Michelle Masayo Kameda-Smith

Purpose: We sought to describe current perceptions and attitudes to management of of brain abscess (BA) or sub-/extra-dural empyema (SDE/EDE) in the United Kingdom (UK) to compare this to the 2024 European Society of Clinical Microbiology and Infectious Diseases BA guidelines. Methods: We conducted a web-based survey of infection specialists (IS) and neurosurgeons (NS) at neurosurgical centres across the UK. Results: IS from 27/39 (69%) and NS from 18/39 (46%) UK neurosurgical centres participated. All IS reported use of a third-generation cephalosporin as empirical antibiotic therapy, 57/61 (93%) alongside metronidazole, 19/57 (33%) preferring oral metronidazole throughout treatment. Most IS (46/60, 76.7%) consider switching to oral antibiotics prior to completing 6 weeks intravenous (IV) therapy, with 33/46 (71.7%) considering a 1–2 week minimum IV duration if there has been neurosurgical intervention. Most NS (22/25, 88%) agreed that neurosurgical intervention is indicated for any BA ≥ 2.5 cm diameter, most (21/25, 84%) favouring burr hole aspiration. For SDE/EDE only 12/25 (48%) of NS would surgically intervene in all circumstances. Most IS and NS (72/76, 94.7%) would consider intrathecal antibiotics in ruptured BA with ventriculitis; only 11/74 (14%) reported experience with intracavitary antimicrobials. 44/74 (59%) reported using steroids in BA, while 20/74 (27%) reported avoiding steroids. Reimaging was favoured at 2–3 weeks by NS, IS favoured 4–8 weeks, or not reimaging. Conclusion: There are areas of marked variation in the management of BA and SDE/EDE in the UK, particularly early switch from IV to oral antibiotics, SDE surgery, repeat brain imaging and use of steroids.

Background An effective strategy for salvage therapy in refractory or relapsed childhood brain tumours is yet to be established. Methods A national retrospective review of 135 children diagnosed with treatment refractory or recurrent MB from 2000 to 2021 at 5 academic Canadian pediatric neurosurgical centers was performed. Results The mean age at diagnosis was 7.09 years (SD 4.37) with a male predominance (64.4%) and 17.8% under the age of 3 years. Most of the tumour histology was classic MB. Just over a third of children experienced disease progression during or after adjuvant therapy with an average disease-free interval of 17.55 months (SD 4.04). The majority of children experienced local disease progression (55.3%). Just over thirty percent of children succumbed to disease progression (n = 47, 34.8%). The mean age of first srelapse was 10.85 years (SD 7.10) and was identified on average 17.55 months (SD 9.76) from diagnosis. Most children with progressive disease (82.9%) were deceased at the time of writing. The mean time from first and second relapse to death was 27.19 months (SD 36.17) and 9.93 months (11.92) respectively. The cause of death was most commonly disease progression followed by a medical complication. Initial response to salvage therapy with recurrence and biopsy at index surgery were independently associated with mortality. The children were followed up for a mean interval of 83.17 months (SD 54.15). Conclusion Recurrent disease in childhood medulloblastoma after provision of upfront therapy confers a very poor prognosis despite salvage therapy and is an unmet need for further study and therapeutic development.

OBJECTIVE: Cerebellar pilocytic astrocytomas (cPAs) in childhood have long been recognized to have a good prognosis after total resection, but the outcome after incomplete resective surgery remains largely unpredictable, with the incidence of radiological progressive disease ranging from 18% to 100%. It has been traditionally thought that gross-total resection was required for long-term survival, and small residuals were classically resected in a subsequent operation. METHODS: The authors analyzed their pediatric low-grade glioma (PLGG) database for cases treated between 1985 and 2020 and filtered for intracranial PAs, to determine what clinical or radiological factors precipitated revisional resective surgery in their single quaternary care center cohort. RESULTS: Using the pediatric low-grade glioma database, 283 patients were identified to have a histopathological diagnosis of intracranial PA between 1985 and 2020, of which 200 lesions were within the cerebellum (70.7%). The majority of patients with cPA were between 1 and 10 years of age (n = 145, 72.5%) without gender predominance (M/F = 99:101), usually presenting with 1 lesion (n = 197, 98.5%). Gross-total resection was achieved in 74.5% (n = 149) of initial surgeries for cPA. In patients with subtotal resection, the mean largest diameter of the postoperative residual tumor was 1.06 cm (range 0–2.95 cm). Seven patients with subtotal resection did not require a second resective intervention. In 31 patients the neuro-oncology multidisciplinary team recommended a second resection at a mean time interval of 22.9 months (range 0.13–81.6 months) from the initial surgery. Proportionally, the children who underwent multiple resections were also more likely to receive adjuvant chemo/radiotherapy. Functionally, the children in the multiple operation cohort experienced more complications of therapy including ongoing endocrinopathy, treatment-associated hearing deficit, and neurocognitive deficits. CONCLUSIONS: Residual disease in cPA should be maintained under clinicocoradiological surveillance postoperatively with adoption of a more conservative approach when residual disease is not significantly changing over time.

