Machine Learning-Based Etiologic Subtyping of Ischemic Stroke Using Circulating Exosomal microRNAs.

Ischemic stroke is a major cause of mortality worldwide. Proper etiological subtyping of ischemic stroke is crucial for tailoring treatment strategies. This study explored the utility of circulating microRNAs encapsulated in extracellular vesicles (EV-miRNAs) to distinguish the following ischemic stroke subtypes: large artery atherosclerosis (LAA), cardioembolic stroke (CES), and small artery occlusion (SAO). Using next-generation sequencing (NGS) and machine-learning techniques, we identified differentially expressed miRNAs (DEMs) associated with each subtype. Through patient selection and diagnostic evaluation, a cohort of 70 patients with acute ischemic stroke was classified: 24 in the LAA group, 24 in the SAO group, and 22 in the CES group. Our findings revealed distinct EV-miRNA profiles among the groups, suggesting their potential as diagnostic markers. Machine-learning models, particularly logistic regression models, exhibited a high diagnostic accuracy of 92% for subtype discrimination. The collective influence of multiple miRNAs was more crucial than that of individual miRNAs. Additionally, bioinformatics analyses have elucidated the functional implications of DEMs in stroke pathophysiology, offering insights into the underlying mechanisms. Despite limitations like sample size constraints and retrospective design, our study underscores the promise of EV-miRNAs coupled with machine learning for ischemic stroke subtype classification. Further investigations are warranted to validate the clinical utility of the identified EV-miRNA biomarkers in stroke patients.

The Impact of age and outcomes of high-risk patients on carotid revascularization.

OBJECTIVES: To validate the accuracy of high-risk criteria for carotid endarterectomy (CEA) and analyze the correlation between age and outcome of CEA and carotid artery stenting (CAS) in risk groups. METHODS: We reviewed a prospectively managed vascular surgery database in a single tertiary referral center, and 2482 internal carotid arteries (ICAs) had undergone carotid revascularization from November 1994 to December 2021. To validate high-risk criteria for CEA, patients were classified as high risk (Hr) and normal risk (Nr). Subgroup analysis was performed with patients older or younger than 75 years to investigate the relationship between age and outcome in each group. Primary endpoints were 30-day outcomes including stroke, death, stroke/death, myocardial infraction (MI), and major adverse cardiovascular events (MACEs). RESULTS: A total of 2345 ICAs in 2256 patients were enrolled. The number of patients in the Hr group was 543 (24%) and the number in the Nr group was 1713 (76%). CEA and CAS were performed on 1384 (61%) and 872 (39%) patients, respectively. The 30-day stroke/death rate was higher with CAS than CEA in both the Hr (1.1% vs. 3.9%, p = 0.032) and Nr (1.2% vs. 6.9%, p < 0.001) groups. In unmatched logistic regression analysis of the Nr group (n = 1778), the rate of 30-day stroke/death (OR, 5.575; 95% CI, 2.922-10.636; p < 0.001) was higher for CAS than CEA. In propensity score matching of the Nr group, the rate of 30-day stroke/death (OR, 5.165; 95% CI, 2.391-11.155; p < 0.001) was also higher for CAS than CEA. In the age <75 subgroup of the Hr group (n = 428), CAS was associated with higher 30-day stroke/death (OR, 14.089; 95% CI, 1.314-151.036; p = 0.029). In the age ≥75 subgroup of the Hr (n = 139), there was no difference in 30-day stroke/death between CEA and CAS. In the age <75 subgroup of the Nr group (n = 1318), 30-day stroke/death (OR, 6.300; 95% CI, 2.797-14.193; p < 0.001) was higher in CAS. In the age ≥75 subgroup of the Nr group (n = 460), 30-day stroke/death (OR, 6.468; 95% CI, 1.862-22.471; p = 0.003) was higher in CAS. CONCLUSIONS: In patients older than 75 years in the Hr group, there were relatively poor 30-day treatment outcomes in both CEA and CAS. Alternative treatment is needed that can expect better outcomes in older high-risk patients. In the Nr group, CEA has a significant benefit compared with CAS, and CEA should be recommended more to these patients.

Incidence and risk of stroke in Korean patients with congenital heart disease.

OBJECTIVES: The incidence and risk of ischemic stroke (IS) and hemorrhagic stroke (HS) in Korean patients with CHD have not been reported, therefore, we aimed to investigate this. MATERIALS AND METHODS: Participants were selected from the Korean National Health Insurance Service benefit records from 2006-2017. Cases were extracted using diagnosis codes related to CHD. Controls without CHD were selected through age- and sex-matched random sampling at a 1:10 ratio. RESULTS: The case and control groups included 232,203 and 3,024,633 participants, respectively. The median (interquartile range) follow-up period was 7.28 (3.59-8.73) years. The incidence rates of IS and HS per 100,000 person-years were much higher in cases than in controls (IS: 135 vs. 47; HS: 41.7 vs. 24.9). After adjusting for confounders, CHD was a risk factor for IS and HS (subdistribution HR; 1.96 and 1.71, respectively). In patients with CHD, the following risk factors were identified: diabetes, heart failure, and atrial fibrillation for any stroke; hypertension, atrial septal defects, and use of antiplatelet agents for IS only; and coronary artery bypass graft surgery for HS only. CONCLUSIONS: Korean patients with CHD have a high risk of stroke. A personalized preventive approach is needed to reduce the incidence of stroke in this population.

