Effects of the COVID-19 Pandemic on Everyday Neurosurgical Practice in Alsace, France: Lessons Learned, Current Perspectives, and Future Challenges-Preliminary Results of a Longitudinal Multicentric Study Registry.

Background and Objectives: The global outbreak caused by the SARS-CoV-2 pandemic disrupted healthcare worldwide, impacting the organization of intensive care units and surgical care units. This study aimed to document the daily neurosurgical activity in Alsace, France, one of the European epicenters of the pandemic, and provide evidence of the adaptive strategies deployed during such a critical time for healthcare services. Materials and Methods: The multicentric longitudinal study was based on a prospective cohort of patients requiring neurosurgical care in the Neurosurgical Departments of Alsace, France, between March 2020 and March 2022. Surgical activity was compared with pre-pandemic performances through data obtained from electronic patient records. Results: A total of 3842 patients benefited from care in a neurosurgical unit during the period of interest; 2352 of them underwent surgeries with a wide range of pathologies treated. Surgeries were initially limited to neurosurgical emergencies only, then urgent cases were slowly reinstated; however, a significant drop in surgical volume and case mix was noticed during lockdown (March-May 2020). The crisis continued to impact surgical activity until March 2022; functional procedures were postponed, though some spine surgeries could progressively be performed starting in October 2021. Various social factors, such as increased alcohol consumption during the pandemic, influenced the severity of traumatic pathologies. The progressive return to the usual profile of surgical activity was characterized by a rebound of oncological interventions. Deferrable procedures for elective spinal and functional pathologies were the most affected, with unexpected medical and social impacts. Conclusions: The task shifting and task sharing approaches implemented during the first wave of the pandemic supported the reorganization of neurosurgical care in its aftermath and enabled the safe and timely execution of a broad spectrum of surgeries. Despite the substantial disruption to routine practices, marked by a significant reduction in elective surgical volumes, comprehensive records demonstrate the successful management of the full range of neurosurgical pathologies. This underscores the efficacy of adaptive strategies in navigating the challenges imposed by the largest healthcare crisis in recent history. Those lessons will continue to provide valuable insights and guidance for health and care managers to prepare for future unpredictable scenarios.

The efficacy of laser interstitial thermal therapy in the management of spinal metastases: a systematic review of the literature.

BACKGROUND: In the last years, laser interstitial thermal therapy (LITT) has started to be used also in neurosurgical setting. Its efficacy for intracranial pathologies, namely, tumors and epilepsy, has been widely demonstrated. However, the literature evidences about the use of LITT for spinal lesions are recent, and it is still a topic of discussion regarding its efficacy. Here, the authors sought to present a systematic review of the literature investigating the utility of LITT for spinal lesions. METHODS: Using PubMed, Scopus, and the Cochrane Library, the authors performed a systematic review of the literature focused on the use of spinal laser interstitial thermal therapy (sLITT). Included in the search were randomized controlled trials, cohort studies, and clinical series. Two independent reviewers conducted the study appraisal, data abstraction, and quality assessments of the studies. RESULTS: Out of the initial 134 studies, 6 met the inclusion criteria for the systematic review, resulting in a total of 206 patients. All the patients have been treated with sLITT for compressive spinal metastases. Most of the lesions were thoracic (88.8%). All the studies reported an effective local control of the disease with a reduction of epidural compression at 30 days. Complication rate was 12.6%, but most of them were transient conditions, and only 3.4% patients needed a revision surgery. CONCLUSION: sLITT is safe and provides effective local control for epidural compression from metastases, particularly in the thoracic spine. The authors propose considering sLITT as an alternative to open surgery in selected patients with spinal metastases.

Toward the End of the Funnel: The Ventriculus Terminalis-The State of Art of an Ancient Entity with a Recent History.

PURPOSE: The ventriculus terminalis (VT), also called the fifth ventricle, is a small cavity containing cerebrospinal fluid (CSF) that is in the conus medullaris in continuity with the central canal of the spinal cord. In adults, persistent VT is a very rare entity, and the diagnosis is incidental in most cases. Rarely, VT may become symptomatic for still-uncertain reasons but most often for its cystic dilatation. The management of these selected cases is still controversial and sometimes associated with unsatisfactory outcomes. METHODS: We performed a critical review of the existing literature on the management of symptomatic VT in adults. The etiology, pathophysiology, and treatment of VT are presented and discussed, focusing on the best timing for surgery. RESULTS: Conservative management, marsupialization, or the placement of a T drain have been reported. The existing classifications describe the most correct approach for each clinical presentation, but scarce importance has been given to the delay from symptoms' onset to surgical treatment. CONCLUSION: Although different cases have been described in the literature, this rare pathology remains unknown to most neurosurgeons.

