Stenosis Length and Degree Interact With the Risk of Cerebrovascular Events Related to Internal Carotid Artery Stenosis

Background and Purpose: Internal carotid artery stenosis (ICAS)≥70% is a leading cause of ischemic cerebrovascular events (ICVEs). However, a considerable percentage of stroke survivors with symptomatic ICAS (sICAS) have <70% stenosis with a vulnerable plaque. Whether the length of ICAS is associated with high risk of ICVEs is poorly investigated. Our main aim was to investigate the relation between the length of ICAS and the development of ICVEs.Methods: In a retrospective cross-sectional study, we identified 95 arteries with sICAS and another 64 with asymptomatic internal carotid artery stenosis (aICAS) among 121 patients with ICVEs. The degree and length of ICAS as well as plaque echolucency were assessed on ultrasound scans.Results: A statistically significant inverse correlation between the ultrasound-measured length and degree of ICAS was detected for sICAS≥70% (Spearman correlation coefficient ρ = –0.57, p < 0.001, n = 51) but neither for sICAS<70% (ρ = 0.15, p = 0.45, n = 27) nor for aICAS (ρ = 0.07, p = 0.64, n = 54). The median (IQR) length for sICAS<70% and ≥70% was 17 (15–20) and 15 (12–19) mm (p = 0.06), respectively, while that for sICAS<90% and sICAS 90% was 18 (15–21) and 13 (10–16) mm, respectively (p < 0.001). Among patients with ICAS <70%, a cut-off length of ≥16 mm was found for sICAS rather than aICAS with a sensitivity and specificity of 74.1% and 51.1%, respectively. Irrespective of the stenotic degree, plaques of the sICAS compared to aICAS were significantly more often echolucent (43.2 vs. 24.6%, p = 0.02).Conclusion: We found a statistically insignificant tendency for the ultrasound-measured length of sICAS<70% to be longer than that of sICAS≥70%. Moreover, the ultrasound-measured length of sICAS<90% was significantly longer than that of sICAS 90%. Among patients with sICAS≥70%, the degree and length of stenosis were inversely correlated. Larger studies are needed before a clinical implication can be drawn from these results

Zusammenhang zwischen der Stenoselänge der Arteria carotis interna und ischämischen zerebrovaskulären Ereignissen sowie der Läsionslast der weißen Substanz

