Incidence and risk factors of intracranial aneurysm: A national cohort study in Korea

Phosphorylated NPY1R regulates phenotypic transition of vascular smooth muscle cells, inflammatory response and macrophage infiltration to promote intracranial aneurysm progression

BACKGROUND

Rupture of intracranial aneurysm (IA) could give rise to spontaneous subarachnoid hemorrhage, leading to a high disability rate and even death. NPY1R expression was upregulated in aneurysm tissues of IA patients. However, the role and underlying mechanism of NPY1R remains unknown.

METHODS

The IA model of mice was established using inducing systemic hypertension and injecting elastase. The expression of genes and proteins was detected by RT-qPCR and western blot. The number of T cells, macrophages, and neutrophils in IA mice was detected using flow cytometry and IF assay. The levels of inflammatory factors were measured using ELISA. Patho-morphology and inflammatory cells in aneurysm tissues were evaluated by HE staining. The interaction between TK and NPY1R was validated using Co-IP.

RESULTS

NPY1R expression was greatly elevated in aneurysm tissues in IA patients and mice, which were positively related to macrophage infiltration. Besides, exogenous overexpression of NPY1R resulted in the promotion of contractile phenotype to the synthetic phenotype of vascular smooth muscle cells (VSMCs), inflammatory response and M1 macrophage polarization. In terms of the underlying mechanism, NPY1R protein could be modified by TK-mediated phosphorylation and TKI could decrease IA formation and suppresse contractile phenotype to synthetic phenotype of VSMCs, inflammatory response and M1 macrophage polarization in IA mice. Furthermore, ablating mouse macrophages abolished NPY1R overexpression-mediated promotion of IA formation and rupture in mice.

CONCLUSION

Phosphorylated NPY1R contributed to IA progression through promoting contractile phenotype to synthetic phenotype of VSMCs, inflammatory response and M1 macrophage polarization in IA.

Risk of Cerebral Aneurysm Rupture After Liver Transplantation: Development and Validation of a Hemorrhagic Stroke Scoring Model

BACKGROUND

Liver transplantation (LT) patients appear to be more prone to neurological events compared to individuals undergoing other types of solid-organ transplantation. The aims of the present study were to analyze the prevalence of unruptured intracranial aneurysms (UIAs) in patients undergoing liver transplantation (LT) and to examine the perioperative occurrence of subarachnoid hemorrhage (SAH). Also, it intended to systematically identify the risk factors of SAH and hemorrhagic stroke (HS) within a year after LT and to develop a scoring system which involves distinct clinical features of LT patients.

METHODS

Patients who underwent LT from January 2012 to March 2022 were analyzed. All included patients underwent neurovascular imaging within 6 months before LT. We conducted an analysis of prevalence and radiological features of UIA and SAH. The clinical factors that may have an impact on HS within one year of LT were also reviewed.

RESULTS

Total of 3,487 patients were enrolled in our study after applying inclusion and exclusion criteria. The prevalence of UIA was 5.4%. The incidence of SAH and HS within one year following LT was 0.5% and 1.6%, respectively. We developed a scoring system based on multivariable analysis to predict the HS within 1-year after LT. The variables were a poor admission mental status, the diagnosis of UIA, serum ammonia levels, and Model for End-stage Liver Disease (MELD) scores. Our model showed good discrimination among the development (C index, 0.727; 95% confidence interval [CI], 0.635-0.820) and validation (C index, 0.719; 95% CI, 0.598-0.801) cohorts.

CONCLUSION

The incidence of UIA and SAH was very low in LT patients. A poor admission mental status, diagnosis of UIA, serum ammonia levels, and MELD scores were significantly associated with the risk of HS within one year after LT. Our scoring system showed a good discrimination to predict the HS in LT patients.

Risk Factors and Location of Intracranial Aneurysm Rupture in a Consecutive Chinese Han Population

OBJECTIVE

The aim of the present study was to retrospectively analyze and investigate the clinical data of 704 cases of ruptured intracranial aneurysms (RIAs) and unruptured intracranial aneurysms (UIAs). The risk factors predicting aneurysm rupture were explored from the perspective of the clinical characteristics of intracranial aneurysm (IA).

METHODS

The clinical data of 704 patients with RIAs (494 patients) and UIAs (210 patients) admitted to the Department of Neurosurgery of Tianjin Medical University General Hospital and Tianjin Fifth Central Hospital between January 2016 and May 2022 were analyzed. A detailed analysis of sex, age, history, personal history, drug intake, and site of aneurysm occurrence was performed. Age was analyzed in segments and strata, and parameters with significant differences in the preliminary analysis results were analyzed by logistic regression to predict factors associated with the risk of aneurysm rupture.

RESULTS

Among 494 patients with RIA (70.2%) and 210 patients with UIA (29.8%), the logistic regression showed that IA location appeared to be the most significant factor associated with RIA (OR, 95% CI: internal carotid artery (ICA), reference; anterior communicating artery,27.864,12.548-61.878; posterior communicating artery,12.408,6.658-23.124; anterior cerebral artery,5.804,2.333-14.440; middle cerebral artery,9.284,4.599-18.744; posterior circulation arteries, 4.224,2.011-8.871). Age was not a significant factor associated with RIA in the model and Hyperlipidemia (OR: 0.365; 95% CI: 0.171-0.779), Atherosclerosis (OR: 0.277; 95% CI: 0.172-0.446) and Multiple aneurysms (OR: 0.275; 95% CI: 0.177-0.425) patients were less likely to have RIA.IA location and age were the best predictors of RIA using the model.

CONCLUSIONS

The present findings indicated that hyperlipidemia and atherosclerosis have a protective effect on aneurysm rupture, and different anatomical sites of IA may be risk factors for the occurrence of IA rupture. Among the anatomical sites of IA, the anterior communicating artery and posterior communicating artery have a higher fracture risk.