Impact of Renal Function on Short-Term Outcome After Reperfusion Therapy in Patients With Ischemic Stroke.

BACKGROUND: A high and low estimated glomerular filtration rate (eGFR) could affect outcomes after reperfusion therapy for ischemic stroke. This study aimed to determine whether renal function based on eGFR affects mortality risk in patients with ischemic stroke within 6 months following reperfusion therapy. METHODS: This prospective registry-based cohort study included 2266 patients who received reperfusion therapy between January 2000 and September 2019 and were registered in the SECRET (Selection Criteria in Endovascular Thrombectomy and Thrombolytic Therapy) study or the Yonsei Stroke Cohort. A high and low eGFR were based on the Chronic Kidney Disease Epidemiology Collaboration equation and defined, respectively, as the 5th and 95th percentiles of age- and sex-specific eGFR. Occurrence of death within 6 months was compared among the groups according to their eGFR such as low, normal, or high eGFR. RESULTS: Of the 2266 patients, 2051 (90.5%) had a normal eGFR, 110 (4.9%) a low eGFR, and 105 (4.6%) a high eGFR. Patients with high eGFR were younger or less likely to have hypertension, diabetes, or atrial fibrillation than the other groups. Active cancer was more prevalent in the high-eGFR group. During the 6-month follow-up, there were 24 deaths (22.9%) in the high-eGFR group, 37 (33.6%) in the low-eGFR group, and 237 (11.6%) in the normal-eGFR group. After adjusting for variables with P<0.10 in the univariable analysis, 6-month mortality was independently associated with high eGFR (hazard ratio, 2.22 [95% CI, 1.36-3.62]; P=0.001) and low eGFR (HR, 2.29 [95% CI, 1.41-3.72]; P=0.001). These associations persisted regardless of treatment modality or various baseline characteristics. CONCLUSIONS: High eGFR as well as low eGFR were independently associated with 6-month mortality after reperfusion therapy. Kidney function could be considered a prognostic factor in patients with ischemic stroke after reperfusion therapy.

Atherosclerotic Burden and Vascular Risk in Stroke Patients With Atrial Fibrillation.

Background and Purpose: Data on the effect on vascular outcomes of concomitant atherosclerotic vascular disease (ASVD) with atrial fibrillation (AF) after stroke are limited. This study evaluated the effect of ASVD with AF versus AF only on the risk of vascular events. Methods: We retrospectively analyzed a prospectively registered multicenter database involving 3213 stroke patients with AF. ASVD included extracranial atherosclerosis measured in the proximal portion of the internal carotid artery, intracranial atherosclerosis (all ≥50% stenosis), coronary artery disease, and peripheral artery disease and was categorized into 4 strata depending on the number of ASVDs (0, 1, 2, and 3­4). The independent associations of ASVD with major adverse cardiovascular events, stroke, and all-cause death were assessed. Results: A total of 2670 patients were included (mean age, 73.5±9.8 years; median CHA2DS2-VASc score, 5; interquartile range, 4−6). During the follow-up (mean, 1.7 years), a total of 672 (25.2%) major adverse cardiovascular events, 170 (6.4%) stroke events, and 501 (18.8%) all-cause deaths were noted. The adjusted hazard ratio for major adverse cardiovascular events versus no ASVD was 1.25 (95% CI, 1.00­1.56) for ASVD 1, 1.34 (95% CI, 1.02­1.76) for ASVD 2, and 1.93 (95% CI, 1.24­2.99) for ASVD 3­4. The adjusted hazard ratio for all-cause death versus no ASVD was 1.32 (1.01­1.74), 1.47 (1.06­2.03), and 2.39 (1.47­3.89), respectively. Among ASVD components, the presence of symptomatic or asymptomatic extracranial atherosclerosis was a more potent predictor of major adverse cardiovascular events (1.27 [1.05­1.54]) and all-cause death (1.45 [1.17­1.81]). Conclusions: ASVD burden with AF can be a cumulative marker of a high risk for untoward vascular outcomes. Among ASVD components, extracranial atherosclerosis seems to have a predominant effect.

Immediate and Long-Term Outcomes of Reperfusion Therapy in Patients With Cancer.

