Minimally invasive foramen magnum decompression using tubular retractors (MIFT) for Chiari I malformations.

BACKGROUND: Chiari malformation type 1 has been traditionally treated with foramen magnum decompression and C1 arch excision with or without duroplasty depending on the surgeon's preference. Each of the various surgical modifications has its advantages and disadvantages. METHODS: We describe a minimally invasive tubular retractor-based approach to achieve bony decompression in these cases. We have had good results comparable to the open approach. CONCLUSIONS: Strict orientation to the midline using soft tissue landmarks in between the muscles and bony landmarks in the deeper planes is important to achieve good surgical results. Operative time decreases with expertise and is comparable to the open technique. Minimal blood loss and decreased hospital stay and an excellent cosmetic scar make this procedure more appealing.

Chaotic lipoma with proximal syrinx -a (not so) rare variant - review of the literature, possible embryology and management.

Chaotic lipomas are an extremely rare variant of spinal lipomas. This entity was first defined in 2009 by Pang and colleagues. Not much has been written about this variant. Its characteristic is the haphazard distribution of DREZ (Dorsal root entry zone), nerve roots and placode-lipoma interface. Thus complete/near-total excision of this lesion is quite difficult. We describe a case of chaotic spinal lipoma and elucidate the challenges faced in the management of this entity and review the literature. We performed a thorough systematic review with the keyword 'chaotic', 'Lipomyelomeningocele', 'Complex Lipomyelomeningocele', 'LMMC', 'Lumbar lipoma', 'spinal lipoma' in the google scholar and PUBMED data system for indexed literature on the above topic with no particular time frame. The studies quoted range earliest from 1970 till currently. Additional potential relevant articles were further retrieved through a manual search of references from original reports. Out of 42 studies, a total of 21 publications were selected which could have encountered a chaotic variant, but due to the term introduced only recently in 2009, may have been described differently. Studies encompassing true lipomeningomyelocele were excluded from our review. What we found out? Chaotic lipoma may not be a new entity. The scarce description in literature may be in part due to non-introduction and unclear description of this term earlier. The management of this variant is particularly challenging with basic principles remaining the same. Meticulous near-total excision and placode-lipoma construct are the major obstacles.

Utility of multiparametric pre-operative magnetic resonance imaging in differentiation of chordoid meningioma from the other histopathological subtypes of meningioma-a retrospective study.

PURPOSE: To determine the magnetic resonance imaging (MRI) features which could pre-operatively differentiate chordoid meningioma (CM) from other histopathological subtypes of meningioma. METHODS: Retrospective analysis of pre-operative MRI of cases with histopathologically confirmed diagnosis of meningioma during the last 5 years at our institute was done. T1W, T2W, FLAIR sequences, and post-contrast enhancement were evaluated on a qualitative scale. Normalized ADC ratios (nADCR) and normalized fractional anisotropy ratios (nFAR) were derived. The intratumoral susceptibility score (ITSS), presence of sunburst pattern of vasculature, bone changes, tumour-parenchyma interface, and oedema-to-tumour ratio were also determined. RESULTS: A total of 81 lesions were analyzed out of which 15 were CM. CM showed a higher relative contrast enhancement as compared to all other subtypes except for angiomatous and microcystic meningioma. Relative signal intensity on FLAIR could differentiate CM from transitional meningioma. nFAR was found to be significantly higher in fibroblastic meningioma and significantly lower in microcystic meningiomas as compared to CM. Anaplastic meningiomas were remarkable for bone changes and an ill-defined tumour-brain interface in significantly higher proportion of cases as compared to CM. nADCR > 1.5 was found to be an independent predictor of CM with a sensitivity of 84.6%, specificity of 89.8%, positive predictive value of 64.7%, and negative predictive value of 96.4%. CONCLUSION: Routine pre-operative MRI may be able to differentiate CM from other meningioma subtypes and a cut-off value of greater than 1.5 for nADCR could be predictive of > 50% chordoid histology of meningioma with a high sensitivity, specificity, and negative predictive value.

Diffusion and perfusion imaging biomarkers of H3 K27M mutation status in diffuse midline gliomas.

