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Background: Recently, common genetic risk factors for intracranial aneurysm (IA) and aneurysmal subarachnoid hemorrhage (ASAH) were found to explain a large amount of disease heritability and therefore have potential to be used for genetic risk prediction. We constructed a genetic risk score to (1) predict ASAH incidence and IA presence (combined set of unruptured IA and ASAH) and (2) assess its association with patient characteristics. Methods: A genetic risk score incorporating genetic association data for IA and 17 traits related to IA (so-called metaGRS) was created using 1161 IA cases and 407 392 controls from the UK Biobank population study. The metaGRS was validated in combination with risk factors blood pressure, sex, and smoking in 828 IA cases and 68 568 controls from the Nordic HUNT population study. Furthermore, we assessed association between the metaGRS and patient characteristics in a cohort of 5560 IA patients. Results: Per SD increase of metaGRS, the hazard ratio for ASAH incidence was 1.34 (95% CI, 1.20–1.51) and the odds ratio for IA presence 1.09 (95% CI, 1.01–1.18). Upon including the metaGRS on top of clinical risk factors, the concordance index to predict ASAH hazard increased from 0.63 (95% CI, 0.59–0.67) to 0.65 (95% CI, 0.62–0.69), while prediction of IA presence did not improve. The metaGRS was statistically significantly associated with age at ASAH (β=−4.82×10 −3 per year [95% CI, −6.49×10 −3 to −3.14×10 −3 ]; P =1.82×10 −8 ), and location of IA at the internal carotid artery (odds ratio=0.92 [95% CI, 0.86–0.98]; P =0.0041). Conclusions: The metaGRS was predictive of ASAH incidence, although with limited added value over clinical risk factors. The metaGRS was not predictive of IA presence. Therefore, we do not recommend using this metaGRS in daily clinical care. Genetic risk does partly explain the clinical heterogeneity of IA warranting prioritization of clinical heterogeneity in future genetic prediction studies of IA and ASAH.

Background: Determine if early venous filling (EVF) after complete successful recanalization with mechanical thrombectomy in acute ischemic stroke is an independent predictor of symptomatic intracranial hemorrhage (sICH) and integrate EVF into a risk score for sICH prediction. Methods: Consecutive patients with anterior acute ischemic stroke treated by mechanical thrombectomy issued from patients enrolled in the THRACE trial (Thrombectomie des Artères Cérébrales) and from 2 prospective registries were included and divided into a derivation (Center I; n=402) and validation cohorts (THRACE and center 2; n=507). EVF was evaluated by 2 blinded readers. sICH was defined according to the modified European cooperative acute stroke study II. Clinical and radiological data were analyzed in the derivation cohort (C1) to identify independent predictors of sICH and construct a predictive score test on the validation cohort (THRACE + C2). Results: Symptomatic ICH rate was similar between the two cohorts (9.9% and 8.9% respectively, P =0.9). Time from onset-to-successful recanalization >270 minutes (odds ratio [OR], 7.8 [95% CI, 2.5–24]), Alberta Stroke Program Early CT Score (≤5 [OR, 2.49 (95% CI, 1.8–8.1) or 6–7 [OR, 1.15 (95% CI, 1.03–4.46)]), glucose blood level >7 mmol/L (OR, 2.92 [95% CI, 1.26–6.7]), and EVF presence (OR, 11.9 [95% CI, 3.8–37.5]) were independent predictors of sICH and constituted the Time–Alberta Stroke Program Early CT–Glycemia–EVF score. Time–Alberta Stroke Program Early CT–Glycemia–EVF score was associated with an increased risk of sICH in the derivation cohort (OR increase per unit, 1.99 [95% CI, 1.53–2.59]; P Conclusions: Time–Alberta Stroke Program Early CT–Glycemia–EVF score is a simple tool with readily available clinical variables with good performances for sICH prediction after mechanical thrombectomy. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01062698.

Background: Diffusion-weighted imaging lesion reversal (DWIR) is frequently observed after mechanical thrombectomy for acute ischemic stroke, but little is known about age-related differences and impact on outcome. We aimed to compare, in patients Methods: We retrospectively analyzed data of patients treated for an anterior circulation acute ischemic stroke with large vessel occlusion in 2 French hospitals, who underwent baseline and 24-hour follow-up magnetic resonance imaging, with baseline DWI lesion volume ≥10 cc. The percentage of DWIR (DWIR%), was calculated as follows: DWIR%=(DWIR volume/baseline DWI volume)×100. Data on demographics, medical history, and baseline clinical and radiological characteristics were collected. Results: Among 433 included patients (median age, 68 years), median DWIR% after mechanical thrombectomy was 22% (6–35) in patients ≥80, and 19% (interquartile range, 10–34) in patients P =0.948). In multivariable analyses, successful recanalization after mechanical thrombectomy was associated with higher median DWIR% in both ≥80 ( P =0.004) and P =0.002) patients. In subgroup analyses performed on a minority of subjects, collateral vessels status score (n=87) and white matter hyperintensity volume (n=131) were not associated with DWIR% ( P >0.2). In multivariable analyses, DWIR% was associated with increased rates of favorable 3-month outcomes in both ≥80 ( P =0.003) and P =0.013) patients; the effect of DWIR% on outcome was not influenced by the age group ( P interaction=0.185) Conclusions: DWIR might be an important and nonage-dependent effect of arterial recanalization, as it seems to beneficially impact 3-month outcomes of both younger and older subjects treated with mechanical thrombectomy for acute ischemic stroke and large vessel occlusion.