Is Thyroid Dysfunction Associated with Unruptured Intracranial Aneurysms? A Population-Based, Nested Case-Control Study from Korea

Background: Few risk factors for the development of intracranial aneurysms (IAs) are known. We investigated the potential role of thyroid diseases in IA development using nationwide real-world data. Methods: A nested case-control study within the National Health Insurance Service-National Sample Cohort data from 2002 to 2019 was performed. A total of 5335 patients with unruptured IA were matched by age and sex with 80,025 controls at a ratio of 1:15. We estimated the odds ratios (ORs) and corresponding confidence intervals [CIs] between thyroid diseases and unruptured IA using a multivariable conditional logistic regression model. Results: Tobacco smoking, use of antihypertensive medication, and hypothyroidism were significantly associated with an elevated risk for unruptured IA in univariate analysis. In multivariable analysis, a history of hypothyroidism was associated with unruptured IA (adjusted OR: 1.46 [CI: 1.26-1.69]). Among patients with hypothyroidism, long-term use of thyroid hormone for >5 years was associated with a reduced risk for unruptured IA (adjusted OR: 0.69 [CI: 0.48-0.99]). A history of hyperthyroidism was associated with a reduced risk for unruptured IAs (adjusted OR: 0.71 [CI: 0.54-0.93]). In secondary analyses of the data according to sex, the respective observed associations between hypothyroidism and hyperthyroidism and the risk of IAs were found to be statistically significant in females but not in males. Conclusions: Hypothyroidism is associated with an increased risk of unruptured IAs, whereas hyperthyroidism is associated with a reduced risk. Overall, the findings suggest that thyroid hormones may play a protective role in the development of unruptured IAs. Further studies are needed to clarify potential direct causality and the biologic mechanisms relating thyroid dysfunction and unruptured IA.

Optimal target blood pressure for the primary prevention of hemorrhagic stroke: a nationwide observational study

Background

There are few reports on the preventative value of intensive blood pressure (BP) management for stroke, especially hemorrhagic stroke (HS), after new criteria for hypertension (HTN) were announced by the American College of Cardiology/American Heart Association in 2017.

Aims

This study aimed to identify the optimal BP for the primary prevention of HS in a healthy population aged between 20 and 65 years.

Methods

We conducted a 10-year observational study on the risk of HS, subclassified as intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH) according to BP categories (e.g., low normal BP, high normal BP, elevated BP, stage 1 HTN, and stage 2 HTN) using the National Health Insurance Service Database.

Results

Out of 8,327,751 participants who underwent a health checkup in 2008, 949,550 were included in this study and observed from 2009 to 2018. The risk of ICH was significantly increased in men with stage 2 HTN {adjusted hazard ratio [aHR] 2.002 [95% confidence interval (CI) 1.203-3.332]} and in women with stage 1 HTN [aHR 2.021 (95% CI, 1.251-3.263)]. The risk of SAH was significantly increased in both men [aHR 1.637 (95% CI, 1.066-2.514)] and women [aHR 4.217 (95% CI, 2.648-6.715)] with stage 1 HTN. Additionally, the risk of HS was significantly increased in men with stage 2 HTN [aHR 3.034 (95% CI, 2.161-4.260)] and in women with stage 1 HTN [aHR 2.976 (95% CI, 2.222-3.986)].

Conclusion

To prevent primary HS, including ICH and SAH, BP management is recommended for adults under the age of 65 years with stage 1 HTN.

Validation of prediction algorithm for risk estimation of intracranial aneurysm development using real-world data

Intracranial aneurysm (IA) is difficult to detect, and most patients remain undiagnosed, as screening tests have potential risks and high costs. Thus, it is important to develop risk assessment system for efficient and safe screening strategy. Through previously published research, we have developed a prediction model for the incidence risk of IA using cohort observational data. This study was designed to verify whether such a prediction model also demonstrates sufficient clinical performance in predicting the prevalence risk at the point of health screening, using cross-sectional data. The study population comprised individuals who visited the Chonnam National University Hwasun Hospital Health Promotion Center in Korea for voluntary medical checkups between 2007 and 2019. All participants had no history of cerebrovascular disease and underwent brain CTA for screening purpose. Presence of IA was evaluated by two specialized radiologists. The risk score was calculated using the previously developed AI model, and 0 point represents the lowest risk and 100 point represents the highest risk. To compare the prevalence according to the risk, age-sex standardization using national database was performed. A study collected data from 5942 health examinations, including brain CTA data, with participants ranging from 20 to 87 years old and a mean age of 52 years. The age-sex standardized prevalence of IA was 3.20%. The prevalence in each risk group was 0.18% (lowest risk, 0-19), 2.12% (lower risk, 20-39), 2.37% (mid-risk, 40-59), 4.00% (higher risk, 60-79), and 6.44% (highest risk, 80-100). The odds ratio between the lowest and highest risk groups was 38.50. The adjusted proportions of IA patients in the higher and highest risk groups were 26.7% and 44.5%, respectively. The median risk scores among IA patients and normal participants were 74 and 54, respectively. The optimal cut-off risk score was 60.5 with an area under the curve of 0.70. We have confirmed that the incidence risk prediction model built through machine learning also shows viable clinical performance in predicting prevalence risk. By utilizing this prediction system, we can effectively predict not only the incidence risk but also the prevalence risk, which is the probability of already having the disease, using health screening data. This may enable us to consider strategies for the early detection of intracranial aneurysms.

Mathematical Analysis of the Effectiveness of Screening for Intracranial Aneurysms in First-Degree Relatives of Persons with Subarachnoid Hemorrhage

OBJECTIVE

Population screening for aneurysms in patients with risk factors and preventive surgical treatment are beneficial according to numerous studies. One of the most significant risk factors is heredity, namely, the presence of first-degree relatives (FDR) with aneurysmal subarachnoid hemorrhage (aSAH). Nevertheless, there are still no generally accepted approaches or evidence bases regarding the benefits of the aneurysm screening strategy.

METHODS

Mathematical modeling of the dynamics of aneurysm development in the population was carried out using an algorithm implementing a discrete Markov's chain. To implement the model, all probabilities of events and distributions are taken from available literature sources. Three-dimensional time of flight noncontrast magnetic resonance angiography was chosen as a screening method. Patients underwent preventive surgical treatment if an aneurysm was detected.

