surgery.

Concerns have been raised in the neurosurgical literature regarding the use of BioGlue®, a tissue sealant initially developed for cardiothoracic surgery, due to reports of an increased incidence of infection, wound breakdown, and CSF fistulae. The aim of this study was to determine if the use of BioGlue® in skull base repair impacts on the sinonasal outcomes and the incidence of post-operative infection following endoscopic pituitary surgery. SNOT-22 questionnaires were completed pre-operatively, and at 6, 12, and 24 weeks post-operatively by 50 patients. Pre- and post-operative MRI scans were reviewed and assessed for evidence of post-operative sinusitis. Patient records were consulted to ascertain the incidence of post-operative infection. Repeated measures ANOVA and Wilcoxon signed rank test were used for data analysis. Statistical analysis revealed a significant difference in the mean SNOT-22 scores across the four time intervals (F(1.605, 78.642) = 9.180, p = 0.001). This difference was powered by a deterioration at 6 weeks that recovered completely by 12 weeks. The mean SNOT-22 score in the study cohort at 24 weeks was 16.84/110 (range 0-57, ± 2.04) which was lower than the mean pre-operative score and is consistent with mild rhinosinusitis. There were no cases of post-operative meningitis and 1/50 (2%) case of post-operative sinusitis in this cohort. The use of BioGlue® in endoscopic endonasal pituitary surgery does not appear to lead to significant sinonasal morbidity. Previous concerns about the use of BioGlue® in transcranial procedures may not apply to extradural application of this tissue sealant in endoscopic transnasal surgery.

S100B, GFAP, UCH-L1 and NSE as predictors of abnormalities on CT imaging following mild traumatic brain injury: a systematic review and meta-analysis of diagnostic test accuracy.

Biomarkers such as calcium channel binding protein S100 subunit beta (S100B), glial fibrillary acidic protein (GFAP), ubiquitin c-terminal hydrolase L1 (UCH-L1) and neuron-specific enolase (NSE) have been proposed to aid in screening patients presenting with mild traumatic brain injury (mTBI). As such, we aimed to characterise their accuracy at various thresholds. MEDLINE, SCOPUS and EMBASE were searched, and articles reporting the diagnostic performance of included biomarkers were eligible for inclusion. Risk of bias was assessed using the QUADAS-II criteria. A meta-analysis was performed to assess the predictive value of biomarkers for imaging abnormalities on CT. A total of 2939 citations were identified, and 38 studies were included. Thirty-two studies reported data for S100B. At its conventional threshold of 0.1 µg/L, S100B had a pooled sensitivity of 91% (95%CI 87-94) and a specificity of 30% (95%CI 26-34). The optimal threshold for S100B was 0.72 µg/L, with a sensitivity of 61% (95% CI 50-72) and a specificity of 69% (95% CI 64-74). Nine studies reported data for GFAP. The optimal threshold for GFAP was 626 pg/mL, at which the sensitivity was 71% (95%CI 41-91) and specificity was 71% (95%CI 43-90). Sensitivity of GFAP was maximised at a threshold of 22 pg/mL, which had a sensitivity of 93% (95%CI 73-99) and a specificity of 36% (95%CI 12-68%). Three studies reported data for NSE and two studies for UCH-L1, which precluded meta-analysis. There is evidence to support the use of S100B as a screening tool in mild TBI, and potential advantages to the use of GFAP, which requires further investigation.

Neurotrauma admissions and COVID-19: a National Centre experience.

BACKGROUND: To investigate the impact of COVID-19 on trauma admissions to a National Neurosurgical Centre in Ireland. METHODS: Retrospective analysis of a prospectively maintained database of all trauma admissions to the National Neurosurgical Centre at Beaumont Hospital, Dublin, during the period March 1 to May 31, 2019 and 2020. Primary outcome was 30-day mortality rate. Secondary outcomes included time transfer time, time from admission to time of surgery, and intensive care unit (ICU) admissions. Patients under the age of 16 were excluded. RESULTS: A total of 32 and 39 patients were admitted to the National Neurosurgical Centre following trauma over the 3-month period in 2020 and 2019 respectively, giving a 17.9% reduction in admissions. The 30-day mortality rate increased from 7.7% in 2019 to 15.6% on 2020 (p = 0.45). Mean transfer time was 4 h 58 min in 2019 and 3 h 55 min in 2020 (0.22). Mean time from admission to time of surgery was 9 h 10 min in 2019 and 5 h 37 min in 2020 respectively (p = 0.35). In 2019, 20 patients (51.3%) were admitted to ICU. This increased to 23 patients (69.7%) in 2020 (p = 0.08). CONCLUSIONS: Traumatic brain injury 30-day mortality rates increased during the first COVID-19 lockdown period. Trauma admission rates to ICU remained unchanged despite an overall reduction in trauma admissions. Transfer time, time to surgery, and length of stay were impacted by COVID-19. Despite the challenges COVID-19 has posed, it is important to maintain a fully functioning neurosurgical and neurocritical care service during the pandemic.

Permeability of the Blood-Brain Barrier after Traumatic Brain Injury: Radiological Considerations.

