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Objective: In vivo visualization of intracranial atherosclerotic plaque has been performed only with high-resolution magnetic resonance imaging (HRMR). We investigated whether atherosclerotic plaque of the basilar artery (BA) can be identified in conventional magnetic resonance imaging (MRI)., Methods: Patients with acute ischemic stroke who had BA stenosis ("symptomatic BAA") were retrospectively recruited using the prospective stroke registry. In the HRMR databank, subjects without BA stenosis were recruited and classified as those with silent plaque ("silent BAA") and without any plaque ("normal controls"). Outer diameter of the BA and T2 plaque sign (an eccentric or complete obscuration of normal flow-void) within the BA were assessed by two blinded raters using conventional T2 MRI., Results: Seventy-five patients with symptomatic BAA, 40 with asymptomatic BAA, and 36 normal controls were included in the study. Maximal BA diameter was significantly larger in symptomatic BAA patients with <30%, 30-50%, 50-70%, and >70% stenosis (all p<0.01 in each subgroup) and silent BAA subjects (p = 0.018) than controls. T2 plaque signs were present in 46 (61.3%) patients with symptomatic BAA and 6 (14.6%) subjects with asymptomatic BAA, while none in normal controls (p <0.001 and 0.057, respectively). Detection rates were increased with an increase in stenosis degree (25.0% in <30% stenosis, 57.9% in 30-50% stenosis, 38.5% in 50-70% stenosis, 92.3% in 70-99% stenosis, and 100.0% in occlusion)., Conclusions: Our data suggest that BA atherosclerosis can be detected by conventional MRI. When the use of HRMR is limited, conventional MR imaging may give additive information to clinicians., Competing Interests: The authors have declared that no competing interests exist.

Goals: This study aimed to determine whether the plasma levels of free fatty acid (FFA) are associated with ischemic lesion characteristics in nonarterial-origin embolic stroke., Materials and Methods: We prospectively recruited 254 patients with acute cerebral infarction caused by cardioembolic stroke (CES, n=121) or with embolic stroke of undetermined source (ESUS, n=133). Plasma levels of FFA were measured during the acute stage (median of 2days after stroke onset). Acute ischemic lesions on diffusion-weighted imaging were measured in terms of size, composition, and pattern. Transthoracic echocardiography parameters were evaluated in all patients., Findings: Plasma levels of FAA were not different in CES and ESUS patients (mEq/L, 0.78±0.52 vs. 0.67±0.61, P=0.120). Echocardiography parameters, including left atrium volume index and E/e', were higher, and the ischemic lesion volume was larger in patients with CES than in those with ESUS. The ischemic lesion volume and the proportion of patients with mixed (small and large) and large cortical lesions increased with FFA quartile in both CES and ESUS groups. In a multivariable analysis, FFA level (coefficient, 5.249; standard error, 3.447; P=0.001), atrial fibrillation (coefficient, 7.673; standard error, 1.855; P<0.001), and fasting glucose (coefficient, 0.104; standard error, 0.023; P<0.001) were associated with ischemic lesion volume in nonarterial-origin embolic stroke., Conclusion: Elevated plasma FFA levels are associated with larger ischemic lesion volumes and a higher prevalence of large cortical infarcts in patients with nonarterial-origin embolic stroke regardless of the presence of a high-risk cardioembolic source., (Copyright © 2017. Published by Elsevier B.V.)

Background and Purpose: Ischemic stroke patients often have intracranial atherosclerosis (ICAS), despite heterogeneity in the cause of stroke. We tested the hypothesis that ICAS burden can independently reflect the risk of long-term vascular outcome., Methods: This was a retrospective cohort study analyzing data from a prospective stroke registry enrolling consecutive patients with acute ischemic stroke or transient ischemic attack. A total of 1081 patients were categorized into no ICAS, single ICAS, and advanced ICAS (ICAS ≥2 different intracranial arteries) groups. Primary and secondary end points were time to occurrence of recurrent ischemic stroke and composite vascular outcome, respectively. Study end points by ICAS burden were compared using Cox proportional hazards models in overall and propensity-matched patients., Results: ICAS was present in 405 patients (37.3%). During a median 5-year follow-up, recurrent stroke and composite vascular outcome occurred in 6.8% and 16.8% of patients, respectively. As the number of ICAS increased, the risk for study end points increased after adjustment of potential covariates (hazard ratio per 1 increase in ICAS, 1.19; 95% confidence interval, 1.01-1.42 for recurrent ischemic stroke and hazard ratio, 1.18; 95% confidence interval, 1.05-1.33 for composite vascular outcome). The hazard ratios (95% confidence interval) for recurrent stroke and composite vascular outcome in patients with advanced ICAS compared with those without ICAS were 1.56 (0.88-2.74) and 1.72 (1.17-2.53), respectively, in the overall patients. The corresponding values in the propensity-matched patients were 1.28 (0.71-2.30) and 1.95 (1.27-2.99), respectively., Conclusions: ICAS burden was independently associated with the risk of subsequent composite vascular outcome in patients with ischemic stroke. These findings suggest that ICAS burden can reflect the risk of long-term vascular outcome., (© 2017 American Heart Association, Inc.)

Background: Warfarin has a narrow therapeutic window. We hypothesized that genetic factors related to warfarin metabolism (CYP2C9) and activity (VKORC1) would show stronger associations than modifiable factors with the quality of anticoagulation control and risks for thromboembolism and hemorrhage., Methods: In this retrospective cohort analysis, clinical and genetic data were collected from 380 patients with atrial fibrillation (AF) who were followed for an average observation period of 4 years. We evaluated the factors associated with time in therapeutic range (TTR, international normalized ratio [INR]: 2-3) and vascular events (either thromboembolic or hemorrhagic), including both genetic (CYP2C9 and VKORC1 genotype) and modifiable factors (anticoagulation service and warfarin dose assessment interval)., Results: The genotypic frequency of CYP2C9*3 (rs1057910) was 9.5% and that of VKORC1 1173C>T (rs9934438) was 16.3%. TTR showed dependence on VKORC1 polymorphism: TTR was higher in carriers of the VKORC1 1173C>T than of the VKORC1 TT genotype (61.7 ± 16.0% versus 56.7 ± 17.4%, P = .031). Multivariate testing showed that the VKORC1 genotype and anticoagulation service were independently related to labile INRs (TTR <65%). Vascular events were observed in 66 patients (18.4%) during the study period. A Cox proportional hazard model showed that the use of anticoagulation service and patients' characteristics, such as AF-thromboembolic risk (CHA 2 DS 2 -VASc score: Congestive heart failure, Hypertension, Age 75 years or older, Diabetes mellitus, previous Stroke or transient ischemic attack, Vascular disease, Age 65 to 74 years, female) and consequence (neurologic disability), but not genetic factors, were independently associated with vascular events., Conclusions: Both genetic factor (VKORC1 genotype) and clinical efforts (anticoagulation service) influenced the quality of anticoagulation control. However, clinical events were more strongly associated with patient characteristics and clinical efforts than with genetic factors., (Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.)