Background and Purpose: Patients with acute stroke are often accompanied by comorbidities, such as active cancer. However, adequate treatment guidelines are not available for these patients. The purpose of this study was to evaluate the association between cancer and the outcomes of reperfusion therapy in patients with stroke. Methods: We compared treatment outcomes in patients who underwent reperfusion therapy, using a nationwide reperfusion therapy registry. We divided the patients into 3 groups according to cancer activity: active cancer, nonactive cancer, and without a history of cancer. We investigated reperfusion processes, 24-hour neurological improvement, adverse events, 3-month functional outcome, and 6-month survival and related factors after reperfusion therapy. Results: Among 1338 patients who underwent reperfusion therapy, 62 patients (4.6%) had active cancer, 78 patients (5.8%) had nonactive cancer, and 1198 patients (89.5%) had no history of cancer. Of the enrolled patients, 969 patients received intravenous thrombolysis and 685 patients underwent endovascular treatment (316 patients received combined therapy). Patients with active cancer had more comorbidities and experienced more severe strokes; however, they showed similar 24-hour neurological improvement and adverse events, including cerebral hemorrhage, compared with the other groups. Although the functional outcome at 3 months was poorer than the other groups, 36.4% of patients with active cancer showed functional independence. Additionally, 52.9% of the patients with determined stroke etiology showed functional independence despite active cancer. During the 6-month follow-up, 46.6% of patients with active cancer died, and active cancer was independently associated with poor survival (hazard ratio, 3.973 [95% CI, 2.528­6.245]). Conclusions: In patients with active cancer, reperfusion therapy showed similar adverse events and short-term outcomes to that of other groups. While long-term prognosis was worse in the active cancer group than the nonactive cancer groups, not negligible number of patients had good functional outcomes, especially those with determined stroke mechanisms.

Pre-Admission CHADS2 and CHA2DS2-VASc Scores on Early Neurological Worsening.

BACKGROUND: Stroke risk scores (CHADS2 and CHA2DS2-VASc) not only predict the risk of stroke in atrial fibrillation (AF) patients, but have also been associated with prognosis after stroke. OBJECTIVE: The aim of this study was to evaluate the relationship between stroke risk scores and early neurological deterioration (END) in ischemic stroke patients with AF. METHODS: We included consecutive ischemic stroke patients with AF admitted between January 2013 and December 2015. CHADS2 and CHA2DS2-VASc scores were calculated using the established scoring system. END was defined as an increase ≥2 on the total National Institutes of Health Stroke Scale (NIHSS) score or ≥1 on the motor NIHSS score within the first 72 h of admission. RESULTS: A total of 2,099 ischemic stroke patients with AF were included. In multivariable analysis, CHA2DS2-VASc score (adjusted odds ratio [aOR] = 1.17, 95% confidence interval [CI] = 1.04-1.31) was significantly associated with END after adjusting for confounders. Initial NIHSS score, use of anticoagulants, and intracranial atherosclerosis (ICAS) were also found to be closely associated with END, independent of the CHA2DS2-VASc score. Multivariable analysis stratified by the presence of ICAS demonstrated that both CHA2DS2-VASc (aOR = 1.20, 95% CI = 1.04-1.38) and CHADS2 scores (aOR = 1.24, 95% CI = 1.01-1.52) were closely related to END in only patients with ICAS. In patients without ICAS, neither of the risk scores were associated with END. CONCLUSIONS: High CHA2DS2-VASc score was associated with END in ischemic stroke patients with AF. This close relationship is more pronounced in patients with ICAS.

Post-Stroke Depressive Symptoms: Varying Responses to Escitalopram by Individual Symptoms and Lesion Location.

OBJECTIVE: The efficacy of antidepressants in post-stroke depressive symptoms (PSD) varies. We aimed to examine whether the effect of escitalopram on PSD differs according to individual depressive symptoms and stroke lesion location. METHODS: This is a post hoc analysis of EMOTION (ClinicalTrials.gov, NCT01278498), a randomized, placebo-controlled, double-blind trial that examined the efficacy of escitalopram on depression in acute stroke patients (237 with placebo, 241 with escitalopram). Depressive symptoms were evaluated with the 10-item Montgomery-Åsberg Depression Rating Scale (MADRS). Changes in MADRS and individual item scores at 12 weeks were compared between the treatment groups and among the stroke lesion location groups. Stroke lesion locations were grouped according to the anatomical distribution of serotonin fibers that originate from the midbrain/pons and spread to the forebrain via subcortical structures: "Midbrain-Pons," "Frontal-Subcortical," and "Others." Least-squares means were calculated to demonstrate the independent effect of lesion location. RESULTS: Total MADRS scores decreased more significantly in the escitalopram than in the placebo group, while a significant effect of escitalopram was observed in only 3 items: apparent sadness, reported sadness, pessimistic thoughts. In the lesion location analyses, escitalopram users in the Frontal-Subcortical group showed significant improvement in total MADRS scores (placebo [n = 130] vs. escitalopram [n = 148], least-square mean [95% CI]: -2.3 [-3.5 to -0.2] vs. -4.5 [-5.5 to -3.4], p = .005), while those in the Midbrain-Pons and Others groups did not. CONCLUSIONS: The effect of escitalopram on PSD may be more prominent in patients with particular depressive symptoms and stroke lesion locations, suggesting the need for tailored treatment strategies.