Background and Purpose: Internal carotid artery stenosis ≥70% is a leading cause of ischemic cerebrovascular events. However, a considerable percentage of stroke survivors with symptomatic internal carotid artery stenosis have <70% stenosis with a vulnerable plaque. Whether the length of internal carotid artery stenosis is associated with high risk of ischemic cerebrovascular events or with white matter lesions is poorly investigated. Our main aim was to investigate the relation between the length of internal carotid artery stenosis and the development of ischemic cerebrovascular events as well as ipsi-, contralateral as well as mean white matter lesion load. Methods: In a retrospective cross-sectional study, 168 patients with 208 internal carotid artery stenosis were identified. The degree and length of internal carotid artery stenosis as well as plaque morphology (hypoechoic, mixed or echogenic) were assessed on ultrasound scans. The white matter lesions were assessed in 4 areas separately, (periventricular and deep white matter lesions on each hemisphere), using the Fazekas scale. The mean white matter lesions load was calculated as the mean of these four values. Results: A statistically significant inverse correlation between the ultrasound-measured length and degree of internal carotid artery stenosis was detected for symptomatic internal carotid artery stenosis ≥70% (Spearman correlation coefficient ρ = –0.57, p < 0.001, n = 51) but neither for symptomatic internal carotid artery stenosis <70% (ρ = 0.15, p = 0.45, n = 27) nor for asymptomatic internal carotid artery stenosis (ρ = 0.07, p = 0.64, n = 54). The median (IQR) length for symptomatic internal carotid artery stenosis <70% and ≥70% was 17 (15–20) and 15 (12–19) mm (p = 0.06), respectively, while that for symptomatic internal carotid artery stenosis <90% and symptomatic internal carotid artery stenosis 90% was 18 (15–21) and 13 (10–16) mm, respectively (p < 0.001). Among patients with internal carotid artery stenosis <70%, a cut-off length of ≥16 mm was found for symptomatic internal carotid artery stenosis rather than asymptomatic internal carotid artery stenosis with a sensitivity and specificity of 74.1% and 51.1%, respectively. Irrespective of the stenotic degree, plaques of the symptomatic internal carotid artery stenosis compared to asymptomatic internal carotid artery stenosis were significantly more often echolucent (43.2 vs. 24.6%, p = 0.02). The length but not the degree of internal carotid artery stenosis showed a very slight trend toward association with ipsilateral white matter lesions and with mean white matter lesions load. Conclusion: We found a statistically insignificant tendency for the ultrasound-measured length of symptomatic internal carotid artery stenosis <70% to be longer than that of symptomatic internal carotid artery stenosis ≥70%. Moreover, the ultrasound-measured length of symptomatic internal carotid artery stenosis <90% was significantly longer than that of symptomatic internal carotid artery stenosis 90%. Among patients with symptomatic internal carotid artery stenosis ≥70%, the degree and length of stenosis were inversely correlated. Furthermore, we have shown that a slight correlation exists between the length of stenosis and the presence of ipsilateral white matter lesions which might be due to microembolisation originating from the carotid plaque. Larger studies are needed before a clinical implication can be drawn from these results.Hintergrund: Stenose der A. carotis interna ≥70% ist eine der führenden Ursachen für ischämische zerebrovaskuläre Ereignisse. Ein beträchtlicher Prozentsatz der Schlaganfall-Überlebenden mit symptomatischer Stenose der A. carotis interna weist jedoch eine Stenose <70% mit einer „vulnerable Plaque“ auf. Ob die Länge der Stenose der A. carotis interna mit einem hohen Risiko für ischämische zerebrovaskuläre Ereignisse oder mit Läsionen der weißen Substanz verbunden ist, wird nur unzureichend untersucht. Unser Hauptziel war es, den Zusammenhang zwischen der Länge der Stenose der Aerteria carotis interna und der Entwicklung von ischämischen zerebrovaskulären Ereignissen sowie der ipsi-, kontralateralen und mittleren Läsionslast der weißen Substanz zu untersuchen. Methode: In einer retrospektiven Querschnittsstudie wurden 168 Patienten mit 208 Stenosen der A. carotis interna identifiziert. Der Stenosegrad und die Stenoselänge sowie die Plaquemorphologie (echoarm, gemischt oder echogen) wurden mittels Ultraschall untersucht. Die Läsionen der weißen Substanz wurden in 4 Bereichen (periventrikuläre und subkortilae Läsionen der weißen Substanz, jeweils auf jeder Hemisphäre) mittels Fazekas-Skala bewertet. Der mittlere dieser vier Werte wurde ebenso berechnet. Ergebnisse: Eine statistisch signifikante inverse Korrelation zwischen der mit Ultraschall gemessenen Länge und dem Stenosegrad der A. carotis interna wurde für eine symptomatische Stenose der A. carotis interna von ≥ 70% festgestellt (Spearman-Korrelationskoeffizient ρ = –0,57, p <0,001, n = 51), jedoch keine bei symptomatischer Stenose der A. carotis interna <70% (ρ = 0,15, p = 0,45, n = 27) und bei asymptomatischer Stenose der A. carotis interna (ρ = 0,07, p = 0,64, n = 54). Die mediane Länge (IQR) für symptomatische Stenosen der A. carotis interna <70% und ≥ 70% betrug 17 (15–20) bzw. 15 (12–19) mm (p = 0,06), die für symptomatische Stenosen der A. carotis interna <90% und symptomatische Stenose der A. carotis interna 90% betrugen 18 (15–21) bzw. 13 (10–16) mm (p <0,001). Bei Patienten mit einer Stenose der A. carotis interna <70% wurde für eine symptomatische Stenose der A. carotis interna einen Grenzwert von ≥ 16 mm gefunden, und nicht für eine asymptomatische Stenose der A. carotis interna mit einer Sensitivität und Spezifität von 74,1% bzw. 51,1%. Unabhängig vom stenotischen Grad waren Plaques der symptomatischen Stenose der A. carotis interna im Vergleich zur asymptomatischen Stenose der A. carotis interna signifikant häufiger echoarm (43,2 vs. 24,6%, p = 0,02). Die Stenoselänge, aber nicht der Stenosegrad der A. carotis interna zeigte einen sehr geringen Trend zur Assoziation mit ipsilateralen Läsionen der weißen Substanz und mit der mittleren Läsionslast der weißen Substanz. Schlussfolgerung: Es wurde eine statistisch nicht signifikante Tendenz gefunden, dass die ultraschallgemessene Länge der symptomatischen Stenose der A. carotis interna <70% länger ist als die der symptomatischen Stenose der A. carotis interna ≥ 70%. Darüber hinaus war die durch Ultraschall gemessene Länge der symptomatischen Stenose der A. carotis interna <90% signifikant länger als die der symptomatischen Stenose der A. carotis interna 90%. Bei Patienten mit symptomatischer Stenose der A. carotis interna ≥ 70% waren Stenosegrad und Stenoselänge invers korreliert. Darüber hinaus haben wir gezeigt, dass eine leichte Korrelation zwischen der Stenoselänge und der ipsilateralen Läsionen der weißen Substanz besteht, die möglicherweise auf eine Mikroembolisation zurückzuführen sind, die vom Carotis-Plaque herrührt. Größere Studien sind erforderlich, bevor aus diesen Ergebnissen eine klinische Implikation abgeleitet werden kann

