Multicenter external validation of prediction models for clinical outcomes after spinal fusion for lumbar degenerative disease.

BACKGROUND: Clinical prediction models (CPM), such as the SCOAP-CERTAIN tool, can be utilized to enhance decision-making for lumbar spinal fusion surgery by providing quantitative estimates of outcomes, aiding surgeons in assessing potential benefits and risks for each individual patient. External validation is crucial in CPM to assess generalizability beyond the initial dataset. This ensures performance in diverse populations, reliability and real-world applicability of the results. Therefore, we externally validated the tool for predictability of improvement in oswestry disability index (ODI), back and leg pain (BP, LP). METHODS: Prospective and retrospective data from multicenter registry was obtained. As outcome measure minimum clinically important change was chosen for ODI with ≥ 15-point and ≥ 2-point reduction for numeric rating scales (NRS) for BP and LP 12 months after lumbar fusion for degenerative disease. We externally validate this tool by calculating discrimination and calibration metrics such as intercept, slope, Brier Score, expected/observed ratio, Hosmer-Lemeshow (HL), AUC, sensitivity and specificity. RESULTS: We included 1115 patients, average age 60.8 ± 12.5 years. For 12-month ODI, area-under-the-curve (AUC) was 0.70, the calibration intercept and slope were 1.01 and 0.84, respectively. For NRS BP, AUC was 0.72, with calibration intercept of 0.97 and slope of 0.87. For NRS LP, AUC was 0.70, with calibration intercept of 0.04 and slope of 0.72. Sensitivity ranged from 0.63 to 0.96, while specificity ranged from 0.15 to 0.68. Lack of fit was found for all three models based on HL testing. CONCLUSIONS: Utilizing data from a multinational registry, we externally validate the SCOAP-CERTAIN prediction tool. The model demonstrated fair discrimination and calibration of predicted probabilities, necessitating caution in applying it in clinical practice. We suggest that future CPMs focus on predicting longer-term prognosis for this patient population, emphasizing the significance of robust calibration and thorough reporting.

Role of Leptin in Obesity, Cardiovascular Disease, and Type 2 Diabetes.

Diabetes mellitus (DM) is a highly prevalent disease worldwide, estimated to affect 1 in every 11 adults; among them, 90-95% of cases are type 2 diabetes mellitus. This is partly attributed to the surge in the prevalence of obesity, which has reached epidemic proportions since 2008. In these patients, cardiovascular (CV) risk stands as the primary cause of morbidity and mortality, placing a substantial burden on healthcare systems due to the potential for macrovascular and microvascular complications. In this context, leptin, an adipocyte-derived hormone, plays a fundamental role. This hormone is essential for regulating the cellular metabolism and energy balance, controlling inflammatory responses, and maintaining CV system homeostasis. Thus, leptin resistance not only contributes to weight gain but may also lead to increased cardiac inflammation, greater fibrosis, hypertension, and impairment of the cardiac metabolism. Understanding the relationship between leptin resistance and CV risk in obese individuals with type 2 DM (T2DM) could improve the management and prevention of this complication. Therefore, in this narrative review, we will discuss the evidence linking leptin with the presence, severity, and/or prognosis of obesity and T2DM regarding CV disease, aiming to shed light on the potential implications for better management and preventive strategies.

Quantitative, Spectro-kinetic Analysis of Oxygen in Electron-Beam Sensitive, Multimetallic Oxide Nanostructures.

The oxygen stoichiometry of hollandite, KxMnO2-δ, nanorods has been accurately determined from a quantitative analysis of scanning-transmission electron microscopy (STEM) X-Ray Energy Dispersive Spectroscopy (XEDS) experiments carried out in chrono-spectroscopy mode. A methodology combining 3D reconstructions of high-angle annular dark field electron tomography experiments, using compressed-sensing algorithms, and quantification through the so-called ζ-factors method of XEDS spectra recorded on a high-sensitivity detector has been devised to determine the time evolution of the oxygen content of nanostructures of electron-beam sensitive oxides. Kinetic modeling of O-stoichiometry data provided K0.13MnO1.98 as overall composition for nanorods of the hollandite. The quantitative agreement, within a 1% mol error, observed with results obtained by macroscopic techniques (temperature-programmed reduction and neutron diffraction) validate the proposed methodology for the quantitative analysis, at the nanoscale, of light elements, as it is the case of oxygen, in the presence of heavy ones (K, Mn) in the highly compromised case of nanostructured materials which are prone to electron-beam reduction. Moreover, quantitative comparison of oxygen evolution data measured at macroscopic and nanoscopic levels allowed us to rationalize beam damage effects in structural terms and clarify the exact nature of the different steps involved in the reduction of these oxides with hydrogen.

