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Background: It is still controversial whether early fluid-attenuated inversion recovery (FLAIR) hyperintensity within acute ischemic lesions carries the risk of hemorrhagic transformation (HT) after reperfusion therapy. Furthermore, the association between the location of FLAIR hyperintensity and HT has not been investigated.Methods: We retrospectively reviewed patients who underwent reperfusion therapy within 6 hours of stroke onset and magnetic resonance imaging including a FLAIR sequence before completing reperfusion therapy. FLAIR hyperintensity within the diffusion-weighted imaging (DWI) lesion was rated qualitatively, and HT was assessed on follow-up gradient echo imaging. The location of the FLAIR change and HT was classified as subcortical, cortical, or cortico-subcortical.Results: Of 134 patients with acute ischemic stroke included in this study, early FLAIR changes within DWI lesions were identified in 56 (41.8%) patients, and HT was noted in 51 (38.1%) patients. FLAIR change was independently associated with HT (odds ratio: 4.37, 95% confidence interval: 1.72-11.12). Geographically, 48.2% of the patients with a FLAIR change developed a matched HT (restricted to the region with the FLAIR change), and the risk of HT was further increased in patients with a FLAIR change in the cortico-subcortical region (68.8%).Conclusions: In patients in the acute stage of stroke, an early FLAIR change is associated with the risk of HT following reperfusion therapy with a highly matched geographic relationship and common risk factors. Thus, identification of FLAIR change may be a useful surrogate marker to assess the likelihood of subsequent HT in patients treated with reperfusion therapy. [ABSTRACT FROM AUTHOR]

Background Early recurrent ischemic lesions detected on diffusion-weighted imaging (DWI) have been proposed as a surrogate marker for clinical recurrence. We hypothesized that cytochrome P450 2C19 ( CYP2C19 ) genotype influences the incidence of early recurrence on DWI in acute stroke patients treated with clopidogrel. Methods We enrolled 76 Korean patients with acute ischemic stroke due to large artery atherosclerosis who were treated with clopidogrel. Early ischemic lesion recurrence was defined as new lesions separate from the index lesion. We compared the rates of early ischemic lesion recurrence on DWI based on the CYP2C19 genotypes. Results Early recurrence on DWI was observed in 36 patients (47.4%). A total of 76 patients were classified into 3 phenotypic groups: extensive metabolizers (EMs; n = 27, 35.5%), intermediate metabolizers (IMs; n = 36, 47.4%), and poor metabolizers (PMs; n = 13, 17.1%). Early recurrence on DWI was more common in PMs (84.6%), followed by IMs (50.0%), and EMs (25.9%; P < .001). PMs had a significantly higher recurrence rate than EMs ( P < .001). In multivariate analysis, CYP2C19 genotypes were independently associated with early DWI recurrence (for PMs: odds ratio, 19.3; 95% confidence interval, 3.15-117.56). Conclusions CYP2C19 genotypes are significantly associated with early lesion recurrence in Korean acute stroke patients treated with clopidogrel. [ABSTRACT FROM AUTHOR]

Objectives: The prognosis of a cerebral artery dissection is known to be benign, but the structural changes of vessel wall at follow-up are not well known. The natural course of an intracranial and extracranial artery dissection may differ due to structural differences. We aimed to figure out how stenosis and other wall features change, according to the dissection location.Materials and Methods: We retrospectively enrolled patients who suffered an ischemic stroke or transient ischemic attack due to a dissection and who had undergone both initial and follow-up high-resolution magnetic resonance imaging (HRMRI). Patients were dichotomized to intracranial or extracranial dissection group. The clinical and HRMRI characteristics of two groups were compared. Factors associated with stenosis changes were also investigated.Results: A total of 57 patients (intracranial, n = 43; and extracranial, n = 14) were enrolled. The mean age (45.6 vs. 32.2, p < 0.001) was higher and hypertension (37.2% vs. 7.1%, p = 0.04) was more frequent in the intracranial dissection group. In HRMRI analysis, stenosis improvement (27.9% vs. 85.7%, p < 0.001) were more frequent whereas residual wall enhancement (86.0% vs. 46.2%, p = 0.006) and intramural hematoma (62.8% vs. 21.4%, p = 0.007) were less frequent in the extracranial dissection group. Multivariate analysis indicated that extracranial location was the only independent factor (odds ratio 8.98, 95 % confidence interval 1.45-55.65; p = 0.02) associated with stenosis improvement.Conclusions: Younger age, stenosis improvement, disappearance of wall enhancement and intramural hematoma were more frequent in an extracranial dissection compared with an intracranial dissection. An extracranial location is independently associated with stenosis improvement in dissection patients. [ABSTRACT FROM AUTHOR]

