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Expansion laryngoplasty is a new, combined procedure which can treat both glottic and subglottic stenosis simulataneously. This is a small case series showing how to perform this surgery as well as outcomes from a 15-year period. Laryngoscope, 2024., (© 2024 The American Laryngological, Rhinological and Otological Society, Inc.)

Introduction: Microbiome research has predominantly focused on the oral cavity and oropharynx's role in disease, while the upper airway, specifically the larynx and trachea, has been relatively overlooked. Examining the microbial communities in these regions can shed light on how dysbiosis influences diseases and their management. This review evaluates laryngotracheal microbial compositions in both healthy and diseased patients., Methods: We conducted a systematic review in EMBASE, MEDLINE, and Cochrane Central databases, yielding 1383 studies in the initial search. Inclusion criteria involved participants aged over 18 years and the use of next-generation 16s ribosomal sequencing methods., Results: We included 10 studies-seven focused on larynx sequencing and four on trachea sequencing (one investigated both sites). In a healthy larynx, diverse species such as Streptococcus, Cloacibacterium, Prevotella, and Helicobacter were found. Benign laryngeal diseases exhibited reduced microbial diversity, mainly dominated by Streptococcus. Subglottic stenosis patients showed diminished diversity in both idiopathic and iatrogenic scars. Laryngeal squamous cell carcinoma displayed increased diversity, primarily featuring Fusobacterium. Among non-respiratory-compromised surgery patients, the tracheal microbiome was more diverse in diabetics and those later developing lower respiratory infections. Pneumonia patients exhibited an abundance of Prevotella and Streptococcus, linked to an increased 28-day survival rate, while Streptococcus and Haemophilus abundance correlated with successful extubation., Conclusions: The laryngotracheal region hosts a unique microbial community influenced by both benign and malignant conditions. Many lesions remain unexplored, underscoring the need for future studies encompassing diverse laryngotracheal conditions. Clinical trials assessing microbiome modifications may unveil novel therapeutic avenues., Level of Evidence: NA Laryngoscope, 134:4167-4175, 2024., (© 2024 The American Laryngological, Rhinological and Otological Society, Inc.)

Objective: The primary objective of this study was to evaluate oncologic outcomes of all published cases of supracricoid partial laryngectomy (SCPL) performed in the United States. The secondary objective was to assess the functional outcomes associated with this procedure., Review Methods: A systematic review of PubMed, SCOPUS, and Embase for all English-language studies pertaining to SCPL performed in the United States was conducted until August 2021. Primary outcomes included disease-specific survival (DSS), overall survival, and local recurrence rate. Secondary outcomes included larynx preservation rate, gastrostromy tube dependency, days to gastrostomy tube removal, decannulation rate, and days to decannulation., Results: A total of six studies were included in the analysis. A total of 113 patients (58.5%) underwent SCPL surgery as a primary treatment method whereas 80 patients (41.5%) underwent SCPL as salvage surgery. The 5-year DSS rates were 87.8% and 100% for primary and salvage procedures, respectively. Approximately 10.3% of patients undergoing a salvage SCPL procedure experienced a local recurrence whereas only 1.85% of primary SCPL procedures resulted in local recurrence. The rates of decannulation following primary and salvage SCPL were 92.7% and 88.1%, respectively. With regard to swallowing, primary and salvage SCPL procedures demonstrated comparably low postoperative gastrostomy tube dependency rates of 3.66% and 4.76%, respectively., Conclusions: SCPL performed in the United States is an effective surgical technique that produces excellent outcomes in qualifying patients, thus validating its viability as an organ-preserving surgical alternative. Laryngoscope, 134:3003-3011, 2024., (© 2024 The American Laryngological, Rhinological and Otological Society, Inc.)

Introduction: The function of the vocal folds (VFs) is determined by the phenotype, abundance, and distribution of differentiated cells within specific microenvironments. Identifying this histologic framework is crucial in understanding laryngeal disease. A paucity of studies investigating VF cellular heterogeneity has been undertaken. Here, we examined the cellular landscape of human VFs by utilizing single-nuclei RNA-sequencing., Methods: Normal true VF tissue was excised from five patients undergoing pitch elevation surgery. Tissue was snap frozen in liquid nitrogen and subjected to cellular digestion and nuclear extraction. Nuclei were processed for single-nucleus sequencing using the 10X Genomics Chromium platform. Sequencing reads were assembled using cellranger and analyzed with the scanpy package in python., Results: RNA sequencing revealed 18 global cell clusters. While many were of epithelial origin, expected cell types, such as fibroblasts, immune cells, muscle cells, and endothelial cells were present. Subcluster analysis defined unique epithelial, immune, and fibroblast subpopulations., Conclusion: This study evaluated the cellular heterogeneity of normal human VFs by utilizing single-nuclei RNA-sequencing. With further confirmation through additional spatial sequencing and microscopic imaging, a novel cellular map of the VFs may provide insight into new cellular targets for VF disease., Level of Evidence: NA Laryngoscope, 134:3193-3200, 2024., (© 2024 The American Laryngological, Rhinological and Otological Society, Inc.)

We propose a modification of the transverse cordotomy procedure which improves the predictable airway outcome and allows for better voice. Laryngoscope, 134:2790-2792, 2024., (© 2023 The American Laryngological, Rhinological and Otological Society, Inc.)