RESULTS

Screening and preventive treatment in the general population reduces the prevalence of aneurysms by 1.74% (3.44% in the FDR group) and the prevalence of aSAH by 14.36% (37.48% in the FDR group). Mortality due to aSAH was reduced by 14.44%. The number of disabilities also decreases. The occurrence of deep disability was reduced by 20.2% in the FDR group. Economic analysis of the part of the population consisting of FDRs showed annual savings of ies also decr CONCLUSIONS: The mathematical model demonstrated that screening and preventive treatment of cerebral aneurysms can reduce aSAH-associated morbidity and mortality. In the FDR group, there was decrease in the prevalence of aSAH and decrease in associated mortality. Screening for cerebral aneurysms is cost-effective.

Saccular intracranial neonatal aneurysm

INTRODUCTION

Neonatal cerebral aneurysms are very rare condition and distinct from those of the adults.

CASE REPORT

We reported a 14-day-old male neonate who presented subarachnoid hemorrhage due to a ruptured anterior cerebral artery saccular aneurysm. In addition, we present a review of the relevant literature.

CONCLUSION

Intracranial hemorrhage due to cerebral aneurysm rupture in a newborn is an uncommon diagnosis, but it must be unequivocally excluded.

Rupture discrimination of multiple small (< 7 mm) intracranial aneurysms based on machine learning-based cluster analysis

BACKGROUND

Small multiple intracranial aneurysms (SMIAs) are known to be more prone to rupture than are single aneurysms. However, specific recommendations for patients with small MIAs are not included in the guidelines of the American Heart Association and American Stroke Association. In this study, we aimed to evaluate the feasibility of machine learning-based cluster analysis for discriminating the risk of rupture of SMIAs.

METHODS

This multi-institutional cross-sectional study included 1,427 SMIAs from 660 patients. Hierarchical cluster analysis guided patient classification based on patient-level characteristics. Based on the clusters and morphological features, machine learning models were constructed and compared to screen the optimal model for discriminating aneurysm rupture.

RESULTS

Three clusters with markedly different features were identified. Cluster 1 (n = 45) had the highest risk of subarachnoid hemorrhage (SAH) (75.6%) and was characterized by a higher prevalence of familiar IAs. Cluster 2 (n = 110) had a moderate risk of SAH (38.2%) and was characterized by the highest rate of SAH history and highest number of vascular risk factors. Cluster 3 (n = 505) had a relatively mild risk of SAH (17.6%) and was characterized by a lower prevalence of SAH history and lower number of vascular risk factors. Lasso regression analysis showed that compared with cluster 3, clusters 1 (odds ratio [OR], 7.391; 95% confidence interval [CI], 4.074-13.150) and 2 (OR, 3.014; 95% CI, 1.827-4.970) were at a higher risk of aneurysm rupture. In terms of performance, the area under the curve of the model was 0.828 (95% CI, 0.770-0.833).

CONCLUSIONS

An unsupervised machine learning-based algorithm successfully identified three distinct clusters with different SAH risk in patients with SMIAs. Based on the morphological factors and identified clusters, our proposed model has good discrimination ability for SMIA ruptures.

Optimal Cost-Effective Screening Strategy for Unruptured Intracranial Aneurysms in Female Smokers

BACKGROUND

The prevalence of intracranial aneurysms among female cigarette smokers was shown to be high in previous studies, yet the cost-effectiveness of screening them has never been explored.

OBJECTIVE

To explore the most cost-effective screening strategy for female smokers.

METHODS

A decision analytical study was performed with a Markov model to compare different screening strategies with no screening and to explore the most optimal screening strategy for female smokers. Input data for the model were extracted from literature. A single screening at different ages and multiple screening every 15 years, 10 years, 5 years, and 2 years were performed for female smokers in different age ranges. Deterministic and probabilistic sensitivity analyses were performed to evaluate the robustness of the model. Finally, value of information analysis was performed to investigate the value of collecting additional data.

RESULTS

Screening female smokers for unruptured intracranial aneurysm is cost-effective. All screening strategies yield extra quality-adjusted life years. Screening at younger age brings more health benefit at lower cost. Frequent screening strategies decrease rupture rate of aneurysms more with higher costs per quality-adjusted life year. Screening after age 70 years and frequent screening (every 2 years) after age 60 years is not optimal. Among all the parameters in the model, collecting additional data on utility of the unscreened population would be most valuable.

CONCLUSION

Screening female smokers for intracranial aneurysms once at younger age is most optimal. However, in clinical practice, the duration and intensity of exposure to cigarettes should be taken into consideration.

Initial severity of aneurysmal subarachnoid hemorrhage (SAH): Trend over time

OBJECTIVE

The trend in the initial severity of aneurysmal subarachnoid hemorrhage (SAH) is unclear. This study aimed to evaluate whether there was an improvement in the initial severity of SAH over time.

METHODS

From January 1, 2005, to December 31, 2020, we identified patients who visited the emergency department of our institution with SAH due to intracranial aneurysm rupture. We identified the Hunt Hess (HH) grade and modified Fisher grade of each patient from the medical records, and the Mann-Kendal method was used to estimate the trend of each grade system.

RESULTS

A total of 547 patients with SAH were identified. The mean age of the patients was 59.3 years (standard deviation (SD), 14.6). The mean aneurysm size was 6.9 mm (SD, 4.6 mm). The most frequent aneurysm location was the anterior communicating artery (28.7%). In the Mann-Kendal estimates for the analysis of the trend, there was no statistically significant grade throughout the HH and modified Fisher grades. Similarly, there was no improvement throughout all grades in the modified Fisher grade over time.

CONCLUSIONS

The initial severity of SAH due to cerebral aneurysm rupture did not improve over time.