Background and Aims: The aim of this study was to investigate the stroke mechanisms and associated conditions influencing the decision regarding stroke thromboprophylaxis in patients with atrial fibrillation (AF) plus ischemic stroke, according to the CHA2DS2-VASc score., Methods: We evaluated 938 consecutive patients with a diagnosis of AF plus transient ischemic attack/ischemic stroke. Based on the CHA2DS2-VASc scores, patients were stratified as score 0 or 1 (n = 151), score 2 (n = 146), score 3 (n = 213), score 4 (n = 185), or score ≥5 (n = 243)., Results: Patients with a higher CHA2DS2-VASc score were more likely to have noncardioembolic stroke mechanism (p = 0.001). Large-artery atherosclerosis causing stenosis >50% was more frequently observed in the high CHA2DS2-VASc group (p < 0.001). Coronary artery disease and the use of antiplatelet agents were more prevalent in the higher group (p < 0.001). A high CHA2DS2-VASc score was associated with a higher frequency of cerebral microbleeds and a higher Fazekas grade for leukoaraiosis (p < 0.001). The HAS-BLED score was correlated with the CHA2DS2-VASc score (γ = 0.650; p < 0.001)., Conclusions: A higher CHA2DS2-VASc score is associated with noncardioembolic mechanisms of stroke and with a higher risk of bleeding. Strategies to treat macro/microangiopathy such as use of statin for plaque stabilization, as well as oral anticoagulants with a lower bleeding risk, are needed in these patients., (© 2017 S. Karger AG, Basel.)

Background/aims: The aim of the study was to evaluate the differential roles of endothelial dysfunction and inflammation in intracranial atherosclerotic stroke (ICAS)., Methods: We prospectively recruited 262 patients with acute cerebral infarcts caused by ICAS and 75 individuals with no history of stroke as controls. Markers of endothelial dysfunction (asymmetric dimethylarginine, ADMA) and inflammation (lipoprotein-associated phospholipase A2, Lp-PLA2) were measured. Acute ischemic lesions were measured in terms of their size, composition, and patterns. Subclinical microangiopathy (degree of leukoaraiosis) and macroangiopathy (presence/number of asymptomatic stenoses) were graded in each patient., Results: Compared to normal controls, serum levels of ADMA (0.69 ± 0.14 vs. 0.47 ± 0.10, p < 0.001) and Lp-PLA2 (138.1 ± 116.8 vs. 19.0 ± 58.0, p < 0.001) were elevated in patients with ICAS. A high ADMA serum level was associated with greater prevalence of preclinical microangiopathy and macroangiopathy. Contrastingly, an elevated serum Lp-PLA2 level was associated with larger ischemic lesions, a greater number of lesions, and a larger cortical pattern., Conclusions: Endothelial dysfunction and inflammation have distinct effects in ICAS patents; endothelial dysfunction is associated with the underlying micro- and macro-atherosclerotic burden, whereas inflammation is associated with acute infarct volume and pattern., (© 2017 S. Karger AG, Basel.)

Background and Purpose: Although high-resolution magnetic resonance imaging (HR-MRI) is considered optimal for the diagnosis of intracranial vertebral artery dissection (IVAD), it is not readily available for all patients with suspected IVAD. The purpose of our study was to determine the factor related to IVAD lesions that are not definitively diagnosed by conventional MRI., Methods: This study included IVAD lesions that were evaluated with both of 3 T conventional MRI and HR-MRI. Definitive dissection was defined as the presence of one or more pathognomonic radiological findings including crescentic intramural hematoma, intimal flap, and double lumen. A total of 30 IVAD lesions definitively diagnosed by HR-MRI were included and grouped into a conventional MRI true-positive group (n = 17) or false-negative group (n = 13) based on the presence of definitive findings on conventional MRI., Results: Clinical characteristics did not differ between the two groups. The absence of vertebral artery aneurysmal dilatation was more common in the conventional MRI false-negative group (84.6% vs. 35.3%; P = .010). Ipsilesional vertebral hypoplasia was observed more frequently in the conventional MRI false-negative IVAD group (53.8% vs. 17.6%; P = .056). In logistic regression, absence of vertebral artery aneurysmal dilatation was independently associated with conventional MRI false-negative IVAD (OR, 16.37; 95% CI, 1.39-192.30; P = .026). Ipsilesional vertebral artery hypoplasia showed only a trend as a predictor of conventional MRI false-negative IVAD (OR, 7.24; 95% CI, .73-71.51; P = 0.090)., Conclusions: HR-MRI may be useful for diagnosing IVAD without aneurysmal dilatation or with ipsilesional vertebral hypoplasia., (Copyright © 2016 by the American Society of Neuroimaging.)

Among embolic strokes of undetermined source, under-recognized etiology such as extra-cardiac shunt could be a potential risk factor. We sought to characterize infarction patterns on diffusion-weighted imaging (DWI) and transesophageal echocardiography (TEE) findings in extra-cardiac shunt-related stroke. We enrolled 96 consecutive patients with cryptogenic stroke who had an extra- or intra-cardiac shunt. Diagnosis of the shunt was performed using TEE with agitated saline contrast and pulmonary vein isolation. Infarction patterns on DWI and total lesion volume were analyzed. Bubble amounts through the shunt were classified via the International Consensus Criteria (ICC). Short-term prognosis, patterns and size of DWI lesions, and involved vascular territories were not significantly different between two groups. Multivariate analysis revealed that extra-cardiac shunt group has a smaller total infarct volume (odds ratio [OR]=0.427, 95% confidence interval [95% CI] 0.228-0.799, p=0.008), and significantly higher bubble grade during resting state and lower grade during the Valsalva maneuver (OR= 0.539, 95% CI 0.438-0.663, p<0.001). Stroke related to an extra-cardiac shunt presented smaller infarct volume, favorable clinical outcomes and characteristic finding on TEE with agitated saline contrast. Further study is needed to confirm whether the extra-cardiac shunt is an independent risk factor., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Cancer and stroke, which are known to be associated with one another, are the most common causes of death in the elderly. However, the pathomechanisms that lead to stroke in cancer patients are not well known. Circulating extracellular vesicles (EVs) play a role in cancer-associated thrombosis and tumor progression. Therefore, we hypothesized that cancer cell-derived EVs cause cancer-related coagulopathy resulting in ischemic stroke., Methods: Serum levels of D-dimer and EVs expressing markers for cancer cells (epithelial cell adhesion molecule [CD326]), tissue factor (TF [CD142]), endothelial cells (CD31+CD42b-), and platelets (CD62P) were measured using flow cytometry in (a) 155 patients with ischemic stroke and active cancer (116 - cancer-related, 39 - conventional stroke mechanisms), (b) 25 patients with ischemic stroke without cancer, (c) 32 cancer patients without stroke, and (d) 101 healthy subjects., Results: The levels of cancer cell-derived EVs correlated with the levels of D-dimer and TF+ EVs. The levels of cancer cell-derived EVs (CD326+ and CD326+CD142+) were higher in cancer-related stroke than in other groups (P<0.05 in all the cases). Path analysis showed that cancer cell-derived EVs are related to stroke via coagulopathy as measured by D-dimer levels. Poor correlation was observed between TF+ EV and D-dimer, and path analysis demonstrated that cancer cell-derived EVs may cause cancer-related coagulopathy independent of the levels of TF+ EVs., Conclusions: Our findings suggest that cancer cell-derived EVs mediate coagulopathy resulting in ischemic stroke via TF-independent mechanisms.