Cystic Dilatation of the Ventriculus Terminalis: Examining the Relevance of the Revised Operative Classification Through a Systematic Review of the Literature, 2011-2021.

The literature features limited evidence on the natural history of the cystic dilatation of the ventriculus terminalis (CDVT) and its response to treatment. The goal of this study is to ascertain which impact the revised operative classification of CDVT had on the management of patients diagnosed over the past 10 years.Ten new clinical articles presenting a total of 30 cases of CDVT were identified and included for qualitative analysis. Two take-home messages can be identified: (1) Adequate consideration should be given to designing national pathways for referral to tertiary centers with relevant expertise in the management of lesions of the conus medullaris, and (2) we suggest that type Ia should be, at least initially, treated conservatively, whereas we reckon that the signs and symptoms described in types Ib, II, and III seem to benefit, although in some patients only partially, from surgical decompression in the form of cystic fenestration, cyst-subarachnoid shunting, or both.While the level of evidence gathered in this systematic review remains low because the literature on CDVT consists only of retrospective studies based on single-center series (level of evidence 4 according to the Oxford Centre for Evidence-Based Medicine (OCEBM)), the strength of recommendation for adopting the revised operative classification of CDVT is moderate.

Pituitary Abscess: A Challenging Preoperative Diagnosis-A Multicenter Study.

Background and Objectives: Pituitary abscess (PA) is a rare occurrence, representing less than 1% of pituitary lesions, and is defined by the presence of an infected purulent collection within the sella turcica. Pas can be classified as either primary, when the underlying pituitary is normal prior to infection, or secondary, when there is associated a pre-existing sellar pathology (i.e., pituitary adenoma, Rathke's cleft cysts, or craniopharyngioma), with or without a recent history of surgery. Preoperative diagnosis, owing to both non-specific symptoms and imaging features, remains challenging. Treatment options include endonasal trans-sphenoidal pus evacuation, as well as culture and tailored antibiotic therapy. Methods: A retrospective multicenter study, conducted on a prospectively built database over a 20-year period, identified a large series of 84 patients harboring primary sellar abscess. The study aimed to identify crucial clinical and imaging features in order to accelerate appropriate management. Results: The most common clinical presentation was a symptom triad consisting of various degrees of asthenia (75%), visual impairment (71%), and headache (50%). Diagnosis was achieved in 95% of cases peri- or postoperatively. Functional recovery was good for visual disturbances and headache. Pituitary function recovery remained very poor (23%), whereas the preoperative diagnosis represented a protective factor. Conclusions: In light of the high prevalence of pituitary dysfunction following the management of PAs, early diagnosis and treatment might represent a crucial issue. Currently, there are no standard investigations to establish a conclusive preoperative diagnosis; however, new, emerging imaging methods, in particular nuclear imaging modalities, represent a very promising tool, whose potential warrants further investigations.

Efficacy of endoscopic management of primary central nervous system lymphoma: a multicentric study and literature review.

INTRODUCTION: To date, confined intra-ventricular localization of primary central nervous system lymphoma (PCNSL) has been usually managed with open surgical resection and/or stereotactic biopsy; nonetheless, the endoscopic approach to such localization can provide many advantages over standard microsurgery and/or stereotactic biopsy. Here we present our experience in managing such a rare pathology through the endoscopic approach. METHOD: In order to gather more information about such a rare pathology, a retrospective multicentric study on a prospectively built database has been performed during a 5 year period. Ten different European centers have been involved. RESULTS: A total of 60 patients, 25 women and 35 men, have been enrolled in the study. The mean age was 65.3 years. The mean lesion size was 40.3 mm. Among all selected patients, 40 (66.6%) had superficial lesions within the ventricle, whereas the remaining 20 (33.4%) had lesions involving/extending to deeper structures. All surgical procedures were uneventful and ETV was deemed necessary only in 20/60 cases. CONCLUSION: In our experience, endoscopic management of intraventricular PCNSL is an effective option. It should be considered after a careful examination of neurological and immunological status, alternative options for diagnostic sampling, location of the lesion, and presence or absence of hydrocephalus. Endoscopic management could be considered as a safe and minimally invasive option to obtain: (a) a biopsy sample of the lesion for further diagnostic workup, (b) CSF diversion through third ventriculostomy or VP shunt for the management of hydrocephalus, and (c) insertion of ventricular access devices for long term medical management and whenever necessary as a rescue option for ventricular tap.