Prevalence and Risk Factors for Unruptured Intracranial Aneurysms in the Population at High Risk for Aneurysm in the Rural Areas of Tianjin

Although the prevalence of unruptured intracranial aneurysm (UIA) lies between 2 and 5%, the consequences of aneurysm rupture are fatal. The burden of UIA is considerable in stroke patients. However, the best prevention and management strategy for UIA is uncertain among patients with a family history of stroke. Therefore, this study aimed to determine the epidemiological characteristics and risk factors for UIA based on a population with a family history of stroke. This study used random sampling to recruit participants with a family history of stroke among rural residents in Jixian, Tianjin, China. All participants underwent a questionnaire survey, physical examination, and cervical computed tomography angiography (CTA). CTA data were used to determine whether the subjects had UIA. The relationship between relevant factors and UIA was assessed using logistic regression analysis. A total of 281 residents were recruited in this study, with a mean age of 50.9 years. The prevalence of UIA in those with a family history of stroke was 10.3% overall (9.8% among men and 10.9% among women). Moreover, with each unit increase in body mass index (BMI), the prevalence of UIA decreased by 12.5%. Particularly among non-obese men, BMI had a stronger protective effect (OR: 0.672; 95%CI: 0.499–0.906; P = 0.009), and among non-obese men, an increase in low-density lipoprotein (LDL) was associated with an increased prevalence of UIA (OR: 3.638; 95%CI: 1.108–11.947; P = 0.033). Among the non-obese with a family history of stroke, BMI may be protective against UIA, especially in men. It is crucial to strictly control the LDL level in non-obese people to reduce the burden of UIA.

Modifiable risk factors for intracranial aneurysms: Evidence from genetic studies

Background:

Intracranial aneurysm (IA) is a crucial health concern with limited strategies for prevention and treatment.

Aim:

To identify potentially modifiable risk factors, such as socioeconomic, behaviors, dietary, and cardiometabolic factors, for IA and its subtypes.

Methods:

Summary statistics for IA were derived from a genome-wide association study with an overall 79,429 participants. Single nucleotide polymorphisms associated with modifiable risk factors at genome-wide significance ( P = 5 × 10–8) were used as instrumental variables. The inverse-variance-weighted method, weighted-median method, Mendelian randomization (MR)-Egger regression, MR-Pleiotropy RESidual Sum and Outlier, and multivariable MR analyses were performed to evaluate the effect estimates.

Results:

Genetically predicted educational attainment, insomnia, smoking, and systolic and diastolic blood pressure (SBP and DBP) were significantly associated with the risk of IA. The odds ratios (ORs) were 0.44 (95% confidence interval (CI): 0.37–0.52) for educational attainment, 1.15 (95% CI: 1.08–1.23) for insomnia, 1.56 (95% CI: 1.38–1.75) for smoking initiation, 2.69 (95% CI: 1.77–4.07) for cigarette per day, 2.65 (95% CI: 1.72–4.08) for lifetime smoking, 1.07 (95% CI: 1.06–1.09), and 1.06 (95% CI: 1.04–1.10) for SBP and DBP, respectively. Similar effect estimates were observed for unruptured IAs and aneurysmal subarachnoid hemorrhage.

Conclusions:

This study provided genetic evidence that several modifiable risk factors, including blood pressure, smoking, educational attainment, and insomnia were associated with the risk of IA.

Intravenous Fluid Selection for Unruptured Intracranial Aneurysm Clipping : Balanced Crystalloid versus Normal Saline

OBJECTIVE

While balanced crystalloid (BC) could be a relevant fluid regimen with buffer system compared with normal saline (NS), there have been no studies on the optimal fluid for surgery of an unruptured intracranial aneurysm (UIA). This study aimed to compare the effects of fluid regimens between NS and BC on the metabolic and clinical outcomes of patients who underwent surgery for UIA.

METHODS

This study was designed as a propensity score matched retrospective comparative study and included adult patients who underwent UIA clipping. Patient groups were categorized as NS and BC groups based on the types of pre-operative fluid and the amount of fluid administered during surgery. The primary outcomes were defined as electrolyte imbalance and acidosis immediately after surgery. The secondary outcomes were the length of stay in the intensive care unit (ICU) and duration from the end of the operation to extubation.

RESULTS

A total of 586 patients were enrolled in this study, with each of 293 patients assigned to the NS and BC groups, respectively. Immediately after surgery, serum chloride levels were significantly higher in the NS group. Compared to the NS group, the BC group had lower incidence rates of acidemia (6.5% vs. 11.6%, p=0.043) and metabolic acidosis (0.7% vs. 4.4%, p=0.007). As compared to NS group, BC group had significantly shorter duration from the end of the operation to extubation (250±824 vs. 122±372 minutes, p=0.016) and length of stay in ICU (1.37±1.11 vs. 1.12±0.61 days, p=0.001). Throughout multivariable analysis, use of BC was found to be significant factor for favorable post-operative results.

CONCLUSION

This study showed that the patients who received BC during UIA clipping had lower incidence of metabolic acidosis, earlier extubation and shorter ICU stay compared to those who received NS. Therefore, using BC as a peri-operative fluid can be recommended for patients who undergo surgery for UIA.

Three-dimensional aneurysm volume measurements show no correlation between coil packing density and recurrence

Objective

Endovascular treatment is the mainstay therapy for brain aneurysms. About 15% of patients need re-treatment within six months due to early recanalization. In this study, we investigate risk factors associated with treatment failure.

Methods

This retrospective cohort study includes endovascularly treated aneurysm cases between July 2012 and December 2015 at the University of California Davis Medical Center with pre-treatment and early post-treatment imaging. Thin cut 3D aneurysm volume rendering was used for morphologic analyses. Univariate and bivariate analyses were conducted to evaluate differences between patients and clinical factors by treatment failure.

Results

Of the 50 patients who met the inclusion criteria, 41 (82.0%) were female, with an average age of 61 years. Most aneurysms were on the anterior communicating artery (40%) or posterior communicating artery (22.0%), and 34 (68%) aneurysms were ruptured. Early treatment failure was observed in 14 (28.0%) of endovascularly treated patients. Raymond-Roy class (RRC) was significantly associated with treatment failure (p = 0.0052), with 10 out of the 14 cases (71.4%) with early recanalization having an RRC of 3. Coil packing density did not associate with aneurysm recanalization (p = 0.61).

Conclusion

In our single institution series, patient characteristics, aneurysm characteristics, or coil packing density did not affect early aneurysm recanalization. RRC was the best predictor of early recanalization; however, further confirmation with additional studies are required. Although this study focused on early treatment failure, late recanalization has been shown with longer follow up. Further investigation into factors associated with late treatment failure will need further investigation. New intrasaccular devices and flow diverters will also likely play a role in reducing recurrence in the future as these treatments gain usage.