White matter hyperintensity determines ischemic stroke severity in symptomatic carotid artery stenosis.

INTRODUCTION: The aim of this study is to investigate the influence of white matter hyperintensity (WMH) on stroke severity and prognosis in patients with symptomatic carotid artery stenosis. METHODS: Patients with symptomatic carotid artery stenosis were retrieved from the Samsung Medical Center stroke registry from January 2011 to December 2016. Stroke severity was categorized into three levels according to National Institutes of Health Stroke Scale (NIHSS): transient ischemic attack (TIA) or transient symptoms with infarction (TSI), mild stroke, and moderate to severe stroke. WMH volume was measured with medical image processing and visualization. The clinical outcome was assessed using the modified Rankin scale on the 90th day from which the latest onset of the neurological symptom. Logistic regression was used to predict stroke severity, and ordinal regression was used to compare the clinical outcome. RESULTS: Among 158 patients, the numbers of patients with TIA or TSI, mild stroke, and moderate to severe stroke were 48 (30.4%), 59 (37.3%), and 51 (32.3%), respectively. The larger WMH volume was associated with moderate to severe strokes (TIA/TSI vs. moderate to severe strokes, odds ratio (OR) 2.318, 95% confidence interval (CI) 1.194-4.502, p = 0.007; mild vs. moderate to severe strokes, OR 1.972, 95% CI 1.118-3.479, p = 0.013). Patients with larger volume of WMH showed poorer clinical outcome (cutoff value: 9.71 cm3, OR 2.099, 95% CI 1.030-4.311, p = 0.042). CONCLUSION: Our study showed that larger WMH volume is associated with more severe stroke and poorer prognosis in patients with symptomatic carotid artery stenosis.

Predictors and Functional Outcomes of Fast, Intermediate, and Slow Progression Among Patients With Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: We aimed to delineate the determinants of the initial speed of infarct progression and the association of speed of infarct progression (SIP) with procedural and functional outcomes. METHODS: From a prospectively maintained stroke center registry, consecutive anterior circulation ischemic stroke patients with large artery occlusion, National Institutes of Health Stroke Scale score ≥4, and multimodal vessel, ischemic core, and tissue-at-risk imaging within 24 hours of onset were included. Initial SIP was calculated as ischemic core volume at first imaging divided by the time from stroke onset to imaging. RESULTS: Among the 88 patients, SIP was median 2.2 cc/h (interquartile range, 0-8.7), ranging most widely within the first 6 hours after onset. Faster SIP was positively independently associated with a low collateral score (odds ratio [OR], 3.30 [95% CI, 1.25-10.49]) and arrival by emergency medical services (OR, 3.34 [95% CI, 1.06-10.49]) and negatively associated with prior ischemic stroke (OR, 0.12 [95% CI, 0.03-0.50]) and coronary artery disease (OR, 0.32 [95% CI, 0.10-1.00]). Among the 67 patients who underwent endovascular thrombectomy, slower SIP was associated with a shift to reduced levels of disability at discharge (OR, 3.26 [95% CI, 1.02-10.45]), increased substantial reperfusion by thrombectomy (OR, 8.30 [95% CI, 0.97-70.87]), and reduced radiological hemorrhagic transformation (OR, 0.34 [95% CI, 0.12-0.94]). CONCLUSIONS: Slower SIP is associated with a high collateral score, prior ischemic stroke, and coronary artery disease, supporting roles for both collateral robustness and ischemic preconditioning in fostering tissue resilience to ischemia. Among patients undergoing endovascular thrombectomy, the speed of infarct progression is a major determinant of clinical outcome.

Luminal and Wall Changes in Intracranial Arterial Lesions for Predicting Stroke Occurrence.