Relation Between the Length of the Internal Carotid Stenotic Segment and Ischemic Cerebrovascular Events as Well as White Matter Lesion Load

Background and Purpose: Internal carotid artery stenosis ≥70% is a leading cause of ischemic cerebrovascular events. However, a considerable percentage of stroke survivors with symptomatic internal carotid artery stenosis have <70% stenosis with a vulnerable plaque. Whether the length of internal carotid artery stenosis is associated with high risk of ischemic cerebrovascular events or with white matter lesions is poorly investigated. Our main aim was to investigate the relation between the length of internal carotid artery stenosis and the development of ischemic cerebrovascular events as well as ipsi-, contralateral as well as mean white matter lesion load. Methods: In a retrospective cross-sectional study, 168 patients with 208 internal carotid artery stenosis were identified. The degree and length of internal carotid artery stenosis as well as plaque morphology (hypoechoic, mixed or echogenic) were assessed on ultrasound scans. The white matter lesions were assessed in 4 areas separately, (periventricular and deep white matter lesions on each hemisphere), using the Fazekas scale. The mean white matter lesions load was calculated as the mean of these four values. Results: A statistically significant inverse correlation between the ultrasound-measured length and degree of internal carotid artery stenosis was detected for symptomatic internal carotid artery stenosis ≥70% (Spearman correlation coefficient ρ = –0.57, p < 0.001, n = 51) but neither for symptomatic internal carotid artery stenosis <70% (ρ = 0.15, p = 0.45, n = 27) nor for asymptomatic internal carotid artery stenosis (ρ = 0.07, p = 0.64, n = 54). The median (IQR) length for symptomatic internal carotid artery stenosis <70% and ≥70% was 17 (15–20) and 15 (12–19) mm (p = 0.06), respectively, while that for symptomatic internal carotid artery stenosis <90% and symptomatic internal carotid artery stenosis 90% was 18 (15–21) and 13 (10–16) mm, respectively (p < 0.001). Among patients with internal carotid artery stenosis <70%, a cut-off length of ≥16 mm was found for symptomatic internal carotid artery stenosis rather than asymptomatic internal carotid artery stenosis with a sensitivity and specificity of 74.1% and 51.1%, respectively. Irrespective of the stenotic degree, plaques of the symptomatic internal carotid artery stenosis compared to asymptomatic internal carotid artery stenosis were significantly more often echolucent (43.2 vs. 24.6%, p = 0.02). The length but not the degree of internal carotid artery stenosis showed a very slight trend toward association with ipsilateral white matter lesions and with mean white matter lesions load. Conclusion: We found a statistically insignificant tendency for the ultrasound-measured length of symptomatic internal carotid artery stenosis <70% to be longer than that of symptomatic internal carotid artery stenosis ≥70%. Moreover, the ultrasound-measured length of symptomatic internal carotid artery stenosis <90% was significantly longer than that of symptomatic internal carotid artery stenosis 90%. Among patients with symptomatic internal carotid artery stenosis ≥70%, the degree and length of stenosis were inversely correlated. Furthermore, we have shown that a slight correlation exists between the length of stenosis and the presence of ipsilateral white matter lesions which might be due to microembolisation originating from the carotid plaque. Larger studies are needed before a clinical implication can be drawn from these results