Background: From a therapeutic viewpoint, it is important to differentiate the underlying causes of embolism in patients with cryptogenic stroke, such as aortic arch atheroma, patent foramen ovale, and paroxysmal atrial fibrillation. We investigated the clinical and radiological characteristics of these 3 common causes of cryptogenic embolism to develop models for decision making in etiologic workups., Methods and Results: A total of 321 consecutive patients with acute infarcts from cryptogenic embolism were included. Patients were divided into 3 groups-aortic arch atheroma (n=40), patent foramen ovale (n=153), and paroxysmal atrial fibrillation (n=128)-based on extensive cardiologic workups. We used a multinomial logistic regression analysis to detect the clinical and diffusion-weighted imaging factors associated with the probability of aortic arch atheroma, patent foramen ovale, and paroxysmal atrial fibrillation. Clinical and radiological features differed among the groups. The patent foramen ovale group had a healthy vascular risk factor profile and showed posterior circulation involvement compared with other groups (P<0.01). In contrast, paroxysmal atrial fibrillation-related strokes had higher initial National Institutes of Health Stroke Scale (NIHSS) scores and larger lesions than the other groups (P<0.001). The aortic arch atheroma group had clinical features similar to those of the paroxysmal atrial fibrillation group but showed small lesions scattered in multiple vascular territories (P<0.001). Multivariate regression analysis revealed that age, initial NIHSS score, lesion size (≥20 mm), multiple (≥3) lesions, and involvement of posterior circulation or multiple vascular territories differentiated the 3 groups (pseudo, R(2)=0.656). The prediction ability of this model was validated in the external validation cohort (n=117, area under the curve 0.78)., Conclusions: Our data indicate that patients with cryptogenic embolic stroke show distinct clinical and radiological features depending on the underlying causes., (© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Objective: We sought to identify the clinical outcome and predictors for ischemic stroke recurrence in adults with symptomatic moyamoya disease (MMD)., Methods: We analyzed 104 adult MMD patients with ischemic stroke or TIA registered at our institution. All patients underwent digital subtraction angiography and single photon emission computed tomography to measure disease severity and cerebral vascular reserve (CVR). A Cox regression model was used to identify predictors of recurrent ischemic stroke., Results: Fifty-nine patients were non-surgically treated and 45 patients were surgically treated. In the non-surgical group, the Kaplan-Meier estimate of ischemic stroke recurrence was 1.6% in the first year and 11.8% in the 5th year. Hypertension (hazard ratio [HR]=0.07, 95% confidence interval [CI] 0.01-0.99), diabetes (HR=35.16, 95% CI 2.61-474.16), presence of steno-occlusive lesion in posterior cerebral arteries (HR=17.53, 95% CI 2.02-152.43), and extended or global decreased CVR (HR=13.62, 95% CI 1.55-119.84) were independent predictors of recurrence. In the surgical group, the Kaplan-Meier estimate of ischemic stroke recurrence was 24.4% in the first year and 24.4% in the 5th year. Half of the recurred patients experienced recurrent ischemic strokes postoperatively. Diabetes was the only predictor of recurrent ischemic stroke (HR=6.17, 95% CI 1.31-29.14)., Conclusions: In non-surgically treated MMD, PCA stenosis and CVR were identified as predictors of ischemic stroke recurrence. Diabetes was an independent predictor of recurrent ischemic stroke in both non-surgical and surgically treated MMD groups., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background and Purpose: Good collateral flow is an important predictor for favorable responses to recanalization therapy and successful outcomes after acute ischemic stroke. Magnetic resonance perfusion-weighted imaging (MRP) is widely used in patients with stroke. However, it is unclear whether the perfusion parameters and thresholds would predict collateral status. The present study evaluated the relationship between hypoperfusion severity and collateral status to develop a predictive model for good collaterals using MRP parameters., Methods: Patients who were eligible for recanalization therapy that underwent both serial diffusion-weighted imaging and serial MRP were enrolled into the study. A collateral flow map derived from MRP source data was generated through automatic postprocessing. Hypoperfusion severity, presented as proportions of every 2-s Tmax strata to the entire hypoperfusion volume (Tmax≥2 s), was compared between patients with good and poor collaterals. Prediction models for good collaterals were developed with each Tmax strata proportion and cerebral blood volumes., Results: Among 66 patients, 53 showed good collaterals based on MRP-based collateral grading. Although no difference was noted in delays within 16 s, more severe Tmax delays (Tmax16-18 s, Tmax18-22 s, Tmax22-24 s, and Tmax>24 s) were associated with poor collaterals. The probability equation model using Tmax strata proportion demonstrated high predictive power in a receiver operating characteristic analysis (area under the curve=0.9303; 95% confidence interval, 0.8682-0.9924). The probability score was negatively correlated with the volume of infarct growth (P=0.030)., Conclusions: Collateral status is associated with more severe Tmax delays than previously defined. The present Tmax severity-weighted model can determine good collaterals and subsequent infarct growth., (© 2015 American Heart Association, Inc.)

Background and Purpose: Recent randomized clinical trials (RCTs) have evaluated the benefit of new oral anticoagulants in reducing the risk of vascular events and bleeding complications in patients with atrial fibrillation (AF). However, abundant and strict enrollment criteria may limit the validity and applicability of results of RCTs to clinical practice. We estimated the eligibility for participation in RCTs of an unselected group of patients with AF. In addition, we compared features favoring new oral anticoagulant use between patients with versus without stroke. Randomized Evaluation of Long-Term Anticoagulation Therapy, Methods: We applied enrollment criteria of 4 RCTs (RE-LY, ROCKET-AF, ARISTOTLE, and ENGAGE-AF-TIMI 48) to 695 patients with AF taking warfarin, prospectively and consecutively collected at a university medical center; 500 patients with and 195 patients without stroke. Time in therapeutic range and bleeding risk scheme (anticoagulation and risk factors in atrial fibrillation) were also measured., Results: The proportions of patients fulfilling the trial enrollment criteria varied, ranging from 39% to 72.8%, depending on the differences in indications/contraindications among studies and presence/absence of stroke. The main reasons for ineligibility for RCTs were hemorrhagic risk (anticoagulation and risk factors in atrial fibrillation [ATRIA] score) (10.8%-40.5%) and planned cardioversion (5.1%-7.7%) for nonstroke patients, and a low creatinine clearance (5.6%-9.2%) and higher risk of bleeding (15.2%-20.8%) for patients with stroke. When compared with nonstroke patients, patients with stroke showed a lower time in therapeutic range (54.4±42.8% versus 65.4±34.9%, especially with severe disability) and a high hemorrhagic risk (ATRIA score) (3.06±2.30 versus 2.18±2.16) (P<0.05 in both cases)., Conclusions: Patients enrolled in RCTs are partly representative of patients with AF in clinical practice. When time in therapeutic range and bleeding tendency with warfarin use were considered, the use of new oral anticoagulants was preferred in patients with stroke than in nonstroke patients, but they were more likely to be excluded in RCTs., (© 2014 American Heart Association, Inc.)