BACKGROUND AND PURPOSE: Luminal imaging (degree of stenosis) currently serves as the gold standard to predict stroke recurrence and guide therapeutic strategies in patients with intracranial large artery diseases (ILADs). We comparatively evaluated the importance of vessel wall and luminal changes in predicting stroke occurrence. METHODS: Consecutive patients with ILAD in the proximal middle cerebral artery or distal internal carotid artery without proximal sources of embolism from the carotid and heart underwent time-of-flight magnetic resonance angiography, high-resolution magnetic resonance imaging, and the ring finger protein 213 (RNF213) gene variant test. Patients were followed up for >3 months. RESULTS: Of the 675 patients, 241 (35.7%) had atherosclerotic ILAD and 434 (64.3%) showed nonatherosclerotic ILAD (315 [46.7%] moyamoya disease cases and 119 [17.6%] dissection cases). The RNF213 variant was detected in 74.9%, 33.6%, and 3.4% patients with moyamoya disease, atherosclerosis, and dissection, respectively. Three hundred (44.4%) patients had asymptomatic ILAD, whereas 375 (55.6%) patients had symptomatic ILAD. Multivariate analysis showed that vessel enhancement and etiological subtypes, not degree of stenosis, determined by high-resolution magnetic resonance imaging and RNF213 gene variant analysis were independently associated with symptomatic ILAD. The presence of the RNF213 variant was also independently associated with recurrent cerebrovascular events. CONCLUSIONS: This study demonstrates the prevalence of nonatherosclerotic ILAD in East Asian patients with ILAD. Unlike luminal changes, wall changes determined by high-resolution magnetic resonance imaging and presence of the RNF213 variant could predict stroke occurrence in patients with ILADs.

Cilostazol Versus Aspirin in Ischemic Stroke Patients With High-Risk Cerebral Hemorrhage: Subgroup Analysis of the PICASSO Trial.

Background and Purpose- Although cilostazol has shown less hemorrhagic events than aspirin, only marginal difference was observed in hemorrhagic stroke events among patients at high risk for cerebral hemorrhage. To identify patients who would most benefit from cilostazol, this study analyzed interactions between treatment and subgroups of the PICASSO trial (Prevention of Cardiovascular Events in Asian Ischemic Stroke Patients With High Risk of Cerebral Hemorrhage). Methods- Ischemic stroke patients with a previous intracerebral hemorrhage or multiple microbleeds were randomized to treatment with cilostazol or aspirin and followed up for a mean 1.8 years. Efficacy, defined as the composite of any stroke, myocardial infarction, and vascular death, and safety, defined as the incidence of hemorrhagic stroke, were analyzed in the 2 groups. Interactions between treatment and age, sex, presence of hypertension and diabetes mellitus, index of high-risk cerebral hemorrhage, and white matter lesion burden were analyzed for primary and key secondary outcomes. Changes in vital signs and laboratory results were compared in the 2 groups. Results- Among all 1534 patients enrolled, a significant interaction between treatment group and index of high risk for cerebral hemorrhage on hemorrhagic stroke (P for interaction, 0.03) was observed. Hemorrhagic stroke was less frequent in the cilostazol than in the aspirin group in patients with multiple microbleeds (1 versus 13 events; hazard ratio, 0.08 [95% CI, 0.01-0.61]; P=0.01). A marginal interaction between treatment group and white matter change on any stroke (P for interaction, 0.08) was observed. Cilostazol reduced any stroke significantly in patients with mild (5 versus 16 events; hazard ratio, 0.36 [95% CI, 0.13-0.97]; P=0.04)-to-moderate (16 versus 32 events; hazard ratio, 0.50 [95% CI, 0.29-0.92]; P=0.03) white matter changes. Heart rate and HDL (high-density lipoprotein) cholesterol level were significantly higher in the cilostazol group than in the aspirin group at follow-up. Conclusions- Cilostazol may be more beneficial for ischemic stroke patients with multiple cerebral microbleeds and before white matter changes are extensive. Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT01013532.

Intensive Statin Treatment in Acute Ischaemic Stroke Patients with Intracranial Atherosclerosis: a High-Resolution Magnetic Resonance Imaging study (STAMINA-MRI Study).

OBJECTIVE: Intracranial atherosclerosis is a major cause of ischaemic stroke worldwide. A number of studies have shown the effects of statin treatment on coronary and carotid artery plaques, but there is little evidence on the effects of statin treatment on intracranial atherosclerotic plaques. METHODS: The Intensive Statin Treatment in Acute Ischaemic Stroke Patients with Intracranial Atherosclerosis - High-Resolution Magnetic Resonance Imaging (STAMINA-MRI) Trial is a single-arm, prospective, observational study monitoring imaging and clinical outcomes of high-dose statin treatment among statin-naive patients with acute ischaemic stroke caused by symptomatic intracranial atherosclerosis. The primary outcome was the change in vascular remodelling and plaque characteristics before and after 6 months (median: 179 days, IQR 163-189 days) of statin treatment measured by high-resolution MRI (HR-MRI). RESULTS: A total of 77 patients (mean age: 62.6±13.7 years, 61.0% women) were included in this study. Low-density lipoprotein cholesterol (LDL-C) levels (mg/dL) at initial and follow-up assessments were 125.81±35.69 and 60.95±19.28, respectively. Overall, statin treatment significantly decreased enhancement of plaque volume (mm3, 32.07±39.15 vs 17.06±34.53, p=0.013), the wall area index (7.50±4.28 vs 5.86±4.05, p=0.016) and stenosis degree (%, 76.47±20.23 vs 64.05±21.29, p<0.001), but not the remodelling index (p=0.195). However, 35% patients showed no change or increased enhancement volume and stenosis degree after statin treatment. Higher reduction of LDL-C and longer duration of statin treatment were associated with decreased enhancement volume after statin treatment. CONCLUSIONS: High-dose statin treatment effectively stabilised symptomatic intracranial atherosclerotic plaques as documented by HR-MRI. Further study is needed to determine laboratory and genetic factors associated with poor response to statins and alternative therapeutic options, such as proprotein convertase subtilisin-kexin type 9 inhibitors, for these patients. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT02458755.

