Full-endoscopic trans-pars interarticularis approach for far lateral lumbar discectomy.

PURPOSE: Surgical management of far lateral disc herniations remains challenging. Current transforaminal full-endoscopic approaches require non-visualized docking in the Kambin's triangle and have been associated with significant risk of inadvertent nerve injury. We develop a full-endoscopic approach based on reliable bony landmarks allowing for visualization of the exiting nerve root prior to the far lateral discectomy. METHODS: The surgical details of a full-endoscopic trans-pars interarticularis approach for far lateral discectomy are described. These descriptions include high quality intraoperative images and important surgical pearls. A small patient cohort is presented to demonstrate feasibility and safety of the procedure. RESULTS: We demonstrate the feasibility of this approach in 14 patients with a mean age of 59.5 ± 14.7 years. At a mean follow up of 21.9 ± 6.8 months, improvement of the visual analogue scale (VAS) for leg pain was 4.3 ± 1.0 resulting in minimally clinically important difference in 78.6% of the patients. The mean improvement in VAS for the back pain was 2.6 ± 0.8 and for Oswestry disability index (ODI) was 20.6 ± 5.3. Nuances of the trans-pars surgical techniques are presented in a patient with a right-sided L4-5 far lateral disc herniation. Preoperative imaging studies, steps of the surgical progression, and intraoperative views are described in detail. CONCLUSION: Using the pars interarticularis as the bony target area allows for safe visualized access to the extraforaminal compartment of the exiting nerve root. This novel surgical technique has the potential benefit of decreasing inadvertent neural injury and subsequent postoperative dysesthesias.

Racial and ethnic disparities among children with primary central nervous system tumors in the US.

INTRODUCTION: Primary central nervous system (CNS) tumors are among the most common and lethal types of cancer in children. However, the existence of health disparities in CNS tumors by race or ethnicity remains poorly understood. This systematic review sought to determine whether racial and ethnic disparities in incidence, healthcare access, and survival exist among pediatric patients diagnosed with CNS tumors. METHODS: A search of MEDLINE, Embase, CINAHL, Web of Science, and Scopus was conducted. Inclusion criteria selected for studies published between January 1, 2005 and July 15, 2020 that focused on pediatric populations in the US, evaluated for potential differences based on racial or ethnic backgrounds, and focused on CNS tumors. A standardized study form was used to collect study information, population of interest, research design, and quality of analysis, sample size, participant demographics, pathology evaluated, and incidence or outcomes observed. RESULTS: A total of 30 studies were inlcuded. Studies suggest White children may be more likely to be diagnosed with a CNS tumor and Hispanic children to present with advanced-stage disease and have worse outcomes. The degree of influence derived from socioeconomic factors is unclear. This review was limited by few available studies that included race and ethnicity as a variable, the overlap in databases used, and unclear categorization of race and ethnicity. CONCLUSIONS: This review identified notable and at times contradicting variations in racial/ethnic disparities among children with CNS tumors, suggesting that the extent of these disparities remains largely unknown and prompts further research to improve health equity.

Cellular allograft for multilevel stand-alone anterior cervical discectomy and fusion.

OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is the most common treatment for degenerative disease of the cervical spine. Given the high rate of pseudarthrosis in multilevel stand-alone ACDF, there is a need to explore the utility of novel grafting materials. In this study, the authors present a single-institution retrospective study of patients with multilevel degenerative spine disease who underwent multilevel stand-alone ACDF surgery with or without cellular allograft supplementation. METHODS: In a prospectively collected database, 28 patients who underwent multilevel ACDF supplemented with cellular allograft (ViviGen) and 25 patients who underwent multilevel ACDF with decellularized allograft between 2014 and 2020 were identified. The primary outcome was radiographic fusion determined by a 1-year follow-up CT scan. Secondary outcomes included change in Neck Disability Index (NDI) scores and change in visual analog scale scores for neck and arm pain. RESULTS: The study included 53 patients with a mean age of 53 ± 0.7 years who underwent multilevel stand-alone ACDF encompassing 2.6 ± 0.7 levels on average. Patient demographics were similar between the two cohorts. In the cellular allograft cohort, 2 patients experienced postoperative dysphagia that resolved by the 3-month follow-up. One patient developed cervical radiculopathy due to graft subsidence and required a posterior foraminotomy. At the 1-year CT, successful fusion was achieved in 92.9% (26/28) of patients who underwent ACDF supplemented with cellular allograft, compared with 84.0% (21/25) of patients who underwent ACDF without cellular allograft. The cellular allograft cohort experienced a significantly greater improvement in the mean postoperative NDI score (p < 0.05) compared with the other cohort. CONCLUSIONS: Cellular allograft is a low-morbidity bone allograft option for ACDF. In this study, the authors determined favorable arthrodesis rates and functional outcomes in a complex patient cohort following multilevel stand-alone ACDF supplemented with cellular allograft.

Prognostic Value of Hemorrhagic Brainstem Injury on Early Computed Tomography: A TRACK-TBI Study.

BACKGROUND: Traumatic brainstem injury has yet to be incorporated into widely used imaging classification systems for traumatic brain injury (TBI), and questions remain regarding prognostic implications for this TBI subgroup. To address this, retrospective data on patients from the multicenter prospective Transforming Research and Clinical Knowledge in TBI study were studied. METHODS: Patients with brainstem and cerebrum injury (BSI+) were matched by age, sex, and admission Glasgow Coma Scale (GCS) score to patients with cerebrum injuries only. All patients had an interpretable head computed tomography (CT) scan from the first 48 hours after injury and a 6-month Glasgow Outcome Scale Extended (GOSE) score. CT scans were reviewed for brainstem lesions and, when present, characterized by location, size, and type (traumatic axonal injury, contusion, or Duret hemorrhage). Clinical, demographic, and outcome data were then compared between the two groups. RESULTS: Mann-Whitney U-tests showed no significant difference in 6-month GOSE scores in patients with BSI+ (mean 2.7) compared with patients with similar but only cerebrum injuries (mean 3.9), although there is a trend (p = 0.10). However, subclassification by brainstem lesion type, traumatic axonal injury (mean 4.0) versus Duret hemorrhage or contusion (mean 1.4), did identify a proportion of BSI+ with significantly less favorable outcome (p = 0.002). The incorporation of brainstem lesion type (traumatic axonal injury vs. contusion/Duret), along with GCS into a multivariate logistic regression model of favorable outcome (GOSE score 4-8) did show a significant contribution to the prognostication of this brainstem injury subgroup (odds ratio 0.08, 95% confidence interval 0.00-0.67, p = 0.01). CONCLUSIONS: These findings suggest two groups of patients with brainstem injuries may exist with divergent recovery potential after TBI. These data support the notion that newer CT imaging classification systems may augment traditional clinical measures, such as GCS in identifying those patients with TBI and brainstem injuries that stand a higher chance of favorable outcome.

Progress in diffuse intrinsic pontine glioma: advocating for stereotactic biopsy in the standard of care.

Diffuse intrinsic pontine glioma (DIPG) is a universally fatal pediatric brainstem tumor affecting approximately 300 children in the US annually. Median survival is less than 1 year, and radiation therapy has been the mainstay of treatment for decades. Recent advances in the biological understanding of the disease have identified the H3K27M mutation in nearly 80% of DIPGs, leading to the 2016 WHO classification of diffuse midline glioma H3K27M-mutant, a grade IV brainstem tumor. Developments in epigenetic targeting of transcriptional tendencies have yielded potential molecular targets for clinical trials. Chimeric antigen receptor T cell therapy has also shown preclinical promise. Recent clinical studies, including prospective trials, have demonstrated the safety and feasibility of pediatric brainstem biopsy in the setting of DIPG and other brainstem tumors. Given developments in the ability to analyze DIPG tumor tissue to deepen biological understanding of this disease and develop new therapies for treatment, together with the increased safety of stereotactic brainstem biopsy, the authors present a case for offering biopsy to all children with suspected DIPG. They also present their standard operative techniques for image-guided, frameless stereotactic biopsy.

Pediatric functional hemispherectomy: operative techniques and complication avoidance.

Functional hemispherectomy/hemispherotomy is a disconnection procedure for severe medically refractory epilepsy where the seizure foci diffusely localize to one hemisphere. It is an improvement on anatomical hemispherectomy and was first performed by Rasmussen in 1974. Less invasive surgical approaches and refinements have been made to improve seizure freedom and minimize surgical morbidity and complications. Key anatomical structures that are disconnected include the 1) internal capsule and corona radiata, 2) mesial temporal structures, 3) insula, 4) corpus callosum, 5) parietooccipital connection, and 6) frontobasal connection. A stepwise approach is indicated to ensure adequate disconnection and prevent seizure persistence or recurrence. In young pediatric patients, careful patient selection and modern surgical techniques have resulted in > 80% seizure freedom and very good functional outcome. In this report, the authors summarize the history of hemispherectomy and its development and present a graphical guide for this anatomically challenging procedure. The use of the osteoplastic flap to improve outcome and the management of hydrocephalus are discussed.

Laser interstitial thermal therapy for pediatric atypical teratoid/rhabdoid tumor: case report.

Herein, the authors describe the successful use of laser interstitial thermal therapy (LITT) for management of metastatic craniospinal disease for biopsy-proven atypical teratoid/rhabdoid tumor in a 16-month-old boy presenting to their care. Specifically, LITT was administered to lesions of the right insula and left caudate. The patient tolerated 2 stages of LITT to the aforementioned lesions without complication and with evidence of radiographic improvement of lesions at the 2- and 6-month follow-up appointments. To the authors' knowledge, this represents the first such published report of LITT for management of atypical teratoid/rhabdoid tumor.

Synchronous identification of a dysembryoplastic neuroepithelial tumor (DNET) and an oligodendroglioma in a patient: A case report.

Synchronous gliomas of different histopathology are quite rare in non-syndromic, non-irradiated patients. Although "mixed" gliomas are not infrequent, and malignant gliomas often contain areas of disparate differentiation (e.g., glioblastoma with ependymal differentiation), it is unusual to find gliomas of different lineage presenting concurrently. We present a case of synchronous gliomas, one dysembryoplastic neuroepithelial tumor (DNET) and the other oligodendroglioma.

The potential impact of the demographic transition in the Senegal-Gambia region of sub-Saharan Africa on the burden of infectious disease and its potential synergies with control programmes: the case of hepatitis B.

BACKGROUND: Sub-Saharan Africa (SSA) continues to suffer high communicable disease burdens as its demographic transition (DT) proceeds. Although the consequent changes in population structures influence age-specific contact patterns relevant for transmission, the age distribution of immunity, and the disease burden, investigation of the potential of DT to affect infectious disease epidemiology in regions of SSA has hitherto been overlooked. With a substantial disease burden and complex epidemiology, hepatitis B virus (HBV) represents a prime example of an infection whose epidemiology may be significantly influenced by the DT. METHODS: An age-structured mathematical model for HBV in the Senegal and Gambia (SG) region was set within a demographic framework with varying vital rates mirroring the entire course of the DT there over 1850-2100, to investigate the effects of the DT on HBV epidemiology, with and without the combined action of vaccination. The model was run from its reconstructed ancien régime (old order) demo-epidemiologic equilibrium and calibrated against SG 1950 age-distribution estimates and Gambian pre-vaccination HBV age-prevalence data. RESULTS: The model, which reproduced well demographic and HBV age-prevalence data, predicted a complex transition of HBV epidemiology over the course of the DT. This included a prolonged epoch of expansion alongside population growth and rejuvenation until 1990-2000, followed by a dramatic retreat, mainly reflecting projected fertility decline during the twenty-first century. This transitional pattern was mostly explained by the underlying demographically driven changes in horizontal transmission resulting from the changes in the age structure of the population. During 2000-2150 the HBV burden is predicted to decline by more than 70% even in the absence of vaccination. CONCLUSIONS: Demographic change alone may strongly affect HBV disease burden and shape HBV endemicity. The onset of the demographically driven decline in HBV prevalence, aligned with the expansion of HBV vaccination, forms a synergy potentially boosting effectiveness of control. Such a synergy currently appears to be presenting a "window of opportunity" facilitating HBV elimination which it would be important to exploit and which underlines the importance of taking demographic change into account when assessing the potential longer term impact of vaccination and other control measures.

Clinicopathologic characteristics of metastatic esophageal carcinoma isolated to the pineal region: A case report and review of the literature.

Metastasis to the pineal region is a rare event, and esophageal adenocarcinoma metastatic to the pineal region is exceptionally rare, with only two cases reported in the current literature. Here, we characterize a third case of metastatic esophageal adenocarcinoma to the pineal region, and compare clinicopathological characteristics among all three cases. The three patients were men, with ages at neurological presentation ranging from 48 to 65years. Time from initial esophageal adenocarcinoma diagnosis to development of neurologic symptoms ranged from 12 to 23months. Neuroimaging in all cases showed an isolated enhancing pineal region mass with sizes ranging from 1.8 to 2.2cm. All cases were believed to have local control of esophageal disease prior to metastatic sequela, with initial treatment including esophageal resection with or without chemoradiation therapy. No cases had evidence of primary site disease progression at time of metastatic presentation, nor were there signs of other sites of metastasis. All patients underwent tumor excision and were referred for subsequent radiotherapy. Overall, all three cases demonstrate similar demographics, histology, and clinical presentations. In the appropriate clinical setting it is important to keep esophageal metastasis in the differential diagnosis, particularly in the setting of isolated pineal lesions.

Consensus standards for introductory e-learning courses in human participants research ethics.

This paper reports the results of a workshop held in January 2013 to begin the process of establishing standards for e-learning programmes in the ethics of research involving human participants that could serve as the basis of their evaluation by individuals and groups who want to use, recommend or accredit such programmes. The standards that were drafted at the workshop cover the following topics: designer/provider qualifications, learning goals, learning objectives, content, methods, assessment of participants and assessment of the course. The authors invite comments on the draft standards and eventual endorsement of a final version by all stakeholders.

Pharyngeal oxygen delivery device sustains manikin lung oxygenation longer than high-flow nasal cannula.

Purpose: Hypoxemia during a failed airway scenario is life threatening. A dual-lumen pharyngeal oxygen delivery device (PODD) was developed to fit inside a traditional oropharyngeal airway for undisrupted supraglottic oxygenation and gas analysis during laryngoscopy and intubation. We hypothesized that the PODD would provide oxygen as effectively as high-flow nasal cannula (HFNC) while using lower oxygen flow rates. Methods: We compared oxygen delivery of the PODD to HFNC in a preoxygenated, apneic manikin lung that approximated an adult functional residual capacity. Four arms were studied: HFNC at 20 and 60 liters per minute (LPM) oxygen, PODD at 10 LPM oxygen, and a control arm with no oxygen flow after initial preoxygenation. Five randomized 20-minute trials were performed for each arm (20 trials total). Descriptive statistics and analysis of variance were used with statistical significance of P < 0.05. Results: Mean oxygen concentrations were statistically different and decreased from 97% as follows: 41 ± 0% for the control, 90 ± 1% for HFNC at 20 LPM, 88 ± 2% for HFNC at 60 LPM, and 97 ± 1% (no change) for the PODD at 10 LPM. Conclusion: Oxygen delivery with the PODD maintained oxygen concentration longer than HFNC in this manikin model at lower flow rates than HFNC.

Concomitant Traumatic Brain Injury Delays Surgery in Patients With Traumatic Spinal Cord Injury.

BACKGROUND AND OBJECTIVES: Growing evidence supports prompt surgical decompression for patients with traumatic spinal cord injury (tSCI). Rates of concomitant tSCI and traumatic brain injury (TBI) range from 10% to 30%. Concomitant TBI may delay tSCI diagnosis and surgical intervention. Little is known about real-world management of this common injury constellation that carries significant clinical consequences. This study aimed to quantify the impact of concomitant TBI on surgical timing in a national cohort of patients with tSCI. METHODS: Patient data were obtained from the National Trauma Data Bank (2007-2016). Patients admitted for tSCI and who received surgical intervention were included. Delayed surgical intervention was defined as surgery after 24 hours of admission. Multivariable hierarchical regression models were constructed to measure the risk-adjusted association between concomitant TBI and delayed surgical intervention. Secondary outcome included favorable discharge status. RESULTS: We identified 14 964 patients with surgically managed tSCI across 377 North American trauma centers, of whom 2444 (16.3%) had concomitant TBI and 4610 (30.8%) had central cord syndrome (CCS). The median time to surgery was 20.0 hours for patients without concomitant TBI and 24.8 hours for patients with concomitant TBI. Hierarchical regression modeling revealed that concomitant TBI was independently associated with delayed surgery in patients with tSCI (odds ratio [OR], 1.3; 95% CI, 1.1-1.6). Although CCS was associated with delayed surgery (OR, 1.5; 95% CI, 1.4-1.7), we did not observe a significant interaction between concomitant TBI and CCS. In the subset of patients with concomitant tSCI and TBI, patients with severe TBI were significantly more likely to experience a surgical delay than patients with mild TBI (OR, 1.4; 95% CI, 1.0-1.9). CONCLUSION: Concomitant TBI delays surgical management for patients with tSCI. This effect is largest for patients with tSCI with severe TBI. These findings should serve to increase awareness of concomitant TBI and tSCI and the likelihood that this may delay time-sensitive surgery.

Evaluation of the Glasgow Coma Scale-Pupils score for predicting inpatient mortality among patients with traumatic subdural hematoma at United States trauma centers.

OBJECTIVE: The Glasgow Coma Scale-Pupils (GCS-P) score has been suggested to better predict patient outcomes compared with GCS alone, while avoiding the need for more complex clinical models. This study aimed to compare the prognostic ability of GCS-P versus GCS in a national cohort of traumatic subdural hematoma (SDH) patients. METHODS: Patient data were obtained from the National Trauma Data Bank (2017-2019). Inclusion criteria were traumatic SDH diagnosis with available data on presenting GCS score, pupillary reactivity, and discharge disposition. Patients with severe polytrauma or nonsurvivable head injury at presentation were excluded. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) of GCS-P versus GCS scores for inpatient mortality prediction were evaluated across the entire cohort, as well as in subgroups based on age and traumatic brain injury (TBI) type (blunt vs penetrating). Calibration curves were plotted based on predicted probabilities and actual outcomes. RESULTS: A total of 196,747 traumatic SDH patients met the study inclusion criteria. Sensitivity (0.707 vs 0.702), specificity (0.821 vs 0.823), and AUC (0.825 vs 0.814, p < 0.001) of GCS-P versus GCS scores for prediction of inpatient mortality were similar. Calibration curve analysis revealed that GCS scores slightly underestimated inpatient mortality risk, whereas GCS-P scores did not. In patients > 65 years of age with blunt TBI (51.9%, n = 102,148), both GCS-P and GCS scores underestimated inpatient mortality risk. In patients with penetrating TBI (2.4%, n = 4,710), the AUC of the GCS-P score was significantly higher (0.902 vs 0.851, p < 0.001). In this subgroup, both GCS-P and GCS scores underestimated inpatient mortality risk among patients with lower rates of observed mortality and overestimated risk among patients with higher rates of observed mortality. This effect was more pronounced in the GCS-P calibration curve. CONCLUSIONS: The GCS-P score provides better short-term prognostication compared with the GCS score alone among traumatic SDH patients with penetrating TBI. The GCS-P score overestimates inpatient mortality risk among penetrating TBI patients with higher rates of observed mortality. For penetrating TBI patients, which comprised 2.4% of our SDH cohort, a low GCS-P score should not justify clinical nihilism or forgoing aggressive treatment.

Acute Extra-Arachnoid Subdural Hematomas in Patients 50 Years and Older: When Subdurals Act Like Epidurals.

BACKGROUND: Some patients with subdural hematoma (SDH) with acute extra-arachnoid lesions and without concomitant subarachnoid blood or contusions may present in similarly grave neurological condition compared with the general population of patients with SDH. However, these patients often make an impressive neurological recovery. This study compared neurological outcomes in patients with extra-arachnoid SDH with all other SDH patients. METHODS: We compared a prospective series of extra-arachnoid SDH patients without subarachnoid hemorrhage or other concomitant intracranial injury with a Transforming Research and Clinical Knowledge in TBI control group with SDH only. We performed inverse probability weighting for key characteristics and ordinal regression with and without controlling for midline shift comparing neurological outcomes (Extended Glasgow Outcome Scale score) at 2 weeks. We used the Corticosteroid Randomization After Significant Head Injury prognostic model to predict mortality based on age, Glasgow Coma Scale score, pupil reactivity, and major extracranial injury. RESULTS: Mean midline shift was significantly different between extra-arachnoid SDH and control groups (7.2 mm vs. 2.7 mm, P < 0.001). After weighting for group allocation and controlling for midline shift, extra-arachnoid SDH patients had 5.68 greater odds (P < 0.001) of a better 2-week Extended Glasgow Outcome Scale score than control patients. Mortality in the extra-arachnoid SDH group was less than predicted by the Corticosteroid Randomization After Significant Head Injury prognostic model (10% vs. 21% predicted). CONCLUSIONS: Patients with extra-arachnoid SDH have significantly better 2-week neurological outcomes and lower mortality than predicted by the Corticosteroid Randomization After Significant Head Injury model. Neurosurgeons should consider surgery for this patient subset even in cases of poor neurological examination, older age, and large hematoma with high degree of midline shift.

GC/MS method for positive detection of Bacillus anthracis endospores.

A simple method was developed for detection of Bacillus anthracis (BA) endospores and for differentiation of them from other species in the Bacillus cereus group. Chemical profiles that include lipids (i.e., fatty acids), carbohydrates (i.e., sugars), and the spore-specific biomarker, dipicolinic acid, were generated by one-step thermochemolysis (TCM) at 140 °C in 5 min to provide specific biomarker signatures. Anthrose, which is a biomarker characteristic of the B. cereus group of bacteria, was determined from a fragment produced by TCM. Surprisingly, several virulent BA strains contained very low levels of anthrose, which confounded their detection. A statistical discrimination algorithm was constructed using a combination of biomarkers, which was robust against different growth conditions (medium and temperature). Fifteen endospore-forming Bacillus species were confirmed in a statistically designed test (~90%) using the algorithm, including six BA strains (four virulent isolates), five B. thuringiensis (BT) isolates, and one isolate each for B. cereus (BC), B. mycoides (BM), B. atrophaeus (BG), and B. subtilis (BS). The detection limit for B. anthracis was found to be 50,000 endospores, on the basis of the GC/MS detection limits for 3-methyl-2-butenoic acid methyl ester, which is the biomarker derived from TCM of anthrose.