Background: Currently, intensive lipid lowering is recommended in patients with atherosclerotic ischemic stroke or transient ischemic attack. However, the role of statin in cardioembolic stroke is unclear. We investigated the association of statin with pretreatment collateral status in cardioembolic stroke., Methods: A collaborative study from two stroke centers in distinct geographic regions included consecutive patients with acute middle cerebral artery (MCA) infarction due to atrial fibrillation (AF) who underwent cerebral angiography. The relationship between pretreatment collateral grade and the use/dose of statin at stroke onset was assessed. The angiographic collateral grade was evaluated according to the ASITN/SIR Collateral Flow Grading System., Results: Ninety-eight patients (76 statin-naïve, 22 statin users) were included. Compared with statin-naïve patients, statin users were older and more frequently had hypertension, hyperlipidemia and coronary heart disease. Excellent collaterals (grade 3-4) were more frequently observed in statin users (11 patients, 50%) than in statin-naïve patients (21 patients, 27.6%; p = 0.049). The use of atorvastatin 10 mg equivalent or higher doses of statin was associated with excellent collaterals (p for trend = 0.025). In multiple regression analysis, prestroke statin use was independently associated with excellent collaterals (odds ratio, 7.841; 95% confidence interval, CI, 1.96-31.363; p = 0.004)., Conclusions: Premorbid use of statin in AF patients is associated with excellent collateral flow. Although most statin trials excluded patients with cardioembolic stroke, our data suggests the possibility that statin may be beneficial in AF-related stroke

Background and Purpose: The clinical significance of microembolic signals (MES) in the posterior circulation remains unclear. The aim of this study was to investigate the sources and consequences of MES in acute posterior circulation cerebral ischemia., Methods: We evaluated a total of 140 consecutive patients (93 males, mean age 62.9 years) who had acute posterior circulation cerebral ischemia. The MES monitoring was conducted at the basilar artery through the suboccipital window for a 30-minute period., Results: MES were detected in 18 (12.9%) of the 140 patients. Clinical characteristics and laboratory data did not differ between the MES-positive and MES-negative groups. Intracranial vertebrobasilar artery (VBA) stenosis was independently associated with the presence of MES (odds ratio, 9.85; 95% confidence interval, 1.22-79.48; P=0.032), whereas the patients with vertebral artery stenosis that was limited to the extracranial portion did not show an association. Microembolic signals occurred significantly more frequently in patients with severe degree of VBA stenosis compared to those with nonsignificant stenosis (odds ratio, 9.88; 95% confidence interval, 1.23-79.07; P=0.031). In a subgroup analysis of the 79 patients who had lesions on diffusion-weighted images and relevant VBA stenosis, the MES-positive group showed more frequent embolic infarction (P=0.010) and multiple lesion patterns (P=0.007) than single perforating infarctions., Conclusions: In acute posterior circulation cerebral ischemia, intracranial and severe VBA stenosis is associated with MES and may be its root causes. The presence of MES in VBA stenosis suggests that multiple and embolic type infarctions are the mechanisms of stroke.

Background and Purpose: The clinical significance of sulcal effacement has been widely investigated in CT studies, but the results are controversial. In this study, we evaluated the presence of perisylvian sulcal effacement (PSE) on fluid attenuation inversion recovery MRI and hypothesized that PSE may be related to collateral flow status together with hyperintense vessels on fluid attenuation inversion recovery in hyperacute stroke. In addition, we investigated whether an association between PSE and clinical outcome could be found in these patients., Methods: Consecutive patients with acute middle cerebral artery infarcts within 6 hours of symptom onset were included. All patients had internal carotid artery or middle cerebral artery occlusion and underwent MRI including FLAIR. The presence of PSE and hyperintense vessels on fluid attenuation inversion recovery and the collateral status and occurrence of early recanalization (ER) on conventional angiography were evaluated., Results: Of 139 patients, 79 (56.8%) had PSE. Multivariate testing revealed PSE was independently associated with collateral status. The association between hyperintense vessels and collaterals was different depending on PSE. Compared to PSE-positive and ER-negative patients, PSE-negative and ER-negative patients (odds ratio, 4.11; 95% confidence interval, 1.12-15.17) and PSE-negative and ER-positive patients (odds ratio, 34.62; 95% confidence interval, 5.75-208.60), but not PSE-positive and ER-positive patients, were more likely to experience favorable clinical outcomes (modified Rankin Scale score ≤ 2 at 3 months)., Conclusions: PSE is independently associated with collateral status in patients with acute middle cerebral artery stroke. Moreover, PSE in conjunction with recanalization status can predict clinical outcomes in these patients.

Background: Assessing collateral status is important in acute ischemic stroke. The purpose of this study was to compare multiphasic perfusion computed tomography (MPCT) with digital subtraction angiography (DSA) in predicting leptomeningeal collateral flow in acute middle cerebral artery (MCA) infarction., Methods: Consecutive patients underwent MPCT and DSA for acute MCA infarction that presented within 6 h of symptom onset. We included patients who showed MCA occlusion in the same location on both modalities and assessed the agreement rate and correlation between the MPCT and DSA collateral grades., Results: Of 54 patients, 44 (81.5%) had proximal MCA (M1) occlusions and 10 (18.5%) had distal MCA (M2) occlusions based on MPCT and DSA. The κ-coefficients were 0.87 and 0.81 in the MPCT and DSA collateral grade systems, respectively. Forty-four patients (81.5%) belonged to the same category in both collateral-grading systems. MPCT collateral grades correlated positively with those of DSA (Spearman's correlation coefficient 0.827, p < 0.001)., Conclusion: Our data show that MPCT can predict leptomeningeal collateral flow in acute ischemic stroke. Based on collateral status assessed by MPCT, different therapeutic approaches might be warranted., (Copyright © 2012 S. Karger AG, Basel.)