Symptomatic vs. asymptomatic 20–40% internal carotid artery stenosis: Does the plaque size matter?

Background: Around 9–15% of ischemic strokes are related to internal carotid artery (ICA)-stenosis ≥50%. However, the extent to which ICA-stenosis <50% causes ischemic cerebrovascular events is uncertain. We examined the relation between plaque cross-sectional area and length and the risk of ischemic stroke or TIA among patients with ICA-stenosis of 20–40%. Methods: We retrospectively identified patients admitted to the Department of Neurology, University Hospital of Würzburg, from January 2011 until September 2016 with ischemic stroke or TIA and concomitant ICA-stenosis of 20–40%, either symptomatic or asymptomatic. Plaque length and cross-sectional area were assessed on ultrasound scans. Results: We identified 41 patients with ischemic stroke or TIA and ICA-stenosis of 20–40%; 14 symptomatic and 27 asymptomatic. The plaque cross-sectional area was significantly larger among symptomatic than asymptomatic ICA-stenosis; median values (IQR) were 0.45 (0.21–0.69) cm2 and 0.27 (0.21–0.38) cm2, p = 0.03, respectively. A plaque cross-sectional area ≥0.36 cm2 had a sensitivity of 71% and a specificity of 76% for symptomatic compared with asymptomatic ICA-stenosis. In a sex-adjusted multivariate logistic regression, a plaque cross-sectional area ≥0.36 cm2 and a plaque length ≥1.65 cm were associated with an OR (95% CI) of 5.54 (1.2–25.6), p = 0.028 and 1.78 (0.36–8.73), p = 0.48, respectively, for symptomatic ICA-stenosis. Conclusion: Large plaques might increase the risk of ischemic stroke or TIA among patients with low-grade ICA-stenosis of 20–40%. Sufficiently powered prospective longitudinal cohort studies are needed to definitively test the stroke risk stratification value of carotid plaque length and cross-sectional area in the setting of current optimal medical treatment

Are cerebral white matter lesions related to the presence of bilateral internal carotid artery stenosis or to the length of stenosis among patients with ischemic cerebrovascular events?

