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Objective: Patient-reported outcome measures (PROMs) are utilized to assess surgical success but are limited by data collection, response bias, and subjectivity. The large volume of digital healthcare data offers a new method to utilize healthcare utilization as a longitudinal, individualized, and objective proxy for health needs among surgical patients. This study aimed to design and evaluate a novel resource utilization in spine healthcare (RUSH) clustering method that complements PROMs in evaluating post-operative patient outcomes., Methods: This retrospective cross-sectional study conducted at a large, tertiary healthcare system included all adult patients undergoing cervical or lumbar surgery between 2014 to 2020 with at least 3 months follow-up. Post-operative healthcare utilization was analyzed using clinic visits, inpatient encounters, telephone encounters, MyChart messages, opioid use, physical therapy, injections, and imaging. Latent profile analysis determined RUSH clusters and changes in PROM Information System Physical Health (PROMIS-PH) scores pre- and 12-months post-operation., Results: This study included 5,602 surgeries (mean age 61.3 ± 13.1, 49.9% female). Four RUSH groups were identified: low utilizers (21.5%), moderate utilizers without advanced imaging (34.7%), moderate utilizers with advanced imaging (10.7%), and high utilizers (33.1%,). Utilization patterns varied by surgery type, with lower-utilization patterns among non-fusion procedures and a consistent sub-population of high utilizers across all surgery types. High RUSH utilizers had the lowest pre-operative PROMIS-PH scores and the worst average postoperative change., Conclusions: RUSH clustering provides a novel, data-driven approach to measure surgical success, complementing traditional PROMs, and leveraging big data to monitor and respond to surgical outcomes., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Neurosurgery residency, known for its rigorous training, must adapt to evolving healthcare demands. Formal education should now encompass areas like quality improvement and patient safety, machine learning, career planning, research infrastructure, grant funding, and socioeconomics. We share our institution's experience with a yearlong enhanced didactics curriculum, complementing our traditional teaching., Methods: Our resident and faculty team evaluated essential skills for trainee success and leadership, identified knowledge gaps, and addressed them with 31 lectures. We conducted pre- and 6-month surveys using a Likert scale (1=strongly disagree, 3=neutral, 5=strongly agree) to assess resident education. Survey results were analyzed using Student t-tests, with P<0.05 indicating statistical significance., Results: Eleven out of 12 residents completed the pre- and 6-month surveys. The surveys revealed improved scores in areas such as research career preparation (3.0/5-4.33/5, P = 0.002), building research skills (3.18/5-4.33/5, P = 0.002), and comfort with quality and patient safety (4.09/5-4.75, P = 0.04). Residents found the lectures highly effective in supplementing their residency training (4.58/5). Qualitative feedback from faculty was highly positive as well., Conclusions: Organized neurosurgery excels in clinical and technical training for residents but lacks formalized training in crucial nonclinical areas, such as quality improvement and patient safety, machine learning/artificial intelligence, research infrastructure, and socioeconomics. Our formal curriculum focused on these topics, with positive resident engagement and feedback over the first six months. However, continuous longitudinal monitoring is needed to confirm the curriculum's efficacy. This program may guide other neurosurgery departments in enhancing resident education in these areas., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Incidental durotomy is a common complication of posterior lumbar spine surgery; however, effective and durable methods for primary repair remain elusive. Multiple existing techniques have previously been reported and extensively described, including sutured repair and the use of nonpenetrating titanium clips. The use of cranial aneurysm clips for primary repair of lumbar durotomy serves as a safe and effective alternative to obtain watertight closure of a dural tear., Methods: We performed a retrospective review of patients at a single institution who underwent primary repair of an incidental lumbar durotomy with the use of an aneurysm clip during open posterior lumbar surgery between 2012 and 2023. Patient demographics, operative details, and postoperative metrics were collected and examined to evaluate the safety and efficacy of the novel technique., Results: A total of 51 patients were included for analysis. Four patients underwent durotomy repair with an aneurysm clip alone, 27 patients were repaired with an aneurysm clip and fibrin glue, and 20 patients underwent repair with an aneurysm clip, fibrin glue, and a collagen dural substitute. Three patients (5.9%) reported headaches: 2 (3.9%) with pseudomeningocele and 1 (2%) with wound leakage. Two patients (3.9%) had treatment failure with a return to the operating room for repair of a cerebrospinal fluid leak., Conclusions: To the best of our knowledge, we report the largest series of patients undergoing primary repair of incidental durotomy with the use of an aneurysm clip. Use of an aneurysm clip is noted to be a safe, quick, and effective method of primary repair compared with existing repair techniques such as sutured repair or nonpenetrating titanium clips., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Introduction: Expandable devices such as interbody cages, vertebral body reconstruction cages, and intravertebral body expansion devices are frequently utilized in spine surgery. Since the introduction of expandable implants in the early 2000s, the variety of mechanisms that drive expansion and implant materials have steadily increased. By examining expandable devices that have achieved commercial success and exploring emerging innovations, we aim to offer an in-depth evaluation of the different types of expandable cages used in spine surgery and the underlying mechanisms that drive their functionality., Areas Covered: We performed a review of expandable spinal implants and devices by querying the National Library of Medicine MEDLINE database and Google Patents database from 1933 to 2024. Five major types of mechanical jacks that drive expansion were identified: scissor, pneumatic, screw, ratchet, and insertion-expansion., Expert Opinion: We identified a trend of screw jack mechanism being the predominant machinery in vertebral body reconstruction cages and scissor jack mechanism predominating in interbody cages. Pneumatic jacks were most commonly found in kyphoplasty devices. Critically reviewing the mechanisms of expansion and identifying trends among effective and successful cages allows both surgeons and medical device companies to properly identify future areas of development.

Tribology, an interdisciplinary field concerned with the science of interactions between surfaces in contact and their relative motion, plays a well-established role in the design of orthopedic implants, such as knee and hip replacements. However, its applications in spine surgery have received comparatively less attention in the literature. Understanding tribology is pivotal in elucidating the intricate interactions between metal, polymer, and ceramic components, as well as their interplay with the native human bone. Numerous studies have demonstrated that optimizing tribological factors is key to enhancing the longevity of joints and implants while simultaneously reducing complications and the need for revision surgeries in both arthroplasty and spinal fusion procedures. With an ever-growing and diverse array of spinal implant devices hitting the market for static and dynamic stabilization of the spine, it is important to consider how each of these devices optimizes these parameters and what factors may be inadequately addressed by currently available technology and methods. In this comprehensive review, the authors' objectives were twofold: 1) delineate the unique challenges encountered in spine surgery that could be addressed through optimization of tribological parameters; and 2) summarize current innovations and products within spine surgery that look to optimize tribological parameters and highlight new avenues for implant design and research.