Odontoid Type II fractures in elderly: what are the real management goals and how to best achieve them? A multicenter European study on functional outcome.

Odontoid fractures constitute the most common cervical fractures in elderly. External immobilization is the treatment of choice for Type I and III; there is still no wide consensus about the best management of Type II fractures. Observational multicenter study was conducted on a prospectively built database on elderly patients (> 75 years) with Type II odontoid fracture managed conservatively during the last 10 years. All patients underwent CT scan on admission and at 3 months; if indicated, selected patient had CT scan at 6 and 12 months. All patients were clinically evaluated by Neck Disability Index (NDI), Charlson Comorbidity Index (CCI), and American Society of Anaesthesiologists classification (ASA) on admission; NDI was assessed also at 6 weeks, 3, 6, 12, and 24 months; furthermore, a quality of life (QoL) assessment with the SF-12 form was performed at 3 and 12 months. Among the 260 patients enrolled, 177 (68%) were women and 83 (32%) men, with a median age of 83 years. Patients were followed up for a minimum of 24 months: 247 (95%) showed an excellent functional outcome within 6 weeks, among them 117 (45%) showed a good bony healing, whereas 130 (50%) healed in pseudo-arthrosis. The residual 5% were still variably symptomatic at 12 weeks; however, only 5 out of 13 (2% of the total cohort) required delayed surgery. This study showed that a conservative approach to odontoid Type II fracture in elderly is an effective and valid option, resulting in an excellent functional outcome (regardless of bony fusion) in the majority of cases. Failure of conservative treatment can be safely addressed with surgical fixation at a later stage.

Learning curve and influencing factors of performing microsurgical anastomosis: a laboratory prospective study.

Despite being a critical component of any cerebrovascular procedure, acquiring skills in microsurgical anastomosis is challenging for trainees. In this context, simulation models, especially laboratory training, enable trainees to master microsurgical techniques before performing real surgeries. The objective of this study was to identify the factors influencing the learning curve of microsurgical training. A prospective observational study was conducted during a 7-month diploma in microsurgical techniques carried out in the anatomy laboratory of the school of surgery. Training focused on end-to-end (ETE) and end-to-side (ETS) anastomoses performed on the abdominal aorta, vena cava, internal carotid and jugular vein, femoral artery and vein, caudal artery, etc. of Wistar strain rats under supervision of 2 expert anatomical trainers. Objective and subjective data were collected after each training session. The 44 microsurgical trainees enrolled in the course performed 1792 anastomoses (1577 ETE, 88%, vs. 215 ETS, 12%). The patency rate of 41% was independent from the trainees' surgical background and previous experience. The dissection and the temporary clamping time both significantly decreased over the months (p < 0.001). Technical mistakes were independently associated with thrombosis of the anastomoses, as assessed by the technical mistakes score (p < 0.01). The training duration (in weeks) at time of each anastomosis was the only significant predictor of permeability (p < 0.001). Training duration and technical mistakes constituted the two major factors driving the learning curve. Future studies should try and investigate other factors (such as access to wet laboratory, dedicated fellowships, mentoring during early years as junior consultant/attending) influencing the retention of surgical skills for our difficult and challenging discipline.

Endoscopic-enhanced supra-cerebellar trans-tentorial (SCTT) approach to temporo-mesial region: a multicenter study.

