Background: and Purpose To determine whether the RNF213 p.R4810K mutation modifies the number of moyamoya disease manifestations and recurrent strokes in isolated intracranial arterial steno-occlusive disease (ICAD). Methods: This retrospective case–control study analyzed patients who visited the Asan Medical Center with steno-occlusive lesions in the M1 segment of the middle cerebral artery and terminal internal carotid artery, and underwent RNF213 genetic testing for screening moyamoya disease between January 2010 and November 2022. Patients with supportive findings of moyamoya disease or moderate-to-severe stenosis in the extracranial arteries were excluded.After matching antiplatelet drugs, the presentation of moyamoya disease and stroke recurrence were analyzed using chi-squared analysis and Kaplan–Meier survival curve analysis. Results: The 1,567 patients who underwent evaluations of RNF213 polymorphisms included 753 with ICAD, among whom females predominated (n=452, 60.0%) and 289 (38.4%) had an RNF213 mutation. The follow-up period was 2.47±3.51 years (mean±standard deviation; median=1.00 year, interquartile range=0–4 years). The risk of progression to moyamoya disease was higher in the RNF213-related-vasculopathy group than the RNF213-negative stenosis group (n=27 [9.3%] versus n=6 [1.3%], p<0.01), as were the risks of ischemic stroke (n=13 [4.5%] versus n=7 [1.5%], p=0.01) and hemorrhagic stroke (n=5 [1.7%] versus n=1 [0.2%], p=0.02, respectively). Furthermore, the presence of an RNF213 mutation was significantly associated with the risk of stroke recurrence (odds ratio=2.34, 95% confidence interval=1.44–3.80, p< 0.01). Conclusions Evaluations of RNF213 polymorphisms may help to identify patients with isolated ICAD at a high risk of progression to moyamoya disease and stroke.

Background: and Purpose To determine whether the RNF213 p.R4810K mutation modifies the number of moyamoya disease manifestations and recurrent strokes in isolated intracranial arterial steno-occlusive disease (ICAD). Methods: This retrospective case–control study analyzed patients who visited the Asan Medical Center with steno-occlusive lesions in the M1 segment of the middle cerebral artery and terminal internal carotid artery, and underwent RNF213 genetic testing for screening moyamoya disease between January 2010 and November 2022. Patients with supportive findings of moyamoya disease or moderate-to-severe stenosis in the extracranial arteries were excluded.After matching antiplatelet drugs, the presentation of moyamoya disease and stroke recurrence were analyzed using chi-squared analysis and Kaplan–Meier survival curve analysis. Results: The 1,567 patients who underwent evaluations of RNF213 polymorphisms included 753 with ICAD, among whom females predominated (n=452, 60.0%) and 289 (38.4%) had an RNF213 mutation. The follow-up period was 2.47±3.51 years (mean±standard deviation; median=1.00 year, interquartile range=0–4 years). The risk of progression to moyamoya disease was higher in the RNF213-related-vasculopathy group than the RNF213-negative stenosis group (n=27 [9.3%] versus n=6 [1.3%], p<0.01), as were the risks of ischemic stroke (n=13 [4.5%] versus n=7 [1.5%], p=0.01) and hemorrhagic stroke (n=5 [1.7%] versus n=1 [0.2%], p=0.02, respectively). Furthermore, the presence of an RNF213 mutation was significantly associated with the risk of stroke recurrence (odds ratio=2.34, 95% confidence interval=1.44–3.80, p< 0.01). Conclusions Evaluations of RNF213 polymorphisms may help to identify patients with isolated ICAD at a high risk of progression to moyamoya disease and stroke.

Background: and Purpose To determine whether the RNF213 p.R4810K mutation modifies the number of moyamoya disease manifestations and recurrent strokes in isolated intracranial arterial steno-occlusive disease (ICAD). Methods: This retrospective case–control study analyzed patients who visited the Asan Medical Center with steno-occlusive lesions in the M1 segment of the middle cerebral artery and terminal internal carotid artery, and underwent RNF213 genetic testing for screening moyamoya disease between January 2010 and November 2022. Patients with supportive findings of moyamoya disease or moderate-to-severe stenosis in the extracranial arteries were excluded.After matching antiplatelet drugs, the presentation of moyamoya disease and stroke recurrence were analyzed using chi-squared analysis and Kaplan–Meier survival curve analysis. Results: The 1,567 patients who underwent evaluations of RNF213 polymorphisms included 753 with ICAD, among whom females predominated (n=452, 60.0%) and 289 (38.4%) had an RNF213 mutation. The follow-up period was 2.47±3.51 years (mean±standard deviation; median=1.00 year, interquartile range=0–4 years). The risk of progression to moyamoya disease was higher in the RNF213-related-vasculopathy group than the RNF213-negative stenosis group (n=27 [9.3%] versus n=6 [1.3%], p<0.01), as were the risks of ischemic stroke (n=13 [4.5%] versus n=7 [1.5%], p=0.01) and hemorrhagic stroke (n=5 [1.7%] versus n=1 [0.2%], p=0.02, respectively). Furthermore, the presence of an RNF213 mutation was significantly associated with the risk of stroke recurrence (odds ratio=2.34, 95% confidence interval=1.44–3.80, p< 0.01). Conclusions Evaluations of RNF213 polymorphisms may help to identify patients with isolated ICAD at a high risk of progression to moyamoya disease and stroke.

