Objective: Flow diverter stents (FDSs) have attracted interest for intracranial aneurysm (IA) treatment; however, occlusion of side branches and related complications have been reported. This study aimed to investigate the effects of FDSs in IA management when different branches of intracranial arteries are covered. Materials and methods: A cross-sectional study was conducted using PUBMED, Embase, Web of Science, and Cochrane databases to include randomized or nonrandomized comparative-designed studies from January 2000 to August 2022 which reported outcomes of occlusion/narrowing of branches after IA treatment using FDSs. The PRISMA guidelines were used for our report. A random-effects meta-analysis was conducted to pool the outcomes, which included incidence rates of occlusion/narrowing of FDS-covered branches, branch occlusion-related symptoms, obliteration of IAs, and ideal clinical outcomes (modified Rankin Scale score ≤2). Results: The authors identified 57 studies involving 3789 patients with IA managed by FDSs covering different branches. During the median imaging follow-up at 12 months, the IA obliteration rate was satisfactory (>70%) when covering the ophthalmic artery (OA), posterior communicating artery (PComA), anterior choroidal artery (AChoA) or anterior cerebral artery (ACA), but not the middle cerebral artery-M2 segment (MCA-M2; 69.5%; 95% CI: 60.8–77.5%) and posterior inferior cerebellar artery (PICA; 59.1%, 13/22). The overall ideal clinical outcome was observed in 97.4% of patients (95% CI: 95.5–98.9%). Higher rates of occlusion/narrowing of branches were identified when FDSs covered the ACA (66.6%; 95% CI: 45.1–85.3%), PComA (44.3%; 95% CI: 34.2–54.6%), or MCA-M2 (39.2%; 95% CI: 24.5–54.7%); the risks were lower when covering the OA (11.8%; 95% CI: 8.8–15.1%), PICA (6.8%; 95% CI: 1.5–14.5%), and AchoA (0.5%; 95% CI: 0.0–2.9%). The risk of branch occlusion-related complications was low (incidence rate <5%) for each of the six evaluated branches. Conclusions: Acceptable outcomes were identified following treatment of IAs when FDSs were placed across each of the six studied cerebral arteries. Treatment decisions regarding FDS placement across branch arteries should be made with the risk of complications from branch occlusion in mind.

Hemorrhagic stroke (HS) is associated with severe morbidity and high mortality. Identifying the trigger factors for HS is critical for disease prevention. This study aimed to assess the associations between short-term environmental triggers (STETs) and HS risk. We systematically searched six databases for articles published up to September 9, 2022. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using random-effect models to evaluate the associations between STETs and the risk of HS. Heterogeneity was assessed using Cochran Q and I² tests. A total of 63 studies were included for analysis. Of these, 40 focused on air pollutants and 23 on meteorological factors. Pooling results showed that exposure to particulate matter 2.5 (PM _2.5; OR, 1.003 per 10 μg/m³; 95% CI, 1.001–1.007), sulfur dioxide (SO_2; OR, 1.022 per 10 ppb; 95% CI, 1.005–1.040), and nitrogen dioxide (NO_2; OR, 1.026 per 10 ppb; 95% CI, 1.004–1.047) was associated with an increase in HS risk. Moreover, exposure to PM_2.5 (OR, 1.018 per 10 μg/m³; 95% CI, 1.009–1.027) and SO₂ (OR, 1.102 per 10 ppb; 95% CI, 1.010–1.204) was positively associated with the risk of intracerebral hemorrhage. In addition, extreme temperature, high pressures, high and low relative humidity were potentially associated with HS risk. Targeted preventive measures to limit the effect of these air pollutants and extreme meteorological factors should be taken to reduce the HS disease burden. Further studies are warranted to verify these findings.

RNF213 rare variant-p.R4810K (rs112735431) was significantly associated with intracranial artery stenosis/occlusion disease (ICASO) in Japan and Korea and to a lesser degree in China. Considering the allelic heterogeneity, we performed target exome sequencing of RNF213 with the aim to identify the rare variants spectrum and their association with ICASO in a Chinese population and further to explore whether the rare variants carrier patients present specific clinical phenotype. Target exome sequencing of RNF213 was performed in 250 ICASO patients using FastTarget sequencing technology. Various filtering process were used to select the candidate variants. Control individuals were obtain from 1000 Genome Project (208 Chinese samples) and GeneSky in-house database (1007 samples). Gene-based association analyses were conducted to identify the association between RNF213 rare variants and ICASO. The clinical characteristics of rare variant carriers and non-carriers were compared using Chi-squared test or Fisher’s exact test. After filtration, 18 rare variants were identified in 39 patients. Gene-based association test showed that rare variants of RNF213 were significantly associated with ICASO (Minor allele frequency < 0.05, WSS p = 4.88 × 10− 10; SKAT p = 9.68 × 10− 6; SKAT-O p = 3.42 × 10− 9). There were no significant clinical characteristic differences other than the diagnosis age which was older in the carriers than the non-carriers (60.5 ± 6.2 vs 57.3 ± 8.9 years old, p = 0.028). Rare variants of RNF213 are associated with ICASO in Chinese. However, there are limited genetic diagnosis values of the gene due to no specific phenotypic presentation in the carriers and non carrier patients.

