Regional Disparities in Prehospital Delay of Acute Ischemic Stroke: The Korean Stroke Registry.

BACKGROUND: Late hospital arrival keeps patients with stroke from receiving recanalization therapy and is associated with poor outcomes. This study used a nationwide acute stroke registry to investigate the trends and regional disparities in prehospital delay and analyze the significant factors associated with late arrivals. METHODS: Patients with acute ischemic stroke or transient ischemic attack between January 2012 and December 2021 were included. The prehospital delay was identified, and its regional disparity was evaluated using the Gini coefficient for nine administrative regions. Multivariate models were used to identify factors significantly associated with prehospital delays of >4.5 h. RESULTS: A total of 144,014 patients from 61 hospitals were included. The median prehospital delay was 460 min (interquartile range, 116-1912), and only 36.8% of patients arrived at hospitals within 4.5 h. Long prehospital delays and high regional inequality (Gini coefficient > 0.3) persisted throughout the observation period. After adjusting for confounders, age > 65 years old (adjusted odds ratio [aOR] = 1.23; 95% confidence interval [CI], 1.19-1.27), female sex (aOR = 1.09; 95% CI, 1.05-1.13), hypertension (aOR = 1.12; 95% CI, 1.08-1.16), diabetes mellitus (aOR = 1.38; 95% CI, 1.33-1.43), smoking (aOR = 1.15, 95% CI, 1.11-1.20), premorbid disability (aOR = 1.44; 95% CI, 1.37-1.52), and mild stroke severity (aOR = 1.55; 95% CI, 1.50-1.61) were found to independently predict prehospital delays of >4.5 h. CONCLUSION: Prehospital delays were lengthy and had not improved in Korea, and there was a high regional disparity. To overcome these inequalities, a deeper understanding of regional characteristics and further research is warranted to address the vulnerabilities identified.

D-dimer to fibrinogen ratio predicts early neurological deterioration in ischemic stroke with atrial fibrillation.

INTRODUCTION: The D-dimer to fibrinogen ratio (DFR) is a good indicator of clot-producing activity in thrombotic disease, but its clinical usefulness in stroke patients with nonvalvular atrial fibrillation (NVAF) has not been studied. We evaluated the association between the DFR and early neurological deterioration (END) in acute ischemic stroke (AIS) patients with NVAF. METHODS: We included consecutive AIS patients with NVAF between 2013 and 2015 from the registry of a real-world prospective cohort from 11 large centers in South Korea. END was defined as an increase ≥2 in the total NIHSS score or ≥ 1 in the motor NIHSS score within the first 72 h of admission. The DFR was calculated as follows: DFR = D-dimer (mg/L)/fibrinogen (mg/dL) x 100. RESULTS: A total of 1018 AIS patients with NVAF were evaluated. In multivariable logistic regression analysis, the highest DFR tertile was closely associated with END (adjusted odds ratio [aOR] = 2.14, 95 % confidence interval [CI]: 1.24-3.69). Hypertension (aOR = 1.71, 95 % CI: 1.09-2.70), initial NIHSS score (aOR = 1.05, 95 % CI: 1.02-1.07) and use of anticoagulants (aOR = 0.41, 95 % CI: 0.28-0.60) were also correlated with END. In addition to END, the DFR was correlated with discharge NIHSS and modified Rankin Scale (mRS) scores and the 3-month mRS score. CONCLUSIONS: High DFR values were associated with END in AIS patients with NVAF. As the DFR is an indicator directly related to the main pathological mechanism of NVAF patients (fibrinolysis and coagulation), it may be useful in predicting their prognosis.

Stroke-Specific Predictors of Major Bleeding in Anticoagulated Patients With Stroke and Atrial Fibrillation: A Nationwide Multicenter Registry-Based Study.