Smoking status and unruptured intracranial aneurysm among brain health check-up examinees: a cross-sectional study in Japan

Objective: Although it is well known that smoking is a risk factor for subarachnoid hemorrhage, the association between smoking and unruptured intracranial aneurysms remains unclear. The aim of the present study was to investigate whether smoking status was associated with unruptured intracranial aneurysms among Japanese brain health check-up examinees.

Materials and Methods: We conducted a cross-sectional study of 1,496 adults (aged 26–90 years) undergoing brain health check-ups at a single community medical support hospital in Akita, Japan between 2009 and 2013. In Japan, people can discretionarily undergo a brain health check-up for early detection of unruptured intracranial aneurysms or subarachnoid hemorrhages. Participants responded to a questionnaire on lifestyle, such as smoking status, and were classified into three groups: never, former, and current smoker. The evaluation of unruptured intracranial aneurysms detected by magnetic resonance angiography was performed by an expert physician. Multiple logistic regression models were used to estimate the odds ratio for unruptured intracranial aneurysms. We performed statistical analyses by age, sex, and family history of stroke.

Results: The number of participants with unruptured intracranial aneurysms was 43 (2.9%). The mean age (standard deviation) and proportion of males was 55.8 (9.5) years and 53.3%, respectively. The adjusted odds ratios (95% confidence intervals) for unruptured intracranial aneurysms of 1.21 (0.48–3.08) among former smokers and 2.88 (1.10–7.50) among current smokers were compared to those of never smokers (p-trend = 0.041). After stratifying by age, sex, and family history of stroke, no interactions were found.

Conclusion: This cross-sectional study conducted in Japan showed that smoking was positively associated with unruptured intracranial aneurysms among brain health check-up examinees.

Exploring the association of long noncoding RNA expression profiles with intracranial aneurysms, based on sequencing and related bioinformatics analysis

Background

The present study aims to investigate the complete long non-coding RNA (lncRNA) and messenger RNA (mRNA) expression profiles in Intracranial aneurysm (IA) patients and controls by RNA sequencing, which reveals the lncRNA with predictive value for IA risk.

Methods

The comprehensive lncRNA and mRNA expression profiles were detected by RNA-Seq in human IA walls and superficial temporal arteries (STAs), followed by bioinformatics analyses, such as GO analysis, KEGG pathway analysis, and CNC network construction. Subsequently, qRT-PCR was used to profile the expression levels of selected lncRNA (lncRNA ENST000000576153, lncRNA ENST00000607042, lncRNA ENST00000471220, lncRNA ENST00000478738, lncRNA MALAT1, lncRNA ENST00000508090 and lncRNA ENST00000579688) in 30 (small) or 130 (large) peripheral blood leukocytes, respectively. Multivariate logistic regression was utilized to analyze the effects of lncRNA on IA. Receiver operating characteristic (ROC) curve was further drawn to explore the value of lncRNA in predicting IA.

Results

Totally 900 up-regulated and 293 down-regulated lncRNAs, as well as 1297 up-regulated and 831 down-regulated mRNAs were discovered in sequencing. Enrichment analyses revealed that they were actively involved in immune/inflammatory response and cell adhesion/extracellular matrix. Co-expression analysis and further enrichment analyses showed that five candidate lncRNAs might participate in IA’s inflammatory response. Besides, after controlling other conventional risk factors, multivariate logistic regression analysis disclosed that low expression of lncRNA ENST00000607042, lncRNA ENST00000471220, lncRNA ENST00000478738, lncRNA MALAT1 in peripheral blood leukocytes were independent risk factors for IA. LncRNA ENST00000607042 has superior diagnostic value for IA.

Conclusions

This study reveals the complete lncRNAs expression profiles in IA. The inflammatory response was closely related to IA. Besides, lncRNA ENST00000607042 might be a novel biomarker for IA risk.

Are Fetal-Type Posterior Cerebral Arteries Associated With an Increased Risk of Posterior Communicating Artery Aneurysms?

BACKGROUND

Fetal-type posterior cerebral arteries (F-PCAs) might result in alterations in hemodynamic flow patterns and may predispose an individual to an increased risk of posterior communicating artery aneurysms (PCoAAs).

OBJECTIVE

To determine the association between PCoAAs and the presence of ipsilateral F-PCAs.

METHODS

We retrospectively reviewed the radiographic findings from 185 patients harboring 199 PCoAAs that were treated at our institution between 2005 and 2015. Our study population consisted of 4 cohorts: (A) patients with 171 internal carotid arteries (ICAs) harboring unilateral PCoAAs; (B) 171 unaffected ICAs in the same patients from the first group; (C) 28 ICAs of 14 patients with bilateral PCoAAs; and (D) 180 ICAs of 90 patients with aneurysms in other locations. We then determined the presence of ipsilateral F-PCAs and recorded all aneurysm characteristics.

RESULTS

Group A had the highest prevalence of F-PCAs (42%) compared to 19% in group B, 3% in group C, and 14% in group D (odds ratio A : B = 3.041; A : C = 19.626; and A : D = 4.308; P < .001). PCoAAs were associated with larger diameters of the posterior communicating arteries (median value 1.05 vs 0.86 mm; P = .001). The presence of F-PCAs was associated with larger sizes of the aneurysm necks (median value 3.3 vs 3.0 mm; P = .02).

CONCLUSION

PCoAAs were associated with a higher prevalence of ipsilateral F-PCAs. This variant was associated with larger sizes of the aneurysm necks but was not associated with the sizes of the aneurysm domes or with their rupture statuses.

Management of incidentally found unruptured intracranial aneurysms

Incidentally found unruptured intracranial aneurysms are increasing because of the popularity of medical checkups with cerebrovascular imaging and the recent growing interest in health. Accordingly, surgical or endovascular treatments are also increasing in prevalence to improve aneurysm-related symptoms or prevent the rupture of aneurysms causing devastating conditions. However, treatment plans should be carefully determined based on the natural history of aneurysms, comorbidities of the patients, and institutional situations because of the relatively low risk of rupture, no uncommon treatment-related complications, and considerable economical and psychological burdens. Recently, domestic and international clinical guidelines for unruptured intracranial aneurysms were introduced, and the guidelines have been continuously revised according to advancements in imaging and treatment techniques. Here, this review paper introduces the clinical characteristics of unruptured intracranial aneurysms including the epidemiology, risk factors of development, growth and rupture, natural course, symptoms and signs, imaging tools for diagnosis and follow-up, and treatment methods. This paper also includes recent international prospective trials, analytic reports with big data from national health insurance and health insurance review and assessment services, and the guidelines of Korea and other foreign countries.