Perfusion recovery on TTP maps after endovascular stroke treatment might predict favorable neurological outcomes.

OBJECTIVES: Early recanalization and adequate collateral blood flow are surrogates for functional recovery in endovascular stroke treatment (EVT). We evaluated the prognostic value of pre- and immediate post-thrombectomy perfusion-weighted magnetic resonance imaging (PWI) parameters. METHODS: Consecutive patients with acute ischemic stroke who underwent EVT were enrolled. Lesion volumes and their corresponding changes on diffusion-weighted (DWI) and PWI were assessed. Outcome was measured with modified Rankin Scale (mRS) at 90 days, and early neurological improvement (> 8 points improvement on National Institutes of Health Stroke Scale [NIHSS] or 0 to 1) at 7 days. RESULTS: Fifty-two patients were enrolled. After control of initial NIHSS and recanalization status, post-thrombectomy time-to-peak (TTP) hypoperfused volume and TTP hypoperfused volume change remained independent predictors of favorable functional outcome (odds ratio [OR] = 0.13, 95% confidence interval [CI] = 0.03-0.54, p = 0.005; OR = 1.018, 95% CI = 1.00-1.03, p = 0.017), and early neurological improvement (OR = 0.20, 95% CI 0.07-0.58, p = 0.003; OR = 1.02, 95% CI = 1.00-1.03, p = 0.010). The areas under the curve of post-thrombectomy TTP hypoperfused volume and TTP hypoperfused volume change were 0.90 and 0.82 (cutoff 68 mL and 56 mL) for favorable outcome and 0.86 and 0.82 (cutoff 76 mL and 58 mL) for early neurological improvement, which had better prognostic values than other MR parameters and recanalization grades. CONCLUSIONS: These results suggest a large amount of perfusion recovery on TTP is associated with favorable outcome as well as early neurological improvement after EVT, and may be a useful prognostic marker. KEY POINTS: • A large amount of perfusion recovery on TTP map is associated with favorable outcome and early neurological improvement after EVT. • The best cutoff value for favorable functional outcome was 68 mL for post-EVT TTP hypoperfused volume and 56 mL decrease for TTP hypoperfused volume. • Amount of perfusion recovery on TTP map has better performance on the prediction of favorable functional recovery and early neurological improvement than other diffusion- and perfusion-weighted MRI parameters and recanalization grades.

Depressive Symptoms in Stroke Patients: Are There Sex Differences?

BACKGROUND: We aimed to examine sex differences in symptom characteristics and pharmacological responses in post-stroke depressive (PSD) symptoms. METHODS: This is a post hoc analysis of EMOTION (ClinicalTrials.gov, NCT01278498), a randomized, placebo-controlled, double-blind trial that examined the efficacy of escitalopram for 3 months on depression in patients with acute stroke. Depressive symptoms were evaluated using the 10-item Montgomery-Åsberg Depression Rating Scale (MADRS). Baseline characteristics, clinical variables, and treatment responses to escitalopram were compared between male and female patients. Treatment responses were defined as changes in MADRS (total score and its components) between baseline and 3 months and were compared between the escitalopram and placebo groups within each sex group. The least square mean was calculated to determine the independent effect of escitalopram, of which interaction was evaluated with patient sex. RESULTS: Of the 478 patients (intention-to-treat population), 187 (39%) were female. Female patients were significantly older than male patients and demonstrated more severe depressive symptoms at baseline (male vs. female, MADRS score, mean [SD]: 9.7 ± 8.0 vs. 12.2 ± 8.4, p = 0.001), especially in apparent sadness, reported sadness, and reduced appetite items. These differences were significant after adjustment for age and the severity of neurologic deficits. The female escitalopram group showed a significant 3-month improvement in MADRS scores (placebo [n = 86] vs. escitalopram [n = 101], least square mean [95% CI] -2.7 [-4.1 to -1.2] vs. -5.0 [-6.4 to -3.6], p = 0.007), and this efficacy was prominent in apparent sadness, reported sadness, and pessimistic thoughts items. However, there was no significant effect of escitalopram on depressive symptoms in the male group. The treatment responses of escitalopram tended to be more pronounced in the female group, particularly in alleviating a subset of depressive symptoms such as apparent sadness (p for interaction = 0.009). CONCLUSION: PSD may differ according to sex in its symptom characteristics and treatment responses to escitalopram, and tailored treatment strategies for PSD may therefore be needed.

