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1.
Neurocrit Care ; 40(1): 177-186, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37610642

ABSTRACT

BACKGROUND: Poor-grade aneurysmal subarachnoid hemorrhage (aSAH), defined as Hunt and Hess (HH) grades IV and V, is a challenging disease because of its high mortality and poor functional outcomes. The effectiveness of bundled treatments has been demonstrated in critical diseases. Therefore, poor-grade aSAH bundled treatments have been established. This study aims to evaluate whether bundled treatments can improve long-term outcomes and mortality in patients with poor-grade aSAH. METHODS: This is a comparative study using historical control from 2008 to 2022. Bundled treatments were introduced in 2017. We compared the rate of favorable outcomes (modified Rankin Scale score 0-2) at 6 months and mortality before and after the introduction of the bundled treatments. To eliminate confounding bias, the propensity score matching method was used. RESULTS: A total of 90 consecutive patients were evaluated. Forty-three patients received bundled treatments, and 47 patients received conventional care. The proportion of patients with HH grade V was higher in the bundle treatment group (41.9% vs. 27.7%). Conversely, the proportion of patients with fixed pupils on the initial examination was higher in the conventional group (30.2% vs. 38.3%). After 1:1 propensity score matching, 31 pairs were allocated to each group. The proportion of patients with 6-month favorable functional outcomes was significantly higher in the bundled treatments group (46.4% vs. 20.7%, p = 0.04). The 6-month mortality rate was 14.3% in the bundled treatments group and 27.3% in the conventional group (p = 0.01). Bundled treatments (odd ratio 14.6 [95% confidence interval 2.1-100.0], p < 0.01) and the presence of an initial pupil reflex (odd ratio 12.0 [95% confidence interval 1.4-104.6], p = 0.02) were significantly associated with a 6-month favorable functional outcome. CONCLUSIONS: The bundled treatments improve 6-month functional outcome and mortality in patients with poor-grade aSAH.


Subject(s)
Subarachnoid Hemorrhage , Humans , Subarachnoid Hemorrhage/diagnosis , Treatment Outcome , Propensity Score
2.
J Neuroradiol ; 51(1): 59-65, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37247754

ABSTRACT

PURPOSE: In the endovascular era, postcoiling recanalization of cerebral aneurysms is occurring with greater frequency. Repeat coiling is usually done to prevent rebleeding, although long-term outcomes of re-embolization have yet to be adequately investigated. The present study was undertaken to assess clinical and radiographic outcomes of re-embolization in recanalized aneurysms, focusing on procedural safety, efficacy, and durability. METHOD: In this retrospective review, we examined 308 patients with 310 recurrent aneurysms. All lesions were re-coiled, once major recanalization (after initial coil embolization) was established. Medical records and radiologic data amassed during extended follow-up were then subject to review. Cox proportional hazards regression analysis was undertaken to identify risk factors for subsequent recurrence. RESULT: During a lengthy follow-up (mean, 40.2 ± 33.0 months), major recanalization developed again in 87 aneurysms (28.1%). Multivariable Cox regression analysis linked re-recanalization to initial saccular neck width (p=.003) and autosomal dominant polycystic kidney disease (ADPKD; p<.001). Stent implantation (p=.038) and successful occlusion at second coiling (p=.012) were protective against later recanalization in this setting. The more recent the second embolization was performed, the lower the risk of further recurrence (p=.023). Procedure-related complications included asymptomatic thromboembolism (n = 9), transient ischemic neurologic deficits (n = 2), procedural bleeding (n = 1), and coil migration (n = 1), but there were no residual effects or deaths. CONCLUSION: Repeat coil embolization is a safe therapeutic option for recanalized cerebral aneurysms. Wide-necked status and ADPKD emerged as risks for subsequent recanalization, whereas successful occlusion and stent implantation seemed to reduce the likelihood of recurrence after re-embolization procedures.