Background and purpose: Previous studies delivered contradicting results regarding the relation between the presence of an internal carotid artery stenosis (ICAS) and the occurence of white matter lesions (WMLs). We hypothesize that special characteristics related to the ICAS might be related to the WMLs. We examined the relation between the presence of bilateral ICAS, the degree and length of stenosis and ipsi-, contralateral as well as mean white matter lesion load (MWMLL). Methods: In a retrospective cohort, patients with ischemic stroke or transient ischemic attack (TIA) as well as ipsi- and/or contralateral ICAS were identified. The length and degree of ICAS, as well as plaque morphology (hypoechoic, mixed or echogenic), were assessed on ultrasound scans and, if available, the length was also measured on magnetic resonance angiography (MRA) scans, and/or digital subtraction angiography (DSA). The WMLs were assessed in 4 areas separately, (periventricular and deep WMLs on each hemispherer), using the Fazekas scale. The MWMLL was calculated as the mean of these four values. Results: 136 patients with 177 ICAS were identified. A significant correlation between age and MWMLL was observed (Spearman correlation coefficient, ρ = 0.41, p < 0.001). Before adjusting for other risk factors, a significantly positive relation was found between the presence of bilateral ICAS and MWMLL (p = 0.039). The length but not the degree of ICAS showed a very slight trend toward association with ipsilateral WMLs and with MWMLL. In an age-adjusted multivariate logistic regression with MWMLL ≥2 as the outcome measure, atrial fibrillation (OR 3.54, 95% CI 1.12–11.18, p = 0.03), female sex (OR 3.11, 95% CI 1.19–8.11, p = 0.02) and diabetes mellitus (OR 2.76, 95% CI 1.16–6.53, p = 0.02) were significantly related to WMLs, whereas the presence of bilateral stenosis showed a trend toward significance (OR 2.25, 95% CI 0.93–5.45, p = 0.074). No relation was found between plaque morphology and MWMLL, periventricular, or deep WMLs. Conclusion: We have shown a slight correlation between the length of stenosis and the presence of WMLs which might be due to microembolisation originating from the carotid plaque. However, the presence of bilateral ICAS seems also to be related to WMLs which may point to common underlying vascular risk factors contributing to the occurrence of WML

Carotid atherosclerosis in a sample of Egyptian patients with or without ischemic vascular events

Abstract Background Ethnic-racial factors are related to the development of extra- and intracranial atherosclerosis. There are extensive data about carotid atherosclerosis from American, European and Asian population. However, data from Egyptian ethnics are extremely rare. We aimed to examine the frequency and determine the predictors of carotid atherosclerosis in a sample of Egyptian patients. In a cross-sectional observational study, we prospectively recruited consecutive patients, with or without ischemic vascular events, either ischemic stroke or transient ischemic attack, who received neurovascular ultrasound in a tertiary hospital. We assessed the presence of carotid plaques and the degree of stenosis according to the hemodynamic North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Results A total of 668 carotid arteries in 334 patients with a mean (IQR) age of 61 (55–70) years were examined; 69.5% presented with and 30.5% without ischemic vascular events. We found carotid plaques in 208 (31.1%) arteries among 147 (44%) patients; 32% of the patients showed non-hemodynamically significant plaques, whereas 3.6% showed 20–40% internal carotid artery (ICA) stenosis and 8.4% showed ≥ 50% ICA stenosis. In patients with ischemic vascular events and at least one risk factor, we detected carotid atherosclerosis, 20–40% ICA stenosis and ≥ 50% ICA stenosis in 40.4%, 3% and 9.1% among patients ≤ 60 years as well as in 64.8%, 5.5% and 13% among patients > 60 years, respectively. In an age and sex adjusted binary logistic regression model, the following factors predicted carotid atherosclerosis: age > 60 years (OR 3.33, 95% CI 1.99–5.57, p < 0.001), hypertension (OR 2.3, 95% CI 1.32–4.02, p = 0.003), current smoking (OR 2.27, 95% CI 1.13–4.55, p = 0.02), diabetes mellitus (OR 2.15, 95% CI 1.27–3.64, p = 0.004) and ischemic vascular events (OR 1.8, 95% CI 1.01–3.19, p = 0.046). Conclusions Among Egyptians, the frequency of carotid atherosclerosis seems to be low. Further multiethnic studies are warranted to compare the prevalence of carotid atherosclerosis among Egyptians with Whites and Chinese populations. Older age, hypertension, smoking, diabetes mellitus and ischemic vascular events are predictors of carotid atherosclerosis