BACKGROUND AND PURPOSE: The congestive heart failure, hypertension, age, diabetes, previous stroke/transient ischemic attack (CHA2DS2-VASc) and hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol (HAS-BLED) scores have been validated in estimating the risks of ischemic stroke and major bleeding, respectively, in patients with atrial fibrillation (AF). This study investigated stroke-specific predictors of major bleeding in patients with stroke and AF who were taking oral anticoagulants (OACs). METHODS: Subjects were selected from patients enrolled in the Korean ATrial fibrillaTion EvaluatioN regisTry in Ischemic strOke patieNts (K-ATTENTION) nationwide multicenter registry between 2013 and 2015. Patients were excluded if they were not taking OACs, had no brain imaging data, or had intracranial bleeding directly related to the index stroke. Major bleeding was defined according to International Society of Thrombosis and Haemostasis criteria. Cox regression analyses were performed to assess the associations between clinical variables and major bleeding and Kaplan-Meier estimates were performed to analyze event-free survival. RESULTS: Of a total of 3,213 patients, 1,414 subjects (mean age of 72.6 years, 52.5% males) were enrolled in this study. Major bleeding was reported in 34 patients during the median follow-up period of 1.73 years. Multivariable analysis demonstrated that initial National Institutes of Health Stroke Scale scores (hazard ratio [HR] 1.07, p=0.006), hypertension (HR 3.18, p=0.030), persistent AF type (HR 2.51, p=0.016), and initial hemoglobin level (HR 0.74, p=0.001) were independently associated with major bleeding risk. Except for hypertension, these associations remained significant after adjusting for the HAS-BLED score. Intracranial atherosclerosis presented a trend of association without statistical significance (HR 2.21, p=0.050). CONCLUSIONS: This study found that major bleeding risk was independently associated with stroke-specific factors in anticoagulated patients with stroke and AF. This has the clinical implication that baseline characteristics of patients with stroke and AF should be considered in secondary prevention, which would bring the net clinical benefit of balancing recurrent stroke prevention with minimal bleeding complications.

Analyses of Head-Impulse Tests in Patients With Posterior Circulation Stroke and Vestibular Neuritis.

BACKGROUND AND OBJECTIVES: The interpretation of video head-impulse tests (video-HITs) can often be complicated, limiting their clinical utility in acute vestibular syndrome. We aimed to determine video-HIT findings in patients with posterior circulation strokes (PCSs) and vestibular neuritis (VN). METHODS: We retrospectively analyzed the results of video-HITs in 59 patients with PCS. Irrespective of the actual lesion revealed later on MRIs, ipsilateral and contralateral sides were assigned according to the direction of slow phase of spontaneous nystagmus (SN). Then, the patterns of video-HIT findings were classified according to the vestibulo-ocular reflex (VOR) gain for the horizontal canals; (1) ipsilaterally positive, (2) contralaterally positive, (3) bilaterally normal, and (4) bilaterally positive. The abnormal responses were further defined into (5) wrong-way saccades, (6) perverted, and (7) early acceleration followed by premature deceleration. We also analyzed the asymmetry of the corrective saccadic amplitude between the sides, calculated from the sum of cumulative saccadic amplitudes on both sides. The results were compared with video-HIT results from 71 patients with VN. RESULTS: Video-HITs were normal in 32 (54%), ipsilaterally positive in 11 (19%), bilaterally positive in 10 (17%), and contralaterally positive in 6 (10%) patients with PCS. Wrong-way saccades were more frequently observed in VN than in PCS (31/71 [44%] vs 5/59 [8%], p < 0.001). Saccadic amplitude asymmetry was greater in VN than in PCS (median 100% [interquartile range 82-144, 95% CI 109-160] vs 0% [-29 to 34, -10 to 22, p < 0.001]). When differentiating VN from PCS, the sensitivity was 81.7%, and specificity was 91.5% at the cutoff value of 71% for saccadic amplitude asymmetry with an area under the curve (AUC) of 0.91 (95% CI 0.86-0.97). The AUC for saccadic amplitude asymmetry was larger than that for the ipsilateral VOR gain (p = 0.041) and other parameters. DISCUSSION: Patients with PCS may show various head-impulse responses that deviate from the findings expected in VN, which include normal, contralaterally positive, and negative saccadic amplitude asymmetry (i.e., greater cumulative saccadic amplitude contralaterally). A thorough analysis of corrective saccades in video-HITs can improve the differentiation of PCS from VN even before MRIs.

