Tseng Tsai Yeo

(1) Background: Intra-operative neuronavigation is currently an essential component to most neurosurgical operations. Recent progress in mixed reality (MR) technology has attempted to overcome the disadvantages of the neuronavigation systems. We present our experience using the HoloLens 2 in neuro-oncology for both intra- and extra-axial tumours. (2) Results: We describe our experience with three patients who underwent tumour resection. We evaluated surgeon experience, accuracy of superimposed 3D image in tumour localisation with standard neuronavigation both pre- and intra-operatively. Surgeon training and usage for HoloLens 2 was short and easy. The process of image overlay was relatively straightforward for the three cases. Registration in prone position with a conventional neuronavigation system is often difficult, which was easily overcome during use of HoloLens 2. (3) Conclusion: Although certain limitations were identified, the authors feel that this system is a feasible alternative device for intra-operative visualization of neurosurgical pathology. Further studies are being planned to assess its accuracy and suitability across various surgical disciplines.

Brain–computer interfacing has been applied in a range of domains including rehabilitation, neuro-prosthetics, and neurofeedback. Neuroimaging techniques provide insight into the structural and functional aspects of the brain. There is a need to identify, map and understand the various structural areas of the brain together with their functionally active roles for the accurate and efficient design of a brain–computer interface. In this review, the functionally active areas of the brain are reviewed by analyzing the research available in the literature on brain–computer interfacing in conjunction with neuroimaging experiments. This review first provides an overview of various approaches of brain–computer interfacing and basic components in the BCI system and then discuss active functional areas of the brain being utilized in non-invasive brain–computer interfacing performed with hemodynamic signals and electrophysiological recording-based signals. This paper also discusses various challenges and limitations in BCI becoming accessible to a novice user, including security issues in the BCI system, effective ways to overcome those issues, and design implementations.

Burrhole craniostomy is commonly performed for subdural hematoma (SDH) evacuation, but residual scalp depressions are often cosmetically suboptimal for patients. Osteoplug^TM, a bioresorbable polycaprolactone burrhole cover, was introduced by the National University Hospital, Singapore, in 2006 to cover these defects, allowing osseous integration and vascular ingrowth. However, the cosmetic and safety outcomes of Osteoplug^TM-C—the latest (2017) iteration, with a chamfered hole for subdural drains—remain unexplored. Data were collected from a single institution from April 2017 to March 2021. Patient-reported aesthetic outcomes (Aesthetic Numeric Analog (ANA)) and quality of life (EQ-5D-3L including Visual Analog Scale (VAS)) were assessed via telephone interviews. Clinical outcomes included SDH recurrence, postoperative infections, and drain complications. Osteoplug^TM-C patients had significantly higher satisfaction and quality of life compared to those without a burrhole cover (ANA: 9 [7, 9] vs. 7 [5, 8], p = 0.019; VAS: 85 [75, 90] vs. 70 [50, 80], p = 0.021), and the absence of a burrhole cover was associated with poorer aesthetic outcomes after multivariable adjustment (adjusted OR: 4.55, 95% CI: 1.09–22.68, p = 0.047). No significant differences in other clinical outcomes were observed between Osteoplug^TM-C, Osteoplug^TM, or no burrhole cover. Our pilot study supports Osteoplug^TM-C and its material polycaprolactone as suitable adjuncts to burrhole craniostomy, improving cosmetic outcomes while achieving comparable safety outcomes.

The infiltrative character of supratentorial lower grade glioma makes it possible for eloquent neural pathways to remain within tumoural tissue, which renders complete surgical resection challenging. Neuromodulation-Induced Cortical Prehabilitation (NICP) is intended to reduce the likelihood of premeditated neurologic sequelae that otherwise would have resulted in extensive rehabilitation or permanent injury following surgery. This review aims to conceptualise current approaches involving Repetitive Transcranial Magnetic Stimulation (rTMS-NICP) and extraoperative Direct Cortical Stimulation (eDCS-NICP) for the purposes of inducing cortical reorganisation prior to surgery, with considerations derived from psychiatric, rehabilitative and electrophysiologic findings related to previous reports of prehabilitation. Despite the promise of reduced risk and incidence of neurologic injury in glioma surgery, the current data indicates a broad but compelling possibility of effective cortical prehabilitation relating to perisylvian cortex, though it remains an under-explored investigational tool. Preliminary findings may prove sufficient for the continued investigation of prehabilitation in small-volume lower-grade tumour or epilepsy patients. However, considering the very low number of peer-reviewed case reports, optimal stimulation parameters and duration of therapy necessary to catalyse functional reorganisation remain equivocal. The non-invasive nature and low risk profile of rTMS-NICP may permit larger sample sizes and control groups until such time that eDCS-NICP protocols can be further elucidated.