Objectives: Tracheal transplantation is an ideal option for the reconstruction of long-segment circumferential tracheal defects. Our group performed the first successful vascularized single-staged tracheal transplantation in January 2021. Although a rigid biocompatible structure is necessary for a functioning tracheal replacement, the importance of ciliated epithelium, which allows for critical mucociliary clearance, is now being appreciated. Here, we examined the histological changes of the first single-staged human tracheal transplant from serial endoscopic biopsies., Methods: Biopsies of the tracheal mucosa were serially obtained since the time of the tracheal transplantation. Samples were examined via hematoxylin and eosin, electron microscopy, and immunohistochemistry., Results: One week after transplantation, there is loss of ciliated epithelium and seromucinous cells, with only a basal layer of epithelium remaining. By 2 weeks, however, the epithelium begins to recover, albeit differently depending on the location of the biopsy. Near the site of tracheal anastomosis, there is epithelial proliferation, with the appearance of early ciliated cells. However, in the midgraft, there appears to be evidence of squamous metaplasia. Over time, however, normal ciliated epithelium and mucous cells appear without signs of chronic inflammation., Conclusions: Critically, the tracheal allograft regained normal appearing respiratory epithelium after initial ischemic injury. The histologic differences at the midgraft versus anastomosis may suggest unique mechanisms of reepithelialization. At the recipient-donor interface, there may be a faster direct migration of recipient-derived epithelial cells, in line with preclinical studies. The midgraft, in contrast, responds with epithelial proliferation from the donor basal cells or dedifferentiated mucous cells., Level of Evidence: N/A Laryngoscope, 134:2664-2671, 2024., (© 2023 The American Laryngological, Rhinological and Otological Society, Inc.)

Long-segment tracheal airway defects may be congenital or result from burns, trauma, iatrogenic intubation damage, or tumor invasion. Although airway defects <6 cm in length may be reconstructed using existing end-to-end reconstructive techniques, defects >6 cm continue to challenge surgeons worldwide. The reconstruction of long-segment tracheal defects has long been a reconstructive dilemma, and these defects are associated with significant morbidity and mortality. Many of these defects are not compatible with life or require a permanent extended-length tracheostomy that is fraught with complications including mucus plugging and tracheoesophageal fistula. Extensive circumferential tracheal defects require a reconstructive technique that provides a rigid structure able to withstand the inspiratory pressures, a structure that will biologically integrate, and contain functional ciliated epithelium to allow for normal mucociliary clearance. Tracheal transplantation has been considered the reconstructive "Holy Grail;" however, there has been a long-held scientific dogma that revascularization of the trachea was not possible. This dogma stifled research to achieve single-staged vascularized tracheal transplantation and prompted the introduction of many creative and inventive alternatives. Throughout history, alloplastic material, nonvascularized allografts, and homografts have been used to address this dilemma. However, these techniques have largely been unsuccessful. The recent introduction of a technique for single-staged vascularized tracheal transplantation may offer a solution to this dilemma and potentially a solution to management of the fatal tracheoesophageal fistula., Competing Interests: The authors declare no funding or conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Tracheal transplantation has been considered the ideal option for the reconstruction of long-segment circumferential tracheal defects. Our group developed a technique for vascularized single-staged tracheal transplantation. Twenty months ago, we performed the first-in-human tracheal transplantation. Herein, we report a twenty-month follow-up., Methods: The recipient presented with a 9.0 cm airway tracheal stenosis and complete cricoid stenosis. The patient previously failed six major conventional surgical procedures. Prior to transplantation, the patient's airway was maintained with an extended tracheostomy and stent. The patient experienced repeated life-threatening airway obstruction because of mucous plugging and obstructive granulation tissue. In January 2020 the patient underwent a single-staged tracheal transplantation treated with triple-therapy immunosuppression. Organ rejection was monitored with endoscopic tracheoscopy, narrow-band imaging, free-cell DNA assessment, and histological and cytogenetic analysis of tracheal biopsies. Mucociliary function was assessed with dye motility studies., Results: Twenty months following transplantation, there has been no evidence of acute or chronic rejection. Since day 60, there has been no detectable free cell DNA, a surrogate marker for immune-mediated allograft rejection. Fluorescence in situ hybridization (FISH) cytogenetics demonstrated that the donor trachea was repopulated with recipient epithelium establishing a chimeric allograft. Narrow-band imaging demonstrates a well-vascularized epithelial mucosa and bronchoscopic biopsies demonstrate normal ciliated epithelial architecture and viable epithelial lining with functional ciliated epithelium. The patient has resumed a normal life without a stent or tracheostomy and has returned to work., Conclusions: Twenty months after single-staged vascularized tracheal transplantation, the trachea is functional and the patient breathes without the need for a tracheostomy or stent. Single-staged long-segment tracheal transplantation is a viable option for tracheal defects that are not amenable to conventional reconstructive techniques., Level of Evidence: 4 Laryngoscope, 133:1839-1845, 2023., (© 2022 The American Laryngological, Rhinological and Otological Society, Inc.)

