title: Cortex-sparing infarctions in patients with occlusion of the middle cerebral artery.
abstract: BACKGROUND
  In patients with a middle cerebral artery (MCA) occlusion, the involvement of the cortex may be affected by the presence of leptomeningeal anastomoses between the cerebral arteries.
  
  
  METHODS
  The authors enrolled consecutive patients with acute infarctions in the MCA territory and MCA occlusion on angiographic studies. Infarct patterns were classified into three categories based on the extent of cortical surface involvement: total cortex (TC), partial cortex (PC) and no cortex (NC). The authors analysed the infarction patterns by stroke subtype, and investigated factors that resulted in cortex sparing.
  
  
  RESULTS
  Out of 73 total patients, cortex-sparing infarctions were seen in 53 patients (72.6%, NC in 39 (53.5%) and PC in 14 (19.1%)). The extent of cortical involvement differed according to stroke subtype (p=0.036). TC was more frequent (42.9% vs 22.2%), and PC was less frequent (10.7% vs 27.9%, p=0.037) in cardioembolism than large-artery atherosclerosis. However, the proportion of patients with complete cortical sparing (NC) was similar between cardioembolism and large-artery atherosclerosis (46.4% vs 49.9%). In the upstream of leptomeningeal collateral arteries, the extent of cortical involvement was associated with significant stenosis of the ipsilateral anterior or posterior cerebral artery (p=0.011).
  
  
  CONCLUSIONS
  This study suggests that pre-existing arteriolar connections, which may cover almost entire cortical surfaces of the MCA territory, exist in many patients. The findings also suggest that the extent of cortical involvement is different between stroke subtypes, and is critically affected by the status of upstream collateral arteries.
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Han Jin
authors.initials: HJ
authors.lastname: Cho
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Yang
authors.forename: Yo Han
authors.initials: YH
authors.lastname: Jung
authors.forename: Young Dae
authors.initials: YD
authors.lastname: Kim
authors.forename: Hye-Yeon
authors.initials: HY
authors.lastname: Choi
authors.forename: Hyo Suk
authors.initials: HS
authors.lastname: Nam
authors.forename: Ji Hoe
authors.initials: JH
authors.lastname: Heo
mesh_terms: D000367:Age Factors; D000368:Aged; D001157:Arterial Occlusive Diseases / Q000473:pathology*; D050197:Atherosclerosis / Q000150:complications; D002545:Brain Ischemia / Q000150:complications / Q000473:pathology; D002536:Cerebral Arteries / Q000473:pathology; D002540:Cerebral Cortex / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D004617:Embolism / Q000150:complications; D005260:Female; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000145:classification / Q000209:etiology / Q000473:pathology; D015912:Thrombolytic Therapy