PURPOSE: H3K27M-mutant diffuse midline gliomas (M-DMGs) exhibit a clinically aggressive course. We studied diffusion-weighted imaging (DWI) and perfusion (PWI) MRI features of DMG with the hypothesis that DWI-PWI metrics can serve as biomarkers for the prediction of the H3K27M mutation status in DMGs. METHODS: A retrospective review of the institutional database (imaging and histopathology) of patients with DMG (July 2016 to July 2020) was performed. Tumoral apparent diffusion coefficient (ADC) and peritumoral ADC (PT ADC) values and their normalized values (nADC and nPT ADC) were computed. Perfusion data were analyzed with manual arterial input function (AIF) and leakage correction (LC) Boxerman-Weiskoff models. Normalized maximum relative CBV (rCBV) was evaluated. Intergroup analysis of the imaging variables was done between M-DMGs and wild-type (WT-DMGs) groups. RESULTS: Ninety-four cases (M-DMGs-n = 48 (51%) and WT-DMGs-n = 46(49%)) were included. Significantly lower PT ADC (mutant-1.1 ± 0.33, WT-1.23 ± 0.34; P = 0.033) and nPT ADC (mutant-1.64 ± 0.48, WT-1.83 ± 0.54; P = 0.040) were noted in the M-DMGs. The rCBV (mutant-25.17 ± 27.76, WT-13.73 ± 14.83; P = 0.018) and nrCBV (mutant-3.44 ± 2.16, WT-2.39 ± 1.25; P = 0.049) were significantly higher in the M-DMGs group. Among thalamic DMGs, the min ADC, PT ADC, and nADC and nPT ADC were lower in M-DMGs while nrCBV (corrected and uncorrected) was significantly higher. Receiver operator characteristic curve analysis demonstrated that PT ADC (cut-off-1.245), nPT ADC (cut-off-1.853), and nrCBV (cut-off-1.83) were significant independent predictors of H3K27M mutational status in DMGs. CONCLUSION: DWI and PWI features hold value in preoperative prediction of H3K27M-mutation status in DMGs.

Neurogenic stunned myocardium resulting from surgical brainstem handling during resection of paediatric recurrent medulloblastoma-a possible brain heart interaction.

BACKGROUND: Neurogenic stunned myocardium (NSM) is characterised by an acute onset cardiac dysfunction following an acute neurological insult which mimics acute coronary syndrome. CASE DETAILS: A 12-year-old male child was admitted to the neuro-intensive care unit (NICU) following midline suboccipital craniotomy and resection of recurrent medulloblastoma. Postoperatively, in NICU, he developed tachycardia and hypotension, which was unresponsive to fluid challenge requiring norepinephrine infusion. Intraoperatively, during tumour resection from the dorsal medulla, episodes of hypertension and bradycardia were observed. Intraoperative blood loss was adequately managed with a stable hemodynamic profile without postoperative anaemia. An electrocardiogram showed sinus tachycardia with T wave inversion, and blood investigation revealed elevated cardiac troponin T levels. Point of care ultrasound (POCUS) of heart and lung showed features of NSM. Infusion dobutamine was added to achieve a target mean arterial pressure of 65 mm Hg with concomitant furosemide infusion and fluid restriction. Daily POCUS assessment of cardiac contractility and volume status was done. The patient was weaned from vasoactive drugs and ventilator following improvement of cardiac function and was discharged from NICU after 17 days. CONCLUSION: NSM results from the excessive release of catecholamines following stimulation of trigger zones in the brain. To date, a handful of cases of pediatric NSM following primary brain tumour are reported where hydrocephalus resulted in trigger zone activation. In this presented case, direct brain stem stimulation during tumour resection might have triggered NSM. Irrespective of the cause, timely diagnosis and execution of supportive management in our patient resulted in a positive outcome.

Syndromic Craniosynostosis: Objective and Parent-Reported Outcome Measurements after Cranio-Facial Remodelling Surgeries.