Plasma Total Homocysteine Level Is Related to Unfavorable Outcomes in Ischemic Stroke With Atrial Fibrillation.

Background Unlike patients with stroke caused by other mechanisms, the effect of elevated plasma total homocysteine (tHcy) on the prognosis of patients with both ischemic stroke and atrial fibrillation (AF) is unknown. This study aimed to evaluate the association between tHcy level and the functional outcome of patients with AF-related stroke. Methods and Results We included consecutive patients with AF-related stroke between 2013 and 2015 from the registry of a real-world prospective cohort from 11 large centers in South Korea. A 3-month modified Rankin Scale score ≥3 was considered an unfavorable outcome. Since tHcy is strongly affected by renal function, we performed a subgroup analysis according to the presence of renal dysfunction. A total of 910 patients with AF-related stroke were evaluated (mean age, 73 years; male sex, 56.0%). The mean tHcy level was 11.98±8.81 µmol/L. In multivariable analysis, the tHcy level (adjusted odds ratio, 1.04; 95% CI, 1.01-1.07, per 1 µmol/L) remained significantly associated with unfavorable outcomes. In the subgroup analysis based on renal function, tHcy values above the cutoff point (≥14.60 µmol/L) showed a close association with the unfavorable outcome only in the normal renal function group (adjusted odds ratio, 3.10; 95% CI, 1.60-6.01). In patients with renal dysfunction, tHcy was not significantly associated with the prognosis of AF-related stroke. Conclusions A higher plasma tHcy level was associated with unfavorable outcomes in patients with AF-related stroke. This positive association may vary according to renal function but needs to be verified in further studies.

Erratum: Mouth-Opening-Induced Vertigo and Downbeat Nystagmus.

This corrects the article on p. 607 in vol. 17, PMID: 34595878.

Vogt-Koyanagi-Harada disease - A diagnostic pitfall for neurologists.

•VKH is an idiopathic autoimmune disease presenting with uveomeningeal syndrome.•Granulomatous uveitis and serious retinal detachments are the most common findings of VKH.•VKH can masquerade as IIH by presenting with severe headache and optic disc edema.•The characteristic retinal finding of VKH can be easily missed by direct funduscopy.

HRGAN: A Generative Adversarial Network Producing Higher-Resolution Images than Training Sets.

The generative adversarial network (GAN) has demonstrated superb performance in generating synthetic images in recent studies. However, in the conventional framework of GAN, the maximum resolution of generated images is limited to the resolution of real images that are used as the training set. In this paper, in order to address this limitation, we propose a novel GAN framework using a pre-trained network called evaluator. The proposed model, higher resolution GAN (HRGAN), employs additional up-sampling convolutional layers to generate higher resolution. Then, using the evaluator, an additional target for the training of the generator is introduced to calibrate the generated images to have realistic features. In experiments with the CIFAR-10 and CIFAR-100 datasets, HRGAN successfully generates images of 64 × 64 and 128 × 128 resolutions, while the training sets consist of images of 32 × 32 resolution. In addition, HRGAN outperforms other existing models in terms of the Inception score, one of the conventional methods to evaluate GANs. For instance, in the experiment with CIFAR-10, a HRGAN generating 128 × 128 resolution demonstrates an Inception score of 12.32, outperforming an existing model by 28.6%. Thus, the proposed HRGAN demonstrates the possibility of generating higher resolution than training images.

Multi-Stage Temporal Convolutional Network with Moment Loss and Positional Encoding for Surgical Phase Recognition.

