This report presents the latest statistics on the stroke population in South Korea, sourced from the Clinical Research Collaborations for Stroke in Korea-National Institute for Health (CRCS-K-NIH), a comprehensive, nationwide, multicenter stroke registry. The Korean cohort, unlike western populations, shows a male-to-female ratio of 1.5, attributed to lower risk factors in Korean women. The average ages for men and women are 67 and 73 years, respectively.Hypertension is the most common risk factor (67%), consistent with global trends, but there is a higher prevalence of diabetes (35%) and smoking (21%). The prevalence of atrial fibrillation (19%) is lower than in western populations, suggesting effective prevention strategies in the general population. A high incidence of large artery atherosclerosis (38%) is observed, likely due to prevalent intracranial arterial disease in East Asians and advanced imaging techniques.There has been a decrease in intravenous thrombolysis rates, from 12% in 2017–2019 to 10% in 2021, with no improvements in door-to-needle and door-to-puncture times, worsened by the coronavirus disease 2019 pandemic. While the use of aspirin plus clopidogrel for noncardioembolic stroke and direct oral anticoagulants for atrial fibrillation is well-established, the application of direct oral anticoagulants for non-atrial fibrillation cardioembolic strokes in the acute phase requires further research. The incidence of early neurological deterioration (13%) and the cumulative incidence of recurrent stroke at 3 months (3%) align with global figures. Favorable outcomes at 3 months (63%) are comparable internationally, yet the lack of improvement in dependency at 3 months highlights the need for advancements in acute stroke care.

Background: During the coronavirus disease 2019 (COVID-19) pandemic, there was a shortage of medical resources and the need for proper treatment guidelines for brain tumor patients became more pressing. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, has undertaken efforts to develop a guideline that is tailored to the domestic situation and that can be used in similar crisis situations in the future. As part II of the guideline, this consensus survey is to suggest management options in specific clinical scenarios during the crisis period. Methods: The KSNO Guideline Working Group consisted of 22 multidisciplinary experts on neuro-oncology in Korea. In order to confirm a consensus reached by the experts, opinions on 5 specific clinical scenarios about the management of brain tumor patients during the crisis period were devised and asked. To build-up the consensus process, Delphi method was employed. Results: The summary of the final consensus from each scenario are as follows. For patients with newly diagnosed astrocytoma with isocitrate dehydrogenase (IDH)-mutant and oligodendroglioma with IDH-mutant/1p19q codeleted, observation was preferred for patients with low-risk, World Health Organization (WHO) grade 2, and Karnofsky Performance Scale (KPS) ≥60, while adjuvant radiotherapy alone was preferred for patients with high-risk, WHO grade 2, and KPS ≥60. For newly diagnosed patients with glioblastoma, the most preferred adjuvant treatment strategy after surgery was radiotherapy plus temozolomide except for patients aged ≥70 years with KPS of 60 and unmethylated MGMT promoters. In patients with symptomatic brain metastasis, the preferred treatment differed according to the number of brain metastasis and performance status. For patients with newly diagnosed atypical meningioma, adjuvant radiation was deferred in patients with older age, poor performance status, complete resection, or low mitotic count. Conclusion It is imperative that proper medical care for brain tumor patients be sustained and provided, even during the crisis period. The findings of this consensus survey will be a useful reference in determining appropriate treatment options for brain tumor patients in the specific clinical scenarios covered by the survey during the future crisis.

Background: During the coronavirus disease 2019 (COVID-19) pandemic, the need for appropriate treatment guidelines for patients with brain tumors was indispensable due to the lack and limitations of medical resources. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, has undertaken efforts to develop a guideline that is tailored to the domestic situation and that can be used in similar crisis situations in the future. Methods: The KSNO Guideline Working Group was composed of 22 multidisciplinary experts on neuro-oncology in Korea. In order to reach consensus among the experts, the Delphi method was used to build up the final recommendations. Results: All participating experts completed the series of surveys, and the results of final survey were used to draft the current consensus recommendations. Priority levels of surgery and radiotherapy during crises were proposed using appropriate time window-based criteria for management outcome. The highest priority for surgery is assigned to patients who are life-threatening or have a risk of significant impact on a patient’s prognosis unless immediate intervention is given within 24–48 hours. As for the radiotherapy, patients who are at risk of compromising their overall survival or neurological status within 4–6 weeks are assigned to the highest priority. Curative-intent chemotherapy has the highest priority, followed by neoadjuvant/adjuvant and palliative chemotherapy during a crisis period. Telemedicine should be actively considered as a management tool for brain tumor patients during the mass infection crises such as the COVID-19 pandemic. Conclusion It is crucial that adequate medical care for patients with brain tumors is maintained and provided, even during times of crisis. This guideline will serve as a valuable resource, assisting in the delivery of treatment to brain tumor patients in the event of any future crisis.