Circulating DNAs, a Marker of Neutrophil Extracellular Traposis and Cancer-Related Stroke: The OASIS-Cancer Study.

Background and Purpose- The role of circulating neutrophil extracellular traps (NETs) in cancer-related stroke is unknown. Methods- We conducted a prospective cohort study to test whether NETs are increased in cancer-related stroke and whether elevated NETs levels are associated with coagulopathy, assessed using D-dimer levels (≥2 µg/mL). Plasma DNA and nucleosome were assessed as NET-specific biomarkers. Results- In total, 138 patients were recruited; 38 patients had cancer-related stroke (active cancer and acute cryptogenic embolic stroke), 33 patients were healthy-controls, 27 patients were cancer-controls (active cancer but no stroke), and 40 patients were stroke-controls (acute ischemic stroke but no cancer). Plasma DNA and nucleosome levels were significantly elevated in cancer-related stroke patients than in healthy-controls (P<0.05). These levels were correlated with the D-dimer levels (P<0.01). In multiple regression analyses, increased plasma DNA levels were associated with cancer-related stroke (odds ratio=11.65 for highest quartile; 95% CI, 3.199-42.46) and D-dimer levels of ≥2 µg/mL (odds ratio=19.09 for highest quartile; 95% CI, 4.143-87.95) after adjusting for possible confounders. Conclusions- Increased circulating DNA levels were associated with cancer-related stroke, suggesting that NETosis is one of the molecular mechanisms of cancer-related stroke. Further long-term follow-up studies in large cohorts are needed to confirm the role of NET-specific biomarkers.

Admission Diffusion-Weighted Imaging Lesion Volume in Patients With Large Vessel Occlusion Stroke and Alberta Stroke Program Early CT Score of ≥6 Points: Serial Computed Tomography-Magnetic Resonance Imaging Collateral Measurements.

Background and Purpose- We hypothesized that the pial collateral status at the time of presentation could predict the infarct size on magnetic resonance imaging in patients with similar degrees of early ischemic changes on computed tomography. We tested the association between serial changes in collateral status and infarct volume defined on diffusion-weighted imaging (DWI) in patients with large vessel occlusion and small core. Methods- Consecutive patients who were candidates for endovascular treatment (Alberta Stroke Program Early CT Score [ASPECTS] of ≥6 points) and who underwent both pretreatment multiphasic computed tomography angiography (mCTA) and multimodal magnetic resonance imaging were enrolled. The baseline early ischemic changes and collateral status were determined using both mCTA and magnetic resonance imaging-based collateral maps. Multivariable linear regression was used to evaluate adjusted estimates of the effect of collateral status on predicting MR DWI lesion volume before endovascular treatment. Results- Of 65 patients (39 men; median age, 76 years; median ASPECTS, 8 points [range, 6-10]), 10 (15.4%), 8 (12.3%), and 47 (72.3%) presented poor, intermediate, and good collaterals on mCTA, respectively. After adjusting for the initial stroke severity, ASPECTS, time to DWI, and mismatch volume, the mCTA collateral grade was the only factor independently associated with the DWI lesion volume (ß=-35.657, SE mean=3.539; P<0.0001). An excellent correlation between the mCTA- and magnetic resonance imaging-based collateral grades was observed (matching grade seen in 92.3%), suggesting a collateral status persistence during the hyperacute stroke phase. Conclusions- The mCTA assessed collateral adequacy is the sole predictor of eventual DWI lesion volume before endovascular treatment. The added value of collateral assessment in early ischemic changes and large vessel occlusion for decision-making regarding more aggressive revascularizations requires further evaluation. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT03234634 and NCT02668627.

Evaluation of Diffusion Lesion Volume Measurements in Acute Ischemic Stroke Using Encoder-Decoder Convolutional Network.