FUSE-ML: development and external validation of a clinical prediction model for mid-term outcomes after lumbar spinal fusion for degenerative disease.

BACKGROUND: Indications and outcomes in lumbar spinal fusion for degenerative disease are notoriously heterogenous. Selected subsets of patients show remarkable benefit. However, their objective identification is often difficult. Decision-making may be improved with reliable prediction of long-term outcomes for each individual patient, improving patient selection and avoiding ineffective procedures. METHODS: Clinical prediction models for long-term functional impairment [Oswestry Disability Index (ODI) or Core Outcome Measures Index (COMI)], back pain, and leg pain after lumbar fusion for degenerative disease were developed. Achievement of the minimum clinically important difference at 12 months postoperatively was defined as a reduction from baseline of at least 15 points for ODI, 2.2 points for COMI, or 2 points for pain severity. RESULTS: Models were developed and integrated into a web-app ( https://neurosurgery.shinyapps.io/fuseml/ ) based on a multinational cohort [N = 817; 42.7% male; mean (SD) age: 61.19 (12.36) years]. At external validation [N = 298; 35.6% male; mean (SD) age: 59.73 (12.64) years], areas under the curves for functional impairment [0.67, 95% confidence interval (CI): 0.59-0.74], back pain (0.72, 95%CI: 0.64-0.79), and leg pain (0.64, 95%CI: 0.54-0.73) demonstrated moderate ability to identify patients who are likely to benefit from surgery. Models demonstrated fair calibration of the predicted probabilities. CONCLUSIONS: Outcomes after lumbar spinal fusion for degenerative disease remain difficult to predict. Although assistive clinical prediction models can help in quantifying potential benefits of surgery and the externally validated FUSE-ML tool may aid in individualized risk-benefit estimation, truly impacting clinical practice in the era of "personalized medicine" necessitates more robust tools in this patient population.

Determinants of felt demand for dengue vaccines in the North Caribbean region of Colombia.

BACKGROUND: The increasing burden associated with dengue in Latin America makes it essential to understand the community's interest in acquiring vaccines, as an input to plan its introduction in endemic regions. The objective of this study is to learn the felt demand for dengue vaccines by estimating the willingness to pay and its associated factors in endemic communities of the North Caribbean region of Colombia. METHODS: A population survey was administered from October to December 2015, including 1037 families in 11 municipalities in Colombia. One adult per family was interviewed on their perception and history of dengue. Participants received a description of four hypothetical scenarios of dengue vaccines, administered in a single dose or in 3 doses, with an effectiveness of 70% for 5 years or 95% for 30 years. The willingness to pay for each one of these vaccines was inquired vs. 5 hypothetical prices in Colombian pesos. RESULTS: Most participants recognized dengue as a serious disease in children (99.3%) and adults (98.6%). 33 (3.2%) of the total respondents reported having suffered dengue and 19 (57.6%) of them required hospitalization. The price of the vaccine was inversely related to the willingness to pay. In addition, single dose vaccines (compared to 3 doses) and one with a protection of 95% for 30 years (compared to an effectiveness of 70% for 5 years), were associated with greater willingness to pay. Greater willingness to pay was observed among the respondents who considered it likely to get the disease, either themselves (OR 1.56; CI 95% 1.08-2.26) or their children (OR 1.89; CI 95% 1.28-2.81), in the next 5 years. The participants who have been diagnosed with dengue also showed greater willingness to pay (OR 1.89; CI 95% 1.01-3.54) compared to those who did not have this history. CONCLUSION: Factors such as price, number of doses and effectiveness can independently influence the decision to purchase a vaccine against an endemic disease, such as dengue. Additionally, this study reveals that background and perceptions of the disease can affect individuals' interest in acquiring this type of preventive interventions.

Air traffic controllers' long-term speech-in-noise training effects: A control group study.