INTRODUCTION: Syndromic craniosynostosis (SC) is a rare entity compared to the non-syndromic variant. Treatment involves a multidisciplinary approach towards a multitude of problems. Early intervention is known to be better for optimum results. We reviewed outcomes of children with SC who underwent reconstructive cranio-facial surgery. MATERIALS AND METHODS: A retrospective study was conducted using data from hospital case files and the picture archival communication system. Objective data like the cephalic index (CI), both preoperatively and post-operatively, were compared. Subjective data for the cosmesis outcome - "Sloan and Whitaker outcome class" - following surgery were assessed. Also, parent-reported outcome measurement (PROM) was performed with various parameters to assess quality of life (QOL). RESULTS: We had 21 operated cases of SC, with 19 needing cranio-facial remodelling. The male to female ratio was 11:10. Crouzon's syndrome was the most common syndromic association followed by Apert's syndrome. Nineteen patients underwent cranio-facial remodelling surgeries and 2 underwent the ventriculo-peritoneal shunt only - for raised intracranial pressure (ICP). Nine patients underwent cranial remodelling with fronto-orbital advancements, and 3 of these patients also received le-fort's type 3 osteotomy and advancement later. Ten patients underwent fronto-orbital advancement with parieto-occipital barrel-stave osteotomies. OUTCOMES: Improvement in the CI was maximum at the 6-month follow-up. Six (37.5%) cases had Sloan class 1 outcome, 9 (56.25%) had class 2 outcomes, and 1 patient had a class 6 outcome. Whitaker cosmesis outcomes - 14 out of 16 cases (87.5%) had Category 1 outcomes. PROM was assessed. All parents reported at least a moderate improvement in cosmesis following surgery. Out of 15 cases, 10 (66%) reported significant improvement, while 4 (26.6%) cases reported moderate improvement with respect to eye and visual problems. Four parents reported snoring as a significant problem even after surgery. Most parents felt that the children were doing well, attending regular school, and social well-being was normal and had an overall good QOL. CONCLUSIONS: SC cases may have a multitude of other problems like raised ICP, ophthalmological problems, poor intelligence, and cognition apart from cosmetic concerns. PROMs revealed good outcomes in terms of cosmesis, cognition, and ophthalmological and oral cavity-related problems. Significant improvement in overall QOL was seen in most patients following cranio-facial remodelling surgery.

Sella Bugged! Abscess Inside a Craniopharyngioma: Case Report with Literature Review.

INTRODUCTION: Abscess within a craniopharyngioma (CPG) is extremely rare and only 8 such cases have been reported in literature. Most patients present with hypopituitarism and visual disturbances. We report the first ever case of a CPG with abscess in a pediatric patient. CASE REPORT: A 10-year-old girl presented with visual deterioration and bitemporal hemianopia. Her CT and MRI brain suggested of a sellar-suprasellar CPG. Due to ill-developed sino-nasal anatomy, a transcranial approach was made for the lesion. The lesion was well capsulated, thick walled, and appeared inflamed. Upon incising the wall, thick yellowish pus was drained out in a controlled manner. This was followed by a partial resection of the CPG wall and eccentric, adhered, calcified residue was left behind with an Ommaya drain. The abscess culture grew Enterococcus species and histopathology revealed adamantinomatous CPG. Patient underwent culture sensitive antibiotics course followed by radiation for the residue. She was doing well at 1-year follow-up with clinical and radiological improvement. CONCLUSION: This is the first report of a pediatric case with secondary abscess in CPG. Operative management of such a case includes controlled drainage of pus without dissemination into the surrounding arachnoid space. The tumor and abscess have to be addressed as separate surgical entities; infection control and wherever complete resection is not feasible, partial safe resection followed by radiotherapy is a viable option.

Heartbroken Child: A Rare Case Report of Neurogenic Pulmonary Edema and Takotsubo Cardiomyopathy following Recurrent Medulloblastoma Excision with Possible Aetio-Patho-Bio-Physiological Mechanisms.