Introduction: Operative cancellations adversely affect patient health and impose resource strain on the healthcare system. Here, our objective was to describe neurosurgical cancellations at five Canadian academic institutions.Methods: The Canadian Neurosurgery Research Collaborative performed a retrospective cohort study capturing neurosurgical procedure cancellation data at five Canadian academic centres, during the period between January 1, 2014 and December 31, 2018. Demographics, procedure type, reason for cancellation, admission status and case acuity were collected. Cancellation rates were compared on the basis of demographic data, procedural data and between centres.Results: Overall, 7,734 cancellations were captured across five sites. Mean age of the aggregate cohort was 57.1 ± 17.2 years. The overall procedure cancellation rate was 18.2%. The five-year neurosurgical operative cancellation rate differed between Centre 1 and 2 (Centre 1: 25.9%; Centre 2: 13.0%, p = 0.008). Female patients less frequently experienced procedural cancellation. Elective, outpatient and spine procedures were more often cancelled. Reasons for cancellation included surgeon-related factors (28.2%), cancellation for a higher acuity case (23.9%), patient condition (17.2%), other factors (17.0%), resource availability (7.0%), operating room running late (6.4%) and anaesthesia-related (0.3%). When clustered, the reason for cancellation was patient-related in 17.2%, staffing-related in 28.5% and operational or resource-related in 54.3% of cases.Conclusions: Neurosurgical operative cancellations were common and most often related to operational or resource-related factors. Elective, outpatient and spine procedures were more often cancelled. These findings highlight areas for optimizing efficiency and targeted quality improvement initiatives.

BACKGROUND AND OBJECTIVES: Anterior basal encephaloceles are considered a rare entity and are often associated with midline cerebral abnormalities. Those with a large skull base defect and herniation of brain parenchyma in the neonate or young infant present unique challenges for surgical management. METHODS: We analyzed the neurosurgical administrative and operative databases between 1986 and 2022 to determine clinical presentation, operative approach, and outcome of basal encephaloceles. RESULTS: Over the 36-year period, 27 pediatric anterior basal encephaloceles were managed, of which 22 had full documentation and images allowing comprehensive review. Mean age at presentation was 5 years (SD 4.94). The majority were transethmoidal encephaloceles (59%), followed by the transsphenoidal-sphenoethmoidal type (32%). Overall, 91% were managed surgically by a transcranial, endoscopic, or combined approach. Four children required subsequent procedures, predominantly for persistent cerebrospinal fluid leak. No significant differences in proportion of patients requiring interval/revision surgery after initial conservative, endoscopic endonasal, or transcranial surgery was identified. Neither age at surgery nor size of the defect on computed tomography scan was associated with the need for revision surgery. Size of cranial defect was significantly smaller in the endoscopic group (P = .01). There was a historic tendency for younger children with larger defects to have a transcranial approach. With the addition of endoscopic skull base expertise, smaller defects in older children were more recently treated endoscopically. CONCLUSION: Basal encephaloceles are rare and complex lesions and are optimally managed within a skull base multidisciplinary team able to provide multiple approaches. Large skull base defects with brain parenchymal involvement often require a transcranial or combined transcranial–endoscopic approach.