INTRODUCTION: Speech perception in noise relies on the capacity of the auditory system to process complex sounds using sensory and cognitive skills. The possibility that these can be trained during adulthood is of special interest in auditory disorders, where speech in noise perception becomes compromised. Air traffic controllers (ATC) are constantly exposed to radio communication, a situation that seems to produce auditory learning. The objective of this study has been to quantify this effect. SUBJECTS AND METHODS: 19 ATC and 19 normal hearing individuals underwent a speech in noise test with three signal to noise ratios: 5, 0 and -5 dB. Noise and speech were presented through two different loudspeakers in azimuth position. Speech tokes were presented at 65 dB SPL, while white noise files were at 60, 65 and 70 dB respectively. RESULTS: Air traffic controllers outperform the control group in all conditions [P<0.05 in ANOVA and Mann-Whitney U tests]. Group differences were largest in the most difficult condition, SNR=-5 dB. However, no correlation between experience and performance were found for any of the conditions tested. The reason might be that ceiling performance is achieved much faster than the minimum experience time recorded, 5 years, although intrinsic cognitive abilities cannot be disregarded. DISCUSSION: ATC demonstrated enhanced ability to hear speech in challenging listening environments. This study provides evidence that long-term auditory training is indeed useful in achieving better speech-in-noise understanding even in adverse conditions, although good cognitive qualities are likely to be a basic requirement for this training to be effective. CONCLUSION: Our results show that ATC outperform the control group in all conditions. Thus, this study provides evidence that long-term auditory training is indeed useful in achieving better speech-in-noise understanding even in adverse conditions.

uORF, a regulatory mechanism of the Arabidopsis polyamine oxidase 2.

The translational efficiency of an mRNA can be modulated by elements located in the 5'-untranslated region. The flavin-containing polyamine oxidases catabolize oxidative deamination of spermidine and spermine, thus contributing to polyamine homeostasis as well as diverse biological processes through their reaction products. In this study, we characterized the uORF of AtPAO2 gene using the GUS reporter gene. Transgenic lines harboring the native AtPAO2 promoter or the constitutive CaMV 35S promoter show that the uORF negatively affects GUS expression. Exogenous applications of PAs positively modulate GUS expression, thus alleviating the negative effect of AtPAO2 uORF, while treatments with MGBG inhibitor show an opposite effect. Our data suggest that AtPAO2 uORF regulatory mechanism is modulated by polyamines. In addition, we present a comparative in silico study of the uORFs identified in several plant transcripts encoding polyamine oxidases in both mono- and dicotyledonous plants as well as in the Bryophyte Physcomitrella patens. The polyamine oxidase uORF-encoded peptides are conserved among families and share conserved features such as their position, length, and amino acid sequence. Our findings provide new insights into the regulatory mechanism of polyamine oxidase genes and encourage further exploration to assess the biological significance of uORFs in the polyamine catabolic pathway.

Can AI pass the written European Board Examination in Neurological Surgery? - Ethical and practical issues.

Introduction: Artificial intelligence (AI) based large language models (LLM) contain enormous potential in education and training. Recent publications demonstrated that they are able to outperform participants in written medical exams. Research question: We aimed to explore the accuracy of AI in the written part of the EANS board exam. Material and methods: Eighty-six representative single best answer (SBA) questions, included at least ten times in prior EANS board exams, were selected by the current EANS board exam committee. The questions' content was classified as 75 text-based (TB) and 11 image-based (IB) and their structure as 50 interpretation-weighted, 30 theory-based and 6 true-or-false. Questions were tested with Chat GPT 3.5, Bing and Bard. The AI and participant results were statistically analyzed through ANOVA tests with Stata SE 15 (StataCorp, College Station, TX). P-values of <0.05 were considered as statistically significant. Results: The Bard LLM achieved the highest accuracy with 62% correct questions overall and 69% excluding IB, outperforming human exam participants 59% (p = 0.67) and 59% (p = 0.42), respectively. All LLMs scored highest in theory-based questions, excluding IB questions (Chat-GPT: 79%; Bing: 83%; Bard: 86%) and significantly better than the human exam participants (60%; p = 0.03). AI could not answer any IB question correctly. Discussion and conclusion: AI passed the written EANS board exam based on representative SBA questions and achieved results close to or even better than the human exam participants. Our results raise several ethical and practical implications, which may impact the current concept for the written EANS board exam.