Relation of infarction location and volume to vertigo in vertebrobasilar stroke

Objective Vertigo is a common presentation of vertebrobasilar stroke. Anecdotal reports have shown that vertigo occurs more often in multiple than in single brainstem or cerebellar infarctions. We examined the relation between the location and volume of infarction and vertigo in patients with vertebrobasilar stroke. Methods Consecutive patients with vertebrobasilar stroke were prospectively recruited. The infarction location and volume were assessed in the diffusion‐weighted magnetic resonance imaging. Results Fifty‐nine patients were included, 32 (54.2%) with vertigo and 27 (45.8%) without vertigo. The infarction volume did not correlate with National Institute of Health Stroke Scale (NIHSS) score on admission (Spearman ρ = .077, p = .56) but correlated with modified Rankin Scale (ρ = .37, p = .004) on discharge. In the vertigo group, the proportion of men was lower (53.1% vs. 77.8%, p = .049), fewer patients had focal neurological deficits (65.6% vs. 96.3%, p = .004), patients tended to present later (median [IQR] was 7.5 [4–46] vs. 4 [2–12] hours, p = .052), numerically fewer patients received intravenous thrombolysis (15.6% vs. 37%, p = .06), and the total infarction volume was larger (5.6 vs. 0.42 cm3, p = .008) than in nonvertigo group. In multivariate logistic regression, infarction location either in the cerebellum or in the dorsal brainstem (odds ratio [OR] 16.97, 95% CI 3.1–92.95, p = .001) and a total infarction volume of >0.48 cm3 (OR 4.4, 95% CI 1.05–18.58, p = .043) were related to vertigo. In another multivariate logistic regression, after adjusting for age, sex, intravenous thrombolysis, serum level of white blood cells, and atrial fibrillation, vertigo independently predicted a total infarction volume of >0.48 cm3 (OR 5.75, 95% CI 1.43–23.08, p = .01). Conclusion Infarction location in the cerebellum and/or dorsal brainstem is an independent predictor of vertigo. Furthermore, larger infarction volume in these structures is associated with vertigo. A considerable proportion of patients with vascular vertigo present without focal neurological deficits posing a diagnostic challenge. National Institute of Health Stroke Scale is not sensitive for vertebrobasilar stroke

Outcome and recanalization rate of tandem basilar artery occlusion treated by mechanical thrombectomy

International audienceArrière-plan: Les occlusions de l’artère basilaire en tandem (tBAO) sont définies comme des occlusions concomitantes de l’artère basilaire basilaire et de l’artère vertébrale dominante extracrânienne. Le pronostic d’une telle tBAO traitée par thrombectomie mécanique (MT) a été peu rapporté. Le but de notre étude était de comparer l’innocuité et l’efficacité de la MT chez les patients atteints de tBAO par rapport à ceux présentant des occlusions d’artères basilaires non tandem (ntBAO).Patients et méthodes: Analyse rétrospective d’une base de données de patients ayant subi une MT dans deux centres universitaires. Tous les patients traités pour BAO ont été récupérés. Les patients atteints de tBAO, défini comme une BAO concomitante et une occlusion extracrânienne de l’artère vertébrale (VA) ou une sténose sévère ≥70% (segment V1 ou proximal V2) ont été comparés aux patients atteints de ntBAO.Résultats: Au total, 15 patients atteints de tBAO et 74 patients atteints de ntBAO ont été recrutés. Une reperfusion réussie (thrombolyse modifiée dans le score d’infarctus cérébral ≥2b) a été obtenue dans 73,3 % contre 90,5 % (RC = 0,29, IC à 95 % : 0,07-1,15), un bon résultat clinique (échelle de Rankin modifiée à 3 mois ≤2) a été atteint par 26,7 % contre 32,4 % (RC = 0,76 ; IC à 95 % : 0,24-2,63) et la mortalité à 3 mois était de 46,7 % contre 31 % (RC = 1,94 ; IC à 95 % : 0,63-6) des patients atteints de tBAO par rapport à ntBAO, respectivement. Deux patients (13,3 %) atteints de tBAO et trois (4 %) de ntBAO présentaient une hémorragie intracrânienne symptomatique (RC = 3,64 ; IC à 95 % : 0,55-24).Conclusion: La thrombectomie mécanique chez les patients présentant une occlusion de l’artère basilaire en tandem a tendance à être associée à des taux plus faibles de reperfusion réussie et à de bons résultats cliniques, ainsi qu’à un taux de mortalité plus élevé. Des études multicentriques plus vastes sont justifiées pour mieux préciser la sélection et la prise en charge appropriées de ces patients