Subject(s)
Embolization, Therapeutic , Intracranial Aneurysm , Polycystic Kidney, Autosomal Dominant , Humans , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/therapy , Intracranial Aneurysm/etiology , Treatment Outcome , Follow-Up Studies , Polycystic Kidney, Autosomal Dominant/etiology , Polycystic Kidney, Autosomal Dominant/therapy , Cerebral Angiography , Stents , Embolization, Therapeutic/methods , Retrospective Studies
3.
J Hum Genet ; 68(10): 713-720, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37365321

ABSTRACT

Genome-wide association study has limited to discover single-nucleotide polymorphisms (SNPs) in several ethnicities. Here, we investigated an initial GWAS to identify genetic modifiers predicting with adult moyamoya disease (MMD) in Koreans. GWAS was performed in 216 patients with MMD and 296 controls using the large-scale Asian-specific Axiom Precision Medicine Research Array. A subsequent fine-mapping analysis was conducted to assess the causal variants associated with adult MMD. A total of 489,966 out of 802,688 SNPs were subjected to quality control analysis. Twenty-one SNPs reached a genome-wide significance threshold (p = 5 × 10-8) after pruning linkage disequilibrium (r2 < 0.8) and mis-clustered SNPs. Among these variants, the 17q25.3 region including TBC1D16, CCDC40, GAA, RNF213, and ENDOV genes was broadly associated with MMD (p = 3.1 × 10-20 to 4.2 × 10-8). Mutations in RNF213 including rs8082521 (Q1133K), rs10782008 (V1195M), rs9913636 (E1272Q), rs8074015 (D1331G), and rs9674961 (S2334N) showed a genome-wide significance (1.9 × 10-8 < p < 4.3 × 10-12) and were also replicated in the East-Asian populations. In subsequent analysis, RNF213 mutations were validated in a fine-mapping outcome (log10BF > 7). Most of the loci associated with MMD including 17q25.3 regions were detected with a statistical power greater than 80%. This study identifies several novel and known variations predicting adult MMD in Koreans. These findings may good biomarkers to evaluate MMD susceptibility and its clinical outcomes.


Subject(s)
Moyamoya Disease , Humans , Adult , Moyamoya Disease/genetics , Genome-Wide Association Study , Genetic Predisposition to Disease , Polymorphism, Single Nucleotide , Transcription Factors/genetics , Ubiquitin-Protein Ligases/genetics , Adenosine Triphosphatases/genetics
4.
Biometrics ; 79(2): 592-596, 2023 06.
Article in English | MEDLINE | ID: mdl-36346088

ABSTRACT

We reinterpret the instrumented difference-in-differences (iDID) under a linear instrumental variables (IV) model. Under the linear IV model, we show why iDID is a clear improvement over two existing methods, difference-in-differences (DID) and a cross-sectional, IV analysis. We also re-express some of the assumptions of iDID using familiar, regression-based identification assumptions. We conclude with a method inspired by the linear IV model that can potentially remedy the weak identification problem in iDID.


Subject(s)
Tolnaftate , Cross-Sectional Studies , Linear Models
5.
Cerebrovasc Dis ; : 1-8, 2023 Sep 11.
Article in English | MEDLINE | ID: mdl-37696264

ABSTRACT

INTRODUCTION: A proper stratification of intracranial aneurysms is critical in identifying rupture-destined aneurysms and unruptured intracranial aneurysms. We aimed to determine the utility of geometric and hemodynamic indexes in differentiating two types of aneurysms and to examine the characteristics of natural evolutionary changes of unruptured aneurysms. METHODS: Rupture-destined aneurysm refers to an aneurysm that undergoes subsequent aneurysmal subarachnoid hemorrhage (SAH). On the other hand, an unruptured intracranial aneurysm is characterized by an aneurysm that does not experience rupture during serial time-of-flight magnetic resonance angiography (TOF-MRA). In addition to geometric indexes, signal intensity gradient (SIG), an in vivo approximated wall shear stress from TOF-MRA, was measured in aneurysms. The difference between the maximum and minimum values of SIG in an aneurysm compared to parent arterial values was designated as the delta-SIG ratio. RESULTS: This study analyzed 20 rupture-destined aneurysms in 20 patients and 45 unruptured intracranial aneurysms in 41 patients with follow-up TOF-MRA. While geometric indexes did not show differences between the two groups, the delta-SIG ratio was higher in the rupture-destined aneurysms (1.5 ± 0.6 vs. 1.1 ± 0.3, p = 0.032). The delta-SIG ratio showed a higher area under the receiver operating characteristic curve for SAH than the size ratio (0.72 [95% CI, 0.58-0.87] vs. 0.56 [95% CI, 0.41-0.72], p = 0.033). The longitudinal re-examination of TOF-MRA in the unruptured intracranial aneurysms revealed evidence of aneurysmal growth, while concurrently exhibiting hemodynamic stability. CONCLUSION: The delta-SIG ratio showed higher discriminatory results between the two groups compared to geometric indexes. Aneurysmal rupture risk should be assessed by considering both geometric and hemodynamic information. This study was registered on ClinicalTrials.gov (NCT05450939).