Background and Purpose: Pediatric nontraumatic intracerebral hemorrhage accounts for half of stroke in children. Early diagnostic of the causative underlying lesion is the first step toward prevention of hemorrhagic recurrence. We aimed to investigate the performance of arterial spin labeling sequence (ASL) in the acute phase etiological workup for the detection of an arteriovenous shunt (AVS: including malformation and fistula), the most frequent cause of pediatric nontraumatic intracerebral hemorrhage. Methods: Children with a pediatric nontraumatic intracerebral hemorrhage between 2011 and 2019 enrolled in a prospective registry were retrospectively included if they had undergone ASL-magnetic resonance imaging before any etiological treatment. ASL sequences were reviewed using cerebral blood flow maps by 2 raters for the presence of an AVS. The diagnostic performance of ASL was compared with admission computed tomography angiography, other magnetic resonance imaging sequences including contrast-enhanced sequences and subsequent digital subtraction angiography. Results: A total of 121 patients with pediatric nontraumatic intracerebral hemorrhage were included (median age, 9.9 [interquartile range, 5.8–13]; male sex 48.8%) of whom 76 (63%) had a final diagnosis of AVS. Using digital subtraction angiography as an intermediate reference, visual ASL inspection had a sensitivity and a specificity of, respectively, 95.9% (95% CI, 88.5%–99.1%) and 79.0% (95% CI, 54.4%–94.0%). ASL had a sensitivity, specificity, and accuracy of 90.2%, 97.2%, and 92.5%, respectively for the detection of the presence of an AVS, with near perfect interrater agreement (κ=0.963 [95% CI, 0.912–1.0]). The performance of ASL alone was higher than that of other magnetic resonance imaging sequences, individually or combined, and higher than that of computed tomography angiography. Conclusions: ASL has strong diagnostic performance for the detection of AVS in the initial workup of intracerebral hemorrhage in children. If our findings are confirmed in other settings, ASL may be a helpful diagnostic imaging modality for patients with pediatric nontraumatic intracerebral hemorrhage. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifiers: 3618210420, 2217698.

Background and Purpose: Significant hemorrhage expansion (sHE) is a known predictor of poor outcome after an intracerebral hemorrhage (ICH) in adults but remains poorly reported in children. In a large inception cohort, we aimed to explore the prevalence of sHE, its associations with clinical outcomes, and its clinical-imaging predictors in children. Methods: Children admitted between January 2000 and March 2020 at a quaternary care pediatric hospital were screened for inclusion. Sample was restricted to children with 2 computed tomography scans within 72 hours of ICH onset, and a minimal clinical follow-up of months. sHE was defined as an increase from baseline ICH volume by 6 cc or 33% on follow-up computed tomography. Clinical outcome was assessed at 12 months with the King’s Outcome Scale for Childhood Head Injury score and defined as favorable for scores ≥5. Results: Fifty-two children met inclusion criteria, among which 8 (15%) demonstrated sHE, and 18 (34.6%) any degree of expansion. Children with sHE had more frequent coagulation disorders (25.0% versus 2.3%; P =0.022). After multivariable adjustment, only the presence of coagulation disorders at baseline remained independently associated with sHE (adjusted odds ratio, 14.4 [95% CI, 1.04–217]; P =0.048). sHE was independently associated with poor outcome (King’s Outcome Scale for Childhood Head Injury P =0.043). Conclusions: sHE is a frequent phenomenon after admission for a pediatric ICH and more so in children with coagulation defects. As sHE was strongly associated with poorer clinical outcomes, these data mandate a baseline coagulation work up and questions the need for protocolized repeat head computed tomography in children admitted for pediatric ICH.

No controlled pharmacological studies are available in the field of pediatric stroke, except for sickle cell disease. Therefore, while pharmacological and mechanical recanalization treatments have repeatedly shown clinical benefit in adults with arterial ischemic stroke, pediatric strokologists still cannot base their therapeutic management (including hyperacute strategies) on high-level evidence. Once again, pediatricians face the same dichotomic choice: adapting adult procedures now versus waiting—for a long time—for the corresponding pediatric trials. One way out is building a compromise based on observational studies with large, longitudinal, comprehensive, real-life, and multisource dataset. Two recent high-quality observational studies have delivered promising conclusions on recanalization treatments in pediatric arterial ischemic stroke. TIPSTER (Thrombolysis in Pediatric Stroke Extended Results) showed that the risk of severe intracranial hemorrhage after intravenous thrombolysis is low; the Save Childs Study reported encouraging data about pediatric thrombectomy. Beyond the conclusion of a satisfactory global safety profile, a thorough analysis of the methods, populations, results, and therapeutic complications of these studies helps us to refine indications/contraindications and highlights the safeguards we need to rely on when discussing thrombolysis and thrombectomy in children. In conclusion, pediatric strokologists should not refrain from using clot lysis/retrieval tools in selected children with arterial ischemic stroke. But the implementation of hyperacute care is only feasible if the right candidate is identified through the sharing of common adult/pediatric protocols and ward collaboration, formalized well before the child’s arrival. These anticipated protocols should never undervalue contraindications from adult guidelines and must involve the necessary pediatric expertise when facing specific causes of stroke, such as focal cerebral arteriopathy of childhood.

Background and Purpose: The influence of prior antiplatelet therapy (APT) uses on the outcomes of patients with acute ischemic stroke treated with endovascular therapy is unclear. We compared procedural and clinical outcomes of endovascular therapy in patients on APT or not before stroke onset. Methods: We analyzed 2 groups from the ongoing prospective multicenter Endovascular Treatment in Ischemic Stroke registry in France: patients on prior APT (APT+) and patients without prior APT (APT−) treated by endovascular therapy, with and without intravenous thrombolysis. Multilevel mixed-effects logistic models including center as random effect were used to compare angiographic (rates of reperfusion at the end of procedure, procedural complications) and clinical (favorable and excellent outcome, 90-day all-cause mortality, and hemorrhagic complications) outcomes according to APT subgroups. Comparisons were adjusted for prespecified confounders (age, admission National Institutes of Health Stroke Scale score, Alberta Stroke Program Early CT Score, intravenous thrombolysis, and time from onset to puncture), as well as for meaningful baseline between-group differences. Results: A total of 2939 patients were analyzed, of whom 877 (29.8%) were on prior APT. Patients with prior APT were older, had more frequent vascular risk factors, cardioembolic stroke mechanism, and prestroke disability. Rates of complete reperfusion (37.9% in the APT− group versus 42.7 % in the APT+ group; aOR, 1.09 [95% CI, 0.88–1.34]; P =0.41) and periprocedural complication (16.9% versus 13.3%; aOR, 0.90 [95% CI, 0.7–1.2]; P =0.66) did not differ between the two groups. Symptomatic intracerebral hemorrhage (aOR, 0.93 [95% CI, 0.63–1.37]; P =0.73), 3 months favorable clinical outcome (modified Rankin Scale score of 0–2; aOR, 0.98 [95% CI, 0.77–1.25]; P =0.89), and mortality (aOR, 0.95 [95% CI, 0.72–1.26]; P =0.76) at 90 days did not differ between the groups. Conclusions: Prior APT does not influence angiographic and functional outcomes following endovascular therapy and should not be taken into account for acute revascularization strategies.

