The utilisation of 3D printing in paediatric neurosurgery.

3D printing technology has evolved over the years and there is a growing interest in its application in paediatric neurosurgery. Modern 3D printers have enabled the development of patient-specific 3D models that provide a realistic representation of complex anatomies and will aid in planning complex procedures. Paediatric neurosurgical operations are challenging and hands-on training is restricted. Surgical simulation training with biomodel has provided a new paradigm for trainees to master their surgical skills before encountering similar scenarios in real-life environment. This paper reviews the aspects of 3D printing for preoperative planning and simulation-based surgical training in paediatric neurosurgery.

Differential responses to breath-holding, voluntary deep breathing and hypercapnia in left and right dorsal anterior cingulate.

NEW FINDINGS: What is the central question of this study? What is the role of dorsal anterior cingulate cortex (ACC) in respiration control in humans? What is the main finding and its importance? Direct evidence is provided for a role of the ACC in respiratory control in humans. The neurophysiological responses in dorsal ACC to different breathing tasks varied and were different between left and right ACC. ABSTRACT: The role of subcortical structures and cerebral cortex in the maintenance of respiratory homeostasis in humans remains poorly understood. Emerging evidence suggests an important role of the anterior cingulate cortex (ACC) in respiratory control. In this study, local field potentials (LFPs) from dorsal ACC were recorded in humans through implanted deep brain electrodes during several breathing activities, including voluntary activities of breath-holding and deep breathing, and involuntary activities of inspiration of varying concentrations of carbon dioxide (1%, 3%, 5% and 7%). We found that the breath-holding task induced significant unilateral left-sided ACC changes in LFP power, including an increased activity in lower frequency bands (3-5 Hz) and decreased activity in higher frequency bands (12-26 Hz). The respiratory task involving reflex increase in ventilation due to hypercapnia (raised inspired CO2 ) was associated with bilateral changes in activity of the ACC (again with increased activity in lower frequency bands and reduced activity in higher frequency bands). The voluntary breathing task with associated hypocapnia (deep breathing) induced bilateral changes in activity within low frequency bands. Furthermore, probabilistic diffusion tractography analysis showed left-sided connection of the ACC with the insula and frontal operculum, and bilateral connections within subsections of the cingulate gyrus and the thalamus. This electrophysiological analysis provides direct evidence for a role of the ACC in respiratory control in humans.

Neural Fiber Integrity in High- Versus Low-Grade Glioma using Probabilistic Fiber Tracking.

RATIONALE AND OBJECTIVES: Gliomatous tumors are known to affect neural fiber integrity, either by displacement or destruction. The aim of this study is to investigate the integrity and distribution of the white matter tracts within and around the glioma regions using probabilistic fiber tracking. MATERIAL AND METHODS: Forty-two glioma patients were subjected to MRI using a standard tumor protocol with diffusion tensor imaging (DTI). The tumor and peritumor regions were delineated using snake model with reference to structural and diffusion MRI. A preprocessing pipeline of the structural MRI image, DTI data, and tumor regions was implemented. Tractography was performed to delineate the white matter (WM) tracts in the selected tumor regions via probabilistic fiber tracking. DTI indices were investigated through comparative mapping of WM tracts and tumor regions in low-grade gliomas (LGG) and high-grade gliomas (HGG). RESULTS: Significant differences were seen in the planar tensor (Cp) in peritumor regions; mean diffusivity, axial diffusivity and pure isotropic diffusion in solid-enhancing tumor regions; and fractional anisotropy, axial diffusivity, pure anisotropic diffusion (q), total magnitude of diffusion tensor (L), relative anisotropy, Cp and spherical tensor (Cs) in solid nonenhancing tumor regions for affected WM tracts. In most cases of HGG, the WM tracts were not completely destroyed, but found intact inside the tumor. DISCUSSION: Probabilistic fiber tracking revealed the existence and distribution of WM tracts inside tumor core for both LGG and HGG groups. There were more DTI indices in the solid nonenhancing tumor region, which showed significant differences between LGG and HGG.

Impact of COVID-19 on Neurosurgical Training in Southeast Asia.

OBJECTIVE: Neurosurgery departments worldwide have been forced to restructure their training programs because of the coronavirus disease 2019 (COVID-19) pandemic. In this study, we describe the impact of COVID-19 on neurosurgical training in Southeast Asia. METHODS: We conducted an online survey among neurosurgery residents in Indonesia, Malaysia, Philippines, Singapore, and Thailand from May 22 to 31, 2020 using Google Forms. The 33-item questionnaire collected data on elective and emergency neurosurgical operations, ongoing learning activities, and health worker safety. RESULTS: A total of 298 of 470 neurosurgery residents completed the survey, equivalent to a 63% response rate. The decrease in elective neurosurgical operations in Indonesia and in the Philippines (median, 100% for both) was significantly greater compared with other countries (P < 0.001). For emergency operations, trainees in Indonesia and Malaysia had a significantly greater reduction in their caseload (median, 80% and 70%, respectively) compared with trainees in Singapore and Thailand (median, 20% and 50%, respectively; P < 0.001). Neurosurgery residents were most concerned about the decrease in their hands-on surgical experience, uncertainty in their career advancement, and occupational safety in the workplace. Most of the residents (n = 221, 74%) believed that the COVID-19 crisis will have a negative impact on their neurosurgical training overall. CONCLUSIONS: An effective national strategy to control COVID-19 is crucial to sustain neurosurgical training and to provide essential neurosurgical services. Training programs in Southeast Asia should consider developing online learning modules and setting up simulation laboratories to allow trainees to systematically acquire knowledge and develop practical skills during these challenging times.