The prevalence of imposter syndrome among neurosurgeons in Europe: An EANS YNC survey.

Introduction: Imposter syndrome (IS), characterized by persistent doubts about one's abilities and fear of exposure as a fraud, is a prevalent psychological condition, particularly impacting physicians. In neurosurgery, known for its competitiveness and demands, the prevalence of IS remains high. Research question: Recognizing the limited literature on IS within the neurosurgical community, this European survey aimed to determine its prevalence among young neurosurgeons and identify associated factors. Material and methods: The survey, conducted by the Young Neurosurgeon Committee of the European Association of Neurosurgical Societies, gathered responses from 232 participants. The survey included demographics, the Clance Imposter Phenomenon Survey (CIPS), and an analysis of potential compensatory mechanisms. Results: Nearly 94% of respondents exhibited signs of IS, with the majority experiencing moderate (36.21%) or frequent (40.52%) symptoms. Analyses revealed associations between IS and factors such as level of experience, sex, and board-certification. Discussion and conclusion: The findings suggest a significant prevalence of IS among young neurosurgeons, with notable associations with sex and level of experience. Compensatory mechanisms, such as working hours, article reading, and participation in events, did not show significant correlations with IS. Notably, male sex emerged as an independent protective factor against frequent/intense IS, while reading more than five articles per week was identified as a risk factor. The identification of protective and risk factors, particularly the influence of gender and reading habits, contributes valuable insights for developing targeted interventions to mitigate IS and improve the well-being of neurosurgeons.

Glanzmann's thrombasthenia associated with gastrointestinal angiodysplasias successfully treated with bevacizumab.

Glanzmann's Thrombasthenia (GT) is a rare hemorrhagic condition caused by a platelet surface receptor disorder of the glycoprotein (GP) IIb/IIIa. Symptoms of GT are various forms of hemorrhages, such as purpura, epistaxis and menorrhagia. Gastrointestinal bleeding (GIB) is a rare expression of the condition and may occur due to traumas in the GI tract or as a consequence of gastrointestinal angiodysplasia (GIADs). In this case report, we present a middle-aged woman with recurrent GIB consequent to GIADs with persistent melena and iron deficiency anemia. After several unsuccessful therapeutic interventions, the patient was studied by the hereditary hemorrhagic telangiectasia's (HHT - Osler-Weber-Rendu disease) unit, where she received bevacizumab, showing a complete improvement in symptoms as well as a reduction in her GIADs. This case shows that bevacizumab could be a possible line of treatment for patients with coagulation disorders with GIADs.

The use of advanced technology for preoperative planning in cranial surgery - A survey by the EANS Young Neurosurgeons Committee.

Introduction: Technological advancements provided several preoperative tools allowing for precise preoperative planning in cranial neurosurgery, aiming to increase the efficacy and safety of surgery. However, little data are available regarding if and how young neurosurgeons are trained in using such technologies, how often they use them in clinical practice, and how valuable they consider these technologies. Research question: How frequently these technologies are used during training and clinical practice as well as to how their perceived value can be qualitatively assessed. Materials and methods: The Young Neurosurgeons' Committee (YNC) of the European Association of Neurosurgical Societies (EANS) distributed a 14-items survey among young neurosurgeons between June 1st and August 31st, 2022. Results: A total of 441 responses were collected. Most responders (42.34%) received "formal" training during their residency. Planning techniques were used mainly in neuro-oncology (90.86%), and 3D visualization of patients' DICOM dataset using open-source software was the most frequently used (>20 times/month, 20.34% of responders). Software for 3D visualization of patients' DICOM dataset was the most valuable technology, especially for planning surgical approach (42.03%). Conversely, simulation based on augmented/mixed/virtual reality was considered the less valuable tool, being rated below sufficiency by 39.7% of responders. Discussion and conclusion: Training for using preoperative planning technologies in cranial neurosurgery is provided by neurosurgical residency programs. Software for 3D visualization of DICOM datasets is the most valuable and used tool, especially in neuro-oncology. Interestingly, simulation tools based on augmented/virtual/mixed reality are considered less valuable and, therefore, less used than other technologies.

Needs, Roles, and Challenges of Young Latin American and Caribbean Neurosurgeons.

