Abstract W MP23: About 30% of Wake-up Stroke Patients May be Candidate for the tPA Therapy Using Negative-FLAIR as a Tissue Clock

Abstract

Background and Purpose: Most of the wake-up stroke (WUS) patients cannot be treated using intravenous thrombolysis (tPA) because of unknown onset time. Recent magnetic resonance imaging (MRI) studies reported that WUS patients may be the candidates for tPA therapy when showing no ischemia on the fluid-attenuated inversion recovery (negative-FLAIR), because negative FLAIR indicates the stroke onset to be within 4.5 h. The aim of the present study is 1) to investigate the frequency of WUS and the clinical and MRI findings of the WUS patients, and 2) calculate how many WUS patients with negative-FLAIR met the tPA criteria except the time parameter. Methods: Consecutive acute stroke patients with anterior-circulation within 12 of onset were enrolled. All patients were examined using diffusion-weighted imaging (DWI), and FLAIR on admission. WUS was defined as stroke on awaking. Neurological severity was assessed using the National Institutes of Health Stroke Scale (NIHSS) score. As a large infarction that is excluded from tPA therapy, the DWI-the Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) of ≤3 was defined. Result: A total of 619 consecutive patients were included in the study. The number of the WUS patients (WUS group) was 117 (19%), and the other (non-WUS group) was 502 (81%). Median NIHSS score on admission was 9 (interquartile range, 3-17) in the WUS group and 8 (3-16) in the non-WUS group (p=0.339). DWI-ASPECTS was similar between the WUS and the non-WUS groups (9 [7-10] vs. 9 [6-10], p=0.994). The number of patients treated using tPA was significantly smaller in WUS group compared to the non-WUS group (3 [3%] vs. 140 [28%], p<0.001). MRI study revealed that negative-FLAIR was seen in 50 (43%) of the 117 patients in the WUS group. Of the 50 patients with negative-FLAIR, 16 patients were excluded from the tPA therapy, the large infarction (6), platelet count <100,000 /mm (2), INR >1.7 (1), recent operation (1), and high blood pressure greater than 185/110 mmHg (6). Therefore, 34 (29%) of the 117 wake-up stroke patients met the tPA criteria. Conclusion: About 30% of the WUS patients may be candidate for the tPA therapy using the negative-FLAIR findings.