Hypertension is a widely prevalent disease and uncontrolled hypertension predisposes affected individuals to severe adverse effects. Though the importance of controlling hypertension is clear, the multitude of therapeutic regimens and patient factors that affect the success of blood pressure control makes it difficult to predict the likelihood to predict whether a patient's blood pressure will be controlled. This project endeavors to investigate whether machine learning can accurately predict the control of a patient's hypertension within 12 months of a clinical encounter. To build the machine learning model, a retrospective review of the electronic medical records of 350,008 patients 18 years of age and older between January 1, 2015 and June 1, 2022 was performed to form model training and testing cohorts. The data included in the model included medication combinations, patient laboratory values, vital sign measurements, comorbidities, healthcare encounters, and demographic information. The mean age of the patient population was 65.6 years with 161,283 (46.1%) men and 275,001 (78.6%) white. A sliding time window of data was used to both prohibit data leakage from training sets to test sets and to maximize model performance. This sliding window resulted in using the study data to create 287 predictive models each using 2 years of training data and one week of testing data for a total study duration of five and a half years. Model performance was combined across all models. The primary outcome, prediction of blood pressure control within 12 months demonstrated an area under the curve of 0.76 (95% confidence interval; 0.75-0.76), sensitivity of 61.52% (61.0-62.03%), specificity of 75.69% (75.25-76.13%), positive predictive value of 67.75% (67.51-67.99%), and negative predictive value of 70.49% (70.32-70.66%). An AUC of 0.756 is considered to be moderately good for machine learning models. While the accuracy of this model is promising, it is impossible to state with certainty the clinical relevancy of any clinical support ML model without deploying it in a clinical setting and studying its impact on health outcomes. By also incorporating uncertainty analysis for every prediction, the authors believe that this approach offers the best-known solution to predicting hypertension control and that machine learning may be able to improve the accuracy of hypertension control predictions using patient information already available in the electronic health record. This method can serve as a foundation with further research to strengthen the model accuracy and to help determine clinical relevance., Competing Interests: The authors declare no competing interest related to this work., (Copyright: © 2024 Mroz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Despite the expanding role of machine learning (ML) in health care and patient expectations for clinicians to understand ML-based tools, few for-credit curricula exist specifically for neurosurgical trainees to learn basic principles and implications of ML for medical research and clinical practice. We implemented a novel, remotely delivered curriculum designed to develop literacy in ML for neurosurgical trainees., Methods: A 4-week pilot medical elective was designed specifically for trainees to build literacy in basic ML concepts. Qualitative feedback from interested and enrolled students was collected to assess students' and trainees' reactions, learning, and future application of course content., Results: Despite 15 interested learners, only 3 medical students and 1 neurosurgical resident completed the course. Enrollment included students and trainees from 3 different institutions. All learners who completed the course found the lectures relevant to their future practice as clinicians and researchers and reported improved confidence in applying and understanding published literature applying ML techniques in health care. Barriers to ample enrollment and retention (e.g., balancing clinical responsibilities) were identified., Conclusions: This pilot elective demonstrated the interest, value, and feasibility of a remote elective to establish ML literacy; however, feedback to increase accessibility and flexibility of the course encouraged our team to implement changes. Future elective iterations will have a semiannual, 2-week format, splitting lectures more clearly between theory (the method and its value) and application (coding instructions) and will make lectures open-source prerequisites to allow tailoring of student learning to their planned application of these methods in their practice and research., (Published by Elsevier Inc.)

Background Context: Identifying optimal stratification techniques for subgrouping patients with low back pain (LBP) into treatment groups for the purpose of identifying optimal management and improving clinical outcomes is an important area for further research., Purpose: Our study aimed to compare performance of the STarT Back Tool (SBT) and 3 stratification techniques involving PROMIS domain scores for use in patients presenting to a spine clinic for chronic LBP., Study Design: Retrospective cohort study., Patient Sample: Adult patients with chronic LBP seen in a spine center between November 14, 2018 and May 14, 2019 who completed patient-reported outcomes (PROs) as part of routine care, and were followed up with completed PROs 1 year later., Outcome Measures: Four stratification techniques, including SBT, and 3 PROMIS-based techniques: the NIH Task Force recommended Impact Stratification Score (ISS), symptom clusters based on latent class analysis (LCA), and SPADE symptom clusters., Methods: The 4 stratification techniques were compared according to criterion validity, construct validity, and prognostic utility. For criterion validity, overlap in characterization of mild, moderate, and severe subgroups were compared to SBT, which was considered the gold standard, using quadratic weighted kappa statistic. Construct validity compared techniques' ability to differentiate across disability groups defined by modified Oswestry LBP Disability Questionnaire (MDQ), median days in the past month unable to complete activities of daily living (ADLs), and worker's compensation using standardized mean differences (SMD). Prognostic utility was compared based on the techniques' ability to predict long-term improvement in outcomes, defined as improvement in global health and MDQ at 1-year., Results: There were 2,246 adult patients with chronic LBP included in our study (mean age 61.0 [SD 14.0], 55.0% female, 83.4% white). All stratification techniques resulted in roughly a third of patients grouped into mild, moderate, and severe categories, with ISS and LCA demonstrating substantial agreement with SBT, while SPADE had moderate agreement. Construct validity was met for all techniques, with large effects demonstrated between mild and severe categories for differentiating MDQ, ADLs, and worker's compensation disability groups (SMD range 0.57-2.48). All stratification techniques demonstrated ability to detect improvement by 1-year, with severe groups experiencing the greatest improvement in multivariable logistic regression models., Conclusions: All 4 stratification techniques demonstrated validity and prognostic utility for subgrouping patients with chronic LBP based on risk of long-term disability. ISS and LCA symptom clusters may be the optimal methods given the improved feasibility of including only a few relevant PROMIS domains. Future research should investigate multidisciplinary treatment approaches to target mild, moderate, and severe patients based on these techniques., Competing Interests: Declarations of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Decision-making in spine surgery is complex due to patients' heterogeneity and complexity of spinal pathologies and the various surgical options applied to a given pathology. Artificial intelligence/machine learning algorithms provide an opportunity to improve patient selection, surgical planning, and outcomes. The purpose of this article is to present the experience and applications of in spine surgery at 2 large academic health care systems., Competing Interests: Declaration of Conflicting Interests : The authors report no conflicts of interest in this work., (This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2023 ISASS. To see more or order reprints or permissions, see http://ijssurgery.com.)