Importance: Involvement of deep margins represents a significant challenge in the treatment of oropharyngeal cancer, and given practical limitations of frozen-section analysis, a need exists for real-time, nondestructive intraoperative margin analysis. Wide-field optical coherence tomography (WF-OCT) has been evaluated as a tool for high-resolution adjunct specimen imaging in breast surgery, but its clinical application in head and neck surgery has not been explored., Objective: To evaluate the utility of WF-OCT for visualizing microstructures at margins of excised oral and oropharyngeal tissue., Design, Setting, and Participants: This nonrandomized, investigator-initiated qualitative study evaluated the feasibility of the Perimeter Medical Imaging AI Otis WF-OCT device at a single academic center. Included participants were adults undergoing primary ablative surgery of the oral cavity or oropharynx for squamous cell carcinoma in 2018 and 2019. Data were analyzed in October 2019., Exposures: Patients were treated according to standard surgical care. Freshly resected specimens were imaged with high-resolution WF-OCT prior to routine pathology. Interdisciplinary interpretation was performed to interpret WF-OCT images and compare them with corresponding digitized pathology slides. No clinical decisions were made based on WF-OCT image data., Main Outcomes and Measures: Visual comparisons were performed between WF-OCT images and hematoxylin and eosin slides., Results: A total of 69 specimens were collected and scanned from 53 patients (mean [SD] age, 59.4 [15.2] years; 35 [72.9%] men among 48 patients with demographic data) undergoing oral cavity or oropharynx surgery for squamous cell carcinoma, including 42 tonsillar tissue, 17 base of the tongue, 4 buccal tissue, 3 mandibular, and 3 other specimens. There were 41 malignant specimens (59.4%) and 28 benign specimens (40.6%). In visual comparisons of WF-OCT images and hematoxylin and eosin slides, visual differentiation among mucosa, submucosa, muscle, dysplastic, and benign tissue was possible in real time using WF-OCT images. Microarchitectural features observed in WF-OCT images could be matched with corresponding features within the permanent histology with fidelity., Conclusions and Relevance: This qualitative study found that WF-OCT imaging was feasible for visualizing tissue microarchitecture at the surface of resected tissues and was not associated with changes in specimen integrity or surgical and pathology workflow. These findings suggest that formal clinical studies investigating use of WF-OCT for intraoperative analysis of deep margins in head and neck surgery may be warranted.

Objectives: Respiratory, voice, and swallowing difficulties after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may result secondary to upper airway disease from prolonged intubation or mechanisms related to the virus itself. We examined a cohort who presented with new laryngeal complaints following documented SARS-CoV-2 infection. We characterized their voice, airway, and/or swallowing symptoms and reviewed the clinical course of their complaints to understand how the natural history of these symptoms relates to COVID-19 infections., Methods: Retrospective review of patients who presented to our department with upper aerodigestive complaints as sequelae of prior infection with, and management of, SARS-CoV-2., Results: Eighty-one patients met the inclusion criteria. Median age was 54.23 years (±17.36). Most common presenting symptoms were dysphonia ( n  = 58, 71.6%), dysphagia/odynophagia ( n  = 16, 19.75%), and sore throat ( n  = 9, 11.11%). Thirty-one patients (38.27%) presented after intubation. Mean length of intubation was 16.85 days (range 1-35). Eighteen patients underwent tracheostomy and were decannulated after an average of 70.69 days (range 23-160). Patients with history of intubation were significantly more likely than nonintubated patients to be diagnosed with a granuloma (8 vs. 0, respectively, p  < .01). Fifty patients (61.73%) were treated for SARS-CoV-2 without requiring intubation and were significantly more likely to be diagnosed with muscle tension dysphonia (19 vs. 1, p  < .01) and laryngopharyngeal reflux (18 vs. 1, p  < .01)., Conclusion: In patients with persistent dyspnea, dysphonia, or dysphagia after recovering from SARS-CoV-2, early otolaryngology consultation should be considered. Accurate diagnosis and prompt management of these common underlying etiologies may improve long-term patient outcomes., Level of Evidence: 4., (© 2022 The Authors. Laryngoscope Investigative Otolaryngology published by Wiley Periodicals LLC on behalf of The Triological Society.)

Objectives/hypothesis: While virtual reality (VR) has been used as analgesia and anxiolysis for invasive procedures, no literature exists on the use of VR in the pediatric otolaryngology setting. The purpose of this study was to determine the efficacy of VR in reducing pain and anxiety for pediatric otolaryngology patients., Study Design: Randomized controlled trial., Methods: A total of 53 patients aged 7-17 undergoing in-office nasal endoscopies were included. Patients were randomized to receive VR or standard of care. Procedural pain, anxiety, and satisfaction scores were recorded from patients and caregivers. The physician filled out a childhood emotional manifestation scale (CEMS)., Results: Patients in VR group reported a significant decrease in pain (0.80 ± 1.06 vs. 2.26 ± 2.38, P = .018) and anxiety (9.50 ± 12.48 vs. 38.48 ± 29.83, P = .0002) and increase in procedural satisfaction (6.40 ± 0.77 vs. 4.74 ± 1.74, P = .0002) compared to patients in control group. CEMS scores were significantly reduced in VR group (5.15 ± 0.46 vs. 9.64 ± 5.66, P = .0001) and caregiver anxiety levels were significantly reduced in VR group (11.50 ± 17.67 vs. 27.39 ± 30.48, P = .041) compared to control group. There were no reported side effects. Procedural time did not significantly differ between groups., Conclusions: For pediatric otolaryngology patients undergoing in-office nasal endoscopies, VR is a safe and effective form of distraction analgesia and anxiolysis, significantly reducing pain and increasing procedural satisfaction for patients. In addition, VR significantly reduces anxiety for both patients and caregivers without disrupting procedural efficiency and workflow., Level of Evidence: 2. Laryngoscope, 131:E1714-E1721, 2021., (© 2020 American Laryngological, Rhinological and Otological Society Inc, "The Triological Society" and American Laryngological Association (ALA).)

