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The recent COVID-19 pandemic has presented challenges to post-secondary education, including that campuses have been closed, removing face-to-face instruction options. Meanwhile, this crisis has also presented unique opportunities to create a "tipping point" or conditions that foster innovative teaching practices. In light of such a "danger-opportunity," the feasibility of introducing microlearning (ML), a technology-mediated teaching and learning (T&L) strategy, has recently been revisited by some institutions. ML offers learning opportunities through small bursts of training materials that learners can comprehend in a short time, according to their preferred schedule and location. Initially considered as "add-on" complementary online learning resources to provide learners with an active and more engaging learning experience through flexible learning modes, the possibility of an institution-wide implementation of ML has been further explored during the COVID-19 lockdown. This paper presents an exploratory case study examining two post-secondary education institutions' ML introductions. Using the SAMR model as the lens, their approaches to adopting ML are examined through analysis of quantitative questionnaires and qualitative teacher reflections. Overall, ML appears to be a promising direction that may not only be able to help institutions survive, but possibly offer an enhanced teaching and learning experience, post-pandemic. However, its current implementations face many challenges, both practical and pedagogical, and their impacts have yet to achieve transformation. With the insights gained, some possible strategies for moving the adoption of ML to the next level are offered., Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest., (© The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd 2021.)

Aim: To compare the risk of postoperative haemorrhage with different sizes of brain biopsy needles., Patients and Method: A cohort of patients using a 2.5-mm outer diameter side-cutting biopsy needle was compared to a subsequent cohort using a 1.8-mm needle of the same type. All data were collected prospectively. A CT scan was done within 12 h after surgery. Any visible haemorrhage at the operated site was documented., Results: From 2007 to 2013, 54 stereotactic brain biopsies (all frameless except for one frame-based) were performed. The 2.5-mm group comprised 29 procedures from 2007 to 2009. The 1.8-mm group comprised the subsequent 25 procedures. The diagnostic yields were 90 and 96% in the 2.5- and the 1.8-mm group, respectively (p = 0.615). Comparing the 2.5- and the 1.8-mm group, haemorrhage was significantly reduced: incidence (72 vs. 40%, p = 0.016); size of haemorrhage (mean 7.2 vs. 2.6 mm, p = 0.002); proportion of haemorrhage size >10 mm (34.5 vs. 4%, p = 0.006). Symptomatic haemorrhage rates were 3.4 and 0.0% in the 2.5- and the 1.8-mm group, respectively (p = 1.00)., Conclusion: The 1.8-mm outer diameter needle carried a lower risk of postoperative haemorrhage than the 2.5-mm one, without compromising the diagnostic yield.

Objective: To investigate the safe displacement range of the foramen of Monro (FM) during single burr hole rigid endoscopic third ventriculostomy (ETV) and endoscopic tumor biopsy (ETB)., Methods: Eleven patients who received ETV/ETB for third ventricular and pineal region tumor were reviewed. The burr-hole location, the size, and the virtual displacement of FM were measured using neuronavigation software., Results: Hydrocephalus was resolved, and no subsequent cerebrospinal fluid (CSF) shunting was required in all cases. Histological diagnosis was established in 11 patients. Ten cases received instrumental cognitive and memory assessment postoperatively. The results were within the normal range for eight cases. The mean burr-hole location was 1.7 cm anterior to coronal suture and 3 cm from the midline. The mean diameters of FM measured on the axial, coronal, sagittal, and views were 5.7, 7.8, and 5.6 mm, respectively. The mean virtual displacements of the FM were 1.9±2.0 mm (range=0-4.8) for ETV and 2.4±2.1 mm (range=0-5.5) for ETB. The maximum displacements were 4.8 mm anteriorly for ETV and 5.5 mm posteriorly for ETB., Conclusion: Single burr hole rigid ETV/ETB is likely to be safe within maximum FM displacements of 4.8 mm anterior for ETV and 5.5 mm posterior for ETB. Preoperative trajectory planning using neuronavigation software is recommended., (Copyright © 2012. Published by Elsevier B.V.)

We here presented a rare disease entity with a clinical presentation mimicking aneurysmal subarachnoid haemorrhage. A 43-year-old woman presented with a 1-week history of neck pain and dizziness. Computed tomography of brain showed communicating hydrocephalus and subarachnoid hyperintensity suspicious of previous subarachnoid haemorrhage. Investigations revealed no underlying vascular lesion and leptomeningeal biopsy showed diffuse melanocytosis. We go on to discuss the diagnostic features and clinical course of this entity.