Background: Atrial fibrillation (AF) is a leading cause of fatal ischemic stroke. It was recently reported that international normalized ratio (INR) levels were associated with infarct volumes. However, factors other than INR levels that affect stroke phenotypes are largely unknown. Therefore, we evaluated the determinants of stroke phenotypes (pattern and volume) among patients with AF who were not adequately anticoagulated., Methods: We analyzed data pertaining to consecutive AF patients admitted over a 6-year period with acute MCA territory infarcts. We divided the patients according to DWI (diffusion-weighted imaging) lesion volumes and patterns, and the relationship between stroke predictors (the CHADS2 and CHA2DS2-VASc score), systemic, and local factors and each stroke phenotype were then evaluated., Results: The stroke phenotypes varied among 231 patients (admission INR median 1.06, interquartile range (IQR) 1.00-1.14). Specifically, (1) the DWI lesion volumes ranged from 0.04-338.62 ml (median 11.86 ml; IQR, 3.07-44.20 ml) and (2) 46 patients had a territorial infarct pattern, 118 had a lobar/deep pattern and 67 had a small scattered pattern. Multivariate testing revealed that the CHADS2 and CHA2DS2-VASc score were not related to either stroke phenotype. Additionally, the prior use of antiplatelet agents was not related to the stroke phenotypes. Congestive heart failure and diastolic dysfunction were not associated with stroke phenotypes., Conclusions: The results of this study indicated that the determinants of stroke phenotypes were different from the predictors (i.e., CHADS2 and CHA2DS2-VASc score) of stroke in patients with AF.

Background and Purpose: Collaterals sustain the ischemic penumbra to limit growth of the infarct core before revascularization, yet the impact of baseline collateral flow on hemorrhagic transformation (HT) after endovascular therapy remains unknown., Methods: A collaborative study from 2 stroke centers in distinct geographic regions included 222 consecutive patients who received endovascular therapy for acute cerebral ischemia. The influence of collaterals on HT was analyzed in distinct case scenarios relative to baseline collateral grade at angiography (0 to 1 versus 2 to 4) and recanalization (Thrombolysis in Myocardial Ischemia scale, 0 to 1 versus 2 to 3): good collaterals and successful recanalization (n=98), poor collaterals with successful recanalization (n=43), good collaterals and no recanalization(n=46), and poor collaterals and no recanalization (n=35)., Results: HT after endovascular therapy occurred in 103 (46.4%) patients; 42 (18.9%) were symptomatic. HT was more frequently observed in patients with poor collaterals and recanalization than in other groups (P=0.048). When revascularization was achieved, patients with poorer collaterals were more likely to have symptomatic worsening with HT (r=-0.181, P=0.032). Multiple logistic regression analysis identified aggressive treatment (OR, 2.558 for Merci clot retrieval; 95% CI, 1.153 to 5.678; OR, 3.618 for combined fibrinolytics and mechanical therapy; 95% CI, 1.551 to 8.437; and OR, 2.085 for intravenous thrombolysis before endovascular therapy; 95% CI, 1.096 to 3.969), poor collaterals and recanalization (OR, 2.666; 95% CI, 1.163 to 6.113), and serum glucose levels (OR, 1.007; 95% CI, 1.000 to 1.014) as independent predictors of HT., Conclusions: Angiographic grade of collateral flow strongly influences the rate of HT after therapeutic recanalization for acute ischemic stroke. Collateral status readily available from baseline angiography may therefore refine therapeutic decision-making in acute cerebral ischemia.

Background and Purpose: Collaterals sustain the penumbra before recanalization and offset infarct growth, yet the influence of baseline collateral flow on recanalization after endovascular therapy remains relatively unexplored., Methods: We analyzed consecutive patients who received endovascular therapy for acute cerebral ischemia from 2 distinct study populations. We assessed the relationship between pretreatment collateral grade and vascular recanalization (Thrombolysis In Myocardial Ischemia [TIMI] scale). In addition, we assessed infarct growth on serial MRI., Results: A total of 222 patients was included, 138 from the United States and 84 from South Korea. Complete revascularization occurred in 14.1% (11 of 78) patients with poor pretreatment collateral grades, whereas it was observed in 25.2% (26 of 103) patients with good collaterals and 41.5% (17 of 41) patients with excellent collaterals (P<0.001). This relationship was consistently observed in both study populations, although the mode of endovascular therapy was different between them. After adjustment for other factors, including mode of endovascular therapy, prior use of intravenous tissue plasminogen activator, and site of occlusion, pretreatment collateral grade was independently associated with recanalization. When revascularization was achieved, greater infarct growth occurred in patients with poor collaterals than in those with good collaterals (P=0.012)., Conclusions: Our data indicate that angiographic collateral grade determines the recanalization rate after endovascular revascularization therapy. When therapeutic revascularization was achieved, beneficial effects were not observed in patients with poor collaterals. Angiographic collateral grade may therefore help guide treatment decision-making in acute cerebral ischemia.

Background: We previously reported that intracranial large-artery atherosclerotic stroke (ICAS) had a relatively large salvageable area of less severe hypoperfusion. However, information regarding the outcome after ICAS is lacking. We hypothesized ICAS would show more favorable clinical and radiological outcomes than other stroke mechanisms., Methods: Consecutive patients underwent admission (n = 149) and follow-up (n = 80) multiparametric magnetic resonance imaging (MRI) for acute middle cerebral artery infarcts within 6 h of symptom onset. T(max) perfusion lesion maps were generated. We assessed the difference in the degree of infarct growth ([follow-up diffusion-weighted imaging (DWI) volume--initial DWI volume]/initial penumbra volume) and the presence of excellent long-term outcome [defined as a modified Rankin scale (mRS) score ≤ 2 and a modified Barthel index (mBI) ≥ 90 at 3 months]., Results: Of 149 patients, 24 (16.1%) had ICAS, 75 (50.3%) had cardioembolic stroke, 21 (14.1%) had extracranial large-artery atherosclerotic stroke, and 29 (19.5%) had cryptogenic embolic stroke. Despite a higher recurrence rate in patients with ICAS compared to other subtypes (p = 0.026), the long-term outcome was better in ICAS (p = 0.003 for an mRS score ≤ 2 and p = 0.004 for an mBI ≥ 90). Among 80 patients who underwent follow-up MRI, patients who had minimal infarct growth (less than 10%) were more prevalent among the patients with ICAS (p = 0.004). Multivariate testing revealed that ICAS was independently associated with both excellent long-term outcome (OR = 3.45; 95% CI = 1.11-10.78) and minimal infarct growth (OR = 10.40; 95% CI = 1.20-90.11)., Conclusion: Our data show that patients with ICAS have favorable clinical and radiological outcomes compared with other subtypes., (Copyright © 2011 S. Karger AG, Basel.)

