Is There a Difference in the Effect of Thrombolytic Therapy according to the Presence of Diffusion-Weighted Imaging (DWI)-Fluid Attenuated Inversion Recovery (FLAIR) Mismatching in Patients with Acute Ischemic Stroke?

ABSTRACT

PURPOSE: We performed this study to investigate whether there is difference in the effect of intravenous (IV) thrombolysis according to the presence of diffusion-weighted imaging- fluid-attenuated inversion recovery (DWI-FLAIR) mismatch among acute ischemic stroke patients who visited the emergency department (ED) within 3 hours from the onset of symptom. METHODS: Among ED patients presenting with an acute ischemic stroke between January 2011 and May 2013, those who underwent MRI and received IV thrombolytic therapy were included in this retrospective study. Patients were divided into DWI-FLAIR mismatch and match groups and compared for their initial NIHSS (National Institutes of Health Stroke Scale), NIHSS 24-hour after the thrombolytic therapy, NIHSS on discharge, early neurologic improvement (ENI), and major neurologic improvement (MNI). RESULTS: During study period, 50 patients were finally included among 213 acute ischemic stroke patients. DWI-FLAIR mismatch group showed significantly more reduction in NIHSS 24-hour after the thrombolytic therapy and NIHSS on discharge than the match group (5.5 vs. 1.2, p<0.001, 6.0 vs. 2.3, p<0.01, respectively). Moreover, ENI and MNI occurred significantly more in DWI-FLAIR mismatch group than match group (27/36 vs. 2/14, p<0.001, 12/36 vs. 0/14, p=0.012, respectively). CONCLUSION: Among acute ischemic stroke patients who visited ED within 3 hours from the onset of symptom, those patients who had DWI-FLAIR mismatch on MRI showed significantly better response to IV thrombolytic therapy than DWI-FLAIR match group in terms of neurologic outcome.