Gamma knife radiosurgery (GKS), a technique which involves delivery of a high dose of radiation to a precisely defined target, has become the predominant treatment option for brain metastases (BM) because of its high effectiveness and relatively minimal toxicity. Herein, we report a case of late-onset radiation-induced edema around an asymptomatic cyst, more than 20 years after salvage GKS, with 27 years of imaging follow-up, allowing the description of the evolutionary trajectory of these relatively rare complications. Our reported case also demonstrated the benign nature of delayed cyst formation (DCF), emphasizing that observation alone is reasonable for asymptomatic patients.

Introduction During the Coronavirus disease 2019 outbreak, while healthcare systems and hospitals are diverting their resources to combat the pandemic, patients who require spinal surgeries continue to accumulate. The aim of this study is to describe a novel hospital capacity versus clinical justification triage score (CCTS) to prioritize patients who require surgery during the “new normal state” of the COVID-19 pandemic. Methodology A consensus study using the Delphi technique was carried out among clinicians from the Orthopaedic Surgery, Neurosurgery, and Anaesthesia departments. Three rounds of consensus were carried out via survey and Webinar discussions. Results A 50-points score system consisting of 4 domains with 4 subdomains was formed. The CCTS were categorized into the hospital capacity, patient factors, disease severity, and surgery complexity domains. A score between 30 and 50 points indicated that the proposed operation should proceed without delay. A score of less than 20 indicates that the proposed operation should be postponed. A score between 20 and 29 indicates that the surgery falls within a grey area where further discussion should be undertaken to make a joint justification for approval of surgery. Conclusion This study is a proof of concept for the novel CCTS scoring system to prioritize surgeries to meet the rapidly changing demands of the COVID-19 pandemic. It offers a simple and objective method to stratify patients who require surgery and allows these complex and difficult decisions to be unbiased and made transparently among surgeons and hospital administrators.

Implant exposure is a known complication of titanium mesh cranioplasty and is usually managed by implant removal and/or exchange. We describe a case of exposed titanium mesh cranioplasty which was managed with implant exchange and bipedicled flap coverage, and showcase an interesting phenomenon of full-thickness skin present beneath the exposed mesh. This was confirmed on histopathology, which showed the presence of dermal appendages including pilosebaceous units and eccrine glands. We postulate that the mechanism behind this phenomenon involves islands of viable skin ‘dropping’ between holes in the mesh and coalescing beneath the exposed implant, as suggested by histopathology findings of nodular protrusions and varying degrees of epidermal hyperplasia. This protects the underlying dura from external infection. We propose for this phenomenon to be called dermointegration. Our findings suggest that similar cases, particularly patients who are not fit for general anaesthesia, may potentially be managed with a more conservative approach.

Health-related quality of life (HRQoL) is a key metric to understand the impact of stroke from patients’ perspective. Yet HRQoL is not readily measured in clinical practice. This study aims to investigate the extent to which clinical outcomes during admission predict HRQoL at 3 months and 1 year post-stroke. Stroke patients admitted to five tertiary hospitals in Singapore were assessed with Shah-modified Barthel Index (Shah-mBI), National Institute of Health Stroke Scale (NIHSS), Modified Rankin Scale (mRS), Mini-Mental State Examination (MMSE), and Frontal Assessment Battery (FAB) before discharge, and the EQ-5D questionnaire at 3 months and 12 months post-stroke. Association of clinical measures with the EQ index at both time points was examined using multiple linear regression models. Forward stepwise selection was applied and consistently significant clinical measures were analyzed for their association with individual dimensions of EQ-5D in multiple logistic regressions. All five clinical measures at baseline were significant predictors of the EQ index at 3 months and 12 months, except that MMSE was not significantly associated with the EQ index at 12 months. NIHSS (3-month standardized β = − 0.111; 12-month standardized β = − 0.109) and mRS (3-month standardized β = − 0.122; 12-month standardized β = − 0.080) were shown to have a larger effect size than other measures. The contribution of NIHSS and mRS as significant predictors of HRQoL was mostly explained by their association with the mobility, self-care, and usual activities dimensions of EQ-5D. HRQoL at 3 months and 12 months post-stroke can be predicted by clinical outcomes in the acute phase. NIHSS and mRS are better predictors than BI, MMSE, and FAB.