clinicaltrials.gov Identifier: NCT01382862.

No abstract

The data suggest that prehospital stroke care in STEMO is feasible. No safety concerns have been raised so far. This new approach using prehospital tPA may be effective in reducing call-to-needle times, but this is currently being scrutinized in a prospective controlled study.

Background and Purpose-It has recently been proposed that fluid-attenuated inversion recovery (FLAIR) imaging may serve as a surrogate marker for time of symptom onset after stroke. We assessed the hypothesis that FLAIR imaging could be used to decide if an MRI was performed within 4.5 hours from symptom onset or later. Methods-All consecutive patients with presumed stroke who underwent an MRI within 12 hours after known symptom onset were included regardless of stroke subtype and severity between May 2008 and May 2009. Blinded to time of symptom onset, 2 raters judged the visibility of lesions on FLAIR. Apparent diffusion coefficient values, lesion volume on diffusion-weighted imaging, and relative signal intensity of FLAIR lesions were determined. Results-In 94 consecutive patients with stroke, we found that median time from symptom onset for FLAIR-positive patients (189 minutes; interquartile range, 110 to 369 minutes) was significantly longer compared with FLAIR-negative patients (103 minutes; interquartile range, 75 to 183 minutes; Pϭ0.011). Negative FLAIR had a sensitivity of 46% and a specificity of 79% for allocating patients to a time window of less than 4.5 hours. FLAIR positivity increased with diffusion-weighted imaging lesion volume (PϽ0.001) but showed no correlation with apparent diffusion coefficient values (Pϭ0.795). There was no significant correlation between relative signal intensity and time from symptom onset (Spearman correlation coefficient Ϫ0.152, Pϭ0.128). Key Words: MRI Ⅲ stroke Ⅲ time from symptom onset S troke is a leading cause of death and disability. 1 Approximately one fourth of patients with ischemic stroke become aware of their neurological deficits on awakening. 2 Current guidelines for intravenous thrombolytic therapies exclude patients with unknown time of symptom onset and only allow for the inclusion of patients within 4.5 hours. 3 However, a recent Korean study suggested that thrombolysis may be safely applied in patients with unknown-onset stroke who fulfilled certain MRI-specific eligibility criteria such as a positive perfusion-diffusion mismatch and absence of well-developed fluid-attenuated inversion recovery (FLAIR) changes of acute diffusion lesions. 4 Although diffusionweighted imaging (DWI) alone allows for the detection of acute ischemic lesions within minutes of stroke onset, 5 it does not offer exact information on the age of these lesions within the first 12 hours. Assessment of signal changes on FLAIR images in areas with diffusion restriction may provide an estimate of ischemic lesion age. 6 Most previous studies have focused on the evolution of FLAIR imaging in the subacute and chronic time window. 7 One recent study showed that a "mismatch" between a positive DWI and a negative FLAIR might allow for the identification of patients who are highly likely to be within the 3-hour time window from stroke symptom onset. 8 The primary aim of this study was to determine whether FLAIR imaging could be used to decide if an MRI was performed within 4.5 hours f...

No abstract