Objective: Nonphysician health care workers are involved in high-risk patient care during the COVID-19 pandemic, placing them at high risk of mental health burden. The mental health impact of COVID-19 in this crucial population has not been studied thus far. Thus, the objective of this study is to assess the psychosocial well-being of these providers., Study Design: National cross-sectional online survey (no control group)., Setting: Academic otolaryngology programs in the United States., Subjects and Methods: We distributed a survey to nonphysician health care workers in otolaryngology departments across the United States. The survey incorporated a variety of validated mental health assessment tools to measure participant burnout (Mini-Z assessment), anxiety (Generalized Anxiety Disorder-7), distress (Impact of Event Scale), and depression (Patient Health Questionnaire-2). Multivariable logistic regression analysis was performed to determine predictive factors associated with these mental health outcomes., Results: We received 347 survey responses: 248 (71.5%) nurses, 63 (18.2%) administrative staff, and 36 (10.4%) advanced practice providers. A total of 104 (30.0%) respondents reported symptoms of burnout; 241 (69.5%), symptoms of anxiety; 292 (84.1%), symptoms of at least mild distress; and 79 (22.8%), symptoms of depression. Upon further analysis, development of these symptoms was associated with factors such as occupation, practice setting, and case load., Conclusion: Frontline otolaryngology health care providers exhibit high rates of mental health complications, particularly anxiety and distress, in the wake of COVID-19. Adequate support systems must be put into place to address these issues., (© The Authors 2020.)

Background: Otolaryngologists are among the highest risk for COVID-19 exposure., Methods: This is a cross-sectional, survey-based, national study evaluating academic otolaryngologists. Burnout, anxiety, distress, and depression were assessed by the single-item Mini-Z Burnout Assessment, 7-item Generalized Anxiety Disorder Scale, 15-item Impact of Event Scale, and 2-item Patient Health Questionnaire, respectively., Results: A total of 349 physicians completed the survey. Of them, 165 (47.3%) were residents and 212 (60.7%) were males. Anxiety, distress, burnout, and depression were reported in 167 (47.9%), 210 (60.2%), 76 (21.8%), and 37 (10.6%) physicians, respectively. Attendings had decreased burnout relative to residents (odds ratio [OR] 0.28, confidence interval [CI] [0.11-0.68]; P = .005). Females had increased burnout (OR 1.93, CI [1.12.-3.32]; P = .018), anxiety (OR 2.53, CI [1.59-4.02]; P < .005), and distress (OR 2.68, CI [1.64-4.37]; P < .005). Physicians in states with greater than 20 000 positive cases had increased distress (OR 2.01, CI [1.22-3.31]; P = .006)., Conclusion: During the COVID-19 pandemic, the prevalence of burnout, anxiety, and distress is high among academic otolaryngologists., (© 2020 Wiley Periodicals, Inc.)

Objective: We describe our experience using the extracorporeal video microscope, the "exoscope" for repair of a temporal bone encephalocele., Method: The patient is a 69-year-old male with a right temporal lobe encephalocele herniating through a tegmen defect. He underwent definitive tegmen defect repair and bipolar cauterization of the encephalocele. The authors elected for a combined transmastoid and transtemporal approach in order to isolate the tegmen defect and provide watertight repair. The Synaptive robotic BrightMatter (Toronto, ON) drive video exoscope monitor system was used for the entirety of the case including both the transmastoid approach and transtemporal craniotomy., Results: No intraoperative complications were encountered during either the transmastoid (mastoidectomy) or transtemporal craniotomy. The authors were able to complete the entire case without abandonment of the exoscope in favor of the traditional binocular microscope. Advantages of this technology in clinical practice includes high-resolution three-dimensional visualization, increased degrees of freedom for exoscope adjustment, and reduced surgeon fatigue in a fixed, unnatural posture. Limitations include decreased depth perception and increased operative time., Conclusion: The exoscope system is a safe and effective alternative or adjunct to the existing binocular operating microscope for lateral skull based procedures. The exoscope provides the surgeon with a comfortable, high-resolution visualization without compromising surgical exposure and patient safety.SDC video link: http://links.lww.com/MAO/A837.

Given the increasing incidence of human papilloma virus (HPV)-positive head and neck cancers (HNCs), discussion of this oncologic outcome should be incorporated into HPV vaccine counseling practices. Yet, preliminary evidence shows that knowledge of the association between HPV and HNC is lacking among most medical trainees. To better characterize this deficit, we nationally assessed knowledge of HPV's association with HNC among medical students and residents across 4 specialties (pediatrics, obstetrics and gynecology, family medicine, and otolaryngology). A total of 3141 responses from 46 states were obtained (n = 402 pediatric residents, n = 346 obstetrics/gynecology residents, n = 260 family medicine residents, n = 87 otolaryngology residents, and n = 2045 medical students). Only 40.3% of surveyed medical students and 56.1% of surveyed obstetrics/gynecology, pediatrics, and family medicine residents identified associations between persistent HPV infection and HNC. When counseling on the vaccine, nonotolaryngology residents more often discussed cervical cancer (99.8%) as compared with HNC (39.7%), commonly because of less HNC knowledge (61.5%). These results suggest that it is imperative to develop educational interventions targeted at medical students and resident trainees on the front line of HPV vaccine counseling and administration.