Background and Purpose: We aimed to evaluate among trained interventional neuroradiologist, whether increasing individual experience was associated with an improvement in mechanical thrombectomy (MT) procedural performance metrics. Methods: Individual MT procedural data from 5 centers of the Endovascular Treatment in Ischemic Stroke registry and 2 additional high-volume stroke centers were pooled. Operator experience was defined for each operator as a continuous variable, cumulating the number of MT procedures performed since January 2015, as MT became standard of care or, if later than this date, since the operator started performing mechanical thrombectomies in autonomy. We tested the associations between operator’s experience and procedural metrics. Results: A total of 4516 procedures were included, performed by 36 operators at 7 distinct centers, with a median of 97.5 endovascular treatment procedures per operator (interquartile range, 57–170.2) over the study period. Higher operator’s experience, analyzed as a continuous variable, was associated with a significantly shorter procedural duration (β estimate, −3.98 [95% CI, −5.1 to −2.8]; P P =0.013). Conclusions: In trained interventional neuroradiologists, increasing experience in MT is associated with significantly shorter procedural duration and better reperfusion rates, with a theoretical ceiling effect observed after around 100 procedures. These results may inform future training and practice guidelines to set minimal experience standards before autonomization, and to set-up operators’ recertification processes tailored to individual case volume and prior experience.

During the coronavirus disease 2019 (COVID-19) pandemic, the World Health Organization recommended measures to mitigate the outbreak such as social distancing and confinement. Since these measures have been put in place, anecdotal reports describe a decrease in the number of endovascular therapy (EVT) treatments for acute ischemic stroke due to large vessel occlusion. The purpose of our study was to determine the effect on EVT for patients with acute ischemic stroke during the COVID-19 confinement. In this retrospective, observational study, data were collected from November 1, 2019, to April 15, 2020, at 17 stroke centers in countries where confinement measures have been in place since March 2020 for the COVID-19 pandemic (Switzerland, Italy, France, Spain, Portugal, Germany, Canada, and United States). This study included 1600 patients treated by EVT for acute ischemic stroke. Date of EVT and symptom onset-to-groin puncture time were collected. Mean number of EVTs performed per hospital per 2-week interval and mean stroke onset-to-groin puncture time were calculated before confinement measures and after confinement measures. Distributions (non-normal) between the 2 groups (before COVID-19 confinement versus after COVID-19 confinement) were compared using 2-sample Wilcoxon rank-sum test. The results show a significant decrease in mean number of EVTs performed per hospital per 2-week interval between before COVID-19 confinement (9.0 [95% CI, 7.8–10.1]) and after COVID-19 confinement (6.1 [95% CI, 4.5–7.7]), ( P P

Background and Purpose: The efficiency of prehospital care chain response and the adequacy of hospital resources are challenged amid the coronavirus disease 2019 (COVID-19) outbreak, with suspected consequences for patients with ischemic stroke eligible for mechanical thrombectomy (MT). Methods: We conducted a prospective national-level data collection of patients treated with MT, ranging 45 days across epidemic containment measures instatement, and of patients treated during the same calendar period in 2019. The primary end point was the variation of patients receiving MT during the epidemic period. Secondary end points included care delays between onset, imaging, and groin puncture. To analyze the primary end point, we used a Poisson regression model. We then analyzed the correlation between the number of MTs and the number of COVID-19 cases hospitalizations, using the Pearson correlation coefficient (compared with the null value). Results: A total of 1513 patients were included at 32 centers, in all French administrative regions. There was a 21% significant decrease (0.79; [95%CI, 0.76–0.82]; P P P R 2 −0.51; P =0.04). Patients treated during the COVID outbreak were less likely to receive intravenous thrombolysis and to have unwitnessed strokes (both P Conclusions: Our study showed a significant decrease in patients treated with MTs during the first stages of the COVID epidemic in France and alarming indicators of lengthened care delays. These findings prompt immediate consideration of local and regional stroke networks preparedness in the varying contexts of COVID-19 pandemic evolution.

Background and Purpose— Absence of arterial wall enhancement (AWE) of unruptured intracranial aneurysms (UIA) has shown promise at predicting which aneurysms will not rupture. We here tested the hypothesis that increased enhancement during follow-up (increased intensity, extension, or thickness or appearance of de novo enhancement), assessed using vessel wall magnetic resonance imaging, was associated with higher rates of subsequent growth. Methods— Patients with UIA were included between 2012 and 2018. Two readers independently rated AWE modification on 3T vessel wall magnetic resonance imaging, and morphological changes on time-of-flight magnetic resonance angiography during follow-up. Results— A total of 129 patients harboring 145 UIA (mean size 4.1 mm) met study criteria, of which 12 (8.3%) displayed morphological growth at 2 years. Of them, 8 demonstrated increased AWE during follow-up before or concurrently to morphological growth, and 4 had preexisting AWE that remained stable before growth. In the remaining 133 (nongrowing) UIAs, no AWE modifications were found. In multivariable analysis, increased AWE, not size, was associated with UIA growth (relative risk, 26.1 [95% CI, 7.4–91.7], P Conclusions— Increased AWE during follow-up of conservatively managed UIAs predicts aneurysm growth over a 2-year period. This may impact UIA management towards closer monitoring or preventive treatment. Replication in a different setting is warranted.

Background and Purpose— We aimed to analyze the long-term outcomes of patients with primary central nervous system vasculitis according to the different therapeutic strategies used to induce remission. Methods— We assessed the rate of prolonged remission (defined by the absence of relapse at ≥12 months after diagnosis) and the functional status at last follow-up in patients with primary central nervous system vasculitis included in the French cohort, who achieved a first remission according to the 3 main groups of treatments administered: glucocorticoids only (group 1); induction treatment with glucocorticoids and an immunosuppressant, but no maintenance (group 2); and combined treatment with glucocorticoids and an immunosuppressant for induction followed by maintenance therapy (group 3). Good functional status was defined as a modified Rankin Scale score ≤2 at the last follow-up. Results— Remission was achieved with the initial induction treatment in 106 (95%) of the 112. Prolonged remission without relapse was observed in 70 (66%) patients after 57 (12–198) months of follow-up. A good functional status at last follow-up (ie, modified Rankin Scale score ≤2) was observed in 63 (56%) patients. Overall mortality was 8%. The initial severity and the radiological presentations were comparable in the 3 treatment groups. More prolonged remissions ( P =0.003) and a better functional status at the last follow-up ( P =0.0004) were observed in group 3. In multivariate analysis, the use of maintenance therapy was associated with prolonged remission (odds ratio, 4.32 [1.67–12.19]; P =0.002) and better functional status (odds ratio, 8.09 [3.24–22.38]; P Conclusions— This study suggests that maintenance therapy with an immunosuppressant combined with glucocorticoids lead to the best long-term clinical and functional outcomes in patients with primary central nervous system vasculitis after having achieved remission with either glucocorticoids alone or in combination with another immunosuppressant.

