Marc‐Antoine Labeyrie

BACKGROUND AND PURPOSE: In acute stroke, diffusion-weighted imaging (DWI) lesions are commonly considered markers of irreversible ischemia yet can occasionally reverse. However, the extent and clinical correlates of DWI reversal in thrombolyzed patients remain unclear. We assessed the extent of reversible acute DWI lesions (RADs) and their relationships with clinical outcome in patients thrombolyzed≤4.5 hours from onset. METHODS: Data were retrospectively analyzed. RAD was defined as an acute DWI lesion not part of a 24-hour DWI lesion as determined voxelwise. Associations with an early neurological improvement (early neurological improvement=ΔNational Institutes of Health Stroke Scale≥8 or National Institutes of Health Stroke Scale≤2 at 24 hours) or an excellent outcome (modified Rankin Scale≤1) were assessed in multivariate analyses. RESULTS: One hundred seventy-six patients were included. The median (interquartile range) time to treatment from onset was 150 minutes (120-194). Eighty-nine patients (50%) exhibited visually-detectable RAD irrespective of its extent. Over the whole population, the median percentage and volume of RAD were 11% (4-36) and 2.4 mL (0.5-8). Subtracting RAD from initial DWI altered perfusion-weighted imaging-DWI classification in 5 of 100 patients (shift from "no mismatch" to "mismatch" profile in all). Percent RAD was significantly greater in patients treated≤3 hours (P=0.049), without proximal occlusion (P=0.003), and in 24-hour recanalizers (P<0.001). Early neurological improvement was independently associated with percent RAD. This association increased with percent RAD split in quartiles in a "dose-dependent" manner (P for trend=0.01). Excellent outcome was independently associated with percent RAD (P for trend<0.001). CONCLUSIONS: DWI reversal was often sizeable in patients treated≤4.5 hours. It was strongly associated with, albeit not necessarily causal for, early neurological improvement.

BACKGROUND AND PURPOSE: Early neurological deterioration (END) after anterior circulation stroke is a serious clinical event strongly associated with poor outcome. Regarding specifically END occurring within 24 hours of intravenous recombinant tissue-type plasminogen activator, apart from definite causes such as symptomatic intracranial hemorrhage and malignant edema whose incidence, predictors, and clinical management are well established, little is known about END without clear mechanism (ENDunexplained). METHODS: We analyzed 309 consecutive patients thrombolysed intravenously ≤4.5 hours from onset of anterior circulation stroke. ENDunexplained was defined as a ≥4-point deterioration on 24-hour National Institutes of Health Stroke Scale, without definite mechanism on concomitant imaging. ENDunexplained and no-END patients were compared for pretreatment clinical and imaging (including magnetic resonance diffusion and diffusion/perfusion mismatch volumes) data and 24-hour post-treatment clinical (including blood pressure and glycemic changes) and imaging (24-hour recanalization) data, using univariate logistic regression. Exploratory multivariate analysis was also performed after variable reduction, with bootstrap analysis for internal validation. RESULTS: Among 33 END patients, 23 (7% of whole sample) had ENDunexplained. ENDunexplained was associated with poor 3-month outcome (P<0.01). In univariate analysis, admission predictors of ENDunexplained included no prior use of antiplatelets (P=0.02), lower National Institutes of Health Stroke Scale score (P<0.01), higher glycemia (P=0.03), larger mismatch volume (P=0.03), and proximal occlusion (P=0.01), with consistent results from the multivariate analysis. Among factors recorded during the first 24 hours, only no recanalization was associated with ENDunexplained in multivariate analysis (P=0.02). CONCLUSIONS: ENDunexplained affected 7% of patients and accounted for most cases of END. Several predictors and associated factors were identified, with important implications regarding underlying mechanisms and potential prevention of this ominous event.

Background and Purpose: Endovascular therapy for tandem occlusion strokes of the anterior circulation is an effective and safe treatment. The best treatment approach for the cervical internal carotid artery (ICA) lesion is still unknown. In this study, we aimed to compare the functional and safety outcomes between different treatment approaches for the cervical ICA lesion during endovascular therapy for acute ischemic strokes due to tandem occlusion in current clinical practice. Methods: Individual patients’ data were pooled from the French prospective multicenter observational ETIS (Endovascular Treatment in Ischemic Stroke) and the international TITAN (Thrombectomy in Tandem Lesions) registries. TITAN enrolled patients from January 2012 to September 2016, and ETIS from January 2013 to July 2019. Patients with acute ischemic stroke due to anterior circulation tandem occlusion who were treated with endovascular therapy were included. Patients were divided based on the cervical ICA lesion treatment into stent and no-stent groups. Outcomes were compared between the two treatment groups using propensity score methods. Results: A total of 603 patients were included, of whom 341 were treated with acute cervical ICA stenting. In unadjusted analysis, the stent group had higher rate of favorable outcome (90-day modified Rankin Scale score, 0–2; 57% versus 45%) and excellent outcome (90-day modified Rankin Scale score, 0–1; 40% versus 27%) compared with the no-stent group. In inverse probability of treatment weighting propensity score–adjusted analyses, stent group had higher odds of favorable outcome (adjusted odds ratio, 1.09 [95% CI, 1.01–1.19]; P=0.036) and successful reperfusion (modified Thrombolysis in Cerebral Ischemia score, 2b-3; adjusted odds ratio, 1.19 [95% CI, 1.11–1.27]; P<0.001). However, stent group had higher odds of any intracerebral hemorrhage (adjusted odds ratio, 1.10 [95%, 1.02–1.19]; P=0.017) but not higher rate of symptomatic intracerebral hemorrhage or parenchymal hemorrhage type 2. Subgroup analysis demonstrated heterogeneity according to the lesion type (atherosclerosis versus dissection; P for heterogeneity, 0.01), and the benefit from acute carotid stenting was only observed for patients with atherosclerosis. Conclusions: Patients treated with acute cervical ICA stenting for tandem occlusion strokes had higher odds of 90-day favorable outcome, despite higher odds of intracerebral hemorrhage; however, most of the intracerebral hemorrhages were asymptomatic.

PURPOSE: Type 2 focal cortical dysplasia (FCD2) is one of the main causes of refractory partial epilepsy, but often remains overlooked by MRI. This study aimed to elucidate whether 3T MRI offers better detection and characterization of FCD2 than 1.5T, using similar coils and acquisition time. METHODS: Two independent readers reviewed the 1.5T and 3T MR images of 25 patients with histologically proven FCD2. For both magnetic fields, the ability to detect a lesion was analyzed. We compared the identification of each of the five criteria typical of FCD2 (cortical thickening, blurring, cortical signal changes, subcortical signal changes, and "transmantle" sign) and artifacts, using a four-point scale (0-3). Interobserver reliability for lesion detection was calculated. KEY FINDINGS: Seventeen lesions (68%) were detected at 3T, two of which were overlooked at 1.5T. Interobserver reliability was better at 3T (κ = 1) than at 1.5T (κ = 0.83). The transmantle sign was more clearly identified at 3T than 1.5T (mean visualization score: 1.72 vs. 0.56; p = 0.002). SIGNIFICANCE: The use of 3T MRI in patients suspected of type 2 FCD improves the detection rate and the lesion characterization owing to the transmantle sign being more clearly seen at 3T. This point is of interest, since this feature is considered as an MR signature of FCD2.