Objective: In clinical spine surgery research, manually reviewing surgical forms to categorize patients by their surgical characteristics is a crucial yet time-consuming task. Natural language processing (NLP) is a machine learning tool used to adaptively parse and categorize important features from text. These systems function by training on a large, labeled data set in which feature importance is learned prior to encountering a previously unseen data set. The authors aimed to design an NLP classifier for surgical information that can review consent forms and automatically classify patients by the surgical procedure performed., Methods: Thirteen thousand two hundred sixty-eight patients who underwent 15,227 surgeries from January 1, 2012, to December 31, 2022, at a single institution were initially considered for inclusion. From these surgeries, 12,239 consent forms were classified based on the Current Procedural Terminology (CPT) code, categorizing them into 7 of the most frequently performed spine surgeries at this institution. This labeled data set was split 80%/20% into train and test subsets, respectively. The NLP classifier was then trained and the results demonstrated its performance on the test data set using CPT codes to determine accuracy., Results: This NLP surgical classifier had an overall weighted accuracy rate of 91% for sorting consents into correct surgical categories. Anterior cervical discectomy and fusion had the highest positive predictive value (PPV; 96.8%), whereas lumbar microdiscectomy had the lowest PPV in the testing data (85.0%). Sensitivity was highest for lumbar laminectomy and fusion (96.7%) and lowest for the least common operation, cervical posterior foraminotomy (58.3%). Negative predictive value and specificity were > 95% for all surgical categories., Conclusions: Utilizing NLP for text classification drastically improves the efficiency of classifying surgical procedures for research purposes. The ability to quickly classify surgical data can be significantly beneficial to institutions without a large database or substantial data review capabilities, as well as for trainees to track surgical experience, or practicing surgeons to evaluate and analyze their surgical volume. Additionally, the capability to quickly and accurately recognize the type of surgery will facilitate the extraction of new insights from the correlations between surgical interventions and patient outcomes. As the database of surgical information grows from this institution and others in spine surgery, the accuracy, usability, and applications of this model will continue to increase.

Background: The increase in use of targeted systemic therapies in cancer treatments has catalyzed the importance of identifying patient- and tumor-specific somatic mutations, especially regarding metastatic disease. Mutations found to be most prevalent in patients with metastatic breast cancer include TP53, PI3K, and CDH1., Objective: To determine the incidence of somatic mutations in patients with metastatic breast cancer to the spine (MBCS). To determine if a difference exists in overall survival (OS), progression-free survival, and progression of motor symptoms between patients who do or do not undergo targeted systemic therapy after treatment for MBCS., Methods: This is a retrospective study of patients with MBCS. Review of gene sequencing reports was conducted to calculate the prevalence of various somatic gene mutations within this population. Those patients who then underwent treatment (surgery/radiation) for their diagnosis of MBCS between 2010 and 2020 were subcategorized. The use of targeted systemic therapy in the post-treatment period was identified, and post-treatment OS, progression-free survival, and progression of motor deficits were calculated for this subpopulation., Results: A total of 131 patients were included in the final analysis with 56% of patients found to have a PI3K mutation. Patients who received targeted systemic therapies were found to have a significantly longer OS compared with those who did not receive targeted systemic therapies., Conclusion: The results of this study demonstrate that there is an increased prevalence of PI3K mutations in patients with MBCS and there are a significant survival benefit and delay in progression of motor symptoms associated with using targeted systemic therapies for adjuvant treatment., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Objective: Neurosurgery program websites serve as a valuable resource for applicants. However, each website exists in isolation, and it can be difficult to understand the general trends in U.S. neurosurgery resident demographics. In the present study, we collected data from program websites and analyzed the trends in the demographics of the current U.S. neurosurgery residents., Methods: We used a program list obtained from the American Association of Medical Colleges Electronic Residency Application System to extract data from the current resident complement listed in each program's website, including program, year in program, medical school, sex (male vs. female), graduate and/or PhD degrees, and assessed the trends during 7 years of resident data using linear regression., Results: We identified 116 neurosurgery residency programs in the United States, with 111 providing information on their current resident complement, yielding a dataset of 1599 residents. Of these 1599 residents, 348 (22%) were female, 301 (19%) had a graduate degree in addition to an MD or DO degree, 151 (9.4%) had a PhD degree, 300 (19%) had matched at the program affiliated with their medical school, and 121 (7.6%) had graduated from a foreign medical school. The proportion of matriculating female residents had increased an average of 2.1% annually (95% confidence interval, 0.6%-3.7%) from 2015 to 2021. The other demographic data had not changed significantly during the same period., Conclusions: In addition to summarizing the current resident demographics, our analysis identified a significant increase in the proportion of female residents between 2015 (15.1%) and 2021 (25.6%). This publicly available dataset should enable additional analyses of the evolution of neurosurgery resident demographics., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: The US-based Spinal Laminectomy versus Instrumented Pedicle Screw (SLIP) trial reported improvement in disability following laminectomy with fusion versus laminectomy alone for patients with lumbar spondylolisthesis. Despite using similar methods, a concurrent Swedish trial investigating the same question did not reach the same conclusion. The authors performed a simulation-based analysis to elucidate potential causes of these divergent results., Methods: The mean and standard deviation of the preoperative and 2-year postoperative Oswestry Disability Index (ODI) scores for each study group (laminectomy with fusion and laminectomy alone) were collected from the spondylolisthesis stratum of the Swedish trial and used to create a MATLAB simulator using linear transformations to predict postoperative ODI distributions. Applying this simulator to both varied and published preoperative ODI distributions from the SLIP trial, the authors simulated the results of the US-based trial using treatment effects from the Swedish study and compared simulated US results to those published in the SLIP trial., Results: Simulated US results showed that as preoperative disability increased, the difference in postoperative ODI scores grew between treatment groups and increasingly favored laminectomy alone (p < 0.0001). In 100 simulations of a similarly sized US trial, the average mean change in ODI scores postoperatively was significantly higher than was published for laminectomy alone in the SLIP trial (-21.3 vs -17.9), whereas it was significantly lower than published for fusion (-16.9 vs -26.3)., Conclusions: The expected benefit of surgical treatments for spondylolisthesis varied according to preoperative disability. Adapting Swedish-estimated treatment effects to the US context mildly overapproximated the improvement in postoperative disability scores for laminectomy, but more severely underapproximated the improvement reported for laminectomy and fusion in the SLIP trial. The observed heterogeneity between these studies is influenced more by patient response to fusion than response to laminectomy. This analysis paves the way for future studies on the impact of preoperative treatment group heterogeneity, differences in surgical methods, and empirical design on reported clinical benefits. Although bayesian reanalysis of published randomized controlled trial data is susceptible to biases that typically limit post hoc analyses, the authors' method offers a simple and cost-effective approach to improve the understanding of published clinical trial results and their implications for future studies.

Background: Prior work by our group developed a stratification tool based on four PROMIS domains for patients with low back pain (LBP). Our study aimed to evaluate the ability of our previously developed symptom classes to predict long-term outcomes, and determine whether there were differential treatment effects by intervention., Methods: This was a retrospective cohort study of adult patients with LBP seen in spine clinics in a large health system between November 14, 2018 and May 14, 2019 who completed patient-reported outcomes as part of routine care at baseline and again at 12-months follow-up. Latent class analysis identified symptom classes based on PROMIS domain scores (physical function, pain interference, social role satisfaction, and fatigue) that were ≥1 standard deviation worse (meaningfully worse) than the general population. The ability of the profiles to predict long-term outcomes at 12-months was evaluated through multivariable models. Differences in outcomes by subsequent treatments (physical therapy, specialist visits, injections, and surgery) were investigated., Results: There were 3,236 adult patients (average age 61.1 ± 14.2, 55.4% female) included in the study with three distinct classes identified: mild symptoms ( n  = 986, 30.5%), mixed ( n  = 798, 24.7%) with poor scores on physical function and pain interference but better scores on other domains, and significant symptoms ( n  = 1,452, 44.9%). The classes were significantly associated with long-term outcomes, with patients with significant symptoms improving the most across all domains. Utilization differed across classes, with the mixed symptom class receiving more PT and injections and significant symptom class receiving more surgeries and specialist visits., Conclusions: Patients with LBP have distinct clinical symptom classes which could be utilized to stratify patients into groups based on risk of future disability. These symptom classes can also be used to provide estimates of the effectiveness of different interventions, further increasing the clinical utility of these classes in standard care., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Author(s).)