Background and Purpose— Efficacy of endovascular treatment (EVT) for ischemic stroke because of large vessel occlusion may depend on patients’ age and stroke severity; we, therefore, developed a prognosis score based on these variables and examined whether EVT efficacy differs between patients with good, intermediate, or poor prognostic score. Methods— A total of 4079 patients with an acute ischemic stroke were identified from the Paris Stroke Consortium registry. We developed the stroke checkerboard (SC) score (SC score=1 point per decade ≥50 years of age and 2 points per 5 points on the National Institutes of Health Stroke Scale) to predict spontaneous outcome. The primary outcome was the adjusted common odds ratio for an improvement in the modified Rankin Scale at 90 days after EVT, in patients with low, intermediate, or high SC scores. To rule out potential selection biases, a nested case-control analysis, with individual matching for all major prognostic factors, was also performed, to compare patients with large vessel occlusion in the anterior circulation treated or not with EVT. Results— In patients untreated with EVT, SC scores 12 were predictive of poor outcomes (modified Rankin Scale score, 4–6; area under the curve, 0.88). In the overall population, there was an interaction between EVT and prognosis group ( P 12 (common odds ratio, 1.70; 95% confidence interval, 1.13–2.56) and SC scores 8 to 12 (odds ratio, 1.37; 95% confidence interval, 1.11–1.69) but not in patients with SC scores Conclusions— In patients stratified with the SC score, EVT was associated with improved functional outcome in older and more severe patients but not in younger and less severe patients.

Background and Purpose— To evaluate hyperacute management of pediatric arterial ischemic stroke, setting up dedicated management pathways is the first recommended step to prove the feasibility and safety of such treatments. A regional pediatric stroke alert protocol including 2 centers in the Paris-Ile-de-France area, France, was established. Methods— Consecutive pediatric patients (28 days–18 years) with confirmed arterial ischemic stroke who had acute recanalization treatment (intravenous r-tPA [recombinant tissue-type plasminogen activator], endovascular procedure, or both) according to the regional pediatric stroke alert were retrospectively reviewed during a 40-month period. Results— Thirteen children, aged 3.7 to 16.6 years, had recanalization treatment. Median time from onset to magnetic resonance imaging was 165 minutes (150–300); 9 out of 13 had large-vessel occlusion. Intravenous r-tPA was used in 11 out of 13 patients, with median time from onset to treatment of 240 minutes (178–270). Endovascular procedure was performed in patients time-out for intravenous r-tPA (n=2) or after intravenous r-tPA inefficiency (n=2). No intracranial or peripheral bleeding was reported. One patient died of malignant stroke; outcome was favorable in 11 out of 12 survivors (modified Rankin Scale score 0–2). Conclusions— Hyperacute recanalization treatment in pediatric stroke, relying on common protocols and adult/pediatric ward collaboration, is feasible. Larger systematic case collection is encouraged.

Background and Purpose- The acute management of stroke patients requires a fast and efficient screening imaging modality. We compared workflow and functional outcome in acute ischemic stroke patients screened by magnetic resonance imaging (MRI) or computed tomography (CT) before treatment in the THRACE trial (Thrombectomie des Artères Cérébrales), with the emphasis on the duration of the imaging step. Methods- The THRACE randomized trial (June 2010 to February 2015) evaluated the efficacy of mechanical thrombectomy after intravenous tPA (tissue-type plasminogen activator) in ischemic stroke patients with proximal occlusion. The choice of screening imaging modality was left to each enrolling center. Differences between MRI and CT groups were assessed using univariable analysis and the impact of imaging modality on favorable 3-month functional outcome (modified Rankin Scale score of ≤2) was tested using multivariable logistic regression. Results- Four hundred one patients were included (25 centers), comprising 299 MRI-selected and 102 CT-selected patients. Median baseline National Institutes of Health Stroke Scale score was 18 in both groups. MRI scan duration (median [interquartile range]) was longer than CT (MRI: 13 minutes [10-16]; CT: 9 minutes [7-12]; P0.001). Stroke-onset-to-imaging time (MRI: median 114 minutes [interquartile range, 89-138]; CT: 107 minutes [88-139]; P=0.19), onset-to-intravenous tPA time (MRI: 150 minutes [124-179]; CT: 150 minutes [123-180]; P=0.38) and onset-to-angiography-suite time (MRI: 200 minutes [170-250]; CT: 213 minutes [180-246]; P=0.57) did not differ between groups. Imaging modality was not significantly associated with functional outcome in the multivariable analysis. Conclusions- Although MRI scan duration is slightly longer than CT, MRI-based selection for acute ischemic stroke patients is accomplished within a timeframe similar to CT-based selection, without delaying treatment or impacting functional outcome. This should help to promote wider use of MRI, which has inherent imaging advantages over CT. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT01062698.

Background and Purpose— Whether all acute stroke patients with large vessel occlusion need to undergo intravenous thrombolysis before mechanical thrombectomy (MT) is debated as (1) the incidence of post-thrombolysis early recanalization (ER) is still unclear; (2) thrombolysis may be harmful in patients unlikely to recanalize; and, conversely, (3) transfer for MT may be unnecessary in patients highly likely to recanalize. Here, we determined the incidence and predictors of post-thrombolysis ER in patients referred for MT and derive ER prediction scores for trial design. Methods— Registries from 4 MT-capable centers gathering patients referred for MT and thrombolyzed either on site (mothership) or in a non MT-capable center (drip-and-ship) after magnetic resonance– or computed tomography–based imaging between 2015 and 2017. ER was identified on either first angiographic run or noninvasive imaging. In the magnetic resonance imaging subsample, thrombus length was determined on T2*-based susceptibility vessel sign. Independent predictors of no-ER were identified using multivariable logistic regression models, and scores were developed according to the magnitude of regression coefficients. Similar registries from 4 additional MT-capable centers were used as validation cohort. Results— In the derivation cohort (N=633), ER incidence was ≈20%. In patients with susceptibility vessel sign (n=498), no-ER was independently predicted by long thrombus, proximal occlusion, and mothership paradigm. A 6-point score derived from these variables showed strong discriminative power for no-ER (C statistic, 0.854) and was replicated in the validation cohort (n=353; C statistic, 0.888). A second score derived from the whole sample (including negative T2* or computed tomography–based imaging) also showed good discriminative power and was similarly validated. Highest grades on both scores predicted no-ER with >90% specificity, whereas low grades did not reliably predict ER. Conclusions— The substantial ER rate underlines the benefits derived from thrombolysis in bridging populations. Both prediction scores afforded high specificity for no-ER, but not for ER, which has implications for trial design.