Prediction of Intracranial Aneurysm Risk using Machine Learning

An efficient method for identifying subjects at high risk of an intracranial aneurysm (IA) is warranted to provide adequate radiological screening guidelines and effectively allocate medical resources. We developed a model for pre-diagnosis IA prediction using a national claims database and health examination records. Data from the National Health Screening Program in Korea were utilized as input for several machine learning algorithms: logistic regression (LR), random forest (RF), scalable tree boosting system (XGB), and deep neural networks (DNN). Algorithm performance was evaluated through the area under the receiver operating characteristic curve (AUROC) using different test data from that employed for model training. Five risk groups were classified in ascending order of risk using model prediction probabilities. Incidence rate ratios between the lowest- and highest-risk groups were then compared. The XGB model produced the best IA risk prediction (AUROC of 0.765) and predicted the lowest IA incidence (3.20) in the lowest-risk group, whereas the RF model predicted the highest IA incidence (161.34) in the highest-risk group. The incidence rate ratios between the lowest- and highest-risk groups were 49.85, 35.85, 34.90, and 30.26 for the XGB, LR, DNN, and RF models, respectively. The developed prediction model can aid future IA screening strategies.

Intracranial aneurysms in patients receiving kidney transplantation for autosomal dominant polycystic kidney disease

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease, leading to kidney failure. One of the most serious extrarenal complications of ADPKD is comorbid intracranial aneurysms. The aim of this study is to evaluate the prevalence, rupture rate, and treatment outcomes of intracranial aneurysms in ADPKD.

METHODS

Adult patients with a documented diagnosis of ADPKD who received kidney transplantation at our center from January 1994 to December 2018 were included in the study. Medical history, physical examination, laboratory findings, imaging studies, and operation records were collected and analyzed from our database.

RESULTS

Among 154 kidney transplant recipients with ADPKD, 113 (73.4%) patients were screened for intracranial aneurysms preoperatively. Twenty three patients (14.9%) had intracranial aneurysms with mean diameter size of 4.5 ± 2.7 mm. Nine patients (5.8%) experienced aneurysm rupture and the mean age at time of rupture was 34.9 ± 9.3 years. Twelve patients (52.2%) presented with multiple aneurysms. The most common aneurysm location was the bifurcation of the middle cerebral artery (34.9%). Clipping was the most common treatment in both ruptured and unruptured aneurysms.

CONCLUSIONS

Intracranial aneurysms are more frequent in patients with ADPKD, and the average age of intracranial artery rupture in patients with ADPKD is earlier than in the general population. It is necessary to consider proper evaluation and management of intracranial aneurysms when counseling ADPKD patients who will undergo kidney transplantation.

Characteristics and Treatment Outcome of Intracranial Aneurysms in Children and Adolescents

Objective

Intracranial aneurysms are not common in young age patients. We sought to find the characteristics of the intracranial aneurysms in patients under 20 years of age.

Methods

We reviewed 23 consecutive patients ≤20 years of age treated for their intracranial aneurysms during the period from 1995 to 2017. From medical records and imaging studies, we gathered data on age, sex, presentation, associated medical condition, location and characteristics of aneurysms, treatment and clinical outcomes.

Results

The patients’ ages ranged from 13 months to 20 years (median, 14 years). There were 16 males and seven females (male to female ratio, 2.3 : 1) with 31 aneurysms. Clinical presentations included sudden severe headache in 61%, followed by altered mentality in 17% and seizure in 17%. More than one-fourth patients had specific medical conditions related to the development of the cerebral aneurysms. The majority of aneurysms occurred in the anterior circulation (71%), and were saccular (71%). There were each three patients with false aneurysms (13%) and giant aneurysms (13%), and only one patient with multiple aneurysms (4%). We treated 22 patients : 21 aneurysms with the endovascular methods, three with open surgery, and one with combined treatment. Good functional outcome could be achieved in 86% during the follow-up period.

Conclusion

In this series, the young-age patients with intracranial aneurysms were characterized by male predominance, related specific medical conditions, low incidence of multiple aneurysms, high incidence of giant aneurysms and good functional outcome after treatment.

Risk Factors for Unruptured Intracranial Aneurysms and Subarachnoid Hemorrhage in a Prospective Population-Based Study

Background and Purpose- We wanted to evaluate potential risk factors for unruptured intracranial aneurysms (UIAs) and aneurysmal subarachnoid hemorrhage (aSAH) in a large, prospective study of the general population with risk factors collected before the detection of UIA or aSAH. Methods- All residents ≥20 years were invited to the HUNT (The Nord-Trøndelag Health Study). In this study, 89 951 participants were included. The study included standardized measurements of blood pressure and self-administered questionnaires. Cases of UIA and aSAH from 1999 to 2014 were identified using hospital records and the Norwegian Cause of Death Register. Hazard ratios with CIs were estimated using Cox regression analysis. Results- The detection rate of UIA was 8.2 per 100 000 person-years (97 patients). Current smoking (hazard ratio, 4.1; 95% CI, 2.4-7.1) and female sex (hazard ratio, 2.8; 95% CI, 1.7-4.5) were associated with markedly increased risk of UIA, but we found no association with systolic blood pressure (P for trend 0.62). The incidence of aSAH was 9.9 per 100 000 person-years (117 patients). The most important risk factors for aSAH were current smoking, female sex and increasing blood pressure (P for trend 0.006 for systolic blood pressure). Conclusions- In contrast to previous studies on risk factors of UIA, we found no association with systolic blood pressure. However, there was a strong association between systolic blood pressure and aSAH in the same population. Current smoking and female sex were associated with both diseases.