6.
Cerebrovasc Dis ; 52(6): 624-633, 2023.
Article in English | MEDLINE | ID: mdl-36889296

ABSTRACT

INTRODUCTION: Concerns about spontaneous intracranial hemorrhages (sICHs) have increased over time with the increasing use of antithrombotic agents. Hence, we aimed to analyze the risk and risk fractions for antithrombotics in sICHs in South Korea. METHODS: From the National Health Insurance Service-National Sample Cohort including 1,108,369 citizens, 4,385 cases, aged 20 years or more and newly diagnosed as sICHs between 2003 and 2015, were included in this study. A total of 65,775 sICH-free controls were randomly selected at a ratio of 1:15 from individuals with the same birth year and sex according to a nested case-control study design. RESULTS: Although the incidence rate of sICHs started to decrease from 2007 onward, the use of antiplatelets, anticoagulants, and statins continued to increase. Antiplatelets (adjusted odds ratio [OR] 3.59, 95% confidence interval [CI] 3.18-4.05), anticoagulants (adjusted OR 7.46, 95% CI 4.92-11.32), and statins (adjusted OR 1.98, 95% CI 1.79-2.18) were significant risk factors for sICHs even after adjusting for hypertension, alcohol intake, and cigarette smoking. From 2003-2008 to 2009-2015, the population-attributable fractions changed from 28.0% to 31.3% for hypertension, from 2.0% to 3.2% for antiplatelets, and from 0.5% to 0.9% for anticoagulants. CONCLUSION: Antithrombotic agents are significant risk factors for sICHs, and their contribution is increasing over time in Korea. These findings are expected to draw the attention of clinicians to precautions to be taken when prescribing antithrombotic agents.


Subject(s)
Hydroxymethylglutaryl-CoA Reductase Inhibitors , Hypertension , Humans , Anticoagulants/adverse effects , Fibrinolytic Agents/adverse effects , Platelet Aggregation Inhibitors/adverse effects , Case-Control Studies , Hydroxymethylglutaryl-CoA Reductase Inhibitors/adverse effects , Intracranial Hemorrhages/chemically induced , Intracranial Hemorrhages/epidemiology , Hypertension/drug therapy
7.
Neurosurg Focus ; 55(4): E12, 2023 10.
Article in English | MEDLINE | ID: mdl-37778045

ABSTRACT

OBJECTIVE: Much emphasis has been put on the use of antiplatelet medication for the prevention of ischemic events in the treatment of cerebral aneurysms with stent assistance. In this regard, the effectiveness and safety of a low-dose prasugrel regimen during the periprocedural period was recently reported. The purpose of this study was to present the outcomes of patients on low-dose prasugrel regimens during the follow-up period after stent-assisted coil embolization (SACE) of cerebral aneurysms. METHODS: For the 396 consecutive patients undergoing SACE procedures, low-dose prasugrel therapy (5 mg of prasugrel and 100 mg of aspirin) was recommended for 3 months after the endovascular treatment. The authors performed a retrospective review of a single-center experience focusing on delayed ischemic events beyond 1 month after treatment. The mean follow-up period was 24.6 ± 11.3 months. RESULTS: In this cohort of patients on a low-dose prasugrel regimen, cerebral infarction occurred in 1 patient (0.3%, 95% CI 0%-1.8%) beyond 1 month after SACE. No intracranial hemorrhage occurred. Overall ischemic events occurred in 14 patients (3.5%, 95% CI 2.1%-5.9%), all within 6 months of the coiling procedure. All patients had transient symptoms. The events occurred within 2 months after cessation of prasugrel in 11 patients (78.6%). Prasugrel maintenance for 6 months was found to result in lower ischemic events compared with maintenance for 3 months. CONCLUSIONS: For patients undergoing SACE, a low-dose prasugrel regimen was a safe and reliable treatment option for the prevention of delayed ischemic events. Transient ischemic events often occurred within 2 months of stopping prasugrel medication.