Surgical access to the temporo-mesial area may be achieved by several routes such as the sub-temporal, the temporal trans-ventricular, the pterional/trans-sylvian, and the occipital interhemispheric approaches; nonetheless, none of them has shown to be superior to the others. The supra-cerebellar trans-tentorial approach allows a great exposure of the middle and posterior temporo-mesial region, while avoiding temporal lobe retraction. A prospective multicenter study was designed to collect data on patients undergoing endoscopic-enhanced SCTT approach to excise left temporo-mesial lesions. The study involved 5 different neurosurgical European centers and ran from 2015 to 2020. All patients had preoperative as well as postoperative brain MRI and ophthalmology evaluation. A total of 30 patients were included in this study, the mean follow-up was 44 months (range 18 to 84 months), male/female ratio was 16/14, and mean age was 39 years. A gross total resection was achieved in 29/30 (96.7%) cases. All surgical procedures were uneventful, without transient or permanent neurological deficits thanks to the preservation of the posterior cerebral artery. The endoscopic-enhanced SCTT approach provides satisfactory exposure to the left temporo-mesial region. Its minimally invasive nature helps minimize the surgical risks related to vascular and white tract manipulation, which represent known limitations of open microsurgical as well as other approaches.

Early and ultra-early surgical decompression for acute spinal cord injury: bracing for the winds of change.

PURPOSE: Until recently, there has been no consensus on the optimal operative window for decompressive surgery in acute spinal cord injury (aSCI). However, recent evidence is now supporting a role for early intervention in improving outcomes in this type of patients. The purpose of this letter is to discuss the implications for clinical practice within the European community. METHODS: Critical appraisal and interpretation of these results for clinical implementation. RESULTS: Leveraging on the evidence that early (< 24 h), and possibly ultra-early (< 8 h), decompressive spinal surgery in aSCI affords better neurological outcomes, the next challenge for our community will be to ensure that spinal surgery services can accommodate this caseload. Here, we discuss the challenges that will be faced by spinal surgeons and draw parallels between the scaling of these services and the implementation of mechanical thrombectomy for acute ischaemic stroke. We outline key lessons that have been learnt from the rapid scaling of mechanical thrombectomy services and highlight the provisions in infrastructure, education, and staffing that will be required. CONCLUSION: This is a call for hospital systems to swiftly restructure spinal services in order to meet the need for early, and possibly ultra-early, spinal decompression in aSCI cases in the near future.

Mechanical thrombectomy in a pediatric patient with sedation aided by contralateral intra-arterial propofol injection: feasibility in an extreme condition.

Pediatric patients undergoing mechanical thrombectomy may be challenging for the anesthesiologists as regards the best anesthetic choice, especially if concomitant to severe comorbidities such as heart failure. A 16-year-old patient affected by arrhythmogenic right ventricle dysplasia/cardiomyopathy underwent mechanical thrombectomy. He was not eligible for deep sedation or general anesthesia since he has been suffering from severe heart failure. The patient stillness was obtained by intra-arterial injection of propofol from the contralateral internal carotid artery. The procedure has been well tolerated, without cardiorespiratory impairment. The case stresses the growing importance to tailor a proper anesthesiologic plan during mechanical thrombectomy, especially in extreme conditions.

Intensive therapies of delayed cerebral ischemia after subarachnoid hemorrhage: a propensity-matched comparison of different center-driven strategies.

BACKGROUND: Intensive therapies of delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH) have still controversial and unproven benefit. We aimed to compare the overall efficacy of two different center-driven strategies for the treatment of DCI respectively with and without vasospasm angioplasty. METHODS: Two hundred consecutive patients with aSAH were enrolled in each of two northern European centers. In an interventional center, vasospasm angioplasty was indicated as first line rather than rescue treatment of DCI using distal percutaneous balloon angioplasty technique combined with intravenous milrinone. In non-interventional center, induced hypertension was the only intensive therapy of DCI. Radiological DCI (new cerebral infarcts not visible on immediate post-treatment imaging), death at 1 month, and favorable outcome at 6 months (modified Rankin scale score ≤ 2) were retrospectively analyzed by independent observers and compared between two centers before and after propensity score (PS) matching for baseline characteristics. RESULTS: Baseline characteristics only differed between centers for age and rate of smokers and patients with chronic high blood pressure. In the interventional center, vasospasm angioplasty was performed in 38% of patients with median time from bleeding of 8 days (Q1 = 6.5;Q3 = 10). There was no significant difference of incidence of radiological DCI (9% vs.14%, P = 0.11), death (8% vs. 9%, P = 0.4), and favorable outcome 74% vs. 72% (P = 0.4) between interventional and non-interventional centers before and after PS matching. CONCLUSIONS: Our results suggest either that there is no benefit, or might be minimal, of one between two different center-driven strategies for intensive treatment of DCI. Despite potential lack of power or unknown confounders in our study, these results question the use of such intensive therapies in daily practice without further optimization and validation.