Background Context: Improving prognostic stratification for patients with low back pain (LBP) outside of a primary care setting has been identified as an important area for further research., Purpose: Our study aimed to identify clinical symptom classes of patients presenting to a spine clinic based on 4 Patient Reported Outcome Measurement Information System (PROMIS) domains and evaluate demographic and clinical differences across classes., Study Design: An observational cross-sectional study of patients seen in spine centers at a large health system., Patient Sample: Adult patients with LBP seen in a spine center between November 14, 2018 and May 14, 2019 who completed patient-reported outcomes as part of routine care., Outcome Measures: PROMIS physical function, pain interference, satisfaction with social roles and activities, and fatigue., Methods: Latent class analysis identified symptom classes based on PROMIS domain scores ≥1 standard deviation worse (meaningfully worse) than the general population. A multivariable multinomial logistic regression model was constructed to evaluate differences in symptom classes based on demographics and socioeconomic characteristics. Lastly, the ability of the profiles to discriminate across levels of disability, based on the modified Oswestry Disability Questionnaire (ODI), was evaluated., Results: There were 7,144 adult patients included in the study who visited spine clinics for a primary complaint of LBP and completed all 4 PROMIS domains (age 58.7±15.9, 54% female). Three distinct classes were identified. Class 1 ("Significant Symptoms," n=3238) had PROMIS scores that were meaningfully worse than the population average for all domains. Class 2 ("Mixed Symptoms," n=1366) had meaningfully worse scores on physical function and pain interference but average scores on other domains. Class 3 ("Mild Symptoms," n=2540) had average scores across all domains. Compared to patients in Class 3, those in Class 2 were more likely older, and those in Classes 1 and 2 were more likely to be divorced, have lower household income, and no employment. Level of disability was significantly different across each class (average (SD) ODI for Classes 1-3: 53.4 (14.3), 39.9 (12.5), 22.9 (12.1), p<.01)., Conclusions: Patients presenting to specialty clinics for LBP demonstrate distinct clinical symptom classes which could be utilized to inform specific symptom-based treatment. Future research should evaluate the ability of these classes to predict long-term disability., Competing Interests: Declarations of Competing Interests The authors have no competing interests to disclose., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Study Design: Narrative review., Objectives: Artificial intelligence (AI) and machine learning (ML) have emerged as disruptive technologies with the potential to drastically affect clinical decision making in spine surgery. AI can enhance the delivery of spine care in several arenas: (1) preoperative patient workup, patient selection, and outcome prediction; (2) quality and reproducibility of spine research; (3) perioperative surgical assistance and data tracking optimization; and (4) intraoperative surgical performance. The purpose of this narrative review is to concisely assemble, analyze, and discuss current trends and applications of AI and ML in conventional and robotic-assisted spine surgery., Methods: We conducted a comprehensive PubMed search of peer-reviewed articles that were published between 2006 and 2019 examining AI, ML, and robotics in spine surgery. Key findings were then compiled and summarized in this review., Results: The majority of the published AI literature in spine surgery has focused on predictive analytics and supervised image recognition for radiographic diagnosis. Several investigators have studied the use of AI/ML in the perioperative setting in small patient cohorts; pivotal trials are still pending., Conclusions: Artificial intelligence has tremendous potential in revolutionizing comprehensive spine care. Evidence-based, predictive analytics can help surgeons improve preoperative patient selection, surgical indications, and individualized postoperative care. Robotic-assisted surgery, while still in early stages of development, has the potential to reduce surgeon fatigue and improve technical precision.

Objective: In a healthcare landscape in which costs increasingly matter, the authors sought to distinguish among the clinical and nonclinical drivers of patient length of stay (LOS) in the hospital following elective lumbar laminectomy-a common spinal surgery that may be reimbursed using bundled payments-and to understand their relationships with patient outcomes and costs., Methods: Patients ≥ 18 years of age undergoing laminectomy surgery for degenerative lumbar spinal stenosis within the Cleveland Clinic health system between March 1, 2016, and February 1, 2019, were included in this analysis. Generalized linear modeling was used to assess the relationships between the day of surgery, patient discharge disposition, and hospital LOS, while adjusting for underlying patient health risks and other nonclinical factors, including the hospital surgery site and health insurance., Results: A total of 1359 eligible patients were included in the authors' analysis. The mean LOS ranged between 2.01 and 2.47 days for Monday and Friday cases, respectively. The LOS was also notably longer for patients who were ultimately discharged to a skilled nursing facility (SNF) or rehabilitation center. A prolonged LOS occurring later in the week was not associated with greater underlying health risks, yet it nevertheless resulted in greater costs of care: the average total surgical costs for lumbar laminectomy were 20% greater for Friday cases than for Monday cases, and 24% greater for late-week cases than for early-week cases ultimately transferred to SNFs or rehabilitation centers. A Poisson generalized linear model fit the data best and showed that the comorbidity burden, surgery at a tertiary care center versus a community hospital, and the incidence of any postoperative complication were associated with significantly longer hospital stays. Discharge to home healthcare, SNFs, or rehabilitation centers, and late-week surgery were significant nonclinical predictors of LOS prolongation, even after adjusting for underlying patient health risks and insurance, with LOSs that were, for instance, 1.55 and 1.61 times longer for patients undergoing their procedure on Thursday and Friday compared to Monday, respectively., Conclusions: Late-week surgeries are associated with a prolonged LOS, particularly when discharge is to an SNF or rehabilitation center. These findings point to opportunities to lower costs and improve outcomes associated with elective surgical care. Interventions to optimize surgical scheduling and perioperative care coordination could help reduce prolonged LOSs, lower costs, and, ultimately, give service line management personnel greater flexibility over how to use existing resources as they remain ahead of healthcare reforms.

Objective  Radiofrequency ablation is widely utilized in otorhinolaryngology. It is used for ablation, coagulation and resection, and hemostasis. It causes tissue destruction through a chemical interaction of ions. The potential benefit is to cause less thermal injury to surrounding tissues compared with other coagulative tools. In this article, we present novel uses of radiofrequency ablation in endoscopic endonasal, and transcranial surgery. This is the first study to describe its use in transcranial cases. Design, Setting, and Participants  This is a retrospective study of patients between 2016 and 2018 who underwent either endoscopic endonasal or transcranial surgery where radiofrequency ablation was used. Main Outcome Measures  We looked at indication for usage, blood loss, postoperative imaging to identify any stroke or edema, and clinical outcomes of these patients. Results  The radiofrequency device was used in eight endoscopic endonasal cases and four craniotomies. Four cases were for encephalocele repair and eight were for various intracranial pathologies. In endonasal encephalocele repair, the radiofrequency ablation helped in shrinking the herniated brain while minimizing thermal injury to the surrounding tissue. In tumors resection, the combination of ablation and coagulation effect was particularly effective for highly vascularized tumors. There were no vascular or major neurologic injuries. Postoperative periencephalocele edema was noted in one case. Conclusion  Initial experience with radiofrequency ablation showed that it was a safe technique to use in both endonasal skull-base and transcranial procedures. It seemed particularly useful for highly vascularized tumors but a greater experience is needed to further clarify its role in these procedures., Competing Interests: Conflict of Interest V.R.K. reports personal fees from Integra, outside the submitted work. All other authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper., (Thieme. All rights reserved.)