Subject(s)
Embolization, Therapeutic , Intracranial Aneurysm , Humans , Prasugrel Hydrochloride/adverse effects , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/drug therapy , Intracranial Aneurysm/surgery , Embolization, Therapeutic/adverse effects , Embolization, Therapeutic/methods , Platelet Aggregation Inhibitors/adverse effects , Stents/adverse effects , Retrospective Studies , Treatment Outcome
8.
Multivariate Behav Res ; 58(2): 408-440, 2023.
Article in English | MEDLINE | ID: mdl-35103508

ABSTRACT

Recently, there has been growing interest in using machine learning methods for causal inference due to their automatic and flexible ability to model the propensity score and the outcome model. However, almost all the machine learning methods for causal inference have been studied under the assumption of no unmeasured confounding and there is little work on handling omitted/unmeasured variable bias. This paper focuses on a machine learning method based on random forests known as Causal Forests and presents five simple modifications for tuning Causal Forests so that they are robust to cluster-level unmeasured confounding. Our simulation study finds that adjusting the default tuning procedure with the propensity score from fixed effects logistic regression or using variables that are centered to their cluster means produces estimates that are more robust to cluster-level unmeasured confounding. Also, when these parametric propensity score models are mis-specified, our modified machine learning methods remain robust to bias from cluster-level unmeasured confounders compared to existing parametric approaches based on propensity score weighting. We conclude by demonstrating our proposals in a real data study concerning the effect of taking an eighth-grade algebra course on math achievement scores from the Early Childhood Longitudinal Study.


Subject(s)
Cluster Analysis , Mathematics , Propensity Score , Random Forest , Bias , Logistic Models , Mathematics/education , Longitudinal Studies , Humans , Child , Computer Simulation , Linear Models , Nonlinear Dynamics
9.
J Neuroradiol ; 50(1): 54-58, 2023 Feb.
Article in English | MEDLINE | ID: mdl-35364131

ABSTRACT

PURPOSE: Antiplatelet maintenance after stent-assisted coil embolization (SACE) is generally considered essential to avoid post-procedural thromboembolic complications. However, there is still debate as to whether it is safe to discontinue antiplatelet drugs after SACE or when is the best time to do so. We investigate herein the clinical outcomes experienced by patients who discontinue antiplatelet agents after SACE. METHODS: From a prospective database, we retrieved the data for 120 consecutive patients (harboring 130 aneurysms) in whom antiplatelet agents were discontinued after SACE between January 2010 and December 2019. We defined thromboembolic complications associated with discontinuation as neurologic or radiographic ischemia that occurred within 6 months of discontinuation of antiplatelet agents; the lesion was required to be correlated with the stented artery. RESULTS: The mean time of discontinuation of antiplatelet medication was 31.4 ± 18.3 months after SACE (median, 26 months). The majority of patients stopped antiplatelet medication between 18 and 36 months after SACE (74 patients, 61.6%). Laser-cut closed-cell stent was most commonly applied in 91 aneurysms (70.0%), followed by braided closed-cell (n=29; 22.3 %) and laser-cut open-cell stent 10 (7.7 %). No patients experienced cerebral ischemia related to discontinuation of antiplatelet medication. CONCLUSION: Our preliminary study suggests that it may be safe to discontinue antiplatelet medication after SACE in patients at low risk for ischemia. The optimal time to discontinue might be around 18 to 36 months after SACE. Large cohort-based studies or randomized clinical trials are warranted to confirm these results.