Background Cerebellar mutism (CM) is characterized by a significant loss of speech in children following posterior fossa (PF) surgery. The biological origin of CM remains unclear and is the subject of ongoing debate. Significant recovery from CM is less likely than previously described despite rigorous multidisciplinary neuro-rehabilitational efforts. Methods A national multi-centered retrospective review of all children undergoing PF resection in four midsized Canadian academic pediatric institutions was undertaken. Patient, tumor and surgical factors associated with the post-operative development of CM were reviewed. Retrospective identification of PF surgery patients including those developing and those that did not (internal control). Results The study identified 258 patients across the 4 centers between 2010 and 2020 (mean age 6.73 years; 42.2% female). Overall, CM was experienced in 19.5% of patients (N = 50). Amongst children who developed CM histopathology included medulloblastoma (35.7%), pilocytic astrocytoma (32.6%) and ependymoma (17.1%). Intraoperative impression of adherence to the floor of the 4th ventricle was positive in 36.8%. Intraoperative abrupt changes in blood pressure and/or heart rate were identified in 19.4% and 17.8% of cases. The clinical resolution of CM was rated to be complete, significant resolution, slight improvement, no improvement and deterioration in 56.0%, 8.0%, 20.0%, 14.0% and 2.0%, respectively. In the cohort of children who experienced post-operative CM as compared to their no-CM counterpart, proportionally more tumors were felt to be adherent to the floor of the 4th ventricle (56.0% vs 49.5%), intraoperative extent of resection was a GTR (74% vs 68.8%) and changes in heart rate were noted (≥ 20% from baseline) (26.0% vs 15.9%). However, a multiple regression analysis identified only abrupt changes in HR (OR 5.97, CI (1.53, 23.1), p = 0.01) to be significantly associated with the development of post-operative CM. Conclusion As a devastating surgical complication after posterior fossa tumor surgery with variable clinical course, identifying and understanding the operative cues and revising intraoperative plans that optimizes the child’s neurooncological and clinical outcome are essential.

Introduction Os odontoideum refers to a rounded ossicle detached from a hypoplastic odontoid process at the body of the axis. The aetiology has been debated and believed to be either congenital or acquired (resulting from trauma). Os odontoideum results in incompetence of the transverse ligament and thus predisposes to atlantoaxial instability and spinal cord injury. Methods/results Three cases of children with severe dystonic cerebral palsy presenting with myelopathic deterioration secondary to atlantoaxial instability due to os odontoideum are presented. This observation supports the hypothesis of os odontoideum being an acquired phenomenon, secondary to chronic excessive movement with damage to the developing odontoid process. Conclusion In children with cerebral palsy and dystonia, pre-existing motor deficits may conceal an evolving myelopathy and result in delayed diagnosis of clinically significant atlantoaxial subluxation.

Background Cerebellar mutism (CM) is characterized by a significant loss of speech in children following posterior fossa (PF) surgery. The biological origin of CM remains unclear and is the subject of ongoing debate. Significant recovery from CM is less likely than previously described despite rigorous multidisciplinary neuro-rehabilitational efforts. Methods A national multi-centered retrospective review of all children undergoing PF resection in 4 midsized Canadian academic pediatric institutions was undertaken. Patient, tumor, and surgical factors associated with the post-operative development of CM were reviewed. Retrospective identification of PF surgery patients including those developing and those that did not (internal control). Results The study identified 258 patients across the 4 centers between 2010–2020 (mean age 6.73 years; 42.2 female). Overall, CM was experienced in 19.5% of patients (N = 50). Amongst children who developed CM histopathology included medulloblastoma (35.7%), pilocytic astrocytoma (32.6%), and ependymoma (17.1%). Intraoperative impression of adherence to the floor of the 4th ventricle was positive in 36.8%. Intraoperative abrupt changes in blood pressure and/or heart rate were identified in 19.4% and 17.8% of cases. The clinical resolution of CM was rated to be complete, significant resolution, slight improvement, no improvement, and deterioration in 56.0%, 8.0%, 20.0%, 14.0%, 2.0%, respectively. In the cohort of children who experienced post-operative CM as compared to their no-CM counterpart, proportionally more tumors were felt to be adherent to the floor of the 4th ventricle (56.0% vs 49.5%), intraoperative extent of resection was a GTR (74% vs 68.8%), and changes in heart rate were noted (≥ 20% from baseline) (26.0% vs 15.9%). However, a logistic regression for experiencing CM identified only intraoperative impression of adherence to the floor of the 4th ventricle (OR 2.32, p = 0.011), abrupt changes in intraoperative HR (> 20% from baseline) (OR 2.34, p = 0.028), and medulloblastoma histology (OR 3.77, p = 0.001) to significantly associated with development of post-operative CM. Conclusion As a devastating surgical complication, identifying and understanding the biological origin of CM is the first step to complication avoidance. Maximal safe resection irrespective of intraoperative pathology remains the strategy to minimize the devastating post-operative development of CM.