INTRODUCTION: Takotsubo (Japanese fishing pot for trapping octopus) cardiomyopathy is a rare phenomenon of acute coronary syndrome presenting usually with the presence of transient apical ballooning of the left ventricle in the absence of obstructive coronary artery disease. It is mainly seen in women of older age secondary to emotional, physical, or psychological stress. In age less than 18 years, it is mainly seen in adolescents suffering from psychiatric disorders and substance abuse. In children, it is rarely described. CASE PRESENTATION: We present here a peculiar case of a 12-year-old child with neurogenic pulmonary oedema and takotsubo cardiomyopathy syndrome after surgery for recurrent medulloblastoma. Also, management challenges are discussed. DISCUSSION/CONCLUSION: Takotsubo cardiomyopathy is not just a classical or inverted type but indeed a spectrum. It can be seen in any case, be it a child or adult secondary to handling or injury to the ponto-medullary junction, rostral pons, or dorsolateral medulla. The density and distribution of beta-adrenergic receptors may be different in children and adults which needs further research. Prognosis is usually excellent across all ages.

An analysis of retractions in neurosurgery and allied clinical and basic science specialties.

BACKGROUND: As the volume of scientific publications increases, the rate of retraction of published papers is also likely to increase. In the present study, we report the characteristics of retracted papers from clinical neurosurgery and allied clinical and basic science specialties. METHODS: Retracted papers were identified using two separate search strategies on PubMed. Attributes of the retracted papers were collected from PubMed and the Retraction Watch database. The reasons for retraction were analyzed. The factors that correlated with time to retraction were identified. Detailed citation analysis for the retracted papers was performed. The retraction rates for neurosurgery journals were computed. RESULTS: A total of 191 retractions were identified; 55% pertained to clinical neurosurgery. The most common reasons for retraction were plagiarism, duplication, and compromised peer review. The countries associated with the highest number of retractions were China, USA, and Japan. The full text of the retraction notice was not available for 11% of the papers. A median of 50% of all citations received by the papers occurred after retraction. The factors that correlated with a longer time to retraction included basic science category, the number of collaborating departments, and the H-index of the journal. The overall rate of retractions in neurosurgery journals was 0.037%. CONCLUSIONS: The retraction notice needs to be freely available on all search engines. Plagiarism checks and reference checks prior to publication of papers (to ensure no retracted papers have been cited) must be mandatory. Mandatory data deposition would help overcome issues with data and results.

DREZotomy in the management of post brachial plexus root avulsion neuropathic pain: fMRI correlates for pain relief.

BACKGROUND: Deafferentiation pain following brachial plexus root avulsion has been documented to be severe enough to affect activities of daily living in patients. Microsurgical DREZotomy is known to alleviate the symptoms by decreasing the afferent signals transmitted from the spinal cord to sensory cortex. OBJECTIVES: To document and analyse the effectiveness of DREZotomy and to evaluate the role of 'sensory cortex' in the cause and relief of dysesthetic pain, using fMRI. MATERIALS AND METHODS: This was a prospective study conducted between 2010 and 2016 and included all patients who underwent DREZotomy for dysesthetic pain following traumatic brachial plexus injury (TBPI). Patients were evaluated both preoperatively and postoperatively with Visual Analogue Scale(VAS), Hospital Anxiety and Depression score (HADS) and SF36 questionnaire and effectiveness of surgery was assessed. Functional magnetic resonance imaging (fMRI) of the brain in resting state was performed before and after surgery and was also compared with controls. Patients underwent standard microsurgical DREZotomy from C5 to D1. Postoperative assessment was done at 6 weeks and 6 months following surgery. RESULTS: Our series had 18 patients aged between 22 and 63 years. RTA was the most common cause of injury. There was significant decrease in pain at 6 months follow up compared to pre-operative values as assessed by VAS, HADS, SF36 questionnaire. fMRI analysis revealed cluster activations in the sensory, motor cortex and in the right cingulate gyrus in the preoperative group which was higher than in normal controls. In the postoperative group, the size of the resting state activation was significantly reduced. CONCLUSION: DREZotomy is an effective procedure for TBPI patients. We hypothesize that these fMRI findings reflect the cortical reorganization that occurs not only after injury but also following successful surgery which explains the cause and relief of dyesthetic pain.

H3K27M, IDH1, and ATRX expression in pediatric GBM and their clinical and prognostic significance.