Objective: Microvascular free tissue transfer has become the standard for reconstruction for large defects. With long operative times and an increased surface area exposed, transient hypothermia is common, but it is unclear how this impacts surgical outcomes. This study evaluated the impact of core body temperature on free tissue flap outcomes in patients undergoing microvascular reconstruction., Study Design: Retrospective data analysis., Setting: Mount Sinai Hospital; NYC, NY; 2007-2016., Subjects and Methods: Demographic information, mean/minimum/maximum body temperatures, and the presence of flap complications (venous thrombosis, arterial insufficiency, flap death, wound infection/dehiscence, fistula, chyle leak, hematoma/seroma) of 519 free tissue transfer patients were documented. Binomial logistic regression was used to examine associations between the presence of flap complications and mean temperature. Statistical analysis used SPSS, with p-values ≤0.05 deemed statistically significant., Results: 393 soft-tissue and 125 osteocutaneous flaps were included. 19.8% (n = 103) patients had the presence of ≥1 flap complication, while 80.2% (n = 416) did not. Average temperature for all patients was 36.12 ± 0.84 °C, with minimum at 34.43 ± 0.97 °C and maximum at 37.24 ± 1.23 °C. After controlling for several factors including: tumor stage, radiation, diabetes, BMI, age, sex, and flap type, there was a significant association between flap complications and mean intraoperative temperature (Exp(B) = 1.559, p = 0.004)., Conclusion: Higher intraoperative temperatures were associated with worse outcomes. A mild relative hypothermia may improve flap outcomes in this population. This represents the largest study to date evaluating the impact of intraoperative temperature on free tissue transfer outcomes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

In this Invited Commentary, the authors present a call to action regarding the paucity of data related to medical student deaths by suicide. They review the limited literature on medical student suicide and suggest that no comprehensive study has ever occurred. They believe that the available data are too limited to conclude what the rate of death by suicide is among medical students compared with their age-matched peers. The authors speculate that the lack of accurate data may be related both to reluctance on the part of schools to report deaths by suicide and to the failure of national organizations like the Association of American Medical Colleges, Accreditation Council for Graduate Medical Education, and Liaison Committee on Medical Education to mandate reporting. The authors believe that without reliable data, the medical education community will never be able to determine whether any trends or predictors are connected to medical student death by suicide and that, as a result, intervening in a meaningful way will remain impossible. The authors call on the national organizing bodies of medical education to mandate reporting of deaths by suicide, and to create and maintain a database for tracking and studying these events. They advocate for public access to unidentified data, linking medical schools to the number of deaths by suicide, as another method of creating accountability and influencing medical school behavior in addressing this tragic phenomenon.

The United States Medical Licensing Examination Step 1 was implemented in the 1990s as the most recent version of the National Board of Medical Examiners' preclinical licensing examination originally created in the late 1960s. For the purposes of state licensure, the exam is pass/fail, but the Step 1 numeric score has in recent years become central to the residency application and selection process. Consequently, a medical student's Step 1 score is increasingly viewed as a key outcome of preclinical medical education.In this Invited Commentary, students from various institutions across the country draw on their shared experiences to argue that the emphasis on Step 1 for residency selection has fundamentally altered the preclinical learning environment, creating a "Step 1 climate." The authors aim to increase awareness of the harms and unintended consequences of this phenomenon in medical education. They outline how the Step 1 climate negatively impacts education, diversity, and student well-being, and they urge a national conversation on the elimination of reporting Step 1 numeric scores.

Objective: We describe our experience using the extracorporeal video microscope, the "exoscope" for various applications within the field of lateral skull base surgery., Study Design: A retrospective case series was performed investigating patient demographics, indications for surgery, procedure type, operative time, approach to the skull base, complications, adequacy of visualization, and surgeon comfortability., Patients: Six cases were performed with a three dimensional surgical exoscope, obviating the use of a traditional binocular microscope., Setting: Academic, tertiary referral center., Main Outcome Measures: Type of surgical approach, operative time, patient demographics, surgical complications, and surgeon comfortability., Results: The following procedures were performed; four vestibular schwannoma resections via suboccipital craniotomy and two combined transmastoid and transtemporal approaches for temporal lobe encephalocele repairs. The average operative time was 227 and 577 minutes for temporal lobe encephalocele repairs and vestibular schwannoma cases, respectively. No intraoperative complications were encountered during these cases. None of the procedures required abandonment of the exoscope in favor of the microscope during the procedure. Advantages include high-resolution three-dimensional visualization, increased degrees of freedom for exoscope adjustment, and reduced surgeon fatigue in a fixed, unnatural posture. Limitations include decreased depth perception and increased operative time., Conclusion: The exoscope system is a safe and effective alternative or adjunct to the existing binocular operating microscope for lateral skull based procedures. The exoscope provides the surgeon with a comfortable, high-resolution visualization without compromising surgical exposure and patient safety., Level of Evidence: 4.

