Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Vertebral arteriovenous fistula (VAVF) is a rare lesion characterized by an abnormal connection between the extracranial vertebral artery and the surrounding venous plexus. It typically arises due to penetrating injury, although it can occasionally result from blunt trauma. Brachial plexus injury (BPI) is also infrequently associated with VAVF. We present a rare case of VAVF caused by blunt trauma, which resulted in BPI. The patient, who had previously sustained a C2 fracture and C2–3 myelopathy from a bicycle accident, presented with new-onset weakness in the right upper extremity. His previous clinical history led to an initial suspicion of either an exacerbation of a pre-existing lesion or a shoulder injury. However, electromyography indicated that the weakness was due to BPI. Further evaluations later revealed VAVF to be the primary cause of the BPI. VAVF must be recognized as a rare potential reason for BPI, as timely intervention is essential for improving patient recovery and prognosis.

Background: Allograft is predominantly used interbody spacers for anterior cervical discectomy and fusion (ACDF). The corticocancellous allograft has weaker mechanical strength as it is an artificial composite of the cancellous and cortical parts. Additionally, whether utilizing a firmer allograft, such as the cortical ring, leads to better outcomes is unclear. Therefore, we aimed to compare the surgical outcomes of cortical ring and cortico-cancellous allografts in ACDF. Methods: Patients who underwent ACDF using allograft and were followed up for > 1 year were retrospectively reviewed. Patient characteristics, including fusion rates (assessed by interspinous motion [ISM], intra-graft bone bridging, and extra-graft bone bridging), subsidence, allograft complications (e.g., allograft fracture and resorption), and patient-reported outcome measures (neck pain visual analog scale [VAS], arm pain VAS, and neck disability index), were assessed. Patients were divided into 2 groups based on the allograft used: cortical ring and cortico-cancellous allograft groups. Subgroup analysis was subsequently conducted in singleand multi-level operation groups. Results: A total of 227 patients were included. Of them, 134 (59.0%) and 93 (41.0%) underwent ACDF using cortical ring and corticocancellous allograft, respectively. In single-level operations, the cortico-cancellous allograft significantly frequented allograft resorption (24 / 66, 36.4%) than the cortical ring allograft (1 / 28, 3.7%) (p = 0.001). The cortico-cancellous allograft group demonstrated significantly greater subsidence. However, the fusion rates did not significantly differ between the 2 groups. In multi-level operations, the cortico-cancellous allograft (5 / 27, 18.5%) resulted in a significantly higher fracture rate than the cortical ring allograft (5 / 105, 4.7%) (p = 0.030). The fusion rate at 1-year postoperative assessed using ISM (63.2% vs. 55.5%) and intra-graft bone bridging (66.7% vs. 40.7%) was higher in the cortical ring group; however, the difference was not significant. The patient-reported outcomes at 1-year postoperative did not demonstrate significant intergroup differences both in single- and multi-level operations. Conclusions Allograft resorption or fracture occurs more frequently with cortico-cancellous than cortical ring allografts. Despite the frequent occurrence of allograft-related complications with cortico-cancellous allografts, the fusion rate was not significantly affected. Due to the higher rate of allograft resorption or fractures and greater subsidence with cortico-cancellous allografts, cortical ring allografts might yield more stable results in ACDF.