BACKGROUND: Barriers to neurosurgery training and practice in Latin American and Caribbean countries (LACs) have been scarcely documented. The World Federation of Neurosurgical Societies Young Neurosurgeons Forum survey sought to identify young neurosurgeons' needs, roles, and challenges. We present the results focused on Latin America and the Caribbean. METHODS: In this cross-sectional study, we analyzed the Young Neurosurgeons Forum survey responses from LACs, following online survey dissemination through personal contacts, social media, and neurosurgical societies' e-mailing lists between April and November 2018. Data analysis was performed using Jamovi version 2.0 and STATA version 16. RESULTS: There were 91 respondents from LACs. Three (3.3%) respondents practiced in high-income countries, 77 (84.6%) in upper middle-income countries, 10 (11%) in lower middle-income countries, and 1 (1.1%) in an unclassified country. The majority (77, or 84.6%) of respondents were male, and 71 (90.2%) were younger than 40. Access to basic imaging modalities was high, with access to computed tomography scan universal among the survey respondents. However, only 25 (27.5%) of respondents reported having access to imaging guidance systems (navigation), and 73 (80.2%) reported having access to high-speed drills. A high GDP per capita was associated with increased availability of high-speed drills and more time dedicated to educational endeavors in neurosurgery, such as didactic teaching and topic presentation (P < 0.05). CONCLUSIONS: This survey found that neurosurgery trainees and practitioners of Latin America and the Caribbean face many barriers to practice. These include inadequate state-of-the-art neurosurgical equipment, a lack of standardized training curricula, few research opportunities, and long working hours.

The thiophene α-terthienylmethanol isolated from Tagetes minuta inhibits angiogenesis by targeting protein kinase C isozymes α and ß2.

Background: Tumor angiogenesis is considered as a crucial pathologic feature of cancer with a key role in multidrug resistance (MDR). Adverse effects of the currently available drugs and the development of resistance to these remain as the hardest obstacles to defeat. Objetive: This work explores flora from Argentina as a source of new chemical entities with antiangiogenic activity. Methods: Tube formation assay using bovine aortic endothelial cells (BAECs) was the experiment of choice to assess antiangiogenic activity. The effect of the pure compound in cell invasiveness was investigated through the trans-well migration assay. The inhibitory effect of the pure compound on VEGFR-2 and PKC isozymes α and ß2 activation was studied by molecular and massive dynamic simulations. Cytotoxicity on peripheral blood mononuclear cells and erythrocyte cells was evaluated by means of MTT and hemolysis assay, respectively. In silico prediction of pharmacological properties (ADME) and evaluation of drug-likeness features were performed using the SwissADME online tool. Results: Among the plants screened, T. minuta, showed an outstanding effect with an IC50 of 33.6 ± 3.4 µg/ml. Bio-guided isolation yielded the terthiophene α-terthienylmethanol as its active metabolite. This compound inhibited VEGF-induced tube formation with an IC50 of 2.7 ± 0.4 µM and significantly impaired the invasiveness of bovine aortic endothelial cells (BAECs) as well as of the highly aggressive breast cancer cells, MDA-MB-231, when tested at 10 µM. Direct VEGFR-2 and PKC inhibition were both explored by means of massive molecular dynamics simulations. The results obtained validated the inhibitory effect on protein kinase C (PKC) isozymes α and ß2 as the main mechanism underlying its antiangiogenic activity. α-terthienylmethanol showed no evidence of toxicity against peripheral blood mononuclear and erythrocyte cells. Conclusion: These findings support this thiophene as a promising antiangiogenic phytochemical to fight against several types of cancer mainly those with MDR phenotype.

Mesenchymal stem cells for critical limb ischemia: their function, mechanism, and therapeutic potential.

Peripheral arterial disease is atherosclerotic occlusive disease of the lower extremity arteries and afflicts hundreds of millions of individuals worldwide. Its most severe manifestation is chronic limb-threatening ischemia (Petersen et al. (Science 300(5622):1140-2, 2003)), which is associated with severe pain at rest in the limbs, which progresses to necrosis, limb amputation, and/or death of the patient. Consequently, the care of these patients is considered a financial burden for both patients and health systems. Multidisciplinary endeavors are required to address this refractory disease and to find definitive solutions that lead to improved living conditions. Revascularization is the cornerstone of therapy for preventing limb amputation, and both open vascular surgery and endovascular therapy play a key role in the treatment of patients with CLI. Around one-third of these patients are not candidates for conventional surgical treatment, however, leading to higher amputation rates (approaching 20-25% at one year) with high morbidity and lower quality of life. Advances in regenerative medicine have enabled the development of cell-based therapies that promote the formation of new blood vessels. Particularly, mesenchymal stem cells (MSCs) have emerged as an attractive therapeutic agent in various diseases, including CLI, due to their role in tissue regeneration and immunomodulation. This review discusses the characteristics of MSCs, as well as their regenerative properties and their action mechanisms on CLI.