Background: In this study, we prepared and evaluated an injectable poloxamer (P407) hydrogel formulation for intratympanic (IT) delivery of dexamethasone (DEX). Methods: DEX-loaded P407 hydrogels were characterized in terms of thermogelation, drug loading capacities, particle size, and drug release. The in vivo toxicity and drug absorption of the DEX-loaded P407 formulation after IT injection were evaluated using an animal model by performing histopathological analysis and drug concentration measurements. Results: The P407 hydrogel effectively solubilized hydrophobic DEX and demonstrated a sustained release compared to the hydrophilic DEX formulation. The in vivo study showed that the hydrogel formulation delivered considerable drug concentrations to the inner ear and displayed a favorable safety profile without apparent cytotoxicity or inflammation. Conclusion P407 hydrogel can be useful as an injectable inner ear delivery formulation for hydrophobic drugs due to their biocompatibility, drug-solubilizing capacity, thermogelation, and controlled release.

Background: and Purpose: The efficacy and safety of GV1001 have been demonstrated in patients with moderate-to-severe Alzheimer’s disease (AD). In this study, we aimed to further demonstrate the effectiveness of GV1001 using subscales of the Severe Impairment Battery (SIB), which is a validated measure to assess cognitive function in patients with moderate-tosevere AD. Methods: We performed a post hoc analysis of data from a 6 month, multicenter, phase 2, randomized, double-blind, placebo-controlled trial with GV1001 (ClinicalTrials.gov, NCT03184467). Patients were randomized to receive either GV1001 or a placebo for 24 weeks. In the current study, nine subscales of SIB—social interaction, memory, orientation, language, attention, praxis, visuospatial ability, construction, and orientation to name— were compared between the treatment (GV1001 1.12 mg) and placebo groups at weeks 12 and 24. The safety endpoints for these patients were also determined based on adverse events. Results: In addition to the considerable beneficial effect of GV1001 on the SIB total score, GV1001 1.12 mg showed the most significant effect on language function at 24 weeks compared to placebo in both the full analysis set (FAS) and per-protocol set (PPS) (p=0.017 and p=0.011, respectively). The rate of adverse events did not differ significantly between the 2 groups. Conclusions Patients with moderate-to-severe AD receiving GV1001 had greater language benefits than those receiving placebo, as measured using the SIB language subscale.

Gastroesophageal reflux disease (GERD) is a condition in which gastric contents regurgitate into the esophagus or beyond, resulting in either troublesome symptoms or complications. GERD is heterogeneous in terms of varied manifestations, test findings, and treatment responsiveness. GERD diagnosis can be established with symptomatology, pathology, or physiology. Recently the Lyon consensus defined the “proven GERD” with concrete evidence for reflux, including advanced grade erosive esophagitis (Los Angeles classification grades C and or D esophagitis), long-segment Barrett’s mucosa or peptic strictures on endoscopy or distal esophageal acid exposure time > 6% on 24-hour ambulatory pH-impedance monitoring. However, some Asian researchers have different opinions on whether the same standards should be applied to the Asian population. The prevalence of GERD is increasing in Asia. The present evidence-based guidelines were developed using a systematic review and meta-analysis approach. In GERD with typical symptoms, a proton pump inhibitor test can be recommended as a sensitive, cost-effective, and practical test for GERD diagnosis. Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

Background: We evaluated the achievement of low-density lipoprotein cholesterol (LDL-C) targets in patients with type 2 diabetes mellitus (T2DM) according to up-to-date Korean Diabetes Association (KDA), European Society of Cardiology (ESC)/European Atherosclerosis Society (EAS), and American Diabetes Association (ADA) guidelines. Methods: This retrospective cohort study collected electronic medical record data from patients with T2DM (≥20 years) managed by endocrinologists from 15 hospitals in Korea (January to December 2019). Patients were categorized according to guidelines to assess LDL-C target achievement. KDA (2019): Very High-I (atherosclerotic cardiovascular disease [ASCVD]) <70 mg/dL; Very High-II (target organ damage [TOD], or cardiovascular risk factors [CVRFs]) <70 mg/dL; high (others) <100 mg/dL. ESC/EAS (2019): Very High-I (ASCVD): <55 mg/dL; Very High-II (TOD or ≥3-CVRF) <55 mg/dL; high (diabetes ≥10 years without TOD plus any CVRF) <70 mg/dL; moderate (diabetes <10 years without CVRF) <100 mg/dL. ADA (2019): Very High-I (ASCVD); Very High-II (age ≥40+ TOD, or any CVRF), for high intensity statin or statin combined with ezetimibe. Results: Among 2,000 T2DM patients (mean age 62.6 years; male 55.9%; mean glycosylated hemoglobin 7.2%) ASCVD prevalence was 24.7%. Of 1,455 (72.8%) patients treated with statins, 73.9% received monotherapy. According to KDA guidelines, LDL-C target achievement rates were 55.2% in Very High-I and 34.9% in Very High-II patients. With ESC/EAS guidelines, target attainment rates were 26.6% in Very High-I, 15.7% in Very High-II, and 25.9% in high risk patients. Based on ADA guidelines, most patients (78.9%) were very-high risk; however, only 15.5% received high-intensity statin or combination therapy. Conclusion According to current dyslipidemia management guidelines, LDL-C goal achievement remains suboptimal in Korean patients with T2DM.

