Wake-Up Stroke and Stroke of Unknown Onset: A Critical Review

Wouters, Anke; Lemmens, Robin; Dupont, Patrick; Thijs, Vincent

doi:10.3389/fneur.2014.00153

Cited by 66 publications

(47 citation statements)

References 70 publications

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“…It has been shown previously that differences in study populations could lead to high variability in the accuracy of DWI/ FLAIR mismatch in relationship to time. 21 In other studies, the sensitivity of DWI/FLAIR mismatch prediction of stroke onset before 4.5 hours ranges from 0.38 to 0.79, while the specificity ranges from 0.78 to 0.96. 3,[22][23][24][25] For example with every 10 mL increase in diffusion volume, the odds to find a FLAIR-positive lesion increases with 7%.…”

Section: Discussionmentioning

confidence: 98%

Association between the Perfusion/Diffusion and Diffusion/FLAIR Mismatch: Data from the AXIS2 Trial

Wouters

Dupont

Ringelstein

et al. 2015

J Cereb Blood Flow Metab

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The perfusion-/diffusion-weighted imaging (PWI/DWI) mismatch and the diffusion/fluid attenuated inversion recovery (DWI/FLAIR) mismatch are magnetic resonance imaging (MRI) markers of evolving brain ischemia. We examined whether the DWI/FLAIR mismatch was independently associated with the PWI/DWI mismatch. Furthermore, we determined whether the presence of the DWI/FLAIR mismatch in patients with the PWI/DWI mismatch would provide additional information regarding last seen normal time (LTM). We used data from the 'AX200 for ischemic stroke' trial (AXIS 2 study NCT00927836). We studied the association between the presence of the DWI/FLAIR and PWI/DWI mismatch, baseline National Institute of Health Stroke Scale (NIHSS), age, ischemic-core volume, gender, intravenous (IV) tissue plasminogen activator (tPA), and perfusion-mismatch volume in univariate analysis. Significant variables (P<0.05) were added into the final multivariate model. We analyzed 197 patients. Seventy-two (37%) had both the PWI/DWI and the DWI/FLAIR mismatch. Patients with the double mismatch pattern had a shorter LTM than patients with the PWI/DWI mismatch alone (Median difference 90 minutes, P<0.01). Multivariate analysis confirmed the independent association between the two mismatch patterns (odds ratio (OR) 2.6, 95% confidence interval (CI) 1.2 to 5.4). Our study implies that the DWI/FLAIR mismatch and PWI/DWI mismatch are strongly associated, independent from LTM. Furthermore, in the presence of the PWI/DWI mismatch, the DWI/FLAIR pattern indicates a shorter LTM. This could have implications in selecting patients for reperfusion therapy.

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Section: Discussionmentioning

confidence: 98%

Association between the Perfusion/Diffusion and Diffusion/FLAIR Mismatch: Data from the AXIS2 Trial

Wouters

Dupont

Ringelstein

et al. 2015

J Cereb Blood Flow Metab

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“…1 Tissue-clock biomarkers are, thus, needed for stroke with unknown onset time in which penumbra salvage may improve clinical outcome. 2 Diffusionweighted imaging (DWI)/fluid-attenuated inversion recovery (FLAIR) mismatch has been proposed for magnetic resonance imaging (MRI) estimation of lesion age in acute stroke 3 but still presents some drawbacks. [4][5][6][7][8] To circumvent the subjectivity of the visual rating of images using this method, different approaches have been proposed with conflicting results, 4,6,[8][9][10][11][12] and further studies are needed to verify their utility.…”

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confidence: 99%

Does b1000–b0 Mismatch Challenge Diffusion-Weighted Imaging–Fluid Attenuated Inversion Recovery Mismatch in Stroke?

Geraldo¹,

Berner²,

Haesebaert³

et al. 2016

Stroke

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Background and Purpose-Our aim was to explore whether the mismatch in lesion visibility between b1000 and b0 images is an alternative to mismatch between diffusion-weighted imaging and fluid-attenuated inversion recovery imaging as a surrogate marker of stroke age. Methods-We analyzed patients from the European multicenter I-KNOW database. Independent readers assessed the visibility of ischemic lesions of the anterior circulation on b0 and fluid-attenuated inversion recovery imaging images. The signal-intensity ratio for b0 and fluid-attenuated inversion recovery imaging images was also measured from the segmented stroke lesion volume on b1000 images. Results-This study included 112 patients (68 men; mean age, 67.4 years) with stroke onset within (n=85) or longer than (n=27) 4.5 hours. b1000-b0 mismatch identified patients within 4.

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“…6,7 Minutes after stroke onset cytotoxic edema can already develop causing a net decrease in water diffusion as visualized by an increased signal on diffusion-weighted imaging (DWI). Hours after stroke onset vasogenic edema gradually appears, causing a visible hyperintensity on fluid attenuated inversion recovery (FLAIR) imaging.…”

Section: Introductionmentioning

confidence: 99%

“…11–14 The sensitivity and specificity of the DWI/FLAIR mismatch vary between studies with sensitivity ranging between 40 and 80% and specificity between 78 and 89%. 7 These differences can be explained by various factors, e.g. variation in imaging techniques used to assess the mismatch or size of the diffusion lesions 11 , but other pathophysiological variables influencing the intensity of the FLAIR lesion have not been extensively studied.…”

Section: Introductionmentioning

confidence: 99%

Association Between Time From Stroke Onset and Fluid-Attenuated Inversion Recovery Lesion Intensity Is Modified by Status of Collateral Circulation

Wouters

Dupont

Christensen

et al. 2016

Stroke

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Background and Purpose In acute stroke patients the intensity of a fluid attenuated inversion recovery (FLAIR) lesion in the region of diffusion restriction is associated with time from symptom onset. We hypothesized that collateral status, as assessed by the hypoperfusion intensity ratio (HIR) could modify the association between time from stroke onset and FLAIR lesion intensity. Methods From the ‘AX200 for ischemic stroke trial’ 141 patients had appropriate FLAIR, diffusion (DWI) and perfusion (PWI) images. In the region of non-reperfused core we calculated voxel based relative FLAIR signal intensity (rFLAIR SI). The HIR was defined as the ratio of the Tmax >10 s lesion over the Tmax > 6 s lesion volume. A HIR-threshold of ≤ 0.4 was used to dichotomize good versus poor collaterals. We studied the interaction between collateral status on the association between time from symptom onset and FLAIR intensity. Results Time from symptom onset was associated with the relative FLAIR intensity in the region of non-reperfused core (B=1.05; 95%CI: 1.0-1.1). We identified an interaction between this association and collateral status; an association was present between time and rFLAIR intensity in patients with poor collaterals (r = 0.53), but absent in patients with good collaterals (r = 0.17, p=0.04). Conclusions Our findings show that the relationship between time from symptom onset and rFLAIR lesion intensity depends on collateral status. In patients with good collaterals the development of a rFLAIR positive lesion is less dependent on time from symptom onset compared to patients with poor collaterals.

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Wake-Up Stroke and Stroke of Unknown Onset: A Critical Review

Cited by 66 publications

References 70 publications

Association between the Perfusion/Diffusion and Diffusion/FLAIR Mismatch: Data from the AXIS2 Trial

Association between the Perfusion/Diffusion and Diffusion/FLAIR Mismatch: Data from the AXIS2 Trial

Does b1000–b0 Mismatch Challenge Diffusion-Weighted Imaging–Fluid Attenuated Inversion Recovery Mismatch in Stroke?

Association Between Time From Stroke Onset and Fluid-Attenuated Inversion Recovery Lesion Intensity Is Modified by Status of Collateral Circulation

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