PURPOSE: Pediatric glioblastoma (pGBM) tumors have been identified as an entity distinct and different from the adult variety of GBM not only with respect to pathogenesis, genetics, and molecular alterations but also in clinical outcomes and overall survival. This study aims to evaluate the immunohistochemical profile of molecular markers in pediatric GBM and correlate them with clinical features and prognosis. MATERIALS AND METHODS: We retrospectively analyzed 29 pGBMs (age range 3 to 18 years), operated at our institute between 2009 and 2014, and evaluated their clinical and histopathological features along with the immunohistochemical expression of clinically relevant molecular markers: H3K27M, p53, ATRX, and IDH1 (R132H), and correlated their expression with clinical features. We further assessed the prognostic value of these markers in our cohort of patients. RESULTS: The median overall survival (OS) of the cohort was 6.00 ± 0.882 months. The mean overall survival was 7.571 ± 1.118 months which was lower than in most studies. Preoperative Karnofsky Performance Score (KPS), extent of surgical resection, and adjuvant radiotherapy were found to be the clinical factors strongly influencing median survival (p < 0.05). Loss of ATRX expression was predominantly noted in hemispheric tumors (84%), while p53 staining was maximum in thalamic tumors (8 out of 9 cases). H3K27M mutant protein expression was noted in 8/9 thalamic tumors and 5/7 tumors in the brain stem-cerebellar-peduncular region. Patients with tumors showing H3K27M immunopositivity had the worst prognosis with a mean OS of 5 months ± 0.832 months, as against patients with H3K27M-immunonegative tumors, which was 10.143 ± 1.866 months(p = 0.006). Other markers like p53, ATRX, and IDH1 did not influence the prognosis in this patient cohort. ATRX loss of expression was associated with a better OS, with a trend to significance, and such an association has not been reported earlier. CONCLUSIONS: Ours is one among the few studies from India describing the clinical parameters and evaluating the key immunohistochemical markers in pGBM and deriving their prognostic significance. The study reiterates the poor prognostic significance of H3K27M immunopositivity.

Predictors of outcome of subdural empyema in children.

OBJECTIVE: The aim of this study was to report the etiology, clinical features, microbiology, surgical outcome, and predictors of outcome of spontaneous subdural empyema (SDE). METHODS: The authors conducted a retrospective study in a tertiary hospital. Children up to 18 years of age, with a diagnosis of SDE with infective etiology, were included in the present cohort. Patients with posttraumatic, postsurgery, and tubercular origin of SDE were excluded from the study. The Glasgow Outcome Scale was used for outcome assessment at the end of 3 months. For analysis purposes, the demographic data, clinical features, radiological data, microbiology, type of surgery, and complication data were categorized, and univariate and multivariable logistic regression analyses were performed to identify the factors associated with outcome. RESULTS: Ninety-eight children were included in the study and the mean age was 10.9 years. Otogenic origin (34.7%) was the most common source of infection, followed by meningitis (14.3%). The mean duration of symptoms was 12 days. Seventy-six children presented with Glasgow Coma Scale (GCS) score > 8 and the supratentorial location was the most common location. Almost 75% of the children underwent craniotomy or craniectomy and the rest had burr-hole evacuation. Beta-hemolytic Streptococcus (10%) was the most common organism isolated. Cerebral venous thrombosis (CVT; 10.2%) was the most frequent complication in this cohort. The other complications were infarction (6.1%), new-onset seizure (4.1%), and bone flap osteomyelitis (4.1%). Thirteen cases had a recurrence of pus collection, which was more common in the craniotomy group than in the burr-hole group. Age (p = 0.02), GCS score ≤ 8 (OR 8.15, p = 0.001), CVT (OR 15.17, p = 0.001), and presence of infarction (OR 7, p = 0.05) were strongly associated with unfavorable outcome. In multivariable logistic regression analysis, only GCS score ≤ 8 (p = 0.01), CVT (p = 0.02), and presence of infarction (p = 0.04) had a significant impact on unfavorable outcome. CONCLUSIONS: Prompt diagnosis and immediate intervention is the goal of management of SDE, especially in children as a delay in diagnosis can result in unconsciousness and secondary complications such as CVT and infarction, which adversely affect outcome.

Carbon dioxide induced cerebral vasomotor reactivity in moderate-to-severe cerebral venous thrombosis patients and its impact on prognosis: A transcranial doppler-based prospective exploratory study.