We aimed to evaluate the association between coronavirus disease 2019 (COVID-19) vaccination and the risk of stroke. We conducted a systematic meta-analysis of studies published until December 24, 2022, using PubMed and the Cochrane database; real-world studies using cohort, self-controlled case series (SCCS), and case-crossover study (CCOS) designs were identified to evaluate the incidence risk ratios (IRRs) and 95% confidence intervals (CIs) of ischemic stroke (IS), hemorrhagic stroke (HS), and cerebral venous sinus thrombosis (CVST) following COVID-19 vaccination. Random-effects meta-analyses were performed to pool the risks of IS and HS among subpopulations categorized by vaccine type, dose, age, and sex. Sensitivity analysis was performed after stratification by defined risk periods. Fourteen observational studies involving 79,918,904 individuals were included. Cohort studies showed decreased risks of IS (IRR [95% CI], 0.82 [0.75-0.90]) and HS (IRR [95% CI], 0.75 [0.67-0.85]) post-vaccination, but no association with CVST was found (IRR [95% CI], 1.18 [0.70-1.98]). SCCS identified increased risks 1-21 days (IRR [95% CI]_IS, 1.05 [1.00-1.10]; IRR [95% CI]_HS, 1.16 [1.06-1.26]) or 1-28 days (IRR [95% CI]_IS, 1.04 [1.00-1.08]; IRR [95% CI]_HS, 1.37 [1.15-1.64]) post-vaccination, similar to CVST (IRR [95% CI], 1.58 [1.08-2.32]). A CCOS reported an increased risk of CVST after vaccination using ChAdOx1 (IRR [95% CI], 2.9 [1.1-7.2]). Although different study designs yielded inconsistent findings, considering the relatively low background incidence of stroke and benefits of vaccination, even a potentially increased risk of stroke post-vaccination should not justify vaccine hesitancy.

Li B, et al. Yonsei Med J. 2019 Jul;60(7):651-658. https://doi.org/10.3349/ymj.2019.60.7.651

Background: Subarachnoid hemorrhage (SAH), primarily caused by rupture of intracranial aneurysm, has a high incidence rate in women. We aimed to evaluate the association between female hormonal and reproductive factors and SAH. Methods: A prospective cohort of 226,469 participants from the UK Biobank was followed for a median period of 14.75 years. Cox proportional hazards models and restricted cubic splines were used to explore the associations between 13 major factors and SAH, including menarche age, menopausal status, age at menopause, reproductive lifespan, pregnancy history, age at first and last live births, number of live births, adverse fertility outcomes, history of oral contraception or hormone-replacement therapy (HRT) use, and surgical history of hysterectomy or bilateral oophorectomy. Results: SAH occurred in 769 of participants during the follow-up period. Both women with a younger age at menarche (< 12 years) and post-menopausal women had a higher SAH risk (hazard ratio (HR), 1.28; 95% confidence interval (CI), 1.06–1.54) and (HR, 1.48; 95% CI, 1.10–1.99), respectively. A higher risk of SAH was identified in those with an earlier age at menopause (< 40 years: HR, 2.09; 95% CI, 1.43–3.06; 40–44 years: HR, 1.68; 95% CI, 1.23–2.29). A shorter reproductive lifespan (< 30 years) was associated with increased SAH risk (HR, 1.64; 95% CI, 1.28–2.11), while a longer reproductive lifespan (> 42 years) showed a protective effect (HR, 0.65; 95% CI, 0.55–0.77). Younger age at first live birth (< 24 years) was associated with SAH (HR, 1.39; 95% CI, 1.13–1.72). Hysterectomy (HR, 2.55; 95% CI, 2.12–3.05) or bilateral oophorectomy (HR, 1.51; 95% CI, 1.14–2.01) also predisposed women to SAH. Age at last live birth, number of live births, pregnancy history, adverse fertility outcomes, and HRT or oral contraceptive use were not associated with SAH. Conclusions: Female hormonal and reproductive factors are important for evaluating SAH risk in women. In particular, earlier menopause is associated with an increased risk of SAH. Data access statement: The data utilized in this study were sourced from a third party and are not publicly accessible. The UK Biobank data that support the findings of this research are available from the UK Biobank (www.ukbiobank.ac.uk), subject to review and approval by the UK Biobank.