Background and Purpose— Rapid and reliable assessment of the perfusion-weighted imaging (PWI)/diffusion-weighted imaging (DWI) mismatch is required to promote its wider application in both acute stroke clinical routine and trials. We tested whether an evaluation based on the Alberta Stroke Program Early CT Score (ASPECTS) reliably identifies the PWI/DWI mismatch. Methods— A total of 232 consecutive patients with acute middle cerebral artery stroke who underwent pretreatment magnetic resonance imaging (PWI and DWI) were retrospectively evaluated. PWI-ASPECTS and DWI-ASPECTS were determined blind from manually segmented PWI and DWI volumes. Mismatch-ASPECTS was defined as the difference between PWI-ASPECTS and DWI-ASPECTS (a high score indicates a large mismatch). We determined the mismatch-ASPECTS cutoff that best identified the volumetric mismatch, defined as Volume T max>6s /Volume DWI ≥1.8, a volume difference≥15 mL, and a Volume DWI Results— Inter-reader agreement was almost perfect for PWI-ASPECTS (κ=0.95 [95% confidence interval, 0.90–1]), and DWI-ASPECTS (κ=0.96 [95% confidence interval, 0.91–1]). There were strong negative correlations between volumetric and ASPECTS-based assessments of DWI lesions (ρ=−0.84, P P Conclusions— The mismatch-ASPECTS method can detect a true mismatch in patients with acute middle cerebral artery stroke. It could be used for rapid screening of patients with eligible mismatch, in centers not equipped with ultrafast postprocessing software.

Background and Purpose— Fluid-attenuated inversion recovery vascular hyperintensities (FVH) beyond the boundaries of diffusion-weighted imaging (DWI) lesion (FVH-DWI mismatch) have been proposed as an alternative to perfusion-weighted imaging (PWI)-DWI mismatch. We aimed to establish whether FVH-DWI mismatch can identify patients most likely to benefit from recanalization. Methods— FVH-DWI mismatch was assessed in 164 patients with proximal middle cerebral artery occlusion before intravenous thrombolysis. PWI-DWI mismatch (PWI Tmax>6sec /DWI>1.8) was assessed in the 104 patients with available PWI data. We tested the associations between 24-hours complete recanalization on magnetic resonance angiography and 3-month favorable outcome (modified Rankin Scale score ≤2), stratified on FVH-DWI (or PWI-DWI) status. Results— FVH-DWI mismatch was present in 121/164 (74%) patients and recanalization in 50/164 (30%) patients. The odds ratio for favorable outcome with recanalization was 16.2 (95% confidence interval, 5.7–46.5; P P =0.22) in those without FVH-DWI mismatch ( P =0.048 for interaction). Recanalization was associated with favorable outcome in patients with PWI-DWI mismatch (odds ratios, 9.9; 95% confidence interval, 3.1–31.3; P =0.0001) and in patients without PWI-DWI mismatch (odds ratios, 7.0; 95% confidence interval, 1.1–44.1; P =0.047), P =0.76 for interaction. Conclusion— The FVH-DWI mismatch may rapidly identify patients with proximal occlusion most likely to benefit from recanalization.

Background and Purpose- We aimed to analyze the long-term outcomes of patients with primary central nervous system vasculitis according to the different therapeutic strategies used to induce remission. Methods- We assessed the rate of prolonged remission (defined by the absence of relapse at ≥12 months after diagnosis) and the functional status at last follow-up in patients with primary central nervous system vasculitis included in the French cohort, who achieved a first remission according to the 3 main groups of treatments administered: glucocorticoids only (group 1); induction treatment with glucocorticoids and an immunosuppressant, but no maintenance (group 2); and combined treatment with glucocorticoids and an immunosuppressant for induction followed by maintenance therapy (group 3). Good functional status was defined as a modified Rankin Scale score ≤2 at the last follow-up. Results- Remission was achieved with the initial induction treatment in 106 (95%) of the 112. Prolonged remission without relapse was observed in 70 (66%) patients after 57 (12-198) months of follow-up. A good functional status at last follow-up (ie, modified Rankin Scale score ≤2) was observed in 63 (56%) patients. Overall mortality was 8%. The initial severity and the radiological presentations were comparable in the 3 treatment groups. More prolonged remissions ( P=0.003) and a better functional status at the last follow-up ( P=0.0004) were observed in group 3. In multivariate analysis, the use of maintenance therapy was associated with prolonged remission (odds ratio, 4.32 [1.67-12.19]; P=0.002) and better functional status (odds ratio, 8.09 [3.24-22.38]; P0.0001). Conclusions- This study suggests that maintenance therapy with an immunosuppressant combined with glucocorticoids lead to the best long-term clinical and functional outcomes in patients with primary central nervous system vasculitis after having achieved remission with either glucocorticoids alone or in combination with another immunosuppressant.

Background and Purpose— Stroke patients with large diffusion-weighted imaging (DWI) volumes are often excluded from reperfusion because of reckoned futility. In those with DWI volume >70 mL, included in the THRACE trial (Mechanical Thrombectomy After Intravenous Alteplase Versus Alteplase Alone After Stroke), we report the associations between baseline parameters and outcome. Methods— We examined 304 patients with anterior circulation stroke and pretreatment magnetic resonance imaging. Variables were extracted from the THRACE database, and DWI volumes were measured semiautomatically. Results— Among 53 patients with DWI volume >70 mL, 12 had favorable outcome (modified Rankin Scale score, ≤2) at 3 months; they had less coronary disease (0/12 versus 12/38; P =0.046) and less history of smoking (1/10 versus 12/31; P =0.013) than patients with modified Rankin Scale score >2. None of the 8 patients >75 years of age reached modified Rankin Scale score ≤2. Favorable outcome occurred in 12 of 37 M1-occluded patients but in 0 of 16 internal carotid-T/L–occluded patients ( P =0.010). Favorable outcome was more frequent (6/13) when DWI lesion was limited to the superficial middle cerebral artery territory than when it extended to the deep middle cerebral artery territory (6/40; P =0.050). Conclusions— Stroke patients with DWI lesion >70 mL may benefit from reperfusion therapy, especially those with isolated M1 occlusion or ischemia restricted to the superficial middle cerebral artery territory. The benefit of treatment seems questionable for patients with carotid occlusion or lesion extending to the deep middle cerebral artery territory.