Current state of global neurosurgery activity amongst European neurosurgeons.

BACKGROUND: The expanding field of global neurosurgery calls for a committed neurosurgical community to advocate for universal access to timely, safe, and affordable neurosurgical care for everyone, everywhere. This study aims to (i) assess the current state of global neurosurgery activity amongst European neurosurgeons and (ii) identify barriers to involvement in global neurosurgery initiatives. METHODS: Cross-sectional study through dissemination of a web-based survey, from September 2019 to January 2020, to collect data from European neurosurgeons at various career stages. Descriptive analysis was conducted on respondent data. RESULTS: Three hundred and ten neurosurgeons from 40 European countries responded. 53.5% regularly follow global neurosurgery developments. 29.4% had travelled abroad with a global neurosurgery collaborative, with 23.2% planning a future trip. Respondents from high income European countries predominantly travelled to Africa (41.6%) or Asia (34.4%), whereas, respondents from middle income European countries frequently traversed Europe (63.2%) and North America (47.4). Cost implications (66.5%) were the most common barrier to global neurosurgery activity, followed by interference with current practice (45.8%), family duties (35.2%), difficulties obtaining humanitarian leave (27.7%) and lack of international partners (27.4%). 86.8% would incorporate a global neurosurgery period within training programmes. CONCLUSIONS: European neurosurgeons are interested in engaging in global neurosurgery partnerships, and several sustainable programmes focused on local capacity building, education and research have been established over the last decade. However, individual and system barriers to engagement persist. We provide insight into these to allow development of tailored mechanisms to overcome such barriers, enabling European neurosurgeons to advocate for the Global Surgery 2030 goals.

Transformation of neurosurgical training from "see one, do one, teach one" to AR/VR & simulation - A survey by the EANS Young Neurosurgeons.

Introduction: Modern technologies are increasingly applied in neurosurgical resident training. To date, no data are available regarding how frequently these are used in the training of neurosurgeons, and what the perceived value of this technology is. Research question: The aim was to benchmark the objective as well as subjective experience with modern- and conventional training technologies. Material and methods: The EANS Young Neurosurgeons Committee designed a 12-item survey. It was distributed to neurosurgical residents and board-certified neurosurgeons between 6th of February and April 13, 2022. Results: We considered 543 survey responses for analysis. Most participants (67%) indicated not having gained any training experience with modern technology. Most (40.7%) indicated lack of any modern or conventional training technology. Cadaver training was available to 27.6% while all modern training technology to <10%. Participants from countries with high gross domestic product per capita had more access to modern training technologies (p â€‹< â€‹0.001). The perceived value of the different technologies was highest for hands-on OR training, followed by cadaver lab. The value of these was rated higher, compared to all modern technologies (p â€‹< â€‹0.001). Discussion and conclusion: Our survey reveals that cadaver labs are used more frequently than modern technologies for today's neurosurgical training. Hands-on training in the operating room (OR) was rated significantly more valuable than any conventional and modern training technology. Our data hence suggest that while modern technologies are well perceived and can surely add to the training of neurosurgeons, it remains critical to ensure sufficient OR exposure.

Neurosurgical emergency management during the lockdown period in health care regions in Spain with different COVID-19 impact: lessons learned to improve outcomes on the future waves.