Objective: Spinal cord astrocytoma (SCA) is a rare tumor whose epidemiology has not been well defined. The authors utilized the Central Brain Tumor Registry of the United States (CBTRUS) to provide comprehensive up-to-date epidemiological data for this disease., Methods: The CBTRUS was queried for SCAs on ICD-O-3 (International Classification of Diseases for Oncology, 3rd edition) histological and topographical codes. The age-adjusted incidence (AAI) per 100,000 persons was calculated and stratified by race, sex, age, and ethnicity. Joinpoint was used to calculate the annual percentage change (APC) in incidence., Results: Two thousand nine hundred sixty-nine SCAs were diagnosed in the US between 1995 and 2016, resulting in an average of approximately 136 SCAs annually. The overall AAI was 0.047 (95% CI 0.045-0.049), and there was a statistically significant increase from 0.051 in 1995 to 0.043 in 2016. The peak incidence of 0.064 (95% CI 0.060-0.067) was found in the 0- to 19-year age group. The incidence in males was 0.053 (95% CI 0.050-0.055), which was significantly greater than the incidence in females (0.041, 95% CI 0.039-0.044). SCA incidence was significantly lower both in patients of Asian/Pacific Islander race (AAI = 0.034, 95% CI 0.028-0.042, p = 0.00015) and in patients of Hispanic ethnicity (AAI = 0.035, 95% CI 0.031-0.039, p < 0.001). The incidence of WHO grade I SCAs was significantly higher than those of WHO grade II, III, or IV SCAs (p < 0.001)., Conclusions: The overall AAI of SCA from 1995 to 2016 was 0.047 per 100,000. The incidence peaked early in life for both sexes, reached a nadir between 20 and 34 years of age for males and between 35 and 44 years of age for females, and then slowly increased throughout adulthood, with a greater incidence in males. Pilocytic astrocytomas were the most common SCA in the study cohort. This study presents the most comprehensive epidemiological study of SCA incidence in the US to date.

Purpose: Chordomas account for 1% to 4% of all bone malignancies and 0.5% of all primary intracranial central nervous system tumors. Prior epidemiologic literature is based on limited population data. The purpose of this study is to provide the largest and most inclusive population based study of the descriptive epidemiology of chordomas., Methods: The Centers for Disease Control and Prevention and National Program of Cancer Registries were queried for chordoma in all locations. Age-adjusted incidence per 100,000 persons was calculated by age, sex, race, and ethnicity. Annual percentage change was calculated using Joinpoint., Results: From 2004 to 2014, a total of 3670 chordomas were diagnosed in the US. The most common location was cranial (38.7%), followed by sacral (34.3%) and spinal (27.0%). The average age-adjusted incidence rate was 0.088 per 100,000 persons per year (95% CI 0.086-0.091), with an annual percentage change of 1.29% (95% CI 0.31-2.28%). For all chordomas, the incidence peaks in the 75-84 year age group. The male-to-female incidence rate ratio is 1.54 (p < 0.001). American Indian/Alaskan Native and Black patients had a statistically lower incidence rate than White and Asian/Pacific Islander patients., Conclusion: Approximately 0.088 chordomas per 100,000 persons are newly diagnosed in the US each year, with cranial location being the most common, followed by sacral and spinal. Incidence increases with age, and men are at a significantly higher risk than women. This investigation represents the largest population-based epidemiologic study of chordomas in the US.

As exponential expansion of computing capacity converges with unsustainable health care spending, a hopeful opportunity has emerged: the use of artificial intelligence to enhance health care quality and safety. These computer-based algorithms can perform the intricate and extremely complex mathematical operations of classification or regression on immense amounts of data to detect intricate and potentially previously unknown patterns in that data, with the end result of creating predictive models that can be utilized in clinical practice. Such models are designed to distinguish relevant from irrelevant data regarding a particular patient; choose appropriate perioperative care, intervention or surgery; predict cost of care and reimbursement; and predict future outcomes on a variety of anchored measures. If and when one is brought to fruition, an artificial intelligence platform could serve as the first legitimate clinical decision-making tool in spine care, delivering on the value equation while serving as a source for improving physician performance and promoting appropriate, efficient care in this era of financial uncertainty in health care., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2020.)

Objective: Spinal schwannoma remains the third most common intradural spinal tumor following spinal meningioma and ependymoma. The available literature is generally limited to single-institution reports rather than epidemiological investigations. As of 1/1/2004, registration of all benign central nervous system tumors in the United States became mandatory after the Benign Brain Tumor Cancer Registries Amendment Act took action, which provided massive resources for United States population-based epidemiological studies. This article describes the epidemiology of spinal schwannoma in the United States from January 1, 2006, through December 31, 2014., Methods: In this study, the authors utilized the Central Brain Tumor Registry of the United States, which corresponds to 100% of the American population. The Centers for Disease Control and Prevention's National Program of Cancer Registries and the National Cancer Institute's Surveillance Epidemiology and End Results program provide the resource for this data registry. The authors included diagnosis years 2006 to 2014. They used the codes per the International Coding of Diseases for Oncology, 3rd Edition: histology code 9560/0 and site codes C72.0 (spinal cord), C70.1 (spinal meninges), and C72.1 (cauda equina). Rates are per 100,000 persons and are age-adjusted to the 2000 United States standard population. The age-adjusted incidence rates and 95% confidence intervals are calculated by age, sex, race, and ethnicity., Results: There were 6989 spinal schwannoma cases between the years 2006 and 2014. The yearly incidence eminently increased between 2010 and 2014. Total incidence rate was 0.24 (95% CI 0.23-0.24) per 100,000 persons. The peak adjusted incidence rate was seen in patients who ranged in age from 65 to 74 years. Spinal schwannomas were less common in females than they were in males (incidence rate ratio = 0.85; p < 0.001), and they were less common in blacks than they were in whites (IRR = 0.52; p < 0.001) and American Indians/Alaska Natives (IRR = 0.50; p < 0.001) compared to whites. There was no statistically significant difference in incidence rate between whites and Asian or Pacific Islanders (IRR = 0.92; p = 0.16)., Conclusions: The authors' study results demonstrated a steady increase in the incidence of spinal schwannomas between 2010 and 2014. Male sex and the age range 65-74 years were associated with higher incidence rates of spinal schwannomas, whereas black and American Indian/Alaska Native races were associated with lower incidence rates. The present study represents the most thorough assessment of spinal schwannoma epidemiology in the American population.