We thank Dr Stanley et al for pointing out a potentially important aspect of the ischemic insult in primary and secondary cerebral vasculitis as assessed by signal changes in diffusion-weighted imaging. The authors report that, in their experience, both diffusion-weighted imaging positivity and decreased diffusion coefficient on apparent diffusion coefficient maps can be sustained long after 3 weeks in those pathological conditions. This is of importance, given the fact that acute ischemic lesions, detected by magnetic resonance imaging diffusion-weighted imaging sequences, are known as the most prevalent feature of primary angiitis of the central nervous system at …

Background and Purpose— Childhood intracerebral hemorrhage is mainly attributable to underlying brain arteriovenous malformations (bAVMs). Multimodal treatment options for bAVMs include microsurgery and embolization, allowing an immediate cure, and radiosurgery, entailing longer obliteration times. Follow-up data on pediatric ruptured bAVMs are scarce, making it difficult to assess the risk of subsequent intracerebral hemorrhage. Our aim was to assess the clinical and angiographic outcome and to analyze risk factors for rebleeding during and after combined treatment of pediatric bAVMs. Methods— A prospectively maintained database of children referred to our institution between January 1997 and October 2012 for bAVMs was retrospectively queried to identify all consecutive ruptured bAVMs treated by surgery, embolization, and radiosurgery. The impact of baseline clinical and bAVM characteristics on clinical outcome, rebleeding rate, annual bleeding rate, and bAVM obliteration was studied using univariate and multivariate Cox regression analysis. Results— One hundred six children with ruptured bAVMs were followed up for a total of 480.5 patient-years (mean, 4.5 years). Thirteen rebleeding events occurred, corresponding to an annual bleeding rate of 2.71±1.32%, significantly higher in the first year (3.88±1.39%) than thereafter (2.22±1.38%; P P =0.004) or any deep venous drainage (relative risk, 2.97; P =0.002), in univariate and multivariate analysis. Partial embolization was associated with a higher annual bleeding rate, whereas initial surgery for intracerebral hemorrhage evacuation was associated with a lower risk of rebleeding. Conclusions— Associated aneurysms and any deep venous drainage are independent risk factors for rebleeding in pediatric ruptured bAVMs. Immediate surgery or total embolization might be advantageous for children harboring such characteristics, whereas radiosurgery might be targeted at patients without such characteristics.

Background and Purpose— Arterial wall enhancement on vessel wall MRI was described in intracranial inflammatory arterial disease. We hypothesized that circumferential aneurysmal wall enhancement (CAWE) could be an indirect marker of aneurysmal wall inflammation and, therefore, would be more frequent in unstable (ruptured, symptomatic, or undergoing morphological modification) than in stable (incidental and nonevolving) intracranial aneurysms. Methods— We prospectively performed vessel wall MRI in patients with stable or unstable intracranial aneurysms. Two readers independently had to determine whether a CAWE was present. Results— We included 87 patients harboring 108 aneurysms. Interreader and intrareader agreement for CAWE was excellent (κ=0.85; 95% confidence interval, 0.75–0.95 and κ=0.90; 95% confidence interval, 0.83–0.98, respectively). A CAWE was significantly more frequently seen in unstable than in stable aneurysms (27/31, 87% versus 22/77, 28.5%, respectively; P P =0.0002). Conclusions— CAWE was more frequently observed in unstable intracranial aneurysms and may be used as a surrogate of inflammatory activity in the aneurysmal wall.

Background and Purpose— The DRAGON score, which includes clinical and computed tomographic scan parameters, showed a high specificity to predict 3-month outcome in patients with acute ischemic stroke treated by intravenous tissue plasminogen activator. We adapted the score for patients undergoing MRI as the first-line diagnostic tool. Methods— We reviewed patients with consecutive anterior circulation ischemic stroke treated ≤4.5 hour by intravenous tissue plasminogen activator between 2003 and 2012 in our center, where MRI is systematically implemented as first-line diagnostic work-up. We derived the MRI-DRAGON score keeping all clinical parameters of computed tomography-DRAGON (age, initial National Institutes of Health Stroke Scale and glucose level, prestroke handicap, onset to treatment time), and considering the following radiological variables: proximal middle cerebral artery occlusion on MR angiography instead of hyperdense middle cerebral artery sign, and diffusion-weighted imaging Alberta Stroke Program Early Computed Tomography Score (DWI ASPECTS) ≤5 instead of early infarct signs on computed tomography. Poor 3-month outcome was defined as modified Rankin scale >2. We calculated c-statistics as a measure of predictive ability and performed an internal cross-validation. Results— Two hundred twenty-eight patients were included. Poor outcome was observed in 98 (43%) patients and was significantly associated with all parameters of the MRI-DRAGON score in multivariate analysis, except for onset to treatment time (nonsignificant trend). The c-statistic was 0.83 (95% confidence interval, 0.78–0.88) for poor outcome prediction. All patients with a MRI-DRAGON score ≤2 (n=22) had a good outcome, whereas all patients with a score ≥8 (n=11) had a poor outcome. Conclusions— The MRI-DRAGON score is a simple tool to predict 3-month outcome in acute stroke patients screened by MRI then treated by intravenous tissue plasminogen activator and may help for therapeutic decision.

Background and Purpose— Early neurological deterioration (END) after anterior circulation stroke is strongly associated with poor outcome. Apart from straightforward causes, such as intracerebral hemorrhage and malignant edema, the mechanism of END occurring after intravenous thrombolysis remains unclear in most instances. We tested the hypothesis that unexplained END is associated with thrombus extension. Methods— From our database of consecutively thrombolysed patients, we identified anterior circulation stroke patients who had both admission and 24-hour T2* magnetic resonance imaging, visible occlusion on admission magnetic resonance angiography and no recanalization on 24-hour magnetic resonance angiography. END was defined as ≥4 National Institutes of Health Stroke Scale–point deterioration on 24-hour clinical assessment and unexplained END as END without clear cause. The incidence of susceptibility vessel sign extension on T2* imaging, defined as any new occurrence or extension of susceptibility vessel sign from admission to 24-hour follow-up magnetic resonance, was compared between patients with unexplained END and those without END. Results— Of 120 eligible patients for the present study, 22 experienced unexplained END. Susceptibility vessel sign extension was present in 41 (34%) patients and was significantly more frequent in the unexplained END than in the no-END group (59% versus 29%, respectively; adjusted odds ratio=3.96; 95% confidence interval, 1.25–12.53; P =0.02). Conclusions— In this study, unexplained END occurring after thrombolysis was independently associated with susceptibility vessel sign extension, suggesting in situ thrombus extension or re-embolization. These findings strengthen the need to further investigate early post-thrombolysis administration of antithrombotics to reduce the risk of this ominous clinical event.