Objectives: Limited information is available concerning the epidemiology of stroke and acute myocardial infarction (AMI) in the Republic of Korea. This study aimed to develop a national surveillance system to monitor the incidence of stroke and AMI using national claims data. Methods: We developed and validated identification algorithms for stroke and AMI using claims data. This validation involved a 2-stage stratified sampling method with a review of medical records for sampled cases. The weighted positive predictive value (PPV) and negative predictive value (NPV) were calculated based on the sampling structure and the correspondingsampling rates. Incident cases and the incidence rates of stroke and AMI in the Republic ofKorea were estimated by applying the algorithms and weighted PPV and NPV to the 2018National Health Insurance Service claims data. Results: In total, 2,200 cases (1,086 stroke cases and 1,114 AMI cases) were sampled from the 2018 claims database. The sensitivity and specificity of the algorithms were 94.3% and 88.6% for stroke and 97.9% and 90.1% for AMI, respectively. The estimated number of cases, including recurrent events, was 150,837 for stroke and 40,529 for AMI in 2018. The age- and sex-standardized incidence rate for stroke and AMI was 180.2 and 46.1 cases per 100,000 person-years, respectively, in 2018. Conclusion This study demonstrates the feasibility of developing a national surveillance system based on claims data and identification algorithms for stroke and AMI to monitor their incidence rates.

Background: and Purpose An intracranial vertebral artery dissecting aneurysm (iVADA) increases the risk of future subarachnoid hemorrhage, which is a severe complication with high rebleeding rates and poor outcomes. Identifying potential risk factors associated with iVADA growth is crucial for their effective management. Methods: This observational study was carried out at a single center and included patients who had been diagnosed with iVADA based on neuroimaging findings. We divided the patients into two groups: with and without iVADA growth. Growth was defined as any enlargement of a dilated region or a morphological change in follow-up imaging. We measured the vertebral artery tortuosity index (VTI) in the contralateral vertebral artery (VA), defined as its actual length divided by its straight length. We investigated the factors associated with iVADA growth. Results: This study included 124 patients. The median follow-up period was 7 months. We observed iVADA growth in 54 patients (43.5%), who were more likely to be current smokers (33.3% vs. 14.3%, p=0.012) and have a higher VTI (1.14±0.11 [mean±standard deviation] vs.1.06±0.12, p=0.035) compared with those without iVADA growth. A multivariate analysis revealed that the VTI (adjusted odds ratio=28.490, 95% confidence interval=1.025–792.046, p=0.048) was independently associated with iVADA growth. Conclusions This study has identified an independent association between VA tortuosity and iVADA growth.

Background: and Purpose The additive effects of intravenous thrombolysis (IVT) before mechanical thrombectomy (MT) remain unclear. We aimed to investigate the efficacy and safety of IVT prior to MT depending on the location of M1 occlusion. Methods: We reviewed the cases of patients who underwent MT for emergent large-vessel occlusion of the M1 segment. Baseline characteristics as well as clinical and periprocedural variables were compared according to the location of M1 occlusion (i.e., proximal and distal M1 occlusion). The main outcome was the achievement of functional independence (modified Rankin Scale score, 0–2) at 3 months after stroke. The main outcomes were compared between the proximal and distal groups based on the use of IVT before MT. Results: Among 271 patients (proximal occlusion, 44.6%; distal occlusion, 55.4%), 33.9% (41/121) with proximal occlusion and 24.7% (37/150) with distal occlusion underwent IVT prior to MT. Largeartery atherosclerosis was more common in patients with proximal M1 occlusion; cardioembolism was more common in those with distal M1 occlusion. In patients with proximal M1 occlusion, there was no association between IVT before MT and functional independence. In contrast, there was a significant association between the use of IVT prior to MT (odds ratio=5.30, 95% confidence interval=1.56–18.05, P=0.007) and functional independence in patients with distal M1 occlusion. Conclusion IVT before MT was associated with improved functional outcomes in patients with M1 occlusion, especially in those with distal M1 occlusion but not in those with proximal M1 occlusion.

Background: and Purpose In young patients (aged 18–60 years) with patent foramen ovale (PFO)- associated stroke, percutaneous closure has been found to be useful for preventing recurrent ischemic stroke or transient ischemic attack (TIA). However, it remains unknown whether PFO closure is also beneficial in older patients. Methods: Patients aged ≥60 years who had a cryptogenic stroke and PFO from ten hospitals in South Korea were included. The effect of PFO closure plus medical therapy over medical therapy alone was assessed by a propensity-score matching method in the overall cohort and in those with a high-risk PFO, characterized by the presence of an atrial septal aneurysm or a large shunt. Results: Out of the 437 patients (mean age, 68.1), 303 (69%) had a high-risk PFO and 161 (37%) patients underwent PFO closure. Over a median follow-up of 3.9 years, recurrent ischemic stroke or TIA developed in 64 (14.6%) patients. In the propensity score-matched cohort of the overall patients (130 pairs), PFO closure was associated with a significantly lower risk of a composite of ischemic stroke or TIA (hazard ratio [HR]: 0.45; 95% confidence interval [CI]: 0.24–0.84; P=0.012), but not for ischemic stroke. In a subgroup analysis of confined to the high-risk PFO patients (116 pairs), PFO closure was associated with significantly lower risks of both the composite of ischemic stroke or TIA (HR: 0.40; 95% CI: 0.21–0.77; P=0.006) and ischemic stroke (HR: 0.47; 95% CI: 0.23–0.95; P=0.035). Conclusion Elderly patients with cryptogenic stroke and PFO have a high recurrence rate of ischemic stroke or TIA, which may be significantly reduced by device closure.