Stereotactic radiosurgery (SRS) has been used as the primary treatment for vestibular schwannoma (VS) over the last two decades. While literature is available on tumor response following SRS, very long-term follow-ups are not yet available. Malignant transformation of benign VS is very rare. There are only a few cases described in the literature, most of which report malignant transformation occurring between 5-10 years after radiosurgery. Here we report a case of a 65-year-old female, with no family history of neurofibromatosis, who presented with worsening mental status, gait instability and facial weakness. Twelve years prior to her presentation, she was diagnosed with a VS that was treated with stereotactic radiosurgery. The tumor had subsequently been stable on serial interval magnetic resonance imaging. She eventually presented with symptoms related to hydrocephalus and brain stem compression. Histopathologic analysis revealed a malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation. She succumbed to her disease and passed away 10 months after her resection surgery. This case highlights the necessity for lifelong follow-up following SRS and the need to be vigilant when performing SRS in large VS., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: Age is commonly thought to be a risk factor in defining lumbar spinal stenosis (LSS) degenerative or developmental subtypes. This article is a follow-up to a previous article ("Redefining Lumbar Spinal Stenosis as a Developmental Syndrome: An MRI-Based Multivariate Analysis of Findings in 709 Patients Throughout the 16- to 82-Year Age Spectrum") that describes the radiological differences between developmental and degenerative types of LSS. MRI-based analysis of "degeneration" variables and spinal canal morphometric characteristics of LSS segments have been thought to correlate with age at presentation., Methods: The authors performed a re-analysis of data from their previously reported prospective MRI-based study, stratifying data from the 709 cases into 3 age categories of equal size (instead of the original < 60 vs ≥ 60 years). Relative spinal canal dimensions, as well as radiological degenerative variables from L1 to S1, were analyzed across age groups in a multivariate mode. The total degenerative scale score (TDSS) for each lumbar segment from L1 to S1 was calculated for each patient. The relationships between age and qualitative stenosis grades, TDSS, disc degeneration, and facet degeneration were analyzed using Pearson's product-moment correlation and multiple regression., Results: Multivariate analysis of TDSS and spinal canal dimensions revealed highly significant differences across the 3 age groups at L2-3 and L3-4 and a weaker, but still significant, association with changes at L5-S1. Age helped to explain only 9.6% and 12.2% of the variance in TDSS at L1-2 and L2-3, respectively, with a moderate positive correlation, and 7.8%, 1.2%, and 1.9% of the variance in TDSS at L3-4, L4-5, and L5-S1, respectively, with weak positive correlation. Age explained 24%, 26%, and 18.4% of the variance in lumbar intervertebral disc (LID) degeneration at L1-2, L2-3, and L3-4, respectively, while it explained only 6.2% and 7.2% of the variance of LID degeneration at L4-5 and L5-S1, respectively. Age explained only 2.5%, 4.0%, 1.2%, 0.8%, and 0.8% of the variance in facet degeneration at L1-2, L2-3, L3-4, L4-5, and L5-S1, respectively., Conclusions: Age at presentation correlated weakly with degeneration variables and spinal canal morphometries in LSS segments. Age correlated with upper lumbar segment (L1-4) degeneration more than with lower segment (L4-S1) degeneration. The actual chronological age of the patients did not significantly correlate with the extent of degenerative pathology of the lumbar stenosis segments. These study results lend support for a developmental contribution to LSS.

Introduction: Central neurocytoma (CN) and extraventricular neurocytoma (EVN) are rare intracranial tumors. There is a paucity of studies reporting the population-based incidence of these tumors. We used the Central Brain Tumor Registry of the United States (CBTRUS), which contains the largest aggregation of population-based data on the incidence of primary central nervous system tumors in the United States to describe these tumors., Methods: The CBTRUS database, provided by CDC representing approximately 100% of the US population, was queried using the following search criteria: diagnosis years 2006-2014, ICD-0-3 histology codes (9506/0: central neurocytoma, benign; 9506/1: central neurocytoma, uncertain). Annual age-adjusted incidence rates are presented per 100,000 population. Incidence was estimated by age, gender, race, and ethnicity., Results: The combined overall annual incidence rate of CN and EVN was 0.032 [0.030-0.034]. The incidence rates were 0.022 [0.021-0.024] and 0.009 [0.008-0.010] for CN and EVN, respectively. The most frequently documented locations for EVN were frontal lobe and cerebellum, followed by temporal lobe. Peak incidence was found in the 20-34 years range for both CN and EVN. The incidence rate was slightly lower in males compared to females for CN and identical for EVN. The overall incidence rate of CN and EVN combined was lower in Blacks 0.026 [0.021-0.032] and Hispanic Whites 0.020 [0.016-0.025] compared to Non-Hispanic Whites 0.035 [0.033-0.038]., Conclusion: CN and EVN are rare tumors with a peak incidence in the 20-34 years age group. This study represents the largest population-based epidemiological study on CN and EVN in the US.

The Cleveland Clinic was established in 1921 under the direction of 4 experienced and iconic physicians: George Crile, Frank Bunts, William Lower, and John Phillips. The Clinic initially employed a staff of only 6 surgeons, 4 internists, 1 radiologist, and 1 biophysicist, but Crile was quick to realize the need for broadening its scope of practice. He asked his close friend, Harvey Cushing, for assistance in finding a suitable candidate to establish a department of neurosurgery at the Cleveland Clinic. With his full endorsement, Cushing recommended Dr. Charles Edward Locke Jr., a former student and burgeoning star in the field of neurosurgery. Unfortunately, Locke's life and career both ended prematurely in the Cleveland Clinic fire of 1929, but not before he would leave a lasting legacy, both at the Cleveland Clinic and in the field of neurosurgery.

Background  T1-weighted magnetic resonance imaging (MRI) remains the standard pituitary imaging sequence. However, up to 50% of pituitary adenomas are missed with standard imaging in Cushing's disease (CD) patients. Utility of other imaging sequences needs be explored. Objective  To compare a T2-gradient echo sequence, constructive interference in steady state (CISS), with a contrast-enhanced (CE) T1-weighted sequence, volume-interpolated breath-hold examination (VIBE), in the detection of pituitary adenomas in CD patients. Design  Retrospective analysis of CD patients who underwent endoscopic transsphenoidal pituitary adenomectomy at our institution. Patients and Measurement  Twelve patients were included in the study. Two neuroradiologists, who were blinded to the patients' clinical and surgical findings, independently reviewed the CE-VIBE and CISS images. Localization of pituitary adenoma from imaging was compared with intraoperative localization. Results  The averaged sensitivity of detecting pituitary adenoma in CD patients was not significantly different between CE-VIBE sequence (63%) and CISS sequence (54%). The positive predictive value was 75% (Observer A) and 100% (Observer B) with CE-VIBE sequence, and 64% (Observer A) and 100% (Observer B) with CISS sequence. In two patients, pituitary adenoma was easily localized with CISS sequence but hard to detect with CE-VIBE sequence. In two other patients, the adenoma was much better delineated on CE-VIBE sequence. Conclusion  In our series, the addition of CISS sequence to T1-weighted MRI imaging protocols improved the detection of pituitary adenomas in CD patients. CISS sequence may be a useful adjunct to T1-weighted pituitary MRI protocols and an appropriate alternative for patients with gadolinium contraindications.