Traumatic brain injury (TBI) is a leading cause of death and disability, especially in young persons, and constitutes a major socioeconomic burden worldwide. It is regarded as the leading cause of mortality and morbidity in previously healthy young persons. Most of the mechanisms underpinning the development of secondary brain injury are consequences of disruption of the complex relationship between the cells and proteins constituting the neurovascular unit or a direct result of loss of integrity of the tight junctions (TJ) in the blood-brain barrier (BBB). A number of changes have been described in the BBB after TBI, including loss of TJ proteins, pericyte loss and migration, and altered expressions of water channel proteins at astrocyte end-feet processes. There is a growing research interest in identifying optimal biological and radiological biomarkers of severity of BBB dysfunction and its effects on outcomes after TBI. This review explores the microscopic changes occurring at the neurovascular unit, after TBI, and current radiological adjuncts for its evaluation in pre-clinical and clinical practice.

Neurosurgery activity levels in the United Kingdom and republic of Ireland during the first wave of the covid-19 pandemic - a retrospective cross-sectional cohort study.

The impact of Covid-19 on surgical patients worldwide has been substantial. In the United Kingdom (UK) and the Republic of Ireland (RoI), the first wave of the pandemic occurred in March 2020. The aims of this study were to: (1) evaluate the volume of neurosurgical operative activity levels, Covid-19 infection rate and mortality rate in April 2020 with a retrospective cross-sectional cohort study conducted across 16 UK and RoI neurosurgical centres, and (2) compare patient outcomes in a single institution in April-June 2020 with a comparative cohort in 2019. Across the UK and RoI, 818 patients were included. There were 594 emergency and 224 elective operations. The incidence rate of Covid-19 infection was 2.6% (21/818). The overall mortality rate in patients with a Covid-19 infection was 28.6% (6/21). In the single centre cohort analysis, an overall reduction in neurosurgical operative activity by 65% was observed between 2020 (n = 304) and 2019 (n = 868). The current and future impact on UK neurosurgical operative activity has implications for service delivery and neurosurgical training.

Derivation of a Clinical Score for Prediction of Recurrence Following Evacuation of Chronic Subdural Hematoma: A Retrospective Cohort Study at a National Referral Centre.

BACKGROUND: Chronic subdural hematoma (cSDH) is a common pathology, and recurrence is a common complication, which may be predicted by certain patient and radiologic factors. Empiric radiologic surveillance has been shown to convey no benefit. METHODS: A retrospective review of a prospectively collated database was performed. Preoperative and postoperative noncontrast computed tomography scans were reviewed. Radiologic appearance, preoperative hematoma volume, patient age, presence of bilateral hematomas, maximal hematoma thickness, and therapeutic coagulopathy were assessed as predictors. Receiver operating characteristic curve analysis, logistic regression, and LASSO regression were used to select potential predictors. A multivariate model was then fitted, and a score was derived. RESULTS: A total of 142 patients were included. Maximal hematoma thickness >12 mm (P = 0.02) and age >65 years (P = 0.01) were found to correlate with the likelihood of recurrence. Bilateral hematomas and a hyperdense or mixed density appearance were also identified on LASSO regression. Bilateral hematomas (P = 0.19), hyperdense or mixed density (P = 0.66), maximum thickness >12 mm (P = 0.01), and age >65 years (P = 0.02) were included in the multivariate model. A 6-point score was derived. A score of >3 had a sensitivity of 89% (95% confidence interval [CI] 78%-97%) and specificity of 26% (95% CI, 17%-34%) for predicting recurrence, with recurrence significantly more likely in patients with a score of 4-6 versus those with a score of 0-3 (P = 0.02). CONCLUSIONS: Certain radiologic findings may predict the recurrence of cSDH following evacuation. The score derived may be useful in identifying patients who might benefit from routine postoperative surveillance imaging.

Exoscope aided trans-sulcal minimally invasive parafascicular resection of a paediatric brainstem pilocytic astrocytoma using a tubular retractor system.

The surgical management of brainstem glioma is challenging and has significant morbidity. Advances in surgical armamentarium has presented the opportunity to tackle these lesions. We present the case of a paediatric patient with a 2.3cm midbrain pilocytic astrocytoma. With the aid of tractography, neuro-navigation, 3-dimensional exoscope and a tubular retractor, near total resection of the tumour was achieved through a trans-sulcal para-fascicular approach without permanent injury to the corticospinal tract. To our knowledge this is the first report of a brainstem tumour resected using this approach and demonstrates what can be achieved with synergistic utility of evolving technologies in neurosurgery.

How I do it: parietal trans-sulcal para-fascicular approach to lateral thalamic/internal capsule cavernous malformation.

BACKGROUND: The surgical management of deep brain lesions is challenging, with significant morbidity. Advances in surgical technology have presented the opportunity to tackle these lesions. METHODS: We performed a complete resection of a thalamic/internal capsule CM using a tubular retractor system via a parietal trans-sulcal para-fascicular (PTPF) approach without collateral injury to the nearby white matter tracts. CONCLUSION: PTPF approach to lateral thalamic/internal capsule lesions can be safely performed without injury to eloquent white matter fibres. The paucity of major vessels along this trajectory and the preservation of lateral ventricle integrity make this approach a feasible alternative to traditional approaches.