COVID-legal study: neurosurgeon experience in Britain during the first phase of the COVID-19 pandemic - medico-legal considerations.

Introduction: The COVID-19 pandemic has resulted in a significant number of changes to elective and emergency neurosurgical practice.Materials and Methods: This paper reports the results of an online survey of Society of British Neurological Surgeons (SBNS) members undertaken between 10th and 24th of June 2020 regarding changes in consent practice in response to COVID-19, as well as the physical challenges experienced while operating under higher levels of personal protective equipment (PPE).Results: Despite the real and substantial risks associated with COVID-19, 23% of surgeons reported they were not made any changes to their usual consent process, and 54% of surgeons indicated that they made reference to COVID-19-associated risks in their written consent documentation. 93% of neurosurgeons reported physical difficulties operating using PPE; 62% reported visors/goggles fogging up, 55% experienced 'overheating', 62% reported fatigue, and 82% of surgeons reported difficulty communicating with the theatre staff.Conclusions: This survey highlights discrepancies in the consent practice between neurosurgeons which needs to be addressed at both local and national levels. The PPE being used in neurosurgical operations is not designed for use with specialist equipment (82% of respondents reported having to remove PPE to use the microscope) and the reported physical difficulties using PPE intraoperatively could significantly impact on both neurosurgeon performance and patient outcomes. This requires urgent attention by NHS procurement and management and should be urgently escalated to trust occupational health authorities as a workplace safety concern.

Mismatch between Tissue Partial Oxygen Pressure and Near-Infrared Spectroscopy Neuromonitoring of Tissue Respiration in Acute Brain Trauma: The Rationale for Implementing a Multimodal Monitoring Strategy.

The brain tissue partial oxygen pressure (PbtO2) and near-infrared spectroscopy (NIRS) neuromonitoring are frequently compared in the management of acute moderate and severe traumatic brain injury patients; however, the relationship between their respective output parameters flows from the complex pathogenesis of tissue respiration after brain trauma. NIRS neuromonitoring overcomes certain limitations related to the heterogeneity of the pathology across the brain that cannot be adequately addressed by local-sample invasive neuromonitoring (e.g., PbtO2 neuromonitoring, microdialysis), and it allows clinicians to assess parameters that cannot otherwise be scanned. The anatomical co-registration of an NIRS signal with axial imaging (e.g., computerized tomography scan) enhances the optical signal, which can be changed by the anatomy of the lesions and the significance of the radiological assessment. These arguments led us to conclude that rather than aiming to substitute PbtO2 with tissue saturation, multiple types of NIRS should be included via multimodal systemic- and neuro-monitoring, whose values then are incorporated into biosignatures linked to patient status and prognosis. Discussion on the abnormalities in tissue respiration due to brain trauma and how they affect the PbtO2 and NIRS neuromonitoring is given.

Dose related acute behavioral and neurochemical profile of pioglitazone.

Diabetics are twice as likely to have depression. It's normal to have long periods of sadness and anxiety. Pioglitazone has important role in the inflammatory response, which suggests that it might have the associated anti-depressant effects being manifested by its anti-depressant profile which needs further exploration. Monitoring changes in behavioral and neurochemical profile of pioglitazone in a dose-dependent manner was the purpose of this study. Pioglitazone was injected to rats at the doses of 0mg/kg, 2.5mg/kg, 5mg/kg and 10mg/kg. Behavioral activities in open field, Skinner's box and elevated plus maze were monitored 20, 35 and 45 minutes respectively after pioglitazone injection. whole brain samples were collected following decapitation of rats one-hour after injection. Samples were kept at -70ºC till HPLC-EC analysis for neurochemical profile. Results show anxiogenic and sedative effects of pioglitazone at all three doses as indicated by Skinner's box, elevated plus maze activity and open field. Also there was an overall decreased dopamine metabolism and increased serotonin turnover. This suggests that diabetic patients using pioglitazone as a therapeutic option, may experience more potent effects of CNS depressants. Findings may help in extending therapeutics in diabetic patients suffering from anxiety and/or depression.

Technologies to Optimize the Care of Severe COVID-19 Patients for Health Care Providers Challenged by Limited Resources.

