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

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

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

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

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

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

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

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

Spontaneous lumbar intraspinal subdural abscess: a case report.

BACKGROUND: Subdural spinous abscess is a rare pathology that carries significant morbidity if not diagnosed and treated early; of the cases reported in the literature, very few are genuinely spontaneous in nature. CASE PRESENTATION: Here we demonstrate the case of an otherwise entirely fit and well 56-year-old White, British female presenting with low back pain, bilateral sciatica and sensate urinary retention; lumbar subdural spinous abscess was diagnosed on urgent magnetic resonance imaging and the patient was successfully managed with surgical evacuation and prolonged antibiotic therapy. The patient made a full neurological recovery and was followed-up in the outpatient setting 12 weeks following her initial surgery; she was pain free with normal inflammatory markers and a normal neurological examination. There have been no further consultations and a telephone call at 20 weeks confirmed that she remains well. CONCLUSIONS: This is the second case reported in the literature of a genuinely spontaneous subdural spinous abscess, which was successfully managed with surgical evacuation following prompt diagnosis. This highlights the need to ensure infective pathologies are kept at the back of one's mind even in the most unlikely circumstances, and that excellent outcomes can be achieved with early surgical intervention.

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

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

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

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

Therapeutic Strategies and Challenges in the Management of Craniospinal Tumors in Pregnancy: A Ten-Year Retrospective Tertiary-Center Study, Systematic Review, and Proposal of Treatment Algorithms.

OBJECTIVE: This study aims to review therapeutic strategies in the management of craniospinal tumors in pregnant patients and the factors that may influence the management along with their influence on maternal and fetal outcomes. METHODS: A retrospective single-center cohort study was performed at a tertiary neurosurgical referral center. Pregnant patients referred to the neuro-oncology multidisciplinary meeting (MDM) with craniospinal tumor were included. Ten-year patient data were collected from hospital records and neuro-oncology MDM outcomes. A systematic review was performed of the available literature as per PRISMA guidelines. RESULTS: Twenty-five patients were identified, with a mean age of 31 years. Of these patients, 88% (n = 22) had cranial lesions and 12% (n = 3) had spinal lesions. Most of the patients had World Health Organization grade I/II tumors. Of the patients, 44% underwent surgery when pregnant, whereas in 40%, this was deferred until after the due date. Of patients, 16% did not require surgical intervention and were followed up with serial imaging in the MDM. The left lateral/park bench position was the preferred position for the spinal and posterior fossa lesions. Systematic review and retrospective data led to proposal of treatment algorithms addressing the therapeutic strategy for management of craniospinal tumors during pregnancy. Factors that may influence maternal and fetal outcomes during management of these tumors were identified, including aggressiveness of the tumor and stage of pregnancy. CONCLUSIONS: Craniospinal tumors presenting in pregnancy are challenging. The surgical management needs to be tailored individually and as part of a multidisciplinary team approach. Factors influencing maternal and fetal outcomes are to be considered during management and patient counseling.

Prognostic factors and surgical outcomes of spontaneous spinal epidural haematoma: a systematic review and meta-analysis.

Spontaneous spinal epidural haematoma (SSEH) is a rare disease defined as blood accumulation within the vertebral epidural space without a cause identified, which can lead to severe neurological deficits. We aim to provide a comprehensive understanding of the prognostic factors affecting surgical outcomes in true SSEH and propose a critical time frame for operative management. A systematic literature search was performed and registered, using OVID Medline and EMBASE, in line with the PRISMA guidelines. Relevant demographic, clinical, surgical, and outcome data were extracted. The ASIA scale was uniformly used throughout our systematic review. Statistical analysis was performed via logistic regression. Of the 1179 articles examined, we included 181 studies involving 295 adult patients surgically treated for SSEH. SSEH were most commonly found in the cervicothoracic spine, with 2-4 spinal segments most commonly involved. Multivariable logistic regression model showed that the following factors were statistically significant in the post-operative outcome: operation type (P = 0.024), pre-operative neurologic status (P < 0.001), use of warfarin (P = 0.039), and operative interval (P = 0.006). Our retrospective analysis confirms the reversibility of severe neurological deficits after surgical intervention, with a prognosis of post-operative outcomes determined by the use of warfarin, pre-operative ASIA grade, and above all surgical evacuation within 12 h.

Continuous Microdebrider-Based Dynamic Subcortical Motor Mapping: A Technical Advance in Tubular Retractor-Assisted Surgery.