Introduction: Medical students have limited preclinical exposure to pediatrics. We created an optional preclinical curriculum for first-year medical students called "Preseason Pediatrics" (PSP). This 6-month curriculum teaches pediatric-specific knowledge and clinical skills, consisting of monthly resident-led didactic sessions followed by complementary resident-mentored clinical experiences., Methods: Participants completed a survey before and after completion of PSP. Knowledge was assessed with multiple-choice questions pertaining to each topic covered in PSP and perceived skills, with a 5-point Likert scale ranging from not at all (1) to extremely (5) for skills taught. Skill maintenance was assessed with a newborn objective structured clinical exam (OSCE) 6 months after PSP completion in 2016. Students beginning their pediatric clerkship also completed a survey, comparing students who did and did not complete PSP., Results: From 2014 to 2017, 135 first-year medical students participated. Percent correct scores on pediatric knowledge increased in 4/5 topics covered, and students perceived increases in their pediatric skills in all course domains. 86.8% ( n  = 92/106) of students reported feeling more prepared for the pediatric clerkship. 94.3% ( n  = 100/106) would recommend the PSP experience to other students. Third-year students who participated in PSP reported higher comfort with pediatric patients prior to their clerkship., Conclusions: PSP is a successful novel preclinical program introducing students to pediatrics. We demonstrated that didactics paired with resident-mentored clinical experiences improved pediatric knowledge, clinical-based skills, and perceived clerkship preparedness. Students may academically and professionally benefit from such earlier exposure to pediatrics., Competing Interests: Conflict of InterestThe authors declare that they have no conflict of interest., (© International Association of Medical Science Educators 2019.)

Objective: This study evaluated the accuracy of the Surgical Risk Calculator (SRC) of the ACS NSQIP (American College of Surgeons National Surgical Quality Improvement Program) in predicting head and neck microvascular reconstruction outcomes., Study Design: Retrospective analysis., Setting: Tertiary medical center., Subjects and Methods: A total of 561 free flaps were included in the analysis. The SRC-predicted 30-day rates of postoperative complications, hospital length of stay (LOS), and rehabilitation discharge were compared with the actual rates and events. The SRC's predictive value was examined with Brier scores and receiver operating characteristic area under the curve., Results: A total of 425 myocutaneous, 134 osseous (84 fibula, 47 scapula, and 3 iliac crest), and 2 omental free flaps were included in this study. All perioperative complications evaluated had area under the curve values ≤0.75, ranging from 0.480 to 0.728. All but 2 postoperative complications had Brier scores >0.01. SRC-predicted LOS was 9.4 ± 2.38 days (mean ± SD), which did not strongly correlate with the actual LOS of 11.98 ± 9.30 days ( r = 0.174, P < .0001)., Conclusion: The SRC is a poor predictor for surgical outcome among patients undergoing microvascular head and neck reconstruction.

We designed a curriculum to help sustain pre-clinical knowledge for MD/PhD trainees in their graduate training phase while securing regular providers for our student-run free clinic. MD/PhD involvement increased from 1.91 to 2.45 students-per-clinic-day following implementation, and participants affirmed increased preparedness and comfort entering medical school clinical clerkships., Competing Interests: Conflict of InterestThe authors declare that they have no conflict of interest., (© International Association of Medical Science Educators 2018.)

Objective: Using the topographical model of multiple sclerosis (MS) to evaluate a longitudinal cohort we (1) test the recapitulation hypothesis, positing that patients' "disease topography" predicts the clinical pattern of disability accumulation; and (2) identify leading indicators of progression., Methods: 10 patients who transitioned from relapsing-remitting MS to secondary progressive MS (SPMS) were evaluated. Neurologic exams were analyzed from relapses, at time of SPMS diagnosis, and most recent visit. Functional systems (FS), location/laterality, and recovery were recorded. The pyramidal/motor system was the target FS assessing symptom laterality and severity at relapse and SPMS time-points. Each patient's clinical course was mapped using the topographical model software., Results: Cohort was 80% female, age 31.6 ± 8.6 years at diagnosis, followed average 23.8 ± 8.8 years, mean 3.1 relapses before SPMS. 83.3 ± 0.2% of relapse symptoms were present at transition to SPMS, increasing to 91.0 ± 0.2% at most recent visit. This demonstrates concordance between the topographical distribution of relapse symptoms and deficits from subsequent progression. In the topographical model, progression became apparent 7.75 years earlier than SPMS was diagnosed in practice., Conclusions: We demonstrate the model's utility in depicting patients' disease topography as the loci of clinical progression. This could allow for earlier recognition of progressive disease by identifying leading indicators of progression.