Hyperventilation-induced intracranial pressure reduction might be impaired in cerebral venous thrombosis (CVT) patients. Using transcranial Doppler, we assessed carbon dioxide-vasomotor reactivity (CO2-VMR) within 24 hours of admission in CVT patients and studied its correlation with patient outcomes. Adult moderate-severe CVT patients (participants of another large observational study) were included. CO2-VMR was calculated as the percentage change in peak flow velocities during maximal hypercapnia and hypocapnia. Outcome was assessed with the modified Rankin scale (mRS) at one - month post-discharge, dichotomized into favourable (mRS≤2) and unfavourable (mRS>2). Twenty patients' data was analysed. Impaired CO2-VMR (<70 %) was observed in 13 patients in the affected hemisphere; among them, 10 had impairments in both hemispheres. CO2-VMR correlated negatively with mRS (Rho = -0.688, p = 0.001). Odds for unfavourable outcomes were reduced by 92 % in patients with intact VMR on the ipsilateral hemisphere (Odds ratio (OR) 0.08, Confidence interval (CI) 0.006---0.636, p = 0.027) and by 94 % with VMR intact on the contralateral hemisphere (OR 0.063, CI 0.003---0.569, p = 0.03). Thus, impaired CO2-VMR in moderate to severe CVT patients is associated with unfavourable outcomes, and has the potential to prognosticate CVT patients objectively.

Pediatric shunt failure: finding predictability in the sea of uncertainty.

OBJECTIVE: Shunt malfunction is a complication that can have devastating implications. In this study, the authors aimed to evaluate the rate of shunt revision in a single institution over 5 years and to determine the factors associated with shunt revision in the pediatric population. METHODS: This retrospective report assimilated data from all patients ≤ 18 years old who underwent shunt surgery between January 2015 and April 2021 at the authors' institute with a minimum of 3 months of follow-up. Patient data regarding demographic characteristics, indications, clinical status, point of entry, operative and CSF findings, revision interval, and cause of failure were collected. RESULTS: Between January 2015 and April 2021, 1112 pediatric patients underwent initial shunt surgery at the authors' institute, among whom 934 patients met the inclusion criteria. Ninety-five patients underwent revision (shunt revision rate 10.2%). The cohort comprised 562 male and 368 female patients (no sex was recorded in 4 cases), with infratentorial tumors (37.8%) being the most common indication for the shunt. Multivariate analyses revealed that younger patient age, right-sided shunt, single surgeon, and shunt placement done in the evening and night were significantly associated with shunt failure. Among all the factors analyzed, female sex had the greatest risk of early shunt failure (OR 2.90 [95% CI 1.09-8.16], p = 0.037). The presence of prior external ventricular drainage was associated with an increased risk of multiple revisions (OR 6.67 [95% CI 1.60-32.52], p = 0.012). The most common cause of failure was obstruction, usually at the cranial end. The most common cause of distal failure was malposition of the abdominal end. CONCLUSIONS: This study identifies various factors associated with shunt failure. Various goal-directed strategies toward modifiable risk factors can significantly improve shunt survival.

Monomelic Amyotrophy/Hirayama Disease: Surgical Outcome in a Large Cohort of Indian Patients.

BACKGROUND: Hirayama disease (HD) is a cervical compressive myelopathy. Anterior cervical discectomy and fusion (ACDF) is identified as the best surgical approach. We evaluated surgical outcomes and factors influencing ACDF in HD. METHODS: Between 2015 and 2019, 126 patients with HD underwent ACDF. Contrast magnetic resonance imaging of the cervical spine in full flexion was performed. Clinical examination and preoperative/postoperative assessment of hand function using Fugl-Meyer assessment, Jebsen-Taylor hand function test, and handheld dynamometry were performed at 3-monthly intervals for 1 year. Surgical outcomes were assessed as per the Odom criteria and Hirayama outcome questionnaire. RESULTS: Age at onset and duration of illness were 12-31 years (mean, 18 ± 2.7) and 1-96 months (32.7 ± 24.4), respectively. All patients had progressive weakness and wasting of the affected limb. Cord atrophy was seen in 97.1%, with epidural detachment and engorgement of the posterior epidural venous plexus in all. All patients underwent ACDF. Of these patients, 54% had an excellent/good outcome and 39% had a satisfactory outcome as per the Odom scale at last follow-up (mean, 44.9 ± 16.5 months) after surgery. Handheld dynamometry showed improvement from preoperative values to 1 year follow-up. Duration of illness and age at onset had a negative correlation and the preoperative Fugl-Meyer score had a positive correlation with improvement. CONCLUSIONS: ACDF resulted in remarkable improvement or stabilization in neurologic deficits in many patients with HD. Because motor disability ensues over time, early surgical intervention during the progressive phase is advocated.