Background and Purpose— We aimed to describe the clinical and imaging features of patients with tumor-like presentation of primary angiitis of the central nervous system. Methods— We retrospectively analyzed 10 patients enrolled in the French primary angiitis of the central nervous system cohort, who initially presented tumor-like brain lesions and compared them with other patients within the cohort. Results— The 10 patients with tumor-like presentation in the cohort were younger and had more seizures at diagnosis than the other 75 patients (median of 37 [30–48] years versus 46 [18–79] years; P =0.008; 9 [90%] with seizures versus 22 [29%], P Conclusions— Patients with tumor-like presentation of primary angiitis of the central nervous system represent a subgroup characterized with mainly small-sized vessel disease that requires histological confirmation because vascular imaging is often normal. Although relapses are not uncommon, global outcomes are good under treatment with glucocorticoids and cyclophosphamide.

Introduction: Primary angiitis of the central nervous system (PACNS) is a potentially severe inflammatory disease of central nervous system vessels and despite its extreme sparsity, knowledge has improved within past decades. PACNS diagnosis, however, remains challenging, mainly because of the multiple mimickers and possible differential diagnoses. Previous MRI/MR Angiography descriptions of PACNS adult patients might have become outdated Hypothesis: To report an updated overview and pictural review of MR/MRA findings in adult PACNS, determine type/distribution of parenchymal, meningeal and vascular lesions in an independent multicentric inception cohort. Methods: Patients from the French mutlicentric COVAC cohort, adults with biopsy/angiographically proven PACNS were included if they had MRI/MRA available imaging upon diagnosis for retrospective review. Systematic imaging review was performed blinded to clinical data. Results: Among the 91 enrolled patients in cohort, 60 met inclusion criteria for this study. Mean age was 45yo (±12.9). Patients presented initially with focal deficit(s) (83%), headaches (53%), cognitive disorder (40%) or seizures (38.3%). MRI was abnormal in all patients, most common finding being ischemic stroke following a small arteries distribution with multi-territorial lesions (50% of evaluated patients), with a predominant anterior distribution. 57% of parenchymal hemorrhagic lesions were hemorrhagic transformation of ischemic strokes. 26% of patients had otherwise subarachnoid hemorrhage. 42% of patients demonstrated preeminent leptomeningeal enhancement. Seven had tumor like presentation. 77% of MRA studies were abnormal revealing proximal/distal stenoses in respectively 57% and 61% of patients. Only 11 patients demonstrated a typical beading aspect on MRA. DSA unmasked distal stenotic lesions in Discussion: We present the largest to date MRI/MRA systematically assessed cohort of adult PACNS patients, extend our current knowledge of this rare and heterogeneous disease and present an extensive analysis of MRI and MR Angiography characteristics of PACNS in adults.

Introduction: To report clinical outcome of aneurysmal subarachnoid hemorrhage (aSAH) patients exposed to cerebral vasospasm (CVS) targeted treatments in a systematic review and meta-analysis and compare the efficacy of endovascular and non-endovascular treatments in severe / refractory vasospasm patients. Methods: The literature was searched using PubMed, EMBASE, and The Cochrane Library database. Eligibility criteria were (1) Rated clinical outcome; (2) at least 10 patients; (3) aSAH; (4) study published in English or French (January 2006 - October 2014); and (5) methodological quality score > 10, according to STROBE criteria. Endpoint included unfavorable outcome rate, defined as mRS 3-6, GOS 1-3 or GOSE 1-4 at latest follow-up. Analyses included stratification per route of administration (oral, i.v., intra-arterial or cisternoventricular) and per study inclusion criteria (severe, CVS, refractory CVS or high risk for CVS). Univariate and multivariate subgroup analyses were performed to identify interventions associated with a better outcome. Results: Sixty-two studies, including 26 randomized controlled trials, were included (8976 patients). Overall 2490 patients had unfavorable outcome including death (random-effect weighted average: 33.7%, 99%CI, 28.1-39.7%; Q-value: 806.0, I 2 =92.7%). Clinical outcome was significantly better in severe or refractory patients for whom, on top of best medical treatment, endovascular intervention was performed (RR=0.76, IC95% [0.66-0.89], p 2 = 0). Conclusion: In case of CVS following aSAH, endovascular treatment in severe / refractory vasospasm patients. including intra-arterial injection of pharmacological agents or balloon angioplasty, improves outcome as compared to other route of administration.

Background and Purpose— Whether to withhold recanalization treatment when the diffusion-weighted imaging (DWI) lesion exceeds a given volume is unsettled. Our aim was to assess the impact of recanalization on outcome in patients with baseline DWI lesion ≥70 mL (DWI≥70 mL) treated ≤4.5 hours from onset. We hypothesized that recanalization is beneficial in a sizeable fraction of these patients and that this is associated with a larger DWI lesion reversal. Methods— We analyzed 267 consecutive patients treated with intravenous recombinant tissue-type plasminogen activator for middle cerebral artery territory stroke in whom an occlusion was present on magnetic resonance angiography and 24-hour recanalization and 90-day clinical outcome could be assessed. After stratification relative to the 70-mL DWI lesion cut point, we calculated the odds ratio for recanalization of the primary arterial occlusive lesion (AOL score ≥2) to predict favorable outcome (modified Rankin scale score ≤2). DWI lesion reversal was compared between recanalizers with DWI≥70 mL with favorable and unfavorable outcomes. Results— Median (interquartile range) DWI lesion volume was 22 mL (10–60), and median onset time to imaging was 116 minutes (86–151). Twelve (22%) of the 54 patients with DWI≥70 mL experienced favorable outcome, of which 9 had recanalized. In patients with DWI≥70 mL, recanalization was significantly associated with favorable outcome after adjustment for age and National Institutes of Health Stroke Scale (odds ratio =4.72 [1.09–20.32]; P =0.0375). Among recanalizers with DWI≥70 mL, absolute and relative DWI reversal volumes were larger in those with favorable as compared with unfavorable outcome (18.8 mL [12.2–47.6] versus 8.5 mL [4.3–31.1]; P =0.17; and 19.6% [10.9–62.8] versus 8.7% [3.9–16.5], respectively; P =0.049). Conclusions— Patients with DWI lesion volume ≥70 mL can benefit from recanalization after intravenous recombinant tissue-type plasminogen activator. This may partly reflect a larger amount of DWI lesion reversal.

