title: Characteristics of subcortical infarction due to distal MCA penetrating artery occlusion.
abstract: OBJECTIVE
  Isolated deep subcortical infarcts develop as a result of occlusion of the penetrating arteries from the internal carotid artery (ICA) and the proximal (M1) and distal middle cerebral artery (MCA). However, the clinical and neuroimaging characteristics of infarcts due to the occlusion of the distal MCA penetrating artery are unclear.
  
  
  METHODS
  Consecutive patients with ischemic stroke or transient ischemic attack with magnetic resonance imaging (MRI) performed within 2days of onset were studied retrospectively. Using coronal MRI data, isolated deep subcortical infarcts were classified into two groups: 1) proximal group, described as being longer than they are wide, which were expected to be related to the occlusion of the ICA or M1 penetrating artery; and 2) distal group, described as oblong, which were expected to be associated with the occlusion of penetrating arteries from the distal MCA (M2/M3/M4).
  
  
  RESULTS
  A total of 653 consecutive acute ischemic stroke patients (proximal group, 50 [7.7%]; distal group, 14 [2.1%]) were enrolled. Baseline clinical characteristics were not different between the 2 groups. Modified Rankin Scale scores were lower in the distal group than in the proximal group 3months after stroke onset (1.43±0.36 vs. 2.26±1.35, p=0.023). We measured the lengths of the infarcts in the X and Y directions using axial MRI. The X/Y ratio was larger in the distal group than in the proximal group (1.3±0.6 vs. 0.7±0.2, p<0.01), which indicated that distal MCA penetrating artery infarcts appear more oblong on axial MRI.
  
  
  CONCLUSIONS
  One cause for deep subcortical infarction is the occlusion of the distal MCA penetrating arteries, which occurs in 22% of patients with deep subcortical infarctions. These patients had better clinical outcomes than those with ICA and M1 penetrating artery infarctions. Distal MCA penetrating artery infarctions appear oblong on axial MRI.
authors.affiliation: Department of Neurological Science, Nippon Medical School Hospital, Tokyo, Japan. Electronic address: kentarow@nms.ac.jp.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Neurological Science, Nippon Medical School Hospital, Tokyo, Japan.
authors.forename: Junya
authors.initials: J
authors.lastname: Aoki
authors.affiliation: Department of Neurosurgery, Institute of Brain and Blood Vessels, Mihara Memorial Hospital, Gunma, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Tanizaki
authors.affiliation: Department of Neurological Science, Nippon Medical School Hospital, Tokyo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sakamoto
authors.affiliation: Department of Neurosurgery, Keio University, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Department of Neurological Science, Nippon Medical School Hospital, Tokyo, Japan.
authors.forename: Arata
authors.initials: A
authors.lastname: Abe
authors.affiliation: Department of Neurology, Institute of Brain and Blood Vessels, Mihara Memorial Hospital, Gunma, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kimura
authors.affiliation: Department of Neurosurgery, Institute of Brain and Blood Vessels, Mihara Memorial Hospital, Gunma, Japan.
authors.forename: Tadashige
authors.initials: T
authors.lastname: Kano
authors.affiliation: Department of Neurological Science, Nippon Medical School Hospital, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Suda
authors.affiliation: Department of Neurological Science, Nippon Medical School Hospital, Tokyo, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nishiyama
authors.affiliation: Department of Neurosurgery, Institute of Brain and Blood Vessels, Mihara Memorial Hospital, Gunma, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Akaji
authors.affiliation: Department of Neurology, Institute of Brain and Blood Vessels, Mihara Memorial Hospital, Gunma, Japan.
authors.forename: Ban
authors.initials: B
authors.lastname: Mihara
authors.affiliation: Department of Neurological Science, Nippon Medical School Hospital, Tokyo, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Kimura
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000150:complications* / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D016896:Treatment Outcome
keywords: Clinical outcome; Diffusion-weighted imaging; Infarct evolution; Ischemic stroke