In recent times, many studies concerning surgical video analysis are being conducted due to its growing importance in many medical applications. In particular, it is very important to be able to recognize the current surgical phase because the phase information can be utilized in various ways both during and after surgery. This paper proposes an efficient phase recognition network, called MomentNet, for cholecystectomy endoscopic videos. Unlike LSTM-based network, MomentNet is based on a multi-stage temporal convolutional network. Besides, to improve the phase prediction accuracy, the proposed method adopts a new loss function to supplement the general cross entropy loss function. The new loss function significantly improves the performance of the phase recognition network by constraining un-desirable phase transition and preventing over-segmentation. In addition, MomnetNet effectively applies positional encoding techniques, which are commonly applied in transformer architectures, to the multi-stage temporal convolution network. By using the positional encoding techniques, MomentNet can provide important temporal context, resulting in higher phase prediction accuracy. Furthermore, the MomentNet applies label smoothing technique to suppress overfitting and replaces the backbone network for feature extraction to further improve the network performance. As a result, the MomentNet achieves 92.31% accuracy in the phase recognition task with the Cholec80 dataset, which is 4.55% higher than that of the baseline architecture.

Atrial Fibrillation Related and Unrelated Stroke Recurrence Among Ischemic Stroke Patients With Atrial Fibrillation.

Background: Ischemic stroke with atrial fibrillation (AF) may recur despite appropriate treatment. It may be AF-related or AF-unrelated. We compared the factors associated with AF-related and AF-unrelated recurrences among ischemic stroke patients with AF. Methods: Patients with ischemic stroke and AF were enrolled from 11 centers in Korea. Ischemic stroke recurrence was classified as AF-related if the lesion pattern was compatible with cardioembolism without significant stenosis or as AF-unrelated if the lesion was more likely due to small vessel disease or arterial stenosis. Factors associated with stroke recurrence (AF-related and AF-unrelated) were investigated. Results: Among the 2,239 patients, 115 (5.1%) experienced recurrence (75 AF-related and 40 AF-unrelated). Factors independently associated with any stroke recurrence included AF diagnosed before stroke, small subcortical infarctions, and small scattered lesions in a single vascular territory. Type of AF was associated with the type of stroke recurrence, with persistent AF being associated with AF-related stroke [hazard ratio (HR) = 2.94, 95% confidence interval (CI) 1.69-5.26; p < 0.001]. By contrast, paroxysmal AF (HR = 3.76, 95% CI 1.56-9.04; p = 0.003), AF diagnosed before stroke (HR = 2.38, 95% CI 1.19-4.55; p = 0.014), small scattered lesions in a single vascular territory (reference: corticosubcortical lesion, HR = 3.19, 95% CI 1.18-8.63; p = 0.022), and the use of antiplatelet agents (HR = 2.11, 95% CI 1.11-4.03; p = 0.024) were independently associated with AF-unrelated stroke. Conclusion: Persistent AF was more associated with AF-related stroke recurrence, whereas paroxysmal AF was more associated with AF-unrelated stroke recurrence. A scattered lesion in a single vascular territory may predict AF-unrelated stroke recurrence.

Influence of Estimated Glomerular Filtration Rate on Clinical Outcomes in Patients with Acute Ischemic Stroke Not Receiving Reperfusion Therapies.

BACKGROUND: We aimed to determine whether estimated glomerular filtration rate (eGFR) is an independent predictor of clinical outcomes in patients with acute ischemic stroke not treated with reperfusion therapy. METHODS: A total of 1420 patients with acute ischemic stroke from a hospital-based stroke registry were included in this study. Patients managed with intravenous thrombolysis or endovascular reperfusion therapy were excluded. The included patients were categorized into five groups according to eGFR, as follows: ≥90, 60-89, 45-59, 30-44, and <30 mL/min/1.73 m2. The effects of eGFR on functional outcome at discharge, in-hospital mortality, neurologic deterioration, and hemorrhagic transformation were evaluated using logistic regression analyses. RESULTS: In univariable logistic regression analysis, reduced eGFR was associated with poor functional outcome at discharge (p < 0.001) and in-hospital mortality (p = 0.001), but not with neurologic deterioration and hemorrhagic transformation. However, no significant associations were observed between eGFR and any clinical outcomes in multivariable analysis after adjusting for clinical and laboratory variables. CONCLUSIONS: Reduced eGFR was associated with poor functional outcomes at discharge and in-hospital mortality but was not an independent predictor of short-term clinical outcomes in patients with acute ischemic stroke who did not undergo reperfusion therapy.