Background and Purpose— The extent of diffusion lesion on pretreatment imaging is a risk factor for poor outcome and hemorrhagic transformation after thrombolysis, and volumes of 70 to 100 mL have been advocated as cut-offs. However, estimating diffusion-weighted imaging (DWI) lesion volume (Vol DWI ) in the acute setting may be cumbersome. We aimed to determine whether the DWI-Alberta Stroke Program Early CT Score (DWI-ASPECTS) can substitute for Vol DWI . Methods— DWI-ASPECTS and Vol DWI were measured retrospectively on pretreatment MRI (median onset-to-MRI delay=122 minutes) in 330 consecutively treated patients with middle cerebral artery stroke. Results— DWI-ASPECTS and Vol DWI were strongly correlated (ρ=−0.82), but each DWI-ASPECTS point corresponded to a wide range of Vol DWI . All patients with DWI-ASPECTS ≥7 (n=207) had Vol DWI DWI >100 mL. However, intermediate DWI-ASPECTS (4–6; n=89) corresponded to highly variable Vol DWI (median, 66 mL; interquartile range, 40–98). Conclusions— Although each DWI-ASPECTS point corresponds to a wide range of volumes, DWI-ASPECTS DWI >100 or

Background and Purpose— In stroke attributable to spontaneous dissection of the cervical artery, it is unclear whether the occurrence and pattern of stroke depend on the degree of stenosis. Methods— In 147 consecutive dissection of the cervical artery patients with (n=88) and without stroke (n=59), we compared the number, volume, and patterns of cerebral diffusion-weighted imaging stroke lesions among patients with Results— The presence (26 of 45 in Group 1, 32 of 59 in Group 2, 30 of 43 in Group 3; P =0.27) and the number of diffusion-weighted imaging lesions (mean±SD [interquartile range], 3.5±3.9 [1–4] in Group 1; 4.2±4.1 [1–5] in Group 2; 3.3±4.0 [1–3] in Group 3; P =0.85) were independent of lumen patency, whereas volume of diffusion-weighted imaging lesions was larger in occlusive dissection of the cervical artery (82±90 mm [17–91] versus 34±54 [2–48]; P =0.03). There were no differences in the breakdown of diffusion-weighted imaging lesion patterns according to degree of stenosis. Conclusions— The occurrence and diffusion-weighted imaging lesion patterns in dissection of the cervical artery patients may not be influenced by the degree of stenosis of the dissected artery. Occlusive dissection of the cervical artery was associated with larger infarcts.

Background and Purpose— To propose a T2*-MR adaptation of the computed tomography angiography-clot burden score (CBS), and assess its value as predictor of 24-hour recanalization and clinical outcome in anterior circulation stroke treated by intravenous thrombolysis ≤4.5 hours from onset. Methods— Two independent observers retrospectively analyzed pretreatment T2* images for evaluation of clot burden, using a 10-point scale T2*-CBS. Three points are subtracted for susceptibility vessel sign in the supraclinoid internal carotid artery, 2 points each for susceptibility vessel sign in the proximal and distal part of middle cerebral artery, and 1 point each for susceptibility vessel sign in middle cerebral artery branches (with a maximum of 2 points) and for susceptibility vessel sign in anterior cerebral artery. Associations with 24-hour recanalization and favorable outcome (3-month modified Rankin Scale score, ≤2) were assessed in multivariate analyses. Results— We analyzed 184 consecutive patients (mean age, 67 years) with median (interquartile range) admission National Institutes of Health Stroke Scale score and onset-to-treatment time of 15 (9–19) and 151 (120–185) minutes, respectively. The intraclass correlation for T2*-CBS between observers was 0.97 (95% confidence interval, 0.97–0.98). In multivariate analyses, T2*-CBS >6 was significantly associated with 24-hour recanalization (adjusted odds ratio, 5.1 [1.9–13.5]; P =0.001) or with favorable outcome (adjusted odds ratio, 4.2 [1.7–10.8]; P =0.003). Conclusions— T2*-CBS, a new reproducible semiquantitative score adapted from the computed tomography angiography-CBS, is associated with 24-hour recanalization and 3-month outcome after intravenous thrombolysis. This score needs external validation and could be useful to identify poor responders to intravenous thrombolysis.

Background and Purpose— It is unclear whether strokes in patients with spontaneous cervical artery dissection (CAD) are due to secondary thromboembolism or to a reduction in cerebral blood flow from the primary cervical lesion. The aim of this study was to identify the most likely mechanism of stroke using cervical and cerebral imaging parameters in patients with CAD. Methods— The study was approved by the local Ethics Committee. Informed consent was waived. We retrospectively evaluated the cerebrovascular ultrasound, cervical MR angiography, and stroke brain MRI in consecutive patients with CAD. An embolic mechanism was considered in the case of direct visualization of an intracranial embolism as a susceptibility vessel sign on T2* or in the case of pial artery territory infarction on diffusion-weighted imaging. A hemodynamic mechanism was considered in the case of watershed infarction and in the case of an association of watershed infarction and pial artery territory infarction when ≥2 of the following were present: severe stenotic or occlusive CAD, reduced intracranial velocity on cerebrovascular ultrasound or signal on MR angiography, or hyperintense vessel sign on fluid-attenuated inversion recovery. The remaining patients were considered to have a mixed mechanism. Results— Of 172 consecutive patients with CAD, 100 (58%) had acute stroke on diffusion-weighted imaging. Stroke was attributed to a thromboembolic mechanism in 85 of 100 patients, a hemodynamic mechanism in 12 of 100 patients, and a mixed mechanism in 3 of 100 patients. Conclusions— Stroke in patients with CAD is most frequently associated with both direct and indirect signs of artery-to-artery embolization on imaging, a finding that should help design future therapeutic trials.

To the Editor: The usefulness of embolic brain protection (EBP) devices in patients treated by carotid artery stenting is a matter of continuous debate. To date, as all available evidence comes from observational studies, no definite conclusions can be established. Tallarita et al1 published their experience with 357 patients treated with carotid artery stenting, including 252 patients treated with EBP. The observed risks of stroke, myocardial infarction, or death were 5/252 (2.0%) and 5/105 (4.8%) in patients treated with and without EBP, respectively. As there were no significant differences between protected and unprotected carotid artery stenting, they concluded that the real efficacy of EBP must be questioned. However, they missed some important previous data and, more importantly, misinterpreted the nonsignificant result of their …