A rare case of perivascular epithelioid cell tumour metastases to the brain.

Perivascular epithelioid cell tumour is a rare mesenchymal tumour with distinct immunohistochemical profile. While it is known to occur in various anatomical sites, the central nervous system had always been a protected site for primary or secondary perivascular epithelioid cell tumours. We describe a 61-year-old lady who presented with symptoms of raised intracranial pressure, 3 months after the resection of duodenal and thoracic tumours which were histologically consistent with perivascular epithelioid cell tumour. She was investigated and then subsequently subjected to resection of two metastatic intracranial lesions. The radiological, intraoperative as well as histopathological findings of the metastatic lesions are discussed. Metastatic perivascular epithelioid cell tumour of the brain is extremely rare. However, patients who are stratified as high risk for recurrence or metastases should undergo an early magnetic resonance imaging/computed tomography of the brain in addition to a whole-body positron emission tomography scan, to allow for early detection and management of these tumours.

Crouzon Syndrome: A Case Series of Craniomaxillofacial Distraction Osteogenesis for Functional Rehabilitation.

Crouzon syndrome (CS) is the most common craniosynostosis syndrome and requires a comprehensive management strategy for the optimization of care and functional rehabilitation. This report presents a case series of 6 pediatric patients diagnosed with CS who were treated with distraction osteogenesis (DO) to treat serious functional issues involving severe orbital proptosis, an obstructed nasopharyngeal airway, and increased intracranial pressure (ICP). Three boy and 3 girls were 8 months to 6 years old at the time of the operation. The mean skeletal advancement was 16.1 mm (range, 10 to 27 mm) with a mean follow-up of 31.7 months (range, 13 to 48 months). Reasonable and successful outcomes were achieved in most patients as evidenced by adequate eye protection, absence of signs and symptoms of increased ICP, and tracheostomy tube decannulation except in 1 patient. Complications were difficult fixation of external stabilizing pins in the distraction device (n = 1) and related to surgery (n = 4). Although DO can be considered very technical and can have potentially serious complications, the technique produces favorable functional and clinical outcomes in treating severe CS.

Video clip transfer of radiological images using a mobile telephone in emergency neurosurgical consultations (3G Multi-Media Messaging Service).

BACKGROUND: The purpose of this study was to validate and assess the accuracy and usefulness of sending short video clips in 3gp file format of an entire scan series of patients, using mobile telephones running on 3G-MMS technology, to enable consultation between junior doctors in a neurosurgical unit and the consultants on-call after office hours. METHOD: A total of 56 consecutive patients with acute neurosurgical problems requiring urgent after-hours consultation during a 6-month period, prospectively had their images recorded and transmitted using the above method. The response to the diagnosis and the management plan by two neurosurgeons (who were not on site) based on the images viewed on a mobile telephone were reviewed by an independent observer and scored. In addition to this, a radiologist reviewed the original images directly on the hospital's Patients Archiving and Communication System (PACS) and this was compared with the neurosurgeons' response. RESULTS: Both neurosurgeons involved in this study were in complete agreement with their diagnosis. The radiologist disagreed with the diagnosis in only one patient, giving a kappa coefficient of 0.88, indicating an almost perfect agreement. CONCLUSION: The use of mobile telephones to transmit MPEG video clips of radiological images is very advantageous for carrying out emergency consultations in neurosurgery. The images accurately reflect the pathology in question, thereby reducing the incidence of medical errors from incorrect diagnosis, which otherwise may just depend on a verbal description.

Teleconferencing using multimedia messaging service (MMS) for long-range consultation of patients with neurosurgical problems in an acute situation.

BACKGROUND: : We present our initial experience using a simple and relatively cost effective system using existing mobile phone network services and conventional handphones with built in cameras to capture carefully selected images from hard copies of scan images and transferring these images from a hospital without neurosurgical services to a university hospital with tertiary neurosurgical service for consultation and management plan. METHODS: : A total of 14 patients with acute neurosurgical problems admitted to a general hospital in a 6 months period had their images photographed and transferred in JPEG format to a university neurosurgical unit. This was accompanied by a phone conference to discuss the scan and the patients' condition between the neurosurgeon and the referring physician. All images were also reviewed by a second independent neurosurgeon on a separate occasion to asses the agreement on the diagnosis and the management plan. RESULTS: : There were nine patients with acute head injury and five patients with acute nontraumatic neurosurgical problems. In all cases both neurosurgeons were in agreement that a diagnosis could be made on the basis of the images that were transferred. With respect to the management advice there were differences in opinion on three of the patients but these were considered to be minor. CONCLUSION: : Accurate diagnosis can be made on images of acute neurosurgical problems transferred using a conventional camera phone and meaningful decisions can be made on these images. This method of consultation also proved to be highly convenient and cost effective.