Thromboelastography (TEG) is a useful for predicting hemorrhagic transformation, early neurological deterioration, and functional outcome after stroke. We aimed to investigate whether TEG value could also be useful in predicting functional outcome via various intraprocedural and postprocedural factors in patients with acute large vessel occlusive stroke who underwent intraarterial thrombectomy (IAT). Patients with ischemic stroke who underwent IAT between March 2018 and March 2020 at two tertiary hospitals were included. The association between reaction time (R) and functional outcome was evaluated. The primary outcome was the achievement of functional independence defined as the achievement of a modified Rankin Scale (mRS) score of 0–2 at 3 months after the index stroke. Among a total of 160 patients (mean age, 70.6 ± 12.3 years; 103 [64.4 %] men), 79 (49.3 %) achieved functional independence at 3 months. R, both as a continuous (odds ratio [OR]: 1.45, 95 % confidence interval [95 % CI]: 1.09–1.92, P = 0.011) and dichotomized parameters (R < 5 min [OR: 0.37, 95 % CI: 0.16–0.82, P = 0.014]), were inversely associated with increased odds of achieving functional independence (mRS score 0–2) after multivariable analysis. The association was still consistent when the outcome was the achievement of disability free (mRS score 0–1) or mRS score analyzed as an ordinal variable. Decreased R, especially R < 5 min, was inversely associated with functional outcome pf stroke after EVT. • Thromboelastography (TEG) could provide the coagulation and fibrinolysis pathways. • We present a study of stroke outcomes after thrombectomy according to the reaction time (R). • Decreased R, especially R < 5 min, was inversely associated with stroke outcome after thrombectomy. • R can be a useful TEG parameter for predicting functional independence after thrombectomy. [ABSTRACT FROM AUTHOR]

Summary: Background: Many patients with stroke are precluded from thrombolysis treatment because the time from onset of their symptoms is unknown. We aimed to test whether a mismatch in visibility of an acute ischaemic lesion between diffusion-weighted MRI (DWI) and fluid-attenuated inversion recovery (FLAIR) MRI (DWI-FLAIR mismatch) can be used to detect patients within the recommended time window for thrombolysis. Methods: In this multicentre observational study, we analysed clinical and MRI data from patients presenting between Jan 1, 2001, and May 31, 2009, with acute stroke for whom DWI and FLAIR were done within 12 h of observed symptom onset. Two neurologists masked to clinical data judged the visibility of acute ischaemic lesions on DWI and FLAIR imaging, and DWI-FLAIR mismatch was diagnosed by consensus. We calculated predictive values of DWI-FLAIR mismatch for the identification of patients with symptom onset within 4·5 h and within 6 h and did multivariate regression analysis to identify potential confounding covariates. This study is registered with ClinicalTrials.gov, number NCT01021319. Findings: The final analysis included 543 patients. Mean age was 66·0 years (95% CI 64·7–67·3) and median National Institutes of Health Stroke Scale score was 8 (IQR 4–15). Acute ischaemic lesions were identified on DWI in 516 patients (95%) and on FLAIR in 271 patients (50%). Interobserver agreement for acute ischaemic lesion visibility on FLAIR imaging was moderate (κ=0·569, 95% CI 0·504–0·634). DWI-FLAIR mismatch identified patients within 4·5 h of symptom onset with 62% (95% CI 57–67) sensitivity, 78% (72–84) specificity, 83% (79–88) positive predictive value, and 54% (48–60) negative predictive value. Multivariate regression analysis identified a longer time to MRI (p<0·0001), a lower age (p=0·0009), and a larger DWI lesion volume (p=0·0226) as independent predictors of lesion visibility on FLAIR imaging. Interpretation: Patients with an acute ischaemic lesion detected with DWI but not with FLAIR imaging are likely to be within a time window for which thrombolysis is safe and effective. These findings lend support to the use of DWI-FLAIR mismatch for selection of patients in a future randomised trial of thrombolysis in patients with unknown time of symptom onset. Funding: Else Kröner-Fresenius-Stiftung, National Institutes of Health. [Copyright &y& Elsevier]

Objectives: We aimed to define the relationship between cerebral atherosclerosis and stroke after coronary artery bypass grafting (CABG). Background: Although cerebral atherosclerosis may play a crucial role in the advent of post-CABG stroke, only extracranial carotid artery disease has been extensively studied, and the effects of atherosclerosis on the mechanisms underlying post-CABG stroke remain unclear. Methods: Pre-operative magnetic resonance angiography was performed on 1,367 consecutive CABG patients to assess intracranial and extracranial cerebral atherosclerosis. Disease severity was evaluated by atherosclerosis score, as determined by the number of steno-occlusions of cerebral arteries and the degree thereof. Post-CABG strokes (within 14 days) were classified as atherosclerotic (strokes attributable to pre-defined atherosclerosis) or other (strokes caused by other mechanisms). Associations between post-CABG stroke and each type of atherosclerotic disease (extracranial carotid artery disease, intracranial, extracranial, or extracranial and/or intracranial cerebral atherosclerosis), differentiated according to the involved arteries, were analyzed. Results: Stroke occurred in 33 patients, and the atherosclerosis score was independently associated with stroke development (odds ratio: 1.35; 95% confidence interval: 1.16 to 1.56). Atherosclerotic stroke was defined in 15 (45%), and constituted >40% of both immediate (within 24 h) and delayed strokes. Intracranial, extracranial, and extracranial and/or intracranial cerebral atherosclerosis were significantly associated with stroke. Conclusions: Cerebral atherosclerosis was closely related to the occurrence of post-CABG stroke, being both an independent risk factor for and the cause of a significant proportion of strokes. Pre-operative evaluation of intracranial and extracranial cerebral arteries, apart from the extracranial carotid artery, may be useful to predict the likelihood of post-CABG stroke. [ABSTRACT FROM AUTHOR]