title: Minor stroke with total mismatch after acute MCA occlusion.
abstract: BACKGROUND
  Recently, "total mismatch," negative diffusion-weighted imaging (DWI) and extensive perfusion defects were introduced and described as having a favorable outcome after intravenous thrombolysis. We sought to determine the clinical characteristics of patients with total mismatch and describe their clinical courses.
  
  
  METHODS
  We retrospectively analyzed subjects from the stroke registry of acute ischemic stroke patients between August 2008 and October 2009. The patients with the following characteristics were included: acute ischemic stroke within 6 hours of symptom onset, a large artery occlusion in the anterior circulation and a negative DWI but large perfusion-weighted imaging (PWI) lesion on mean transit time maps. According to our stroke imaging protocol, the patients underwent emergent MR imaging immediately after admission and follow-up imaging within 96 hours of symptom onset.
  
  
  RESULTS
  Four patients were identified as suitable for the imaging criteria (negative DWI and MTT delay) of this study. All patients presented with a spontaneous recovery of ischemic symptoms related to the middle cerebral artery occlusion had a potential source of cardioembolism and eventually developed new lesions on follow-up DWI and recanalization without thrombolysis.
  
  
  CONCLUSIONS
  In our study, total mismatch seems to suggest favorable outcome after recanalization, regardless of thrombolysis. Further attention should be focused on the considerable variations in PWI and DWI findings in acute stroke.
authors.affiliation: Department of Neurology, Cerebrovascular Center, Chonnam National University Hospital, Gwangju, Korea. alldelight2@jnu.ac.kr
authors.forename: Joon-Tae
authors.initials: JT
authors.lastname: Kim
authors.forename: Man-Seok
authors.initials: MS
authors.lastname: Park
authors.forename: Myeong-Kyu
authors.initials: MK
authors.lastname: Kim
authors.forename: Ki-Hyun
authors.initials: KH
authors.lastname: Cho
mesh_terms: D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology*; D008297:Male; D020768:Middle Cerebral Artery / Q000473:pathology*; D012189:Retrospective Studies; D020521:Stroke / Q000473:pathology*