Proper regulation of the coordinated transcriptional program that drives oligodendrocyte (OL) differentiation is essential for central nervous system myelin formation and repair. Nuclear import, mediated in part by a group of karyopherin alpha (Kpna) proteins, regulates transcription factor access to the genome. Understanding how canonical nuclear import functions to control genomic access in OL differentiation may aid in the creation of novel therapeutics to stimulate myelination and remyelination. Here, we show that members of the Kpna family regulate OL differentiation, and may play distinct roles downstream of different pro-myelinating stimuli. Multiple family members are expressed in OLs, and their pharmacologic inactivation dose-dependently decreases the rate of differentiation. Additionally, upon differentiation, the three major Kpna subtypes (P/α2, Q/α3, S/α1) display differential responses to the pro-myelinating cues T3 and CNTF. Most notably, the Q/α3 karyopherin Kpna4 is strongly upregulated by CNTF treatment both compared with T3 treatment and other Kpna responses. Kpna4 inactivation results in inhibition of CNTF-induced OL differentiation, in the absence of changes in proliferation or viability. Collectively, these findings suggest that canonical nuclear import is an integral component of OL differentiation, and that specific Kpnas may serve vital and distinct functions downstream of different pro-myelinating cues., Competing Interests: The authors have declared that no competing interests exist.

Growth factors of the gp130 family promote oligodendrocyte differentiation, and viability, and myelination, but their mechanisms of action are incompletely understood. Here, we show that these effects are coordinated, in part, by the transcriptional activator Krüppel-like factor-6 (Klf6). Klf6 is rapidly induced in oligodendrocyte progenitors (OLP) by gp130 factors, and promotes differentiation. Conversely, in mice with lineage-selective Klf6 inactivation, OLP undergo maturation arrest followed by apoptosis, and CNS myelination fails. Overlapping transcriptional and chromatin occupancy analyses place Klf6 at the nexus of a novel gp130-Klf-importin axis, which promotes differentiation and viability in part via control of nuclear trafficking. Klf6 acts as a gp130-sensitive transactivator of the nuclear import factor importin-α5 (Impα5), and interfering with this mechanism interrupts step-wise differentiation. Underscoring the significance of this axis in vivo, mice with conditional inactivation of gp130 signaling display defective Klf6 and Impα5 expression, OLP maturation arrest and apoptosis, and failure of CNS myelination.

Alterations in the structure and organization of the aging central nervous system (CNS), and associated functional deficits, result in cognitive decline and increase susceptibility to neurodegeneration. Age-related changes to the neurovascular unit (NVU), and their consequences for cerebrovascular function, are implicated as driving cognitive impairment during aging as well as in neurodegenerative disease. The molecular events underlying these effects are incompletely characterized. Similarly, the mechanisms underlying effects of factors that reduce the impact of aging on the brain, such as physical exercise, are also opaque. A study in this issue of PLOS Biology links the NVU to cognitive decline in the aging brain and suggests a potential underlying molecular mechanism. Notably, the study further links the protective effects of chronic exercise on cognition to neurovascular integrity during aging.

In inflammatory central nervous system conditions such as multiple sclerosis, breakdown of the blood-brain barrier is a key event in lesion pathogenesis, predisposing to oedema, excitotoxicity, and ingress of plasma proteins and inflammatory cells. Recently, we showed that reactive astrocytes drive blood-brain barrier opening, via production of vascular endothelial growth factor A (VEGFA). Here, we now identify thymidine phosphorylase (TYMP; previously known as endothelial cell growth factor 1, ECGF1) as a second key astrocyte-derived permeability factor, which interacts with VEGFA to induce blood-brain barrier disruption. The two are co-induced NFκB1-dependently in human astrocytes by the cytokine interleukin 1 beta (IL1B), and inactivation of Vegfa in vivo potentiates TYMP induction. In human central nervous system microvascular endothelial cells, VEGFA and the TYMP product 2-deoxy-d-ribose cooperatively repress tight junction proteins, driving permeability. Notably, this response represents part of a wider pattern of endothelial plasticity: 2-deoxy-d-ribose and VEGFA produce transcriptional programs encompassing angiogenic and permeability genes, and together regulate a third unique cohort. Functionally, each promotes proliferation and viability, and they cooperatively drive motility and angiogenesis. Importantly, introduction of either into mouse cortex promotes blood-brain barrier breakdown, and together they induce severe barrier disruption. In the multiple sclerosis model experimental autoimmune encephalitis, TYMP and VEGFA co-localize to reactive astrocytes, and correlate with blood-brain barrier permeability. Critically, blockade of either reduces neurologic deficit, blood-brain barrier disruption and pathology, and inhibiting both in combination enhances tissue preservation. Suggesting importance in human disease, TYMP and VEGFA both localize to reactive astrocytes in multiple sclerosis lesion samples. Collectively, these data identify TYMP as an astrocyte-derived permeability factor, and suggest TYMP and VEGFA together promote blood-brain barrier breakdown., (© The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Ten-eleven translocation (TET) enzymes mediate the conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), which is enriched in brain, and its ultimate DNA demethylation. However, the influence of TET and 5hmC on gene transcription in brain remains elusive. We found that ten-eleven translocation protein 1 (TET1) was downregulated in mouse nucleus accumbens (NAc), a key brain reward structure, by repeated cocaine administration, which enhanced behavioral responses to cocaine. We then identified 5hmC induction in putative enhancers and coding regions of genes that have pivotal roles in drug addiction. Such induction of 5hmC, which occurred similarly following TET1 knockdown alone, correlated with increased expression of these genes as well as with their alternative splicing in response to cocaine administration. In addition, 5hmC alterations at certain loci persisted for at least 1 month after cocaine exposure. Together, these reveal a previously unknown epigenetic mechanism of cocaine action and provide new insight into how 5hmC regulates transcription in brain in vivo.