Objective: Gastrostomy tube placement can temporarily seed the peritoneal cavity with bacteria and thus theoretically increases the risk of shunt infection when the two procedures are performed contemporaneously. The authors hypothesized that gastrostomy tube placement would not increase the risk of ventriculoperitoneal shunt infection. The object of this study was to test this hypothesis by utilizing a large patient cohort combined from multiple institutions., Methods: A retrospective study of all adult patients admitted to five institutions with a diagnosis of aneurysmal subarachnoid hemorrhage between January 2005 and January 2015 was performed. The primary outcome of interest was ventriculoperitoneal shunt infection. Variables, including gastrostomy tube placement, were tested for their association with this outcome. Standard statistical methods were utilized., Results: The overall cohort consisted of 432 patients, 47% of whom had undergone placement of a gastrostomy tube. The overall shunt infection rate was 9%. The only variable that predicted shunt infection was gastrostomy tube placement (p = 0.03, OR 2.09, 95% CI 1.07-4.08), which remained significant in the multivariate analysis (p = 0.04, OR 2.03, 95% CI 1.04-3.97). The greatest proportion of shunts that became infected had been placed more than 2 weeks (25%) and 1-2 weeks (18%) prior to gastrostomy tube placement, but the temporal relationship between shunt and gastrostomy was not a significant predictor of shunt infection., Conclusions: Gastrostomy tube placement significantly increases the risk of ventriculoperitoneal shunt infection.

OBJECTIVE Stereotactic radiosurgery (SRS) is the primary modality for treating brain metastases. However, effective radiosurgical control of brain metastases ≥ 2 cm in maximum diameter remains challenging and is associated with suboptimal local control (LC) rates of 37%-62% and an increased risk of treatment-related toxicity. To enhance LC while limiting adverse effects (AEs) of radiation in these patients, a dose-dense treatment regimen using 2-staged SRS (2-SSRS) was used. The objective of this study was to evaluate the efficacy and toxicity of this treatment strategy. METHODS Fifty-four patients (with 63 brain metastases ≥ 2 cm) treated with 2-SSRS were evaluated as part of an institutional review board-approved retrospective review. Volumetric measurements at first-stage stereotactic radiosurgery (first SSRS) and second-stage SRS (second SSRS) treatments and on follow-up imaging studies were determined. In addition to patient demographic data and tumor characteristics, the study evaluated 3 primary outcomes: 1) response at first follow-up MRI, 2) time to local progression (TTP), and 3) overall survival (OS) with 2-SSRS. Response was analyzed using methods for binary data, TTP was analyzed using competing-risks methods to account for patients who died without disease progression, and OS was analyzed using conventional time-to-event methods. When needed, analyses accounted for multiple lesions in the same patient. RESULTS Among 54 patients, 46 (85%) had 1 brain metastasis treated with 2-SSRS, 7 patients (13%) had 2 brain metastases concurrently treated with 2-SSRS, and 1 patient underwent 2-SSRS for 3 concurrent brain metastases ≥ 2 cm. The median age was 63 years (range 23-83 years), 23 patients (43%) had non-small cell lung cancer, and 14 patients (26%) had radioresistant tumors (renal or melanoma). The median doses at first and second SSRS were 15 Gy (range 12-18 Gy) and 15 Gy (range 12-15 Gy), respectively. The median duration between stages was 34 days, and median tumor volumes at the first and second SSRS were 10.5 cm 3 (range 2.4-31.3 cm 3 ) and 7.0 cm 3 (range 1.0-29.7 cm 3 ). Three-month follow-up imaging results were available for 43 lesions; the median volume was 4.0 cm 3 (range 0.1-23.1 cm 3 ). The median change in volume compared with baseline was a decrease of 54.9% (range -98.2% to 66.1%; p < 0.001). Overall, 9 lesions (14.3%) demonstrated local progression, with a median of 5.2 months (range 1.3-7.4 months), and 7 (11.1%) demonstrated AEs (6.4% Grade 1 and 2 toxicity; 4.8% Grade 3). The estimated cumulative incidence of local progression at 6 months was 12% ± 4%, corresponding to an LC rate of 88%. Shorter TTP was associated with greater tumor volume at baseline (p = 0.01) and smaller absolute (p = 0.006) and relative (p = 0.05) decreases in tumor volume from baseline to second SSRS. Estimated OS rates at 6 and 12 months were 65% ± 7% and 49% ± 8%, respectively. CONCLUSIONS 2-SSRS is an effective treatment modality that resulted in significant reduction of brain metastases ≥ 2 cm, with excellent 3-month (95%) and 6-month (88%) LC rates and an overall AE rate of 11%. Prospective studies with larger cohorts and longer follow-up are necessary to assess the durability and toxicities of 2-SSRS.

Pyogenic ventriculitis is a rare but severe post-neurosurgical complication. The infection is often resistant to antibiotic treatment alone. Continuous intraventricular irrigation has been suggested but the technique is cumbersome, increases the risk for secondary infection, and is inadequate in removing adherent purulence. We used a novel neuroendoscopic approach assisted with a side-cutting aspiration device to treat four cases of post-neurosurgical pyogenic ventriculitis. Ventricular empyema was cleared in all patients and three of the four patients had favorable outcomes., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Carotid-cavernous fistula was one of the first intracranial vascular lesions to be recognized. This paper focuses on the historical progression of our understanding of the condition and its symptomatology-from the initial hypothesis of ophthalmic artery aneurysm as the cause of pulsating exophthalmos to the recognition and acceptance of fistulas between the carotid arterial system and cavernous sinus as the true etiology. The authors also discuss the advancements in treatment from Benjamin Travers' early common carotid ligation and wooden compression methods to today's endovascular approaches.

Stereotactic radiosurgery (SRS) has emerged as a treatment option for patients with spinal metastatic disease. Although SRS has been shown to be successful in a multitude of extradural metastatic tumors causing cord compression, very few cases of intradural treatment have been reported. The authors present a rare case of an intradural extramedullary metastatic small cell lung cancer lesion to the cervical spine resulting in cord compression in an area that had also been extensively pretreated with conventional external-beam radiation therapy. The patient underwent successful SRS to this metastatic site, with rapid and complete resolution of his lesion.