Background: Clinical response immediately after revascularisation therapy differs among patients. Although reperfusion is the deciding factor with respect to this dramatic response to revascularisation therapy, the influence of pre- and post-treatment diffusion-perfusion status on the speed and degree of recovery are unknown., Methods: Consecutive stroke patients who were eligible for revascularisation therapy underwent serial diffusion-perfusion MRI. Tmax perfusion maps were generated, and stroke severity and recovery were assessed up to day 90. The relationship of diffusion and perfusion lesion indices with the speed and degree of recovery were evaluated., Results: 69 patients (42 men; aged 66.3±15.9 years) were included; National Institutes of Health Stroke Scale (NIHSS) score was 13.3±6.4 points. 19 received intravenous tissue plasminogen activator (tPA) and 50 received endovascular therapy with/without intravenous tPA. Early dramatic improvement (NIHSS score reduction of ≥40% within 24 h) was observed in 24 (34.8%) patients. Among the other 45 patients, 18 (40%) showed good outcomes (modified Rankin score 0-2 at day 90), suggesting delayed recovery. The volume of post-treatment perfusion delay was similar between the early and delayed recovery groups (p=0.329) but smaller than in the non-responders group (p<0.05). Multivariate testing revealed that smaller post-treatment perfusion delay volumes were independently associated with both early dramatic improvement and delayed recovery. In addition, initial diffusion weighted imaging lesion volume was smaller in the former than in the latter (p=0.029) and was independently associated with early dramatic recovery., Conclusions: A significant proportion of patients with a lack of early dramatic improvement (40%) showed delayed recovery. Both pretreatment infarct volume and post-treatment reperfusion correlated with the degree and speed of recovery.

Background and Purpose: An effective stroke code system that can expedite rapid thrombolytic treatment requires effective notification/communication and an organized team approach. We developed a stroke code program based on the computerized physician order entry (CPOE) system and investigated whether implementation of this CPOE-based program is useful for reducing the time from arrival at emergency departments (ED) to evaluation steps and the initiation of thrombolytic treatment in various hospital settings., Methods: The CPOE-based program was implemented by 10 hospitals. Time intervals from arrival at the ED to blood tests, computed tomography scanning, and thrombolytic treatment during the 1-year period before and the 1-year period after the program implementation were compared., Results: Time intervals from ED arrival to evaluation steps were significantly reduced after implementation of the CPOE-based program. Times from ED arrival to CT scan, complete blood counts, and prothrombin time testing were reduced by 7.7 minutes, 5.6 minutes, and 26.8 minutes, respectively (P<0.001). The time from ED arrival to intravenous thrombolysis was reduced from 71.7+/-33.6 minutes to 56.6+/-26.9 minutes (P<0.001). The number of patients who were treated with thrombolysis increased from 3.4% (199/5798 patients) before the CPOE-based program to 5.8% (312/5405 patients) afterward (P<0.001). The CPOE implementation also improved the inverse relationship between onset-to-door time and door-to-needle time., Conclusions: The CPOE-based stroke code could be successfully implemented to reduce in-hospital time delay in thrombolytic therapy in various hospital settings. CPOE may be used as an efficient tool to facilitate in-hospital notification/communication and an organized team approach.

Background: Recently, the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution (DEFUSE) and the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) trialists suggested that diffusion-perfusion magnetic resonance imaging (MRI) can classify patients into 4 subgroups likely to differentially experience benefit or harm from reperfusion therapies. However, there is a lack of data comparing MR mismatch profiles between different race-ethnic groups. In addition, clinical factors affecting MR mismatch profiles are not well described., Methods: We analyzed clinical and pretreatment MRI data of patients from 2 geographically and ethnically distinct study populations (Seoul, South Korea, and Los Angeles, Calif., USA) who are eligible for recanalization therapy. Diffusion-perfusion mismatch regions were classified among the 4 DEFUSE MR profiles: target mismatch, no mismatch, small lesion and malignant., Results: A total of 147 South Korean and 162 Southern Californian subjects (64.2% Whites) were included. Pretreatment MRIs revealed that the MR mismatch profiles were different in the 2 study populations (p < 0.001). Target mismatch was more prevalent in Southern Californian subjects (67.9%) compared with South Korean subjects (58.5%), whereas the small lesion pattern was more prevalent in the latter (9.9 vs. 23.1%). After adjusting for covariables, 3 features independently decreased the likelihood of presence of target mismatch: history of diabetes (OR 0.369, 95% CI 0.196-0.694), small versus large arterial occlusion (OR 0.052, 95% CI 0.01-0.255) and largest size (highest tertile) of diffusion-weighted imaging (DWI) lesion volume (OR 0.516, 95% CI 0.266-0.999). The one feature independently increasing target mismatch likelihood was intermediate size (middle tertile) DWI volume (OR 2.977, 95% CI 1.431-6.195)., Conclusions: Target mismatch profiles are present in 55-70% of patients. Target mismatch is less common in patients with diabetes, small vessel occlusion, Asian ethnicity and extensive DWI lesions, and more common in patients with DWI lesions of intermediate size.

Background: Despite many studies that investigated the neural correlates of hemispatial neglect (HN) with structural imaging, studies using voxel-wise analyses of functional imaging are not available. Furthermore, previous studies neither considered the neglect severity nor investigated whether there are differences in these neural correlates according to each neglect subtest. This study aimed to investigate the neural correlates of HN by correlating the total and the individual neglect score with hypoperfusion value on single photon emission computed tomography (SPECT) using voxel-wise analyses., Methods: Forty-two patients with acute right hemisphere strokes underwent a neglect test battery consisting of 3 bisection tasks, 2 cancellation tasks and 2 copying tasks. The SPECT images were acquired in these patients and 10 age- and education-matched normal controls., Results: Patients with HN, compared to those without HN, had hypoperfusion in the right middle temporal-occipital junction, inferior frontal gyrus and retrosplenial area. The total neglect score correlated with the hypoperfusion in the right middle temporal-occipital junction, fusiform gyrus, parahippocampal gyrus, inferior temporal gyrus, anterior part of the superior and middle temporal gyri, cuneus, lingual gyrus, angular gyrus, and the cerebellum. Across the neglect subtests similar correlation patterns were observed with minor variations., Conclusions: Unlike the results of previous studies showing that the critical neural correlates for HN are inferior parietal lobule or superior temporal gyrus, our study showed that the lesions that critically contribute to the neglect severity were located in the posterior parts of the middle temporal gyrus (temporal-occipital junction)., (Copyright © 2010 S. Karger AG, Basel.)

Objective: Damage to premotor and prefrontal regions results in motor-intentional disorders (MIDs) that disrupt initiation, maintenance, and termination of volitional movements. MIDs more frequently occur in right hemisphere rather than in left hemisphere injury. The aim of this study was to evaluate the prevalence of MIDs in patients with right hemisphere stroke and the factors that have influence on MIDs., Methods: Subjects consisted of 25 consecutive patients with right hemisphere stroke and 12 normal controls. They underwent a series of experiments using force dynamometer along with bedside examination., Results: It was identified that the force control test screened for MIDs with a higher sensitivity than bedside examinations: motor akinesia (38% vs. 11%), motor impersistence (50% vs. 10%), and motor perseveration (47% vs. 25%). The patients were significantly inferior to the controls in terms of force control capabilities in the 4 force control phases (1.6 to 16.3 times). The location and area of lesion and space of force production were not related to the severity of MIDs whereas the presence of neglect was related to the severity of MIDs., Conclusions: Our results suggest force dynamometer is a sensitive method to detect MIDs and the presence of neglect may influence the frequency of MIDs.