In the embryonic CNS, development of myelin-forming oligodendrocytes is limited by bone morphogenetic proteins, which constitute one arm of the transforming growth factor-β (Tgfβ) family and signal canonically via Smads 1/5/8. Tgfβ ligands and Activins comprise the other arm and signal via Smads 2/3, but their roles in oligodendrocyte development are incompletely characterized. Here, we report that Tgfβ ligands and activin B (ActB) act in concert in the mammalian spinal cord to promote oligodendrocyte generation and myelination. In mouse neural tube, newly specified oligodendrocyte progenitors (OLPs) are first exposed to Tgfβ ligands in isolation, then later in combination with ActB during maturation. In primary OLP cultures, Tgfβ1 and ActB differentially activate canonical Smad3 and non-canonical MAP kinase signaling. Both ligands enhance viability, and Tgfβ1 promotes proliferation while ActB supports maturation. Importantly, co-treatment strongly activates both signaling pathways, producing an additive effect on viability and enhancing both proliferation and differentiation such that mature oligodendrocyte numbers are substantially increased. Co-treatment promotes myelination in OLP-neuron co-cultures, and maturing oligodendrocytes in spinal cord white matter display strong Smad3 and MAP kinase activation. In spinal cords of ActB-deficient Inhbb(-/-) embryos, apoptosis in the oligodendrocyte lineage is increased and OLP numbers transiently reduced, but numbers, maturation and myelination recover during the first postnatal week. Smad3(-/-) mice display a more severe phenotype, including diminished viability and proliferation, persistently reduced mature and immature cell numbers, and delayed myelination. Collectively, these findings suggest that, in mammalian spinal cord, Tgfβ ligands and ActB together support oligodendrocyte development and myelin formation., (© 2014. Published by The Company of Biologists Ltd.)

Fragmentation of rapid eye movement sleep (REMS) is well described in individuals with posttraumatic stress disorder (PTSD) and likely has significant functional consequences. Fear-conditioned rodents may offer an attractive model of the changes in sleep that characterize PTSD. Following fear conditioning (FC), Wistar-Kyoto (WKY) rats, a strain known to be particularly stress-sensitive, have increased REMS fragmentation that can be quantified as a shift in the distribution of REMS episodes towards the more frequent occurrence of sequential REMS (inter-REMS episode interval≤3 min) vs. single REMS (interval>3 min). The α1 adrenoceptor antagonist prazosin has demonstrated efficacy in normalizing sleep in PTSD. To determine the utility of fear-conditioned WKY rats as a model of sleep disturbances typical of PTSD and as a platform for the development of new treatments, we tested the hypothesis that prazosin would reduce REMS fragmentation in fear-conditioned WKY rats. Sleep parameters and freezing (a standard measure of anxiety in rodents) were quantified at baseline and on Days 1, 7, and 14 following FC, with either prazosin (0.01mg/kg, i.p.) or vehicle injections administered prior to testing in a between-group design. Fear conditioning was achieved by pairing tones with a mild electric foot shock (1.0mA, 0.5s). One, 7, and 14 days following FC, prazosin or vehicle was injected, the tone was presented, freezing was measured, and then sleep was recorded from 11 AM to 3 PM. WKY rats given prazosin, compared to those given vehicle, had a lower amount of seq-REMS relative to total REMS time 14 days after FC. They also had a shorter non-REMS latency and fewer non-REMS arousals at baseline and on Days 1 and 7 after FC. Thus, in FC rats, prazosin reduced both REMS fragmentation and non-REMS discontinuity., (Published by Elsevier Inc.)

Recent investigations of rapid eye movement sleep (REMS) continuity have emphasized the importance of transitions both into and out of REMS. We have previously reported that, compared to Wistar rats (WIS), Wistar-Kyoto rats (WKY) responded to fear conditioning (FC) with more fragmented REMS. Gamma oscillations in the electroencephalogram (EEG) are synchronized throughout the brain in periods of focused attention, and such synchronization of cell assemblies in the brain may represent a temporal binding mechanism. Therefore, we examined the effects of FC on EEG gamma range activity (30-50Hz) at REMS transitions in WKY compared to WIS. Relative power in the gamma range (measured as a percent of total power) at Baseline and upon re-exposure to the fear-inducing conditioning stimulus was measured 35s before REMS onset to 105s after REMS onset (ARO) and 85s before REMS termination (BRT) to 35s after REMS termination. After baseline recording, rats received 10 tones, each co-terminating with an electric foot shock. On Days 1 and 14 post-conditioning, rats were re-exposed to three tones. Fast-Fourier transforms created power spectral data in the gamma frequency domain. Relative power was extracted from an average of 4-5 REMS transitions. Relative gamma power was always higher in WIS. On Day 14, at 15s and 25s ARO, WKY had significant increases in relative gamma power from Baseline. WIS had a significant increase on Day 1 at 25s ARO. Despite the increases in relative gamma power, WKY never achieved levels attained by WIS. Moreover, at 5s BRT, only WKY had a significant decrease in relative gamma power from Baseline to Day 14. Gamma range activity may indicate neural activity underlying maintenance of REMS continuity. Low relative gamma power at REMS transitions may be associated with increased REMS fragmentation in WKY after FC., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)