Computer Assisted Objective Assessment of Micro-Neurosurgical Skills From Intraoperative Videos.

Goal: Conventionally, a surgeon's skill is assessed through visual observation by experts and by tracking patient outcomes. These techniques are very subjective and demands enormous time and effort. Hence, the aim of this study is to construct a framework for automated objective assessment of micro-neurosurgical skill. Methods: A mask region-based convolution neural network (RCNN) is trained to identify and localize instances of surgical instruments from the recorded neurosurgery videos. Then the tool motion and tool handling metrics are computed by tracking the detected instrument locations through time. Microscope adjustment patterns are also investigated via the proposed time based metrics.Results: This study highlights the metrics that could potentially emphasize the variance in expertise between a veteran and a novice. These variations include an expert exhibiting a lower velocity, lower acceleration, lower jerks, reduced path length, higher normalized angular displacement, increased bi-manual handling, shorter idle time and smaller inter tool-tip distances while handling tools accompanied with frequent microscope adjustments and reduced maximum and median intervals between adjustments when compared to a novice. Conclusions: The developed vision based framework has proven to be a reliable method to assess the degree of surgical skill objectively and offer prompt and precise feedback to the neurosurgeons.

Automated Microsurgical Tool Segmentation and Characterization in Intra-Operative Neurosurgical Videos.

Checklist based routine evaluation of surgical skills in any medical school demands quality time and effort from the supervising expert and is highly influenced by assessor bias. Alternatively, automated video based surgical skill assessment is a simple and viable method to analyse surgical dexterity offline without the need for acute presence of an expert surgeon throughout the surgery. In this paper, a novel approach and results for the automated segmentation of microsurgical instruments from the real-world neurosurgical video dataset was presented. The proposed tool segmentation model showcased mean average precision of 96.7% in detecting, and localizing five surgical instruments from the real-world neurosurgical videos. Accurate detection and characterization of motion features of the microsurgical tool from the novel annotated neurosurgical video dataset forms the key step towards automated surgical skill evaluation. Clinical Relevance- Tool segmentation, localization, and characterization in neurosurgical video, has several applications including assessing surgeons skills, training novice surgeons, understanding critical operating procedures post surgery, characterizing any critical anatomical response to the tool that leads to the success or failure of the surgery, and building models for conducting autonomous robotic surgery. Semantic segmentation, and characterization of the microsurgical tools forms the basis of the modern neurosurgery.

Microsurgical Tool Detection and Characterization in Intra-operative Neurosurgical Videos.

Brain surgery is complex and has evolved as a separate surgical specialty. Surgical procedures on the brain are performed using dedicated micro-instruments which are designed specifically for the requirements of operating with finesse in a confined space. The usage of these microsurgical tools in an operating environment defines the surgical skill of a surgeon. Video recordings of micro-surgical procedures are a rich source of information to develop automated surgical assessment tools that can offer continuous feedback for surgeons to improve their skills, effectively increase the outcome of the surgery, and make a positive impact on their patients. This work presents a novel deep learning system based on the Yolov5 algorithm to automatically detect, localize and characterize microsurgical tools from recorded intra-operative neurosurgical videos. The tool detection achieves a high 93.2% mean average precision. The detected tools are then characterized by their on-off time, motion trajectory and usage time. Tool characterization from neurosurgical videos offers useful insight into the surgical methods employed by a surgeon and can aid in their improvement. Additionally, a new dataset of annotated neurosurgical videos is used to develop the robust model and is made available for the research community.Clinical relevance- Tool detection and characterization in neurosurgery has several online and offline applications including skill assessment and outcome of the surgery. The development of automated tool characterization systems for intra-operative neurosurgery is expected to not only improve the surgical skills of the surgeon, but also leverage in training the neurosurgical workforce. Additionally, dedicated neurosurgical video based datasets will, in general, aid the research community to explore more automation in this field.