Subject(s)
Brain Ischemia , Embolization, Therapeutic , Intracranial Aneurysm , Thromboembolism , Humans , Platelet Aggregation Inhibitors/adverse effects , Intracranial Aneurysm/therapy , Intracranial Aneurysm/drug therapy , Stents/adverse effects , Cohort Studies , Brain Ischemia/etiology , Embolization, Therapeutic/adverse effects , Embolization, Therapeutic/methods , Retrospective Studies , Treatment Outcome
10.
Biometrics ; 78(4): 1699-1713, 2022 12.
Article in English | MEDLINE | ID: mdl-34213007

ABSTRACT

Mendelian randomization (MR) has been a popular method in genetic epidemiology to estimate the effect of an exposure on an outcome using genetic variants as instrumental variables (IV), with two-sample summary-data MR being the most popular. Unfortunately, instruments in MR studies are often weakly associated with the exposure, which can bias effect estimates and inflate Type I errors. In this work, we propose test statistics that are robust under weak-instrument asymptotics by extending the Anderson-Rubin, Kleibergen, and the conditional likelihood ratio test in econometrics to two-sample summary-data MR. We also use the proposed Anderson-Rubin test to develop a point estimator and to detect invalid instruments. We conclude with a simulation and an empirical study and show that the proposed tests control size and have better power than existing methods with weak instruments.


Subject(s)
Genetic Pleiotropy , Mendelian Randomization Analysis , Mendelian Randomization Analysis/methods , Likelihood Functions , Computer Simulation , Bias
11.
Biometrics ; 78(1): 24-34, 2022 03.
Article in English | MEDLINE | ID: mdl-33616910

ABSTRACT

Instrumental variables have been widely used to estimate the causal effect of a treatment on an outcome. Existing confidence intervals for causal effects based on instrumental variables assume that all of the putative instrumental variables are valid; a valid instrumental variable is a variable that affects the outcome only by affecting the treatment and is not related to unmeasured confounders. However, in practice, some of the putative instrumental variables are likely to be invalid. This paper presents two tools to conduct valid inference and tests in the presence of invalid instruments. First, we propose a simple and general approach to construct confidence intervals based on taking unions of well-known confidence intervals. Second, we propose a novel test for the null causal effect based on a collider bias. Our two proposals outperform traditional instrumental variable confidence intervals when invalid instruments are present and can also be used as a sensitivity analysis when there is concern that instrumental variables assumptions are violated. The new approach is applied to a Mendelian randomization study on the causal effect of low-density lipoprotein on globulin levels.


Subject(s)
Mendelian Randomization Analysis , Bias , Causality
12.
Stat Med ; 41(14): 2523-2541, 2022 06 30.
Article in English | MEDLINE | ID: mdl-35355302

ABSTRACT

Recently, in genetic epidemiology, Mendelian randomization (MR) has become a popular approach to estimate causal exposure effects by using single nucleotide polymorphisms from genome-wide association studies (GWAS) as instruments. The most popular type of MR study, a two-sample summary-data MR study, relies on having summary statistics from two independent GWAS and using parametric methods for estimation. However, little is understood about using a nonparametric bound-based analysis, a popular approach in traditional instrumental variables frameworks, to study causal effects in two-sample MR. In this article, we explore using a nonparametric, bound-based analysis in two-sample MR studies, focusing primarily on implications for practice. We also propose a framework to assess how likely one can obtain more informative bounds if we used a different MR design, notably a one-sample MR design. We conclude by demonstrating our findings through two real data analyses concerning the causal effect of smoking on lung cancer and the causal effect of high cholesterol on heart attacks. Overall, our results suggest that while a bound-based analysis may be appealing due to its nonparametric nature, it is far more conservative in two-sample settings than in one-sample settings to get informative bounds on the causal exposure effect.


Subject(s)
Genome-Wide Association Study , Mendelian Randomization Analysis , Causality , Humans , Hypercholesterolemia/complications , Lung Neoplasms/etiology , Mendelian Randomization Analysis/methods , Myocardial Infarction/etiology , Polymorphism, Single Nucleotide , Smoking/adverse effects
13.
Neuroradiology ; 64(2): 333-342, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34431003