Health care systems are belligerently responding to the new coronavirus disease 2019 (COVID-19). The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a specific condition, whose distinctive features are severe hypoxemia associated with (>50% of cases) normal respiratory system compliance. When a patient requires intubation and invasive ventilation, the outcome is poor, and the length of stay in the intensive care unit (ICU) is usually 2 or 3 weeks. In this article, the authors review several technological devices, which could support health care providers at the bedside to optimize the care for COVID-19 patients who are sedated, paralyzed, and ventilated. Particular attention is provided to the use of videolaryngoscopes (VL) because these can assist anesthetists to perform a successful intubation outside the ICU while protecting health care providers from this viral infection. Authors will also review processed electroencephalographic (EEG) monitors which are used to better titrate sedation and the train-of-four monitors which are utilized to better administer neuromuscular blocking agents in the view of sparing limited pharmacological resources. COVID-19 can rapidly exhaust human and technological resources too within the ICU. This review features a series of technological advancements that can significantly improve the care of patients requiring isolation. The working conditions in isolation could cause gaps or barriers in communication, fatigue, and poor documentation of provided care. The available technology has several advantages including (a) facilitating appropriate paperless documentation and communication between all health care givers working in isolation rooms or large isolation areas; (b) testing patients and staff at the bedside using smart point-of-care diagnostics (SPOCD) to confirm COVID-19 infection; (c) allowing diagnostics and treatment at the bedside through point-of-care ultrasound (POCUS) and thromboelastography (TEG); (d) adapting the use of anesthetic machines and the use of volatile anesthetics. Implementing technologies for safeguarding health care providers as well as monitoring the limited pharmacological resources are paramount. Only by leveraging new technologies, it will be possible to sustain and support health care systems during the expected long course of this pandemic.

Which neuroimaging techniques are really needed in Chiari I? A short guide for radiologists and clinicians.

PURPOSE: To describe the most appropriate techniques and suggested protocols meant to address the various scenarios that clinicians and pediatric neurosurgeons may face in their day-to-day practice connected with Chiari I. METHODS: Current literature related to image indications and findings in Chiari I has been reviewed. The authors focused on both standard and advanced techniques for clinical diagnosis and preoperative planning purposes. DISCUSSION AND CONCLUSION: The complexity of providing neuroimaging guidelines for children investigated for Chiari I lies in defining the most appropriate neuroradiology tool to approach what is in fact a very heterogeneous condition with different etiopathogenetic mechanisms and associated abnormalities. Other variables that may influence the diagnostic strategy include the age of the patient, the presence of additional pathological conditions, the type of presenting symptoms, and the indication for surgical or conservative management. Although the average age at time of diagnosis is 10 years, the initial diagnosis may be done at any age, and the referral for neuroradiology workup may come from general practitioners/pediatricians, orthopedic surgeons, and endocrinologists following various baseline investigations including plain x-rays of skull and spine and/or CT head and/or MRI brain and spine.

The Endonasal Endoscopic Approach to Pathologies of the Anterior Craniocervical Junction: Analytical Review of Cases Treated at Four European Neurosurgical Centres.

Supported by preliminary anatomical and clinical studies exploring the feasibility and usefulness of approaching many ventral pathologies of the craniocervical junction (CCJ) using the endoscopic endonasal approach, four European centres have joined forces to accumulate and share their growing surgical experience of this advanced technique. By describing the steps that led to the development and continuous refinement of this approach to the CCJ, this article delves deeply into an analysis of the cases operated on since 2010 at these four institutions, and discusses in detail the operative nuances that so far have allowed achievement of successful outcomes with excellent perioperative patient comfort and satisfactory long-term quality of life.

Differential diagnosis of posterior fossa tumours in children: new insights.

Central nervous system neoplasms are the most common solid tumours that develop in children, with the greatest proportion located in the infratentorium. The 2016 World Health Organization Central Nervous System tumour classification evolved from the 2007 edition with the integration of molecular and genetic profiling into the diagnosis, the addition of new entities and the removal of others. Radiology can assist with the subtyping of tumours from certain characteristics described below to provide prognostic information and guide further management. The latest insights into the radiologic characteristics of these posterior fossa tumours are presented below: medulloblastoma, ependymoma, pilocytic astrocytoma, embryonal tumours with multilayered rosettes, atypical teratoid rhabdoid tumours, diffuse midline glioma and the new entity of diffuse leptomeningeal glioneuronal tumours.