ANXA3 Silencing Ameliorates Intracranial Aneurysm via Inhibition of the JNK Signaling Pathway

Intracranial aneurysm (IA) rupture is a major cause of stroke death. Alteration of vascular smooth muscle cell (VSMC) function and phenotypic modulation plays a role in aneurysm progression. In the present study, we investigated the role of Annexin A3 (ANXA3) silencing in IA with the interaction of the c-Jun N-terminal kinase (JNK) signaling pathway. In IA and VSMCs of IA, the relationship between ANXA3 and the JNK signaling pathway was verified. To investigate the specific mechanism of ANXA3 silencing in IA, we transfected VSMCs with the overexpressed or small interfering RNA (siRNA) of ANXA3, or treated them with an inhibitor of the JNK signaling (SP600125). Cell counting kit-8 (CCK-8) assay was conducted to detect cell viability, and flow cytometry was conducted to assess cell cycle and apoptosis so as to evaluate the gain- and loss-of-function of ANXA3 and investigate the involvement of the JNK signaling pathway. The aneurysm wall of IA cells demonstrated an elevated level of ANXA3 expression and an activated JNK signaling pathway. VSMCs treated with siRNA-ANXA3 or SP600125 showed decreased expression of JNK, caspase-3, osteopontin (OPN), Bax, and matrix metalloproteinase-9 (MMP-9), as well as phosphate (p)-JNK, but increased the expression of α smooth muscle actin (α-SMA), β-tubulin, and Bcl-2. ANXA3 silencing or inactivation of the JNK signaling pathway also enhanced proliferation and repressed apoptosis of VSMCs. Collectively, this study shows that the silencing of ANXA3 can rescue VSMC function in IAs by inhibiting the phosphorylation and activation of the JNK signaling pathway. These findings may provide a potential therapy for the molecular treatment of IAs.

Epidemiology of ruptured brain arteriovenous malformation: a National Cohort Study in Korea

OBJECTIVE

Brain arteriovenous malformation (BAVM) is a rare cerebrovascular disease that causes intracranial hemorrhage. Although several reports have demonstrated the epidemiological features of BAVM in Western countries, no epidemiological investigations regarding BAVM have been reported in Korea. The authors aimed to investigate the national epidemiology of ruptured BAVM in a Korean population.

METHODS

The authors used data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC). The original cohort included approximately 1 million individuals (2% of the Korean population) with 12-year claim data (2002-2013). To construct an initial cohort for investigation, the authors selected 1,016,820 registered individuals in 2005. Subjects with a history of cerebrovascular disease (code I6xx) and BAVM (Q282) between 2002 and 2004 were washed-out to identify incident cases. During the 9-year follow-up (2005-2013), the incidence of BAVM was calculated using the earliest date of diagnosis of ruptured or unruptured BAVM. Direct standardization was applied to the crude incidence. Mortality and disability were evaluated using registration data. Related diagnostic procedures were also analyzed.

RESULTS

A total of 8,802,696 person-years of observation were noted. During observation, 308 patients were diagnosed with a ruptured BAVM. The crude incidence of ruptured BAVM was 3.5 per 100,000 person-years. There was no sex difference in incidence. The mortality rate for patients with a ruptured BAVM 1 month after diagnosis was 12.7%. At 1-year and 5-year follow-up examinations, mortality rates were 17.2% and 22.1%, respectively. Severe disability-free survival rates of patients with ruptured AVMs were 75.3% and 69.8% at 1-year and 5-year follow-up, respectively.

CONCLUSIONS

The standardized incidence of ruptured BAVMs was 3.6 per 100,000 person-years in Korea. Ruptured BAVMs resulted in high mortality and disability rates.

The Ottawa subarachnoid hemorrhage clinical decision rule for classifying emergency department headache patients

BACKGROUND

Subarachnoid hemorrhage (SAH) is a serious cause of headaches. The Ottawa subarachnoid hemorrhage (OSAH) rule helps identify SAH in patients with acute nontraumatic headache with high sensitivity, but provides limited information for identifying other intracranial pathology (ICP).

OBJECTIVES

To assess the performance of the OSAH rule in emergency department (ED) headache patients and evaluate its impact on the diagnosis of intracranial hemorrhage (ICH) and other ICP.

METHOD

We conducted a retrospective cohort study from January 2016 to March 2017. Patients with acute headache with onset within 14 days of the ED visit, were included. We excluded patients with head trauma that occurred in the previous 7 days, new onset of abnormal neurologic findings, or consciousness disturbance. According to the OSAH rule, patients with any included predictors required further investigation.

RESULTS

Of 913 patients were included, 15 of them were diagnosed with SAH. The OSAH rule had 100% (95% CI, 78.2%-100%) sensitivity and 37.0% (95% CI, 33.8-40.2%) specificity for identifying SAH. Twenty-two cases were identified as SAH or ICH with 100% sensitivity (95% CI, 84.6%-100%) and 37.3% (95% CI, 34.1%-40.5%) specificity. As for non-hemorrhagic ICP, both the sensitivity and negative predictive values (NPV) decreased to 75.0% (95% CI, 53.3%-90.2%) and 98.2% (95% CI, 96.1%-99.3%), respectively.

CONCLUSIONS

The OSAH rule had 100% sensitivity and NPV for diagnosing SAH and ICH with acute headache. The sensitivity and specificity were lower for non-hemorrhagic ICP. The OSAH rule may be an effective tool to exclude acute ICH and SAH in our setting.

A Phantom Menace to Medical Personnel During Endovascular Treatment of Cerebral Aneurysms: Real-Time Measurement of Radiation Exposure During Procedures

BACKGROUND

The number of endovascular treatment procedures performed for cerebral aneurysms has markedly increased. However, little is known about the annual effective radiation dose to medical staff in neurointervention fields. We performed a retrospective observational study to investigate the real-time radiation dose to surgeons, nurses, anesthesiologists, and radiologic technologists during endovascular treatment of intracranial aneurysms.

METHODS

We measured the real-time radiation doses for 2 weeks using standard and reinforced protection, during which 28 procedures were performed, including 23 coil embolizations for unruptured intracranial aneurysms. Four procedures were excluded because of an inadequately equipped sensor, which resulted in inappropriate data collection. The procedure time was defined from intubation to extubation. Five RaySafe i2 detectors were installed at the chest level of the operator, attending nurse, radiologic technologist, and anesthesiologist and just inside the front door of the hybrid operating room.

