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The expected growth of stroke burden in Korea in early 2000s led to the initiation of a government-funded clinical research project with the goal of development and implementation of national stroke guidelines. The CRCS-K (Clinical Research Collaboration for Stroke in Korea) began as a part of this project. For stroke epidemiology and quality of care research, the CRCS-K developed a multicenter, prospective, stroke registry and began collection of data in 2008. Now, about 100 000 cases have been registered at 17 university hospitals or regional stroke centers and about 200 articles have been published based on the registry experience. The analysis of the 10-year secular trends showed overall improvement of stroke care and outcomes and areas for improvement. This large-scale, high-quality dataset provides opportunities to explore and compare treatment disparities using the comparative effectiveness research methods, design and conduct a registry-based randomized clinical trial, connect the registry data with other data sources including the national claims data and neuroimaging or genetic data, and collaborate with other international researchers. An international stroke registry consortium may be a viable future direction.

BackgroundWe investigated the microRNA expression pattern from thrombus retrieved by mechanical thrombectomy in acute stroke patients to understand the stroke mechanism.MethodsThis study included acute ischemic stroke patients who had undergone intra-arterial thrombectomy at Chung-Ang University Hospital in Seoul, Korea between February 2016 and March 2019. The thrombus was retrieved and stored at −70℃ after obtaining informed consent. MicroRNA microarray analysis was performed for the patients with identified stroke mechanisms including (1) large artery atherosclerosis, (2) cardioembolism with atrial fibrillation, and (3) cardioembolism with valvular heart disease. The microRNAs derived from microarray analysis were validated by quantitative real-time polymerase chain reaction (qRT-PCR) from different patient populations. The correlation analysis was performed between microRNA levels and laboratory data to understand the functional relevance of the altered microRNA.ResultsIn total, 55 thrombi were obtained from 74 patients, and the microRNAs were analyzed in 45 samples. Microarray analysis of 2578 microRNAs revealed that 50 microRNAs were significantly altered among the three groups. Validation using qRT-PCR showed that miR-378f and miR-450b-5p were significantly elevated among the cardioembolic thrombi; both microRNAs were inversely correlated with the ejection fraction from echocardiography. Thrombi from patients with early neurological deterioration exhibited higher levels of miR-93-5p and lower levels of miR-629-5p than those from neurologically stable patients.ConclusionsThe microRNA expression pattern can provide information regarding the mechanism of stroke by reflecting the underlying pathological status of the organ from which the thrombus was derived.

Background The tendency of amyloid-β to form oligomers in the blood as measured with Multimer Detection System-Oligomeric Amyloid-β (MDS-OAβ) is a valuable biomarker for Alzheimer’s disease and has been verified with heparin-based plasma. The objective of this study was to evaluate the performance of ethylenediaminetetraacetic acid (EDTA)-based MDS-OAβ and to develop machine learning algorithms to predict amyloid positron emission tomography (PET) positivity. Methods The performance of EDTA-based MDS-OAβ in predicting PET positivity was evaluated in 312 individuals with various machine learning models. The models with various combinations of features (i.e., MDS-OAβ level, age, apolipoprotein E4 alleles, and Mini-Mental Status Examination [MMSE] score) were tested 50 times on each dataset. Results The random forest model best-predicted amyloid PET positivity based on MDS-OAβ combined with other features with an accuracy of 77.14 ± 4.21% and an F1 of 85.44 ± 3.10%. The order of significance of predictive features was MDS-OAβ, MMSE, Age, and APOE. The Support Vector Machine using the MDS-OAβ value only showed an accuracy of 71.09 ± 3.27% and F−1 value of 80.18 ± 2.70%. Conclusions The Random Forest model using EDTA-based MDS-OAβ combined with the MMSE and apolipoprotein E status can be used to prescreen for amyloid PET positivity.

Background Marked protein catabolism is common in patients with critical illness. We hypothesized that optimal protein supplementation using nitrogen balance might be associated with better clinical outcomes in patients in the neurointensive care unit (NICU).Methods A retrospective observational analysis was performed among patients admitted to the NICU between July 2017 and December 2018. Nitrogen balance was measured within 72 hours after NICU admission and measurements were repeated after 10 days in those who stayed in the NICU for more than 7 days. Nitrogen balance was calculated using a standard formula: total protein intake (grams)/6.25 – (urine urea nitrogen + 4 grams). Included patients were categorized into two groups (positive or negative) based on the initial nitrogen balance results. The rate of neurological worsening, defined by a worsening of ≥2 in the Glasgow Coma Scale (GCS) score, and in-hospital mortality were compared between patients who achieved the improvement of nitrogen balance on a follow-up measurement and those who failed to.Results A total of 175 patients were included, and 140 (80.0%) had a negative nitrogen balance on the initial assessment. The negative nitrogen balance group had a lower GCS, longer NICU stay, more events of neurological worsening, and higher in-hospital mortality. Among the 77 patients (44.0%) who underwent a follow-up measurement of nitrogen balance (on a median day of 10), 39 (50.6%) showed an improvement in nitrogen balance and thus received a higher amount of protein (1.94 g/kg/day) than those who did not show this improvement (1.28 g/kg/day) ( P < 0.001). The improvement group had fewer events of neurological worsening (15.4% vs. 36.8%, P = 0.032) and lower in-hospital mortality (12.8% vs. 31.6%, P = 0.047). However, there were no significant differences in baseline nitrogen balance, GCS, and the development of acute kidney injury between the two groups.Conclusions This study demonstrated that a significant proportion of patients in NICU were under protein hypercatabolism. An adequate provision of protein was associated with improved outcomes, suggesting the importance of protein supplementation in neurocritically ill patients.