ABSTRACT

PURPOSE: Dural arteriovenous fistulas (AVFs) draining to medullary bridging vein (MBV) are located at foramen magnum (FM) and craniocervical junction (CCJ). Such fistulas are rare but pose a challenge to endovascular management. This study was undertaken to assess clinical manifestations, angiographic features, and outcomes of endovascular treatment in patients with MBV dural AVFs. METHODS: A number of our patients (N = 22) were diagnosed with MBV dural AVF and treated by endovascular means. There were 9 FM lesions and 13 CCJ lesions. We reviewed clinical records and imaging studies to define clinical characteristics, vascular anatomic details, and treatment outcomes, comparing FM- and CCJ-level subsets. RESULTS: Subjects ranged from 37 to 74 years of age (mean, 57.7 years) with male predominance (2.7:1). They presented with intracranial hemorrhage (11/22, 50%), myelopathy (8/22, 36%), or nonspecific symptoms (3/22, 14%). In 17 patients (77.3%), the shunts showed complete or near-complete occlusion following endovascular treatment (FM, 100%; CCJ, 61.5%). However, seven patients experienced ischemic events (FM, 11.1%; CCJ, 46.2%) and one patient sustained a hemorrhagic complication. No hemorrhages recurred during follow-up monitoring, and myelopathic symptoms abated. CONCLUSION: MBV dural AVFs are highly aggressive lesions for which proper diagnosis and treatment are of utmost importance. Although transarterial embolization proved highly successful in FM lesions, shunt occlusion was less frequent in the CCJ subset, with greater risk of ischemic complications.


Subject(s)
Central Nervous System Vascular Malformations , Embolization, Therapeutic , Angiography , Central Nervous System Vascular Malformations/diagnostic imaging , Central Nervous System Vascular Malformations/therapy , Female , Foramen Magnum/diagnostic imaging , Foramen Magnum/surgery , Humans , Male , Middle Aged , Treatment Outcome
14.
Clin Trials ; 19(4): 375-379, 2022 08.
Article in English | MEDLINE | ID: mdl-35510562

ABSTRACT

In some cluster randomized trials, subjects may not comply with their assigned treatment status. Such treatment noncompliance can create opportunities for spillover effects within clusters. Little research has focused on what can be learned in such context. This article provides a non-technical review of recent work on the complications that arise in cluster randomized trials where some units within treated clusters do not comply with treatment but the treatment spillovers over to these units. We motivate concepts using a hypothetical vaccine cluster randomized trial. We review that standard instrumental variable methods cannot recover the complier average causal effect in the presence of these spillovers. In fact, we review that without additional assumptions, little can be learned about compliance effects or spillover effects. We discuss one additional assumption that allows for bounds on a key causal effect. We also outline an estimator for these bounds.


Subject(s)
Patient Compliance , Causality , Humans , Randomized Controlled Trials as Topic
15.
PLoS Genet ; 15(4): e1007973, 2019 04.
Article in English | MEDLINE | ID: mdl-30946739

ABSTRACT

Facial attractiveness is a complex human trait of great interest in both academia and industry. Literature on sociological and phenotypic factors associated with facial attractiveness is rich, but its genetic basis is poorly understood. In this paper, we conducted a genome-wide association study to discover genetic variants associated with facial attractiveness using 4,383 samples in the Wisconsin Longitudinal Study. We identified two genome-wide significant loci, highlighted a handful of candidate genes, and demonstrated enrichment for heritability in human tissues involved in reproduction and hormone synthesis. Additionally, facial attractiveness showed strong and negative genetic correlations with BMI in females and with blood lipids in males. Our analysis also suggested sex-specific selection pressure on variants associated with lower male attractiveness. These results revealed sex-specific genetic architecture of facial attractiveness and provided fundamental new insights into its genetic basis.


Subject(s)
Beauty , Face/anatomy & histology , Genetic Variation , Adolescent , Alleles , Female , Genome-Wide Association Study , Humans , Longitudinal Studies , Male , Multifactorial Inheritance , Polymorphism, Single Nucleotide , Sex Characteristics
16.
Cerebrovasc Dis ; 50(3): 339-346, 2021.
Article in English | MEDLINE | ID: mdl-33706308