BACKGROUND: The vocal cord tissue consists of three anatomical layers from the surface to deep inside: the epithelium that contains almost no collagen, the lamina propria that is composed of abundant collagen, and the vocalis muscle layer. It is clinically important to visualize the tissue microstructure using a non-invasive method, especially in the case of vocal cord nodules or cancer, since histological changes in each layer of the vocal cord cause changes in the voice. Polarizationsensitive optical coherence tomography (PS-OCT) enables phase retardation measurement to evaluate birefringence of tissue with varied organization of collagen fibers in different tissue layers. Therefore, PS-OCT can visualize structural changes between normal and abnormal vocal cord tissue.METHOD: A rabbit laryngeal tumor model with different stages of tumor progression was investigated ex-vivo by PSOCT. A phase retardation slope-based analysis, which quantifies the birefringence in different layers, was conducted to distinguish the epithelium, lamina propria, and muscle layers. RESULTS: The PS-OCT images showed a gradual decrease in birefringence from normal tissue to advanced tumor tissue.The quantitative analysis provided a more detailed comparison among different stages of the rabbit laryngeal tumor model, which was validated by the corresponding histological findings. CONCLUSION Differences in tissue birefringence was evaluated by PS-OCT phase retardation measurement. It is also possible to indirectly infer the dysplastic changes based on the mucosal and submucosal alterations.

BACKGROUND: Polarization sensitive-optical coherence tomography (PS-OCT) provides the unique advantage of being able to measure the optical characteristics of tissues by using polarized light. Although the well-organized fibers of healthy muscle can change the polarization states of passing light, damaged tissue has different behaviors. There are studies on optical imaging methods applied to the respiratory organs; however, they are restricted to structural imaging. In particular, the intercostal muscle situated under the pleura is very challenging to visualize due to the difficulty of access.METHOD: In this study, PS-OCT was used to identify subpleural cancer in male New Zealand white rabbits (3.2–3.4 kg) and to assess the phase retardation changes in normal and cancerous chest walls. VX2 cell suspension was injected between the intercostal muscle and parietal pleura and a tented area was observed by thoracic scope. A group of rabbits (n = 3) were sacrificed at day 7 after injection and another group (n = 3) at day 14. RESULTS: In the PS-OCT images, pleura thickness changes and muscle damage were criteria to understand the stages of the disease. The results of image and phase retardation analysis matched well with the pathologic examinations. CONCLUSION We were able to visualize and analyze subpleural cancer by PS-OCT, which provided structural and functional information. The measured phase retardation could help to identify the margin of the tumor. For further studies, various approaches into other diseases using polarization light are expected to have positive results.

BACKGROUND: The vocal cord tissue consists of three anatomical layers from the surface to deep inside: the epithelium that contains almost no collagen, the lamina propria that is composed of abundant collagen, and the vocalis muscle layer. It is clinically important to visualize the tissue microstructure using a non-invasive method, especially in the case of vocal cord nodules or cancer, since histological changes in each layer of the vocal cord cause changes in the voice. Polarizationsensitive optical coherence tomography (PS-OCT) enables phase retardation measurement to evaluate birefringence of tissue with varied organization of collagen fibers in different tissue layers. Therefore, PS-OCT can visualize structural changes between normal and abnormal vocal cord tissue.METHOD: A rabbit laryngeal tumor model with different stages of tumor progression was investigated ex-vivo by PSOCT. A phase retardation slope-based analysis, which quantifies the birefringence in different layers, was conducted to distinguish the epithelium, lamina propria, and muscle layers. RESULTS: The PS-OCT images showed a gradual decrease in birefringence from normal tissue to advanced tumor tissue.The quantitative analysis provided a more detailed comparison among different stages of the rabbit laryngeal tumor model, which was validated by the corresponding histological findings. CONCLUSION Differences in tissue birefringence was evaluated by PS-OCT phase retardation measurement. It is also possible to indirectly infer the dysplastic changes based on the mucosal and submucosal alterations.