BACKGROUND: Transsulcal minimally invasive parafasicular (TsMIP) approaches to brain tumor resection use tubular retractors to minimize iatrogenic brain injury. Dynamic cortical and subcortical continuous neurophysiological mapping facilitates safer resection of motor-eloquent tumors. OBJECTIVE: To describe a new technique to address the challenge of combining TsMIP with tubular retractors and dynamic subcortical mapping using a single electrified stimulating microdebrider instrument. METHODS: We adapted the NICO Myriad microdebrider with continuous monopolar stimulation electrification using high-frequency stimulation with the train-of-5 technique. We performed continuous subcortical mapping using this device and compared it with standard dynamic monopolar subcortical mapping using a suction stimulation device. We found no significant difference in recorded stimulation response. RESULTS: Using a single operating instrument that provides synchronous tumor resection and monopolar subcortical mapping with the NICO Brainpath tubular retractor, we observed increased degrees of movement, faster surgical resection times with an enlarged working channel down the retractor, and improved safety because the stimulating probe sits 2 mm deep to the resection window. CONCLUSION: We show that the adapted device is reliable and provides similar stimulation response as conventional subcortical mapping. We advocate the use of our adapted microdebrider in TsMIP tubular retractor approaches.

Infected cephalhaematoma causing osteomyelitis: case report and literature review.

Infected cephalhaematomas are rare and can lead to complications such as sepsis, meningitis and osteomyelitis. We present an infected cephalhaematoma in a neonate with resultant underlying osteomyelitis and a review of the literature. Our patient presented 6 days following birth with a fever and a swelling consistent with cephalhaematoma. He was managed with intravenous antibiotics and early surgical intervention. Imaging demonstrated underlying osteomyelitis. The patient made a full recovery and was discharged home on completing his antibiotic course. On reviewing the literature, it is clear that early diagnosis and treatment with surgical intervention and antibiotic therapy are associated with improved outcome and can reduce the possibility of osteomyelitis developing.

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

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

Survival and prognostic factors in childhood medulloblastoma: A Brazilian single center experience from 1995 to 2016.

BACKGROUND: Medulloblastoma is the most common malignant brain tumor in the pediatric population. Despite prognosis improvement in the past two decades, one-third of the patients still remain incurable. New evidence suggests that medulloblastoma comprises four distinct entities; therefore, treatment de-escalation is required. The aim of this article is to evaluate epidemiological data from patients treated at our institution. The primary objective is to analyze overall survival (OS) and event-free survival (EFS) and the secondary objective is to identify prognostic factor from this cohort. METHODS: We retrospectively analyzed 69 patients who underwent surgical resection for medulloblastoma among 423 children from the tumor registry data bank of Santo Antônio Children's Hospital from 1995 to 2016. Kaplan-Meier method and Cox regression analysis were used to identify OS, EFS, and prognostic factors. RESULTS: The 5-year OS and EFS rates found were 44.5% and 36.4%, respectively. The extent of resection and radiotherapy as adjuvant treatments was positively correlated to outcome while metastatic disease at diagnosis was negatively related to OS. Age younger than 3 years old did not have a worse outcome in our cohort. CONCLUSION: Similar results to population-based studies were found, but we still face difficulties due to living in a developing country. In the near future, we look forward to new diagnostic techniques that will enable us to classify medulloblastomas according to molecular subgroups.

Olfactory function and Parkinson's disease in Southern Brazil.

UNLABELLED: The idiopathic Parkinson disease (IPD) is traditionally diagnosed by motor signs, but non-motor symptoms and signs are frequent and may help in the clinical diagnosis. PURPOSE: To evaluate the olfactory function in Brazilian healthy subjects, patients with early-onset PD (EOPD) and late-onset PD (LOPD) using the Sniffin' Sticks odor-identification test (SST). METHOD: We studied 70 patients with IPD (19 EOPD and 51 LOPD) and 70 controls matched for gender, age and years of schooling. Subjects with dementia and loss of smell for other reasons were excluded. RESULTS: The SST showed a significant difference (p<0.001) between groups: control groups (12.0 + or - 0.3), EOPD (8.3 + or - 0.7), and LOPD (6.7 + or - 0.4) when the groups were adjusted for gender, age, disease duration, and years of schooling. CONCLUSION: Both groups of IPD patients presented olfactory impairments, but those whose symptoms started before 45 years-old (EOPD) had better sense of smell than the LOPD patients.

