AUTHOR=Choi Hee Young , Lee Kyung Mi , Kim Hyug-Gi , Kim Eui Jong , Choi Woo Suk , Kim Bum Joon , Heo Sung Hyuk , Chang Dae-Il 

TITLE=Role of Hyperintense Acute Reperfusion Marker for Classifying the Stroke Etiology

JOURNAL=Frontiers in Neurology

VOLUME=Volume 8 - 2017

YEAR=2017

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2017.00630

DOI=10.3389/fneur.2017.00630

ISSN=1664-2295

ABSTRACT=Purpose: The hyperintense acute reperfusion marker (HARM) is a delayed enhancement of the subarachnoid or subpial space observed on post contrast FLAIR images, and is associated with permeability changes to the blood-brain barrier (BBB) in acute stroke. We investigated the relationship between HARM and stroke etiology based on the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. In addition, we evaluated the relationship between HARM and stroke locations with respect to vascular territories and anatomic compartments.
Materials and Methods: We recruited 264 consecutive patients (109 women; mean age 68.63 years) who were diagnosed with acute ischemic stroke and underwent brain MRI including post contrast FLAIR and DWI within 7 days of symptom onset from May 2015 to March 2016 for this retrospective study. Post contrast FLAIR images were obtained 5 minutes after gadolinium administration. The mean time interval between the onset of stroke symptoms and MRI acquisition in total included patients was 18 hours and 7 minutes (median 12 hour 57 minutes, range 2 to 309 hours). We analyzed the overall incidence and distribution patterns of HARM in acute ischemic stroke cases and compared the relative incidence and distribution patterns of HARM between the subgroups of stroke etiology based on conventional TOAST classification. We obtained odds ratio (OR) of HARM in different stroke locations based on vascular territories and anatomical compartments. This study was approved by our institutional review board.
Results: Among the 264 patients, 67 (25.38%) were HARM-positive and 197 (74.62%) were HARM-negative. There was significant difference in HARM incidence among the stroke subgroups (p<0.001). Small vessel occlusion was associated with the HARM-negative group (p<0.001), while large artery atherosclerosis (LAA) and cardioembolism (CE) were associated with the HARM-positive group (p=0.001). Also regional pattern of HARM on the same vascular territory as the acute infarction was dominantly demonstrated regardless of stroke etiology. The OR for HARM from MCA infarction was 1.868 (95% CI: 1.025–3.401). The OR for HARM from cortical infarction was 9.475 (95% CI: 4.754–18.883) compared with other anatomic compartments.
Conclusion: The presence of the HARM was significantly associated with embolic infarctions including LAA and CE. Conversely,