Background: Minimally-invasive approaches are attractive alternative to standard craniotomy for large intracranial tumors with potentially lesser morbidity. In this report, we describe a sequential combination of two minimally-invasive surgical techniques to treat a large intracranial tumor., Clinical Presentation: A 49year-old woman presented with a history of breast cancer and large left parietal metastasis with significant perilesional edema. This was initially managed by whole brain radiation therapy and stereotactic radiosurgery. The patient underwent laser ablation of the tumor followed by internal tumor debulking using an exoscopic-assisted tubular retractor system. Post-operative MRI showed gross total coverage of the tumor by laser ablation and alleviation of mass effect. The patient recovered well and discharged on second postoperative day., Conclusion: The minimally-invasive combination of laser ablation followed by internal debulking using a tubular retractor device could be done safely and effectively as a minimally invasive alternative to standard craniotomy for large intracranial tumors., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

OBJECTIVE Laser interstitial thermal therapy (LITT) has been increasingly used to treat deep-seated tumors. Despite its being minimally invasive, there is a risk of LITT damaging adjacent critical structures, including corticospinal tracts (CSTs). In this study, the authors investigated the predictive value of overlap between the hyperthermic field and CSTs in determining postoperative motor deficit (PMDs). METHODS More than 140 patients underwent an LITT procedure in our institution between April 2011 and June 2015. Because of the tumor's proximity to critical structures, 80 of them underwent preoperative diffusion tensor imaging and were included in this study. Extent of the hyperthermic field was delineated by the software as thermal-damage-threshold (TDT) lines (yellow [43°C for 2 minutes], blue [43°C for 10 minutes], and white [43°C for 60 minutes]). The maximum volume and the surface area of overlaps between motor fibers and the TDT lines were calculated and compared with the PMDs. RESULTS High-grade glioma (n = 46) was the most common indication for LITT. Postoperative motor deficits (partial or complete) were seen in 14 patients (11 with permanent and 3 with temporary PMDs). The median overlap volumes between CSTs with yellow, blue, and white TDT lines in patients with any PMD (temporary or permanent) were 1.15, 0.68, and 0.41 cm 3 , respectively. The overlap volumes and surface areas revealed significant differences in those with PMDs and those with no deficits (p = 0.0019 and 0.003, 0.012 and 0.0012, and 0.001 and 0.005 for the yellow, blue, and white TDT lines, respectively). The receiver operating characteristic was used to select the optimal cutoff point of the overlapped volumes and areas. Cutoff points for overlap volumes and areas based on optimal sensitivity (92%-100%) and specificity (80%-90%) were 0.103, 0.068, and 0.046 cm 3 and 0.15, 0.07, and 0.11 mm 2 for the yellow, blue, and white TDT lines, respectively. CONCLUSIONS Even a minimal overlap between the TDT lines and CSTs can cause a PMD after LITT. Precise planning and avoidance of critical structures and important white matter fibers should be considered when treating deep-seated tumors.

Purpose: Cerebrospinal fluid shunt infection is associated with patient morbidity and high cost. We conducted a systematic review of the current evidence of comprehensive surgical protocols or individual interventions designed to reduce shunt infection incidence., Methods: A systematic review using PubMed and SCOPUS identified studies evaluating the effect of a particular intervention on shunt infection risk. Systemic prophylactic antibiotic or antibiotic-impregnated shunt efficacy studies were excluded. A total of 7429 articles were screened and 23 articles were included., Results: Eight studies evaluated the effect of comprehensive surgical protocols. Shunt infection was reduced in all studies (absolute risk reduction 2.2-12.3 %). Level of evidence was low (level 4 in seven studies) due to the use of historical controls. Compliance ranged from 24.6 to 74.5 %. Surgical scrub with antiseptic foam and omission of a 5 % chlorhexidine gluconate preoperative hair wash were both associated with increased shunt infection. Twelve studies evaluated the effect of a single intervention. Only antibiotic-impregnated suture, a no-shave policy, and double gloving with glove change prior to shunt handling, were associated with a significant reduction in shunt infection. In a hospital with high methicillin-resistant staphylococcus aureus (MRSA) prevalence, a randomized controlled trial found that perioperative vancomycin rather than cefazolin significantly reduced shunt infection rates., Conclusion: Despite wide variation in compliance rates, the implementation of comprehensive surgical protocols reduced shunt infection in all published studies. Antibiotic-impregnated suture, a no-shave policy, double gloving with glove change prior to device manipulation, and 5 % chlorhexidine hair wash were associated with significant reductions in shunt infection.

Somatic hypermutation (SHM) of antibody variable region genes is initiated in germinal center B cells during an immune response by activation-induced cytidine deaminase (AID), which converts cytosines to uracils. During accurate repair in nonmutating cells, uracil is excised by uracil DNA glycosylase (UNG), leaving abasic sites that are incised by AP endonuclease (APE) to create single-strand breaks, and the correct nucleotide is reinserted by DNA polymerase β. During SHM, for unknown reasons, repair is error prone. There are two APE homologs in mammals and, surprisingly, APE1, in contrast to its high expression in both resting and in vitro-activated splenic B cells, is expressed at very low levels in mouse germinal center B cells where SHM occurs, and APE1 haploinsufficiency has very little effect on SHM. In contrast, the less efficient homolog, APE2, is highly expressed and contributes not only to the frequency of mutations, but also to the generation of mutations at A:T base pair (bp), insertions, and deletions. In the absence of both UNG and APE2, mutations at A:T bp are dramatically reduced. Single-strand breaks generated by APE2 could provide entry points for exonuclease recruited by the mismatch repair proteins Msh2-Msh6, and the known association of APE2 with proliferating cell nuclear antigen could recruit translesion polymerases to create mutations at AID-induced lesions and also at A:T bp. Our data provide new insight into error-prone repair of AID-induced lesions, which we propose is facilitated by down-regulation of APE1 and up-regulation of APE2 expression in germinal center B cells.

The optic nerve has been widely studied for insights into mechanisms that suppress or promote axon regeneration after central nervous system injury. Following optic nerve damage in adult mammals, retinal ganglion cells (RGCs) normally fail to regenerate their axons, resulting in blindness in patients who suffer from neurodegenerative diseases such as glaucoma or who have sustained traumatic injury to the optic nerve. Over the past several decades, many groups have investigated the basis of regenerative failure in the hope of developing strategies to stimulate the regrowth of axons and restore visual function. New findings show that a combination of therapies that act synergistically to activate RGCs' intrinsic growth state enables these cells to regenerate their axons the full length of the optic nerve, across the optic chiasm, and into the brain, where they establish synapses in appropriate target zones and restore limited visual responses. These treatments involve the induction of a limited inflammatory response in the eye to increase levels of oncomodulin and other growth factors; elevation of intracellular cAMP; and deletion of the pten gene in RGCs. Although these methods cannot be applied in the clinic, they point to strategies that might be., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Introduction: Overuse of antibiotics has contributed to the development of organism resistance. The acquisition of antibiotics without prescription by the general population seems to be common practice in pharmacies of Damascus, Syria. This study aimed to determine the proportion of pharmacies dispensing antibiotics without medical prescription and without seeing the patient., Methodology: A cross-sectional study involving a sample of 224 pharmacies was conducted in Damascus. To obtain antibiotics without medical prescription, the investigators posed as individuals who had a sister with symptoms of sinusitis., Results: From 200 pharmacies visited, 87% agreed without insistence from the investigator to sell antibiotics without prescription. This figure increased to 97% when the investigators who were at first denied antibiotics insisted on having the antibiotics., Conclusion: Dispensing of antibiotics is high in Damascus despite federal regulations. Health education programs should be directed to pharmacies and also to the population.