title: Ischemic involvement of the primary motor cortex is a prognostic factor in acute stroke.
abstract: BACKGROUND
  The location of the primary motor cortex can be detected in healthy adults using the findings of 'T2 hypointensity' and the 'double layer sign' on 3 T diffusion-weighted imaging. The aim of this study was to assess whether ischemic involvement of the primary motor cortex can be identified on 3 T diffusion-weighted imaging within six-hours after stroke onset and to evaluate whether this finding could predict clinical outcome three-months after ischemic stroke.
  
  
  METHODS
  Sixty-five patients who had paralysis and ischemia of the anterior circulation underwent 3 T magnetic resonance imaging within six-hours of symptom onset. Follow-up MRI was obtained at 72 h. Anatomic localization and ischemic involvement of the primary motor cortex were evaluated on diffusion-weighted imaging by two investigators. Ischemic involvement on the primary motor cortex was classified into three grades. Ischemic lesion volumes were measured. We compared the favorable outcomes at three-months between subjects with and without ischemic involvement on the primary motor cortex using the NIHSS and modified Rankin Scale.
  
  
  RESULTS
  Ischemic involvement on the primary motor cortex was identified in 52% of patients. Interrater agreement coefficients were 0·93 for the identification of ischemic involvement of primary motor cortex. As defined by scores on the modified Rankin Scale, among the patients with ischemic involvement of the primary motor cortex were worse than the patients without ischemic involvement of the primary motor cortex (P = 0·01). The mean ischemic lesion volume at baseline diffusion-weighted imaging was 38·7 ± 41·7 cm(3) and was 89·8 ± 93·6 cm(3) at follow-up T2-WI. Ischemic involvement on the primary motor cortex (odds ratio: 14·7) was a determinant for worse outcome.
  
  
  CONCLUSIONS
  3T diffusion-weighted imaging can identify ischemic involvement on the primary motor cortex and may provide useful information for predicting outcome during the hyperacute stage. Ischemic involvement on the primary motor cortex has a significant negative impact on recovery.
authors.affiliation: Department of Neurology, Acibadem University School of Medicine, Istanbul, Turkey.
authors.forename: Dilaver
authors.initials: D
authors.lastname: Kaya
authors.affiliation: Department of Radiology, Acibadem University School of Medicine, Istanbul, Turkey.
authors.forename: Alp
authors.initials: A
authors.lastname: Dincer
authors.affiliation: Department of Neurology, Acibadem University School of Medicine, Istanbul, Turkey.
authors.forename: Fehim
authors.initials: F
authors.lastname: Arman
authors.affiliation: Department of Public Health, Acibadem University School of Medicine, Istanbul, Turkey.
authors.forename: Nadi
authors.initials: N
authors.lastname: Bakirci
authors.affiliation: Department of Radiology, Acibadem University School of Medicine, Istanbul, Turkey.
authors.forename: Canan
authors.initials: C
authors.lastname: Erzen
authors.affiliation: Departments of Neurosurgery, Acibadem University School of Medicine, Istanbul, Turkey.
authors.forename: M Necmettin
authors.initials: MN
authors