ABSTRACT

BACKGROUND: The occurrence of intracranial aneurysms is higher in patients with autosomal dominant polycystic kidney disease (ADPKD) than in the healthy population. However, research concerning the factors related to the risk of intracranial aneurysm rupture in patients with ADPKD is still insufficient. OBJECTIVES: The aim of the study was to investigate the prevalence of intracranial aneurysms and aneurysmal subarachnoid hemorrhage (SAH) and to analyze the systemic factors associated with high-risk aneurysms in patients with ADPKD. METHODS: We screened patients who underwent cerebral angiography between January 2007 and May 2017 in the ADPKD registry. Patients were examined for the presence of intracranial aneurysms and subsequently reclassified into 3 groups based on the risk of aneurysmal rupture: the aneurysm-negative (group 1), low-risk aneurysm (group 2), or high-risk aneurysm (group 3). Various systemic factors were compared, and independent factors associated with high-risk aneurysms were analyzed. RESULTS: Among the 926 patients, 148 (16.0%) had intracranial aneurysms and 11 (1.2%) had previous aneurysmal SAH. Patients with intracranial aneurysms were further classified into group 2 (low-risk aneurysms, 15.5%) or group 3 (high-risk aneurysms, 84.5%). Age (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.05, p = 0.004), female sex (OR 3.13, 95% CI 1.94-5.0 6, p < 0.001), dolichoectasia (OR 8.57, 95% CI 1.53-48.17, p = 0.015), and mitral inflow deceleration time (DT) (OR 1.01, 95% CI 1.00-1.01, p = 0.046) were independently associated with high-risk aneurysms, whereas hypercholesterolemia (OR 0.46, 95% CI 0.29-0.72, p = 0.001) was negatively associated. CONCLUSION: In the present study among patients with ADPKD, the prevalence of intracranial aneurysms and aneurysmal SAH was 16 and 1.2%, respectively. Age, female sex, dolichoectasia, and mitral inflow DT were positively associated with high-risk aneurysms, whereas hypercholesterolemia was negatively associated. A subsequent large-scaled longitudinal study is needed to define the plausibility of the clinical parameters.


Subject(s)
Aneurysm, Ruptured/epidemiology , Intracranial Aneurysm/epidemiology , Polycystic Kidney, Autosomal Dominant/epidemiology , Subarachnoid Hemorrhage/epidemiology , Adult , Aneurysm, Ruptured/diagnostic imaging , Cerebral Angiography , Cross-Sectional Studies , Female , Humans , Intracranial Aneurysm/diagnostic imaging , Male , Middle Aged , Polycystic Kidney, Autosomal Dominant/diagnosis , Prevalence , Retrospective Studies , Risk Assessment , Risk Factors , Seoul/epidemiology , Subarachnoid Hemorrhage/diagnostic imaging
17.
Multivariate Behav Res ; 56(6): 829-852, 2021.
Article in English | MEDLINE | ID: mdl-32856937

ABSTRACT

There is a growing interest in using machine learning (ML) methods for causal inference due to their (nearly) automatic and flexible ability to model key quantities such as the propensity score or the outcome model. Unfortunately, most ML methods for causal inference have been studied under single-level settings where all individuals are independent of each other and there is little work in using these methods with clustered or nested data, a common setting in education studies. This paper investigates using one particular ML method based on random forests known as Causal Forests to estimate treatment effects in multilevel observational data. We conduct simulation studies under different types of multilevel data, including two-level, three-level, and cross-classified data. Our simulation study shows that when the ML method is supplemented with estimated propensity scores from multilevel models that account for clustered/hierarchical structure, the modified ML method outperforms preexisting methods in a wide variety of settings. We conclude by estimating the effect of private math lessons in the Trends in International Mathematics and Science Study data, a large-scale educational assessment where students are nested within schools.


Subject(s)
Machine Learning , Causality , Computer Simulation , Humans , Multilevel Analysis , Propensity Score
18.
J Neuroradiol ; 48(1): 21.e1-21.e5, 2021 Feb.
Article in English | MEDLINE | ID: mdl-31229579

ABSTRACT

During coil embolization of wide-necked posterior communicating artery (PcomA) aneurysms, stent assistance is sometimes limited if PcomA is acutely angled at its origins from saccular neck. Herein, we present two instances where retrograde stenting was used for coil embolization of PcomA aneurysms. Both procedures involved a contralateral approach via anterior communicating artery (AcomA). To achieve this, the stent-delivery microcatheter was inserted retrograde from contralateral to ipsilateral internal carotid artery (ICA) across AcomA, arriving at ipsilateral PcomA. A separate microcatheter, passed through ipsilateral ICA, was then used to select the aneurysm sac for coil delivery. Coil embolization ultimately took place under protection of a horizontally placed stent extending from PcomA to terminal ICA. Each aneurysm was properly coiled and occluded, without procedural complications. This stenting technique is a reasonable option, offering a means of strategic coil embolization in wide-necked PcomA aneurysms and providing complete neck coverage through contralateral access.