Surgical outcomes of Supra- Infra Tentorial Extradural Hematoma (SIEDH): A retrospective study from a single institution.

INTRODUCTION: Bicompartmental Supra plus Infratentorial Extra Dural Hematoma (SIEDH) is an uncommon yet important category of Extradural Hematoma (EDH) straddling the transverse sinus. It requires quick decision making and proper surgical evacuation. METHODS: We did a retrospective chart review of all SIEDH cases from prospectively maintained operative database in our institute between 2011 & 2017. Clinical status at discharge and follow up were used to assess outcome. Ordinal regression analysis was used for analysis of factors predicting the outcome. We also describe the surgical procedure we follow at our high-volume trauma center for this unique entity. RESULTS: We had 61 operated cases of SIEDH in our series. The median age of the cohort was 30 years (IQR: 21.5-42). Road Traffic Accident was the most common mode of injury (67.2 %). Median pre-operative GCS was 12 (IQR: 9-12). The median volume of SIEDH was 50cc (IQR: 40-70). Mass effect on 4thventricle and brainstem was seen in 47 and 34 patients respectively. An associated fracture was seen in 54 patients. Sinus injury related bleed was noted intra-operatively in 57 % (N = 35). Follow up was available for 60 cases with a median of 130 days. On evaluating with ordinal regression analysis, we found that, the GCS at presentation, pupillary asymmetry, volume of SIEDH, infratentorial volume, blood loss and mass effect on 4thventricle were statistically significant factors affecting GCS at discharge. However, the GCS at presentation, infratentorial volume and blood loss were the only factors determining GOS at follow-up. CONCLUSION: SIEDH are uncommon yet important type of injury type which requires prompt attention and appropriate nuanced approach. Large SIEDH are commonly associated with sinus injury, and large volume blood loss may be anticipated. In addition, SIEDH may be associated with other traumatic brain injuries which may require surgical evacuation.

Prediction of H3K27M mutation status of diffuse midline gliomas using MRI features.

BACKGROUND AND PURPOSE: Presurgical prediction of H3K27M mutation in diffuse midline gliomas (DMGs) on MRI is desirable. The purpose of this study is to elaborate conventional MRI (cMRI) features of H3K27M-mutant DMGs and identify features that could discriminate them from wild-type (WT) DMGs. METHODS: CMRI features of 123 patients with DMG were evaluated conforming to the institutional research protocols. Multimodality MRI was performed on 1.5 or 3.0 Tesla MR Scanners with imaging protocol, including T1-weighted (w), T2w, fluid-attenuated inversion recovery, diffusion-weighted, susceptibility-weighted, and postcontrast T1w sequences. Pertinent cMRI features were annotated along the lines of Visually AcceSAble Rembrandt Images features, and Intra Tumoral Susceptibility Signal score (ITSS) was evaluated. R software was used for statistical analysis. RESULTS: Sixty-one DMGs were H3K27M-mutant (mutant DMGs). The patients in the H3K27M-mutant DMG group were younger compared to the WT-DMG group (mean age 24.13 ± 13.13 years vs. 35.79±18.74 years) (p = 0.016). The two groups differed on five cMRI features--(1) enhancement quality (p = 0.032), (2) thickness of enhancing margin (p = 0.05), (3) proportion of edema (p = 0.002), (4) definition of noncontrast-enhancing tumor (NCET) margin (p = 0.001), and (5) cortical invasion (p = 0.037). The mutant DMGs showed greater enhancement and greater thickness of enhancing margin, while the WT DMGs exhibited significantly larger edema proportion with poorly defined NCET margins and cortical invasion. ITSS was not significantly different among the groups. CONCLUSION: CMRI features like enhancement quality, the thickness of the enhancing margin, proportion of edema, definition of NCET margin, and cortical invasion can discriminate between the H3K27M-mutant and WT DMGs.