Most clinical trials have focused on the presence of perfusion- and diffusion-weighted imaging (PWI-DWI) mismatch by more than 20%, and different stroke subtypes were lumped together. We hypothesized that intracranial large artery atherosclerotic stroke (IC-LAA) would show different PWI-DWI and magnetic resonance angiography (MRA)-DWI mismatch profiles, compared with other stroke subtypes. Consecutive patients underwent pretreatment multiparametric magnetic resonance imaging for the acute middle cerebral artery infarcts within 6 h of symptom onset. We assessed the difference in the DWI-PWI mismatch ratio, severity of hypoperfusion, and MRA-DWI mismatch among the stroke subtypes. Of 86 patients, 19 (22.1%) had IC-LAA; 42 (48.8%) cardioembolic stroke, 15 (17.4%) extracranial-LAA, and 10 (11.6%) had cryptogenic embolic stroke. Although the volume of the penumbra was not different among the groups, the mismatch ratio was higher (P=0.003) and the severity of hypoperfusion was lower in the IC-LAA group (P=0.001). The MRA-DWI mismatch was more prevalent in the IC-LAA group than in other groups (P<0.001). Collateral grading, assessed in 41 patients, was more likely to be intermediate/excellent in the IC-LAA group (P<0.001). Multivariate testing revealed that a larger mismatch ratio and less severe hypoperfusion, and MRA-DWI mismatch were independently associated with IC-LAA. Our data show that patients with IC-LAA had different mismatch profiles, which were related to better collaterals, compared with other subtypes.

Background: Little is known about whether vascular risk factors predispose to atherosclerotic stroke depending on age. We evaluated predictors of large vessel atherosclerotic stroke (LVAS) stratified by age in two geographically and racially distinct study populations., Methods: Data collected over a 4-year period in prospectively maintained registries on 3,053 subjects with ischemic cerebrovascular events were analyzed: 1,982 patients from a hospital in South Korea and 1,071 patients admitted to a hospital in Los Angeles, Calif., USA. Independent vascular risk factor associations with LVAS mechanism were evaluated in three groups stratified by age (years) at symptom onset: young (75 years)., Results: Altogether at both study sites, 972 (31.8%) patients had LVAS mechanism, of whom 391 (40.2%) were female. Risk factor profiles were not significantly different between LVAS versus other stroke mechanisms. Among young patients, after adjusting for covariates, current smoking was the only predictor of atherosclerotic stroke at both Korean (OR 2.04; 95% CI: 1.13-3.69) and Californian sites (OR 4.78, 95% CI 1.54-14.89), while the metabolic syndrome was the only predictor of atherosclerotic stroke among the older patients (OR 1.58, 95% CI 1.17-2.12 for Korean; OR 1.75, 95% CI 1.07-2.84 for Californian), but not in the young or oldest groups., Conclusions: Across race and region, the estimated impact of vascular risk factors for LVAS varies by age, and this is most prominently seen among persons of less than 76 years of age. Some risk factors have an early effect (smoking) and others an effect that plays out over time., (Copyright 2008 S. Karger AG, Basel.)

Background: Smoking is a well-known risk factor for ischaemic stroke or transient ischaemic attack. Paradoxically, smokers have been reported to have better prognosis after myocardial infarction when compared to nonsmokers. This study examined the independent effect of smoking status on long-term prognosis after ischaemic stroke in male patients., Methods: A total 476 male patients with acute cerebral infarction within the middle cerebral artery territory were reviewed. Baseline characteristics and long-term prognosis were compared among smokers, ex-smokers, and nonsmokers., Results: Although the baseline severity of stroke did not differ among the groups, poor long-term outcome (Barthel index<60 or modified Rankin score>3) at 6 months after ischaemic stroke was more frequently observed in nonsmokers than in smokers (P=0.013); the outcome for ex-smokers was intermediate. After adjustment for age and other variables, current smoking was negatively correlated to poor long-term outcome (odds ratio, 0.286; 95% confidence interval, 0.119-0.686; P=0.005). On subgroup analysis, the impact of smoking on stroke prognosis was significant only in younger patients (<65 years of age) and those with atherosclerotic stroke., Conclusions: There was a strong independent correlation between smoking status and long-term outcome in patients with ischaemic stroke. Further studies about the impact of smoking habit on stroke outcome depending on the characteristics of patients (ie. age and stroke subtype) are needed.

Background: Lacunar stroke has been defined as an infarct <15 mm in diameter in the presence of symptoms of lacunar syndromes. We investigated a new approach in predicting whether a deep infarct is caused by small arterial occlusion., Methods: A total of 319 consecutive patients with acute symptomatic infarcts within the striatocapsular territory underwent diffusion-weighted imaging (DWI) and diagnostic workups, including vascular and cardiological studies. Predictors for nonlacunar mechanisms were evaluated by logistic regression analysis, with the size of infarct (1-mm increase) and stroke syndrome (traditional vs. atypical lacunar syndrome vs. cortical syndrome) graded rather than dichotomized., Results: Amongst the 171 patients who did not meet the established criteria for lacunar stroke, that is, deep infarct of >or=15 mm or presenting symptoms of nontraditional lacunar syndrome, a documented etiology could not be determined in 97 (56.7%) patients. In contrast, amongst the 148 patients who met the criteria, 27 (18.2%) had nonlacunar mechanisms. Logistic regression analysis identified the variables that predicted nonlacunar stroke mechanisms with statistical significance as nontraditional lacunar syndromes (OR 2.19 for atypical lacunar syndrome, and OR 6.72 for cortical syndrome), infarct size on DWI (OR 1.05 per 1-mm increase), and unilateral multiple deep infarcts on DWI (OR 2.22, p < 0.05 in all cases). Receiver operating characteristic curves showed that discrimination power of the model derived from logistic regression analysis (grading system) was better than that of the previously established dichotomizing criterion in predicting nonlacunar mechanisms (p = 0.004)., Conclusions: A clinically significant proportion of clinical MRI lacunae are associated with underlying nonlacunar mechanisms. Decisions regarding the extent of diagnostic procedures in patients with subcortical infarcts can be guided by the point value in terms of the stroke syndrome and infarct patterns, as well as the size of infarct., ((c) 2007 S. Karger AG, Basel.)