Background: A 24-item early-onset scoliosis questionnaire (EOSQ-24) has been developed as a valid tool for assessing the physical and emotional function of patients with early-onset scoliosis (EOS). Previous studies that conducted transcultural adaptation of the original EOSQ-24 into other languages have demonstrated the high reliability of the questionnaire. However, a Korean version of the EOSQ-24 is not available, limiting optimal patient assessment in this nation. Therefore, this study was conducted to develop and validate a Korean version of EOSQ-24. Methods: The original English version of the EOSQ-24 was cross-culturally adapted following standard guidelines. The final version of the Korean EOSQ-24 was prospectively applied to a group of patients who were native Korean speakers. Internal consistency was evaluated using the Cronbach α coefficient and item-total correlations. The mean, standard deviation, floor effect, and ceiling effect of each item were also assessed. Results: A total of 102 caregivers of patients with EOS (45 males and 57 females) completed the Korean EOSQ-24. The patients’ average age was 6.39 ± 2.16 years. The Cronbach α coefficient for the 24-item scale was 0.942, indicating excellent reliability. The corrected item-total correlation coefficients ranged between 0.449 and 0.788. The mean value of the EOSQ-24 questionnaire was 3.19. Floor and ceiling effects for all questionnaires were below 30%, which could be considered acceptable. Conclusions Our study successfully developed and validated the Korean version of the EOSQ-24, providing a reliable instrument for assessing the physical and emotional well-being of patients with EOS and their caregivers in the Korean context. The widespread adoption of the Korean EOSQ-24 in clinical practice and research settings can enhance the quality of care and improve outcomes for individuals affected by EOS in Korea.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: The positive relationship between triiodothyronine (T3) and steatotic liver disease (SLD) demonstrated only in crosssectional study. We aimed to evaluated whether total T3 (TT3) is associated with the development/resolution of SLD in longitudinal design. Methods: This retrospective, longitudinal, population-based cohort study included 1,665 South Korean euthyroid adults with ≥4 thyroid function test. We explored the impact of mean TT3 during follow-up on development/resolution of either SLD (diagnosed by ultrasound) or modified metabolic dysfunction-associated steatotic liver disease (MASLD) using Cox proportional hazards regression models. Results: During about median 5 years follow-up, 807/1,216 (66.3%) participants among participants without SLD at baseline developed SLD, and 253/318 (79.5%) participants among participants with SLD at baseline SLD resolved fatty liver. Mean TT3 rather than thyroid stimulating hormone or mean free thyroxine was significantly related with development (adjusted hazard ratio [HR], 1.01; 95% confidence interval [CI], 1.00 to 1.02; P=0.002) and resolution (adjusted HR, 0.97; 95% CI, 0.96 to 0.99; P=0.005) of SLD. Compared with low mean TT3 group, high mean TT3 group was positively associated with development of SLD (adjusted HR, 1.20; 95% CI, 1.05 to 1.38; P=0.008) and inversely associated with resolution of SLD (adjusted HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). The statistical significance remained for development (adjusted HR, 1.29; 95% CI, 1.10 to 1.51; P=0.001) and resolution (adjusted HR, 0.71; 95% CI, 0.54 to 0.94; P=0.018) of modified MASLD. Conclusion In Korean euthyroid adults, TT3 level was associated with development and resolution of either SLD or modified MASLD.

Background/Aims: The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H.pylori infection in Korea. Methods: This interim report describes the adherence to the revised guidelines and their impact on firstline eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form. Results: A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed.The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001). Conclusions The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.

Background: and Purpose Previous research on patients with acute ischemic stroke (AIS) has shown a 0.5% incidence of major gastrointestinal bleeding (GIB) requiring blood transfusion during hospitalization. The existing literature has insufficiently explored the long-term incidence in this population despite the decremental impact of GIB on stroke outcomes. Methods: We analyzed the data from a cohort of patients with AIS admitted to 14 hospitals as part of a nationwide multicenter prospective stroke registry between 2011 and 2013. These patients were followed up for up to 6 years. The occurrence of major GIB events, defined as GIB necessitating at least two units of blood transfusion, was tracked using the National Health Insurance Service claims data. Results: Among 10,818 patients with AIS (male, 59%; mean age, 68±13 years), 947 (8.8%) experienced 1,224 episodes of major GIB over a median follow-up duration of 3.1 years. Remarkably, 20% of 947 patients experienced multiple episodes of major GIB. The incidence peaked in the first month after AIS, reaching 19.2 per 100 person-years, and gradually decreased to approximately one-sixth of this rate by the 2nd year with subsequent stabilization. Multivariable analysis identified the following predictors of major GIB: anemia, estimated glomerular filtration rate <60 mL/min/1.73 m2 , and a 3-month modified Rankin Scale score of ≥4. Conclusion Patients with AIS are susceptible to major GIB, particularly in the first month after the onset of AIS, with the risk decreasing thereafter. Implementing preventive strategies may be important, especially for patients with anemia and impaired renal function at stroke onset and those with a disabling stroke.