National multicentered retrospective review of clinical and intraoperative factors associated with the development of cerebellar mutism after pediatric posterior fossa tumor resection

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.

A nationwide prospective multicenter study of external ventricular drainage: accuracy, safety, and related complications

OBJECTIVE

External ventricular drainage (EVD) catheters are associated with complications such as EVD catheter infection (ECI), intracranial hemorrhage (ICH), and suboptimal placement. The aim of this study was to investigate the rates of EVD catheter complications and their associated risk factor profiles in order to optimize the safety and accuracy of catheter insertion.

METHODS

A total of 348 patients with urgently placed EVD catheters were included as a part of a prospective multicenter observational cohort. Strict definitions were applied for each complication category.

RESULTS

The rates of misplacement, ECI/ventriculitis, and ICH were 38.6%, 12.2%, and 9.2%, respectively. Catheter misplacement was associated with midline shift (p = 0.002), operator experience (p = 0.031), and intracranial length (p < 0.001). Although mostly asymptomatic, ICH occurred more often in patients receiving prophylactic low-molecular-weight heparin (LMWH) (p = 0.002) and those who required catheter replacement (p = 0.026). Infectious complications (ECI/ventriculitis and suspected ECI) occurred more commonly in patients whose catheters were inserted at the bedside (p = 0.004) and those with smaller incisions (≤ 1 cm) (p < 0.001). ECI/ventriculitis was not associated with preinsertion antibiotic prophylaxis (p = 0.421), catheter replacement (p = 0.118), and catheter tunneling length (p = 0.782).

CONCLUSIONS

EVD-associated complications are common. These results suggest that the operating room setting can help reduce the risk of infection, but not the use of preoperative antibiotic prophylaxis. Although EVD-related ICH was associated with LMWH prophylaxis for deep vein thrombosis, there were no significant clinical manifestations in the majority of patients. Catheter misplacement was associated with operator level of training and midline shift. Information from this multicenter prospective cohort can be utilized to increase the safety profile of this common neurosurgical procedure.

EPCT-12. NATIONAL MULTICENTERED RETROSPECTIVE REVIEW OF DEMOGRAPHIC, TUMOUR AND INTRAOPERATIVE FEATURES ASSOCIATED WITH THE DEVELOPMENT OF CEREBELLAR MUTISM AFTER PEDIATRIC POSTERIOR FOSSA TUMOUR RESECTION

Background

Cerebellar mutism (CM) is a condition characterized by a significant lack or loss of speech in children following posterior fossa (PF) surgery. The biological origin of CM remains largely unclear and remains the subject of ongoing debate. Despite multidisciplinary rehabilitative interventions, the outcome is less favorable than initially described. Given the treatment refractory nature of CM, central to its management is prevention.

Methods

A national multi-centered retrospective review of all the children undergoing posterior fossa resection at 4 Canadian academic pediatric institutions was undertaken. Patient, tumour, surgical features suggested to be associated with the post-operative development of CM were reviewed to identify pre-operative and intra-operative factors that may predict post-operative CM occurrence.

Results

258 pediatric patients were identified after posterior fossa lesion resection. Mean age at surgery was 6.74 years (SD 4.60) and 42.2% were female. Frozen section was available in 90.3% of cases. The majority of final tumour histology was medulloblastoma (35.7%), pilocytic astrocytoma (32.6%), ependymoma (17.1%) and exophytic glioma (1.2%). Intra-operative impression of adherence to the floor of the 4th ventricle was negative in 47.7%, positive in 36.8% of cases. The extent of resection assessed intraoperatively as gross total resection was 69.8% of cases. Intra-operative abrupt changes in blood pressure and/or heart rate was identified in 19.4% and 17.8% of cases. CM was experienced in 19.5% of patients (N=50), with the majority of cases identified by post-operative day 7. The clinical resolution of CM as mainly assessed by a neurosurgeon (86%) and was complete, significantly resolved, slight improvement, no improvement or deterioration in 56.0%, 8.0%, 20.0%, 14.0%, 2.0% respectively.

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 intra-operative pathology remains the goal to avoid the devastating complication of CM.

The clinical utility of the Spinal Instability Neoplastic Score (SINS) system in spinal epidural metastases: a retrospective study

STUDY DESIGN

A retrospective study.

OBJECTIVES

This study assessed the clinical utility of the Spinal Instability Neoplastic Score (SINS) in relation to the surgical treatment of spinal epidural metastasis and factors important for surgical decision-making. These factors include epidural spinal cord compression (ESCC), patient prognosis and neurologic status.

SETTING

Queen Elizabeth II Health Sciences Centre, Halifax, Canada.

METHODS

We identified 285 patients with spinal metastatic disease. Data were extracted through a retrospective review. SINS and ESCC were scored based on CT and MRI, respectively.

RESULTS

Patients were grouped into stable (35%), potentially unstable (52%), and unstable (13%) groups. The overall incidence of metastatic spinal deformity was 9%. Surgical interventions were performed in 21% of patients, including decompression and instrumented fusion (70%), decompression alone (17%), percutaneous vertebral augmentation (9%), and instrumented vertebral augmentation (5%). The use of spinal instrumentation was significantly associated with unstable SINS (p = 0.005). Grade 3 ESCC was also significantly associated with unstable SINS (p < 0.001). Kaplan-Meier analysis revealed that SINS was not a predictor of survival (p = 0.98). In the radiotherapy-alone group, a significant proportion of patients with potentially unstable SINS (30%) progressed into unstable SINS category at an average 364 ± 244 days (p < 0.001).

CONCLUSION

This study demonstrated that more severe categories of SINS were associated with higher degrees of ESCC, and surgical interventions were more often utilized in this group with more frequent placement of spinal instrumentation. Although SINS did not predict patient prognosis, it correlates with the progression of metastatic instability in patients treated with radiotherapy.

Mobile Applications in Neurosurgery: A Systematic Review, Quality Audit, and Survey of Canadian Neurosurgery Residents

BACKGROUND

In the past decade, smartphone applications (Apps) have experienced remarkable development across all fields of medicine, including neurosurgery. However, owing to a lack of regulatory oversight and peer review, a clear need exists for a comprehensive review and audit of the existing available Apps. In the present study, we systematically reviewed the existing mobile Apps in neurosurgery, evaluated their clinical use by neurosurgery residents in Canada, and performed a quality audit of the most popular Apps.

METHODS

Indexed Apps were identified from either the Google Play Store or the iOS App Store using a comprehensive list of keywords related to neurosurgery. A subsequent cross-sectional survey of 76 Canadian neurosurgery residents was conducted, including a section on smartphone App use. We next evaluated the most popular Apps among the residents using the Healthcare Smartphone App Evaluation Tool and performed a quality audit of their content using established medical references.

RESULTS

The survey identified 118 mobile Apps related to neurosurgery. The 3 most used Apps used by the current cohort of Canadian neurosurgery residents were Neurosurgery Survival Guide, Neuromind, and the Journal of Neurosurgery App. Each of these 3 Apps received an excellent score on the Healthcare Smartphone App Evaluation Tool. A quality audit of 30 pages of the Neurosurgery Survival Guide and 40 clinical scores of the Neuromind App, performed by 10 neurosurgery residents, failed to reveal inaccurate or false statements.

CONCLUSION

The present study has highlighted the current landscape of neurosurgery mobile Apps and their use among neurosurgery residents.

Smartphone Usage Patterns by Canadian Neurosurgery Residents: A National Cross-Sectional Survey

BACKGROUND

Smartphones and their apps are used ubiquitously in medical practice. However, in some cases their use can be at odds with current patient data safety regulations such as Canada's Personal Health Information Protection Act of 2004. To assess current practices and inform mobile application development, we sought to better understand mobile device usage patterns among Canadian neurosurgery residents.

METHODS

Through the Canadian Neurosurgery Research Collaborative, an online survey characterizing smartphone ownership and usage patterns was developed and sent to all Canadian neurosurgery resident in April of 2016. Questionnaires were collected and completed surveys analyzed.

RESULTS

Of 146 eligible residents, 76 returned completed surveys (52% response rate). Of these 99% of respondents owned a smartphone, with 79% running on Apple's iOS. Four general mobile uses were identified: 1) communication between members of the medical team, 2) decision support, 3) medical reference, and 4) documentation through medical photography. Communication and photography were areas where the most obvious breaches in the Canadian Personal Health Information Protection Act were noted, with 89% of respondents taking pictures of patients' radiologic studies and 75% exchanging them with Short Message System. Hospital policies had no impact on user behaviors.

CONCLUSIONS

Smartphones are used daily by most neurosurgery residents. Identified usage patterns are associated with perceived gains in efficacy and challenges in privacy and data reliability. We believe creating and improving workflows that address these usage patterns has a greater potential to improve privacy than changing policies and enforcing regulations.

Virtual Reality Surgical Simulation: Implications for Resection of Intracranial Gliomas

Surgical simulation has the potential to play important roles in surgical training and preoperative planning. The advent of virtual reality (VR) with tactile haptic feedback has revolutionized surgical simulation, creating a novel environment for residents to learn manual skills without compromising patient safety. This concept is particularly relevant in neurosurgical training where the acquired skill set demands performance of technically challenging tasks under pressure and where the consequences of error are significant. The evolution of VR simulation is discussed here within the context of neurosurgical training and its implications for resection of intracranial gliomas. VR holds the promise of providing a useful educational tool for neurosurgical residents to hone their surgical skills and for neurosurgeons to rehearse specific segments of the surgery prior to the actual operation. Also discussed are several important issues related to simulation and simulation-based training that will need to be addressed before widespread adoption of VR simulation as a useful technology.

Granular expression of prolyl-peptidyl isomerase PIN1 is a constant and specific feature of Alzheimer's disease pathology and is independent of tau, Aβ and TDP-43 pathology

Alzheimer's disease (AD) manifests with progressive memory loss and decline of spatial awareness and motor skills. Neurofibrillary tangles (NFTs) represent one of the pathological hallmarks of AD. Previous studies suggest that the enzyme prolyl-peptidyl cis-trans isomerase PIN1 [protein interacting with NIMA (never in mitosis A)-1] recognizes hyperphosphorylated tau (in NFTs) and facilitates its dephosphorylation, thereby recovering its function. This study aims to determine the frequency, severity and distribution of PIN1 immunoreactivity and its relationship to NFTs and other neuropathological markers of neurodegeneration such as amyloid-β (Aβ) plaques and transcription-responsive DNA-binding protein of M(r) 43 kDa (TDP-43). Immunohistochemical analysis of 194 patients (46 with AD, 43 with Parkinson's disease/dementia with Lewy bodies, 12 with progressive supranuclear palsy/corticobasal degeneration, 36 with frontotemporal lobar degeneration, 21 with motor neuron disease and 34 non-demented (ND) individuals) revealed an increased frequency and severity of PIN1 immunoreactive inclusions in AD as compared to all diagnostic groups (P < 0.001). The hippocampal and cortical distribution of PIN1 granules was distinct from that of NFTs, Aβ and TDP-43 pathologies, though the frequency of neurons with PIN1 immunoreactivity increased with increasing NFT pathology. There was a progressive increase in PIN1 changes in ND individuals as the degree of AD-type pathological changes increased. Present findings indicate that PIN1 changes are a constant feature of AD pathology and could serve as a biomarker of the onset or spread of AD neuropathology independent of tau or Aβ.