Background and Purpose: Although there is some early evidence showing the value of repetitive transcranial magnetic stimulation (rTMS) in stroke rehabilitation, the therapeutic effect of high-frequency rTMS, along with the physiology of rTMS-induced corticomotor excitability supporting motor learning in stroke, has not been established. This study investigated high-frequency rTMS-induced cortical excitability and the associated motor skill acquisition in chronic stroke patients., Methods: Fifteen patients with chronic hemiparetic stroke (13 men; mean age 53.5 years) practiced a complex, sequential finger motor task using their paretic fingers either after 10 Hz or sham rTMS over the contralateral primary motor cortex (M1). Both the changes in the behavior and corticomotor excitability before and after the intervention were examined by measuring the movement accuracy, the movement time, and the motor-evoked potential (MEP) amplitude. A separate repeated-measures ANOVA and correlation statistics were used to determine the main and interaction effects as well as relationship between the changes in the behavioral and corticomotor excitability., Results: High-frequency rTMS resulted in a significantly larger increase in the MEP amplitude than the sham rTMS (P<0.01), and the plastic change was positively associated with an enhanced motor performance accuracy (P<0.05)., Conclusions: High-frequency rTMS of the affected motor cortex can facilitate practice-dependent plasticity and improve the motor learning performance in chronic stroke victims.

Background and Purpose: MR imaging may help in predicting hemorrhagic transformation (HT) in acute ischemic stroke. Our purpose was to determine whether the lesion volumes on diffusion-weighted (DW) imaging, apparent diffusion coefficient (ADC) values, and early parenchymal enhancement are predictive of HT and to investigate the mechanism of the enhancement., Methods: We retrospectively examined 55 patients with acute ischemic stroke who underwent gadolinium-enhanced MR imaging within 6 hours of symptom onset and follow-up CT or MR imaging within 72 hours. Intravenous thrombolysis was performed in 15 patients. DW imaging lesion volumes and ADC values were compared between patients with and those without HT. ADCs and perfusion parameters were compared between lesions with and those without parenchymal enhancement., Results: Nineteen (34.5%) patients had HT (14 with hemorrhagic infarction, five with parenchymal hematoma). Patients with HT had decreased mean ADCs and large lesion volumes on DW imaging, but differences were not significant (P > .05). HT occurred in five patients (100%) with parenchymal enhancement, which corresponded to the site of HT. In enhancing lesions, the ADC ratio (0.76 +/- 0.06) was slightly higher and the delay in time to peak (0.10 +/- 2.79) was less than respective values in the rest of the ischemic lesion (0.66 +/- 0.06 and 8.79 +/- 4.86, respectively; P = .068)., Conclusion: Early parenchymal enhancement is highly specific for HT and may be associated with early reperfusion and damage to the blood-brain barrier in ischemic tissue. DW imaging lesion volumes and ADC values had no strong relationship with HT.

Purpose: The purpose of this study was to compare multiphasic perfusion computed tomography (CT) with diffusion and perfusion magnetic resonance imaging (MRI) in predicting final infarct volume, infarct growth, and clinical severity in patients with hyperacute ischemia untreated by thrombolytic therapy., Method: Multiphasic perfusion CT was performed in 19 patients with ischemic stroke within 6 hours of symptom onset. Two CT maps of peak and total perfusion were generated from CT data. Diffusion-weighted imaging (DWI) and perfusion MRI were obtained within 150 minutes after CT. Lesion volumes on CT and MRI were compared with final infarct volume and clinical scores, and mismatch on CT or MRI was compared with infarct growth., Results: The lesion volume on the CT total perfusion map strongly correlated with MRI relative cerebral blood volume (rCBV), and that on the CT peak perfusion map strongly correlated with MRI relative cerebral blood flow (rCBF) and rCBV (P < 0.001). The lesion volume on unenhanced CT or DWI moderately correlated with final infarct volume, but only lesion volume on unenhanced CT weakly correlated with baseline clinical scores (P = 0.024). The lesion volumes on the CT peak perfusion map and MRI rCBF similarly correlated with final infarct volume and clinical scores and more strongly than those on mean transit time (MTT) or time to peak (TTP). DWI-rCBF or CT mismatch was more predictive of infarct growth than DWI-MTT or DWI-TTP mismatch., Conclusion: Multiphasic perfusion CT is useful and of comparable utility to diffusion and perfusion MRI for predicting final infarct volume, infarct growth, and clinical severity in acute ischemic stroke.

BackgroundIt has recently been suggested that diffusion and perfusion MRI can identify subgroups likely to benefit or potentially be harmed by reperfusion therapies.Case reportWe investigated serial MRI data of two patients with occlusion of the proximal middle cerebral artery (MCA). In both cases, acute multiple cortical infarcts evident on diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) showed extensive areas of severe perfusion delays, indicating a malignant MRI profile. However, despite the malignant MRI profiles in these cases, no new ischemic lesions or hemorrhage evolved even in the presence of persistent arterial occlusion, and the patients recovered without sequelae.ConclusionsThese two cases suggest that time-domain PWI findings should be interpreted with caution in certain scenarios of acute ischemic stroke.

The objective of this study was to investigate the potential benefits of statin therapy initiation in acute stroke in patients with active cancer. This study was conducted in two parts. First, data from patients who are presented with stroke and active cancer were obtained from prospectively collected multicenter hospital-based stroke registries. Patients were classified into statin user and non-user groups; the statin group was further divided into low-potency and high-potency statin subgroups. The primary outcome was time to mortality. Second, we obtained data from the Korean National Health Information Service-National Sample Cohort (NHIS-NSC) database for external validation and analyzed the effect of statins on mortality, taking compliance into consideration. For the stroke registry cohort, statin use was independently associated with reduced mortality in a multivariable model [hazard ratio (HR) = 0.675, 95% confidence interval (CI) = 0.457-0.996]. There was no interaction between statin use and cancer characteristics, vascular risk factors, or laboratory findings. A dose-dependent relationship between statin use and survival was also demonstrated. Analysis of the NHIS-NSC database found a similar association between statin therapy and reduced mortality (adjusted HR = 0.64, 95% CI = 0.45-0.90) and this effect persisted even after controlling for the adherence of statin use (HR = 0.60, 95% CI = 0.41-0.89). Statin therapy could be associated with reduced mortality in patients with acute stroke and active cancer. [ABSTRACT FROM AUTHOR]

Aims: This study was conducted to evaluate the clinical and MRI profiles in acute cancer strokes, and to demonstrate our experience with thrombolytic therapy in cancer stroke patients. Methods: We prospectively studied active cancer patients with acute ischemic stroke who underwent MRI within 48 h of the onset of symptoms. Patients were grouped based on the presence of conventional stroke mechanisms (CSM). Clinical characteristics and MRI profiles were evaluated. Results: A total of 70 patients were finally included in this study. Patients without CSM were more frequently presented with encephalopathy than those with CSM (29.4 vs. 2.8%, p = 0.002). The diffusion-perfusion mismatch pattern was more prevalent in patients with CSM (21 patients, 58.3%) than in patients without CSM (8 patients, 23.5%). Patients who had a higher tertiles of D-dimer level were significantly less likely to have the diffusion-perfusion mismatch pattern (p = 0.015). Among patients who presented within 6 h of the onset of stroke, revascularization therapy was performed in 4 of 16 (25%) patients with CSM, but none of the patients without CSM. Conclusion: Based on the stroke mechanisms, the optimal strategy of thrombolytic therapy should be considered differently in cancer patients with acute ischemic stroke. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]