Olfactory function and Parkinson's disease in Southern Brazil / Função olfatória e doença de Parkinson no sul do Brasil

The idiopathic Parkinson disease (IPD) is traditionally diagnosed by motor signs, but non-motor symptoms and signs are frequent and may help in the clinical diagnosis. PURPOSE: To evaluate the olfactory function in Brazilian healthy subjects, patients with early-onset PD (EOPD) and late-onset PD (LOPD) using the Sniffin' Sticks odor-identification test (SST). METHOD: We studied 70 patients with IPD (19 EOPD and 51 LOPD) and 70 controls matched for gender, age and years of schooling. Subjects with dementia and loss of smell for other reasons were excluded. RESULTS: The SST showed a significant difference (p<0.001) between groups: control groups (12.0±0.3), EOPD (8.3±0.7), and LOPD (6.7±0.4) when the groups were adjusted for gender, age, disease duration, and years of schooling. CONCLUSION: Both groups of IPD patients presented olfactory impairments, but those whose symptoms started before 45 years-old (EOPD) had better sense of smell than the LOPD patients.

A doença de Parkinson idiopática (DPI) tradicionalmente é diagnosticada pelos sinais motores, porém os sinais e sintomas não-motores são freqüentes. OBJETIVO: Avaliar a função olfatória em sujeitos brasileiros saudáveis e em pacientes com doença de Parkinson precoce (DPP) e doença de Parkinson tardia (DPT) utilizando o teste Sniffin' Sticks (TSS) de identificação de odores. MÉTODO: Setenta pacientes com DPI (19 DPP e 51 DPT) e 70 controles pareados para as variáveis gênero, idade e anos de escolaridade foram estudados. Foram excluídos sujeitos com demência e/ou perda de olfato por outros motivos. RESULTADOS: O TSS mostrou uma diferença significativa (p<0,001) entre os grupos controle (12,0±0,3), DPP (8,3±0,7) e DPT (6,7±0,4) quando os grupos foram ajustados para sexo, idade, duração da doença e anos de escolaridade. CONCLUSÃO: Pacientes com DPI apresentam redução do olfato, sendo mais importante entre aqueles com DPT. A disfunção olfatória pode ser uma ferramenta muito útil no diagnóstico de DPI.

Immunohistochemical evaluation of the microvascular density through the expression of TGF-beta (CD 105/endoglin) and CD 34 receptors and expression of the vascular endothelial growth factor (VEGF) in oligodendrogliomas.

Angiogenesis has been proposed as essential for the growth of solid tumors. The determinants of this process, the growth factors and the vascular endothelial receptors have brought a potential in the tumor prognostic determination as well as perspectives of "targets" for antiangiogenic therapy. In oligodendrogliomas (OL), angiogenesis is little known and/or has generated conflicting results. In order to clarify angiogenesis in OL, we have evaluated the immunohistochemical expression of vascular endothelial growth factor (VEGF) and the microvascular density (MVD) through the expression of TGF-beta (CD105/endoglin) (MVD-CD105) and CD34 (MVD-CD34) receptors using the Chalkley point method in 30 OL. No significant immune reaction was found for the VEGF. There was expression in <10% of tumor cells and/or staining of weak intensity in 15 (50.0%), >10% of cells and moderate intensity staining in 1 (3.33%), and negative expression in 14 (46.67%). If present, the expression was restricted to tumor and endothelial cells. Our findings suggest that VEGF has little influence on OL angiogenesis. All specimens showed CD105 and CD34 expression in the intratumor vascular endothelium, suggesting involvement of CD105 in OL angiogenesis. The mean +/- SD MVD-CD105 and MVD-CD34 were 10.83 +/- 2.24 and 11.00 +/- 2.76 in OL (P = 0.086; r = 0.319); 10.00 +/- 2.00 and 10.40 +/- 3.02 in OL grade II (n = 15) (P = 0.547; r = 0.105), and 11.67 +/- 2.22 and 11.53 +/- 2.45 in OL grade III (n = 15) (P = 0.817; r = 0.551), respectively. The absence of correlation between DMV-CD105, DMV-CD34 and tumor grades suggests that anti-CD105 and anti-CD34 antibodies have different vascular specificities. MVD-CD105 was greater in OL grade III than in OL grade II (P = 0.0032), indicating an increase in the vascular neoformation, something which must be evaluated as a possible prognostic factor in OL. Both TGF-beta and CD105 bring perspectives as "targets" for antiangiogenic treatments in OL.