BACKGROUND: COVID-19 has overloaded health care systems, testing the capacity and response in every European region. Concerns were raised regarding the impact of resources' reorganization on certain emergency pathology management. The aim of the present study was to assess the impact of the outbreak (in terms of reduction of neurosurgical emergencies) during lockdown in different regions of Spain. METHODS: We analyzed the impact of the outbreak in four different affected regions by descriptive statistics and univariate comparison with same period of two previous years. These regions differed in their incidence level (high/low) and in the time of excess mortality with respect to lockdown declaration. That allowed us to analyze their influence on the characteristics of neurosurgical emergencies registered for every region. RESULTS: 1185 patients from 18 neurosurgical centers were included. Neurosurgical emergencies that underwent surgery dropped 24.41% and 28.15% in 2020 when compared with 2019 and 2018, respectively. A higher reduction was reported for the most affected regions by COVID-19. Non-traumatic spine experienced the most significant decrease in number of cases. Life-threatening conditions did not suffer a reduction in any health care region. CONCLUSIONS: COVID-19 affected dramatically the neurosurgical emergency management. The most significant reduction in neurosurgical emergencies occurred on those regions that were hit unexpectedly by the pandemic, as resources were focused on fighting the virus. As a consequence, life-threating and non-life-threatening conditions' mortality raised. Results in regions who had time to prepare for the hit were congruent with an organized and sensible neurosurgical decision-making.

Technical aspects of core needle biopsy and fine needle aspiration in the diagnosis of bone lesions.

OBJECTIVE: Percutaneous needle biopsy is an effective and safe technique for obtaining diagnostic material from bone lesions. STUDY DESIGN: We describe the technical details of fine needle aspiration and core needle biopsy performed in our laboratory of orthopedic pathology. RESULTS: With these procedures, we obtained accurate diagnosis in 83% of 7,375 cases, sent by different orthopedic centers in our country, over a period of 21 years (1986-2007). CONCLUSION: We describe the percutaneous needle procedure (fine needle aspiration, core needle biopsy), the handling of the materials in detail, the different cytological techniques, as well as the advantages of the procedures and how to avoid its disadvantages. We believe that accurate diagnosis with bone needle biopsy mainly depends on the training of the surgical cytologist and the pathologist, who must integrate all the knowledge on the clinical data, image diagnosis, histological procedures and the experience in the histopathological interpretation of bone lesions.

Normative data of a smartphone app-based 6-minute walking test, test-retest reliability, and content validity with patient-reported outcome measures.

OBJECTIVE: The 6-minute walking test (6WT) is used to determine restrictions in a subject's 6-minute walking distance (6WD) due to lumbar degenerative disc disease. To facilitate simple and convenient patient self-measurement, a free and reliable smartphone app using Global Positioning System coordinates was previously designed. The authors aimed to determine normative values for app-based 6WD measurements. METHODS: The maximum 6WD was determined three times using app-based measurement in a sample of 330 volunteers without previous spine surgery or current spine-related disability, recruited at 8 centers in 5 countries (mean subject age 44.2 years, range 16-91 years; 48.5% male; mean BMI 24.6 kg/m2, range 16.3-40.2 kg/m2; 67.9% working; 14.2% smokers). Subjects provided basic demographic information, including comorbidities and patient-reported outcome measures (PROMs): visual analog scale (VAS) for both low-back and lower-extremity pain, Core Outcome Measures Index (COMI), Zurich Claudication Questionnaire (ZCQ), and subjective walking distance and duration. The authors determined the test-retest reliability across three measurements (intraclass correlation coefficient [ICC], standard error of measurement [SEM], and mean 6WD [95% CI]) stratified for age and sex, and content validity (linear regression coefficients) between 6WD and PROMs. RESULTS: The ICC for repeated app-based 6WD measurements was 0.89 (95% CI 0.87-0.91, p < 0.001) and the SEM was 34 meters. The overall mean 6WD was 585.9 meters (95% CI 574.7-597.0 meters), with significant differences across age categories (p < 0.001). The 6WD was on average about 32 meters less in females (570.5 vs 602.2 meters, p = 0.005). There were linear correlations between average 6WD and VAS back pain, VAS leg pain, COMI Back and COMI subscores of pain intensity and disability, ZCQ symptom severity, ZCQ physical function, and ZCQ pain and neuroischemic symptoms subscores, as well as with subjective walking distance and duration, indicating that subjects with higher pain, higher disability, and lower subjective walking capacity had significantly lower 6WD (all p < 0.001). CONCLUSIONS: This study provides normative data for app-based 6WD measurements in a multicenter sample from 8 institutions and 5 countries. These values can now be used as reference to compare 6WT results and quantify objective functional impairment in patients with degenerative diseases of the spine using z-scores. The authors found a good to excellent test-retest reliability of the 6WT app, a low area of uncertainty, and high content validity of the average 6WD with commonly used PROMs.