RESULTS

The median doses per session with standard protection to the operator, attending nurse, anesthesiologist, and radiologic technologist were 11.16, 2.60, 4.76, and 1.93 μSv, respectively. The dose to the operator, attending nurse, and anesthesiologist had decreased to 6.63, 0.39, and 1.52 μSv under reinforced protection, respectively. However, the session dose for the radiologic technologist had increased to 3.12 μSv.

CONCLUSIONS

We confirmed the differences in the amount of radiation exposure for different roles. An additional lead screen, which provided more effective protection on the operator side, was proved effective for attenuating radiation exposure during endovascular treatment. All personnel involved in the hybrid operating room were exposed to acceptable effective doses.

Atrial fibrillation in patients with first-ever stroke: Incidence trends and antithrombotic therapy before the event

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia among adults. Despite the proven advantages in primary and secondary stroke prevention in patients with AF, oral anticoagulation (OAC) therapy is still underused in many countries. In this study, we investigated the incidence of AF-related ischemic stroke over the past decade in South Korea and trends of preventive antithrombotic therapy use before stroke in a nationwide cohort.

Methods and findings

The data source for this study was a nationwide sample cohort comprising 1,025,340 individuals that was established by the nationwide health insurance system in 2002. A total of 10,215 patients with acute ischemic stroke (AIS) were selected from the cohort between 2004 and 2013. AF was identified in 1,662 patients, and 979 patients had preexisting AF before AIS. The annual proportion of patients with AIS with AF gradually increased from 13.4% to 22.6% over the study period (p for trends <0.001). Only 14.0% of patients with high risk AF were receiving OAC before the stroke, and this proportion remained relatively constant during the study period. However, the proportion of patients treated with antiplatelet agents had increased from 18.8% in 2004 to 45.3% in 2013, while that of patients receiving no antithrombotic agent decreased from 64.6% in 2004 to 43.9% in 2013. As a limitation, no information was available about non-vitamin K antagonist oral anticoagulants, because they were widely used since late 2014 in Korea.

Conclusions

The number of patients with AIS and AF has steadily increased over the last 10 years in Korea. However, a small portion of patients with AF were receiving OAC therapy before the stroke and about half of the patients did not receive any antithrombotic medication. Our study demonstrates that there is huge gap between clinical practice and treatment guidelines for patients with AF in Korea.

TLR4 gene polymorphisms rs11536889 is associated with intracranial aneurysm susceptibility

Intracranial aneurysm (IA) is a common lesion which often present asymptomatic until the time of rupture and result in subarachnoid hemorrhage (SAH). The pathogenesis of IA formation is complex and is influenced by both genetic and environmental risk factors. For exploring the detailed molecular and cellular mechanisms involved in the pathogenesis of IA, recent studies indicated inflammatory pathways and their genetic variants may as potential biomarkers. In this study, functionally relevant polymorphisms in the toll-like receptor 4 (TLR4) were screened in 330 IA patients and 313 controls from a Han Chinese population. Eight single nucleotide gene polymorphisms (SNPs) genotyped by the Improved Multiple Ligase Detection Reaction (iMLDR) method. Our results indicated that the presence of the minor allele (C) of the TLR4 SNP rs11536889 was associated with a decreased risk of IA (C vs. G, OR = 0.731; 95% CI 0.567-0.943; P = 0.017). This association was also present at the genotype level in a codominant model (GC vs. GG, OR = 0.447; 95% CI 0.226-0.884; P = 0.020) and a recessive model (CC vs. GG + GC, OR = 0.489; 95% CI 0.250-0.955; P = 0.035). In summary, we firstly found that the TLR4 SNP rs11536889 was significantly associated with the susceptibility of IA. Our results indicated TLR4 SNP rs11536889 may be a marker for IA risk, though the exact functional roles of TLR4 SNP rs11536889 in IA formation are still not very clear.

Nationwide Mortality Data after Flow-Diverting Stent Implantation in Korea

Objective

To investigate nationwide statistics on flow-diverting stent usage for cerebral aneurysm treatment and related mortality data.

Methods

We requested data extraction from the National Health Insurance Service claims database using electronic data interchange codes (J3207064, J3207073). Patient and hospital information as well as death statistics were collected from the database.

Results

A total of 169 procedures were performed using flow-diverting stents for cerebral aneurysm treatment from November 2014 to December 2016 in Korea. The majority of primary diagnosis was unruptured intracranial aneurysm. During the study period, nine subjects died, including one patient initially diagnosed with subarachnoid hemorrhage. The crude mortality rate was 5.3%. Five patients died within one month after the procedure; therefore, the estimated periprocedural mortality rate was 3.0±1.3%. The mortality rate as of the last day of 2016 was 6.3±2.1%.

Conclusion

In a 171 person-year follow-up in a Korean series, nine deaths occurred after flow-diverting stent treatment. The crude mortality rate in Korea (5.3%) was higher than that reported in a previous meta-analysis (3.8%).

Aneurysm of azygos anterior cerebral artery associated with falcine meningioma: Case Report and review of the literature

BACKGROUND

The azygos anterior cerebral artery (ACA) is an uncommon intracranial vascular anomaly of the circle of Willis. Identification of aneurysm from azygos ACA with anterior falcine meningioma is an extremely rare association. The aim of the present study is to report the case of an adult female with a ruptured aneurysm from azygos ACA in association with an anterior falcine meningioma.

CASE DESCRIPTION

A 65-year-old female was admitted in the Emergency Department reporting sudden onset of severe headache. Computed tomography (CT) revealed an intracerebral hematoma and an expansive calcified lesion. AngioCT showed the presence of a large aneurysm in the distal portion of the azygos ACA. During the surgical procedure, it was possible to visualize the aneurysm in contact with an expansive lesion arising from the anterior third of the falx. Microsurgical clipping of the aneurysm was performed uneventfully and partial resection of the tumor was done. Histopathological analysis showed a fibrous meningioma. The patient was discharged home on the seventh postoperative day in good clinical conditions.

CONCLUSION

The association of aneurysm from azygos ACA and falcine meningioma is an extremely rare event and must be remembered when expansive masses are present in the vicinity of vascular lesions.