Subject(s)
Embolization, Therapeutic , Intracranial Aneurysm , Arteries , Blood Vessel Prosthesis , Humans , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/therapy , Stents
19.
Neurocrit Care ; 33(2): 575-581, 2020 10.
Article in English | MEDLINE | ID: mdl-32096118

ABSTRACT

BACKGROUND/OBJECTIVE: Cerebral herniation due to brain edema is the major cause of neurological worsening in patients suffering large hemispheric strokes. In this study, we investigated whether quantitative pupillary response could help identify the neurological worsening due to brain swelling in patients with large hemispheric strokes. METHODS: Quantitative pupillary assessment using an automated pupillometer (NPi-100) was performed between April 2017 and August 2019 for patients suffering large hemispheric strokes. Consecutive pupillary responses were measured every 2 or 4 h as a part of routine clinical care. We compared the mean neurological pupil index (NPi) values, NPi value at the time of neurological deterioration, and percentage change in NPi from the immediate previous value between patients with and without neurological worsening. RESULTS: In this study, 2442 quantitative pupillary assessments were performed (n = 30; mean age, 67.9 years; males, 60.0%). Among the included patients, 10 (33.3%) experienced neurological worsening. Patients with neurological worsening had a significantly lower mean value of NPi and a sudden decrease in the NPi value as compared to those without neurological worsening during the whole monitoring period (3.88 ± 0.65 vs. 4.45 ± 0.46, P < 0.001; and 29.5% vs. 11.1%, P = 0.006, respectively). All patients with NPi values below 2.8 showed neurological deterioration. CONCLUSIONS: Quantitative monitoring of the pupillary response using an automated pupillometer could be a useful and noninvasive tool for detecting neurological deterioration due to cerebral edema in large hemispheric stroke patients.


Subject(s)
Brain Edema , Stroke , Aged , Humans , Male , Pupil , Reflex, Pupillary , Stroke/complications
20.
Retina ; 39(8): 1551-1561, 2019 Aug.
Article in English | MEDLINE | ID: mdl-29863533

ABSTRACT

PURPOSE: This work aimed to describe the morphology of pigment epithelial detachment (PED) using optical coherence tomography angiography and to investigate its potential to detect choroidal neovascularization in various types of PEDs. METHODS: In this retrospective study, 53 patients diagnosed with PED after undergoing both optical coherence tomography angiography (AngioPlex, CIRRUS HD-OCT) and spectral domain optical coherence tomography (Spectralis SD-OCT) were included. RESULTS: Among the 53 eyes, flat vascularized PED (vPED) affected 21 eyes (40%), peaked vPED affected 10 eyes (19%), serous PED affected 12 eyes (23%), drusenoid PED affected 6 eyes (11%), and 4 eyes (7%) had multiple PED subtypes. The main underlying etiologies were pachychoroid spectrum disorder (30.2%), wet age-related macular degeneration (28.3%), central serous chorioretinopathy (18.9%), dry age-related macular degeneration (11.3%), and polypoidal choroidal vasculopathy (11.3%). Optical coherence tomography angiography identified neovascularization in 29 (94%) of the vPED eyes, 2 (17%) of the serous PED eyes, and all 4 (100%) mixed PED eyes. CONCLUSION: Optical coherence tomography angiography successfully identified neovascularization in both vPEDs and PEDs previously considered to be nonneovascular. However, structural OCT and blood flow analysis should be combined to interpret PED-associated neovascularization accurately in the clinic.


Subject(s)
Choroid/blood supply , Choroidal Neovascularization/diagnosis , Geographic Atrophy/diagnosis , Retinal Detachment/diagnosis , Retinal Pigment Epithelium/physiopathology , Wet Macular Degeneration/diagnosis , Adult , Aged , Aged, 80 and over , Blood Flow Velocity , Choroidal Neovascularization/physiopathology , Coloring Agents/administration & dosage , Female , Fluorescein Angiography , Geographic Atrophy/physiopathology , Humans , Indocyanine Green/administration & dosage , Male , Middle Aged , Regional Blood Flow , Retinal Detachment/physiopathology , Retrospective Studies , Tomography, Optical Coherence , Visual Acuity/physiology , Wet Macular Degeneration/physiopathology
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