Mechanical Thrombectomy for Acute Ischemic Stroke Amid the COVID-19 Outbreak

International audienceBackground 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 <0.001) in MT case volumes during the epidemic period, and a significant increase in delays between imaging and groin puncture, overall (mean 144.9±SD 86.8 minutes versus 126.2±70.9; P <0.001 in 2019) and in transferred patients (mean 182.6±SD 82.0 minutes versus 153.25±67; P <0.001). After the instatement of strict epidemic mitigation measures, there was a significant negative correlation between the number of hospitalizations for COVID and the number of MT cases ( 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 <0.05). 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

Quantitative Signal Intensity in Fluid-Attenuated Inversion Recovery and Treatment Effect in the WAKE-UP Trial

International audienceBackground and Purpose— Relative signal intensity of acute ischemic stroke lesions in fluid-attenuated inversion recovery (fluid-attenuated inversion recovery relative signal intensity [FLAIR-rSI]) magnetic resonance imaging is associated with time elapsed since stroke onset with higher intensities signifying longer time intervals. In the randomized controlled WAKE-UP trial (Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke Trial), intravenous alteplase was effective in patients with unknown onset stroke selected by visual assessment of diffusion weighted imaging fluid-attenuated inversion recovery mismatch, that is, in those with no marked fluid-attenuated inversion recovery hyperintensity in the region of the acute diffusion weighted imaging lesion. In this post hoc analysis, we investigated whether quantitatively measured FLAIR-rSI modifies treatment effect of intravenous alteplase. Methods— FLAIR-rSI of stroke lesions was measured relative to signal intensity in a mirrored region in the contralesional hemisphere. The relationship between FLAIR-rSI and treatment effect on functional outcome assessed by the modified Rankin Scale (mRS) after 90 days was analyzed by binary logistic regression using different end points, that is, favorable outcome defined as mRS score of 0 to 1, independent outcome defined as mRS score of 0 to 2, ordinal analysis of mRS scores (shift analysis). All models were adjusted for National Institutes of Health Stroke Scale at symptom onset and stroke lesion volume. Results— FLAIR-rSI was successfully quantified in stroke lesions in 433 patients (86% of 503 patients included in WAKE-UP). Mean FLAIR-rSI was 1.06 (SD, 0.09). Interaction of FLAIR-rSI and treatment effect was not significant for mRS score of 0 to 1 ( P =0.169) and shift analysis ( P =0.086) but reached significance for mRS score of 0 to 2 ( P =0.004). We observed a smooth continuing trend of decreasing treatment effects in relation to clinical end points with increasing FLAIR-rSI. Conclusions— In patients in whom no marked parenchymal fluid-attenuated inversion recovery hyperintensity was detected by visual judgement in the WAKE-UP trial, higher FLAIR-rSI of diffusion weighted imaging lesions was associated with decreased treatment effects of intravenous thrombolysis. This parallels the known association of treatment effect and elapsing time of stroke onset