Background and Purpose- Automatic segmentation of cerebral infarction on diffusion-weighted imaging (DWI) is typically performed based on a fixed apparent diffusion coefficient (ADC) threshold. Fixed ADC threshold methods may not be accurate because ADC values vary over time after stroke onset. Deep learning has the potential to improve the accuracy, provided that a large set of correctly annotated lesion data is used for training. The purpose of this study was to evaluate deep learning-based methods and compare them with commercial software in terms of lesion volume measurements. Methods- U-net, an encoder-decoder convolutional neural network, was adopted to train segmentation models. Two U-net models were developed: a U-net (DWI+ADC) model, trained on DWI and ADC data, and a U-net (DWI) model, trained on DWI data only. A total of 296 subjects were used for training and 134 for external validation. An expert neurologist manually delineated the stroke lesions on DWI images, which were used as the ground-truth reference. Lesion volume measurements from the U-net methods were compared against the expert's manual segmentation and Rapid Processing of Perfusion and Diffusion (RAPID; iSchemaView Inc) analysis. Results- In external validation, U-net (DWI+ADC) showed the highest intraclass correlation coefficient with manual segmentation (intraclass correlation coefficient, 1.0; 95% CI, 0.99-1.00) and sufficiently high correlation with the RAPID results (intraclass correlation coefficient, 0.99; 95% CI, 0.98-0.99). U-net (DWI+ADC) and manual segmentation resulted in the smallest 95% Bland-Altman limits of agreement (-5.31 to 4.93 mL) with a mean difference of -0.19 mL. Conclusions- The presented deep learning-based method is fully automatic and shows a high correlation of diffusion lesion volume measurements with manual segmentation and commercial software. The method has the potential to be used in patient selection for endovascular reperfusion therapy in the late time window of acute stroke.

Medium-Chain Acylcarnitines Are Associated With Cardioembolic Stroke and Stroke Recurrence.

Objective- Stroke is a heterogeneous disease with diverse causes, which affect the risk of recurrence. This study aimed to identify novel biomarkers that are clinically relevant to the diagnosis of cardioembolic stroke (CE) and the prediction of stroke recurrence using metabolomics. Approach and Results- We obtained blood samples and clinical data from a consecutively registered, hospital-based acute stroke registry and from healthy controls. Mass-spectrometry-based profiling was performed, and several metabolomic signatures were selected for the discrimination of CE and stroke recurrence, coupled with multivariate statistical analysis. Finally, 190 acute ischemic stroke participants (43 CE patients and 147 non-CE patients) and 30 control participants were included. We obtained 29 metabolomics signatures, and of these, 2 medium-chain acylcarnitines (decanoylcarnitine and octanoylcarnitine) were selected as independent discriminants for CE (odds ratio, 2.839; 95% CI, 1.241-6.493 for decanoylcarnitine; odds ratio, 2.839; 95% CI, 1.241-6.493 for octanoylcarnitine). Elevated medium-chain acylcarnitines were also associated with a higher risk of stroke recurrence (hazard ratio, 3.767; 95% CI, 1.276-11.117 for decanoylcarnitine; hazard ratio, 5.519; 95% CI, 1.22-18.781 for octanoylcarnitine). The levels of decanoylcarnitine and octanoylcarnitine were correlated as known surrogate markers of CE. The levels of decanoylcarnitine and octanoylcarnitine were significantly higher in stroke patients with a high-risk potential of cardioembolism than in those with low or intermediate risk. Conclusions- Metabolomics provided an improved understanding of CE pathogenesis and stroke recurrence. We have identified decanoylcarnitine and octanoylcarnitine as novel biomarkers for CE and stroke recurrence.

paraFaceTest: an ensemble of regression tree-based facial features extraction for efficient facial paralysis classification.

BACKGROUND: Facial paralysis (FP) is a neuromotor dysfunction that losses voluntary muscles movement in one side of the human face. As the face is the basic means of social interactions and emotional expressions among humans, individuals afflicted can often be introverted and may develop psychological distress, which can be even more severe than the physical disability. This paper addresses the problem of objective facial paralysis evaluation. METHODS: We present a novel approach for objective facial paralysis evaluation and classification, which is crucial for deciding the medical treatment scheme. For FP classification, in particular, we proposed a method based on the ensemble of regression trees to efficiently extract facial salient points and detect iris or sclera boundaries. We also employ 2nd degree polynomial of parabolic function to improve Daugman's algorithm for detecting occluded iris boundaries, thereby allowing us to efficiently get the area of the iris. The symmetry score of each face is measured by calculating the ratio of both iris area and the distances between the key points in both sides of the face. We build a model by employing hybrid classifier that discriminates healthy from unhealthy subjects and performs FP classification. RESULTS: Objective analysis was conducted to evaluate the performance of the proposed method. As we explore the effect of data augmentation using publicly available datasets of facial expressions, experiments reveal that the proposed approach demonstrates efficiency. CONCLUSIONS: Extraction of iris and facial salient points on images based on ensemble of regression trees along with our hybrid classifier (classification tree plus regularized logistic regression) provides a more improved way of addressing FP classification problem. It addresses the common limiting factor introduced in the previous works, i.e. having the greater sensitivity to subjects exposed to peculiar facial images, whereby improper identification of initial evolving curve for facial feature segmentation results to inaccurate facial feature extraction. Leveraging ensemble of regression trees provides accurate salient points extraction, which is crucial for revealing the significant difference between the healthy and the palsy side when performing different facial expressions.