Objectives: To investigate the frequency of pseudoprogression of glioblastoma in Chinese patients receiving concomitant chemoradiotherapy and investigate its association with pseudoprogression and tumour molecular marker O(6)-methylguanine-DNA methyltransferase promoter methylation status., Design: Case series with internal comparisons., Setting: University teaching hospital, Hong Kong., Patients: Patients with glioblastoma treated with concomitant chemoradiotherapy during April 2005 to June 2010 were reviewed. Magnetic resonance imaging brain scans, pre- and post-concomitant chemoradiotherapy and 3-monthly thereafter were reviewed by an independent neuroradiologist according to Macdonald's criteria. Relevant patient information (clinical condition, performance score, development of new neurological deficits, use of steroids, and survival) was retrieved. For each patient, O(6)-methylguanine-DNA methyltransferase methylation status was investigated with genomic DNA from formalin-fixed or paraffin-embedded sections of tumour tissues by methylation-specific polymerase chain reaction., Results: During the study period, 28 primary glioblastoma patients underwent concomitant chemoradiotherapy. The mean age of the patients was 48 (range, 16-71) years. Thirteen patients (13/28, 46%) developed early radiological progression of the tumour after completion of concomitant chemoradiotherapy, of whom five (39%) were subsequently found to have had pseudoprogression. Patients with pseudoprogression showed a trend towards longer survival (22 months in pseudoprogression vs 17 months in all others vs 11 months in those with genuine progression). Among the 27 patients tested for O(6)-methylguanine-DNA methyltransferase promoter status, 12 (44%) were methylated. Two (2/12, 17%) in the methylated group had pseudoprogression, while three (3/15, 20%) in the unmethylated group had pseudoprogression., Conclusions: Nearly half of all patients (46%) developed early radiological progression (within 3 months of completing concomitant chemoradiotherapy). Moreover, about one in three of such patients had pseudoprogression. Pseudoprogression is an important clinical condition to be aware of to prevent premature termination of an effective treatment.

The ultimate treatment goal for intracranial aneurysms is to reconstruct the vessel wall and correct the hemodynamic disturbance. A flow diverter is a stent placed in the parent artery to reduce blood flow in the aneurysm sac to the point of stagnation, gradual thrombosis, and neointimal remodeling to maintain outflow in the side branches and perforators. Here, we review the two commercially available flow diverters, the Pipeline Embolization Device (PED) and the SILK flow diverter (SFD). The rates of severe hemorrhagic complications have been reported to be 2% for the PED and 0.8% for the SFD. The results of studies completed thus far show that endovascular reconstruction with flow diverters is an effective treatment of wide-necked, fusiform, large, and giant unruptured intracranial aneurysms, with 5% to 10% of patients experiencing permanent major morbidity and mortality. The results of ongoing studies may resolve whether flow diverters can replace coil embolization for the treatment of all, or selected, intracranial aneurysms., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Background: In recent years, cranial ventricular catheters impregnated with antimicrobial agents have become available. Theoretically, they provide antibiotic prophylaxis locally without the associated complications of opportunistic nosocomial infections. This study aims to compare antibiotic impregnated catheters with conventional catheters coupled with systemic antibiotics., Methods: Patients undergoing emergency neurosurgical operations were recruited. Patients were randomly assigned to antibiotic impregnated catheters (Bactiseal, Codman, Johnson & Johnson, Raynham, MA, USA) or conventional catheters coupled with systemic antibiotics., Results: 184 neurosurgical patients were enrolled between April 2004 and December 2008. Mean duration of ventricular catheter was 10 days for both groups. The proportion of patients with nosocomial infection was not significantly different: 57% (51/90) in the Bactiseal group and 51% (48/94) in the conventional group (OR 1.3, 0.7 to 2.2). There were also no differences in secondary outcome measures (CSF infection, intensive care unit stay, acute hospital stay and functional outcome) between the two groups., Conclusions: Antibiotic impregnated catheters are as effective as systemic antibiotics in the prevention of CSF infection and their corresponding nosocomial infection rates are not significantly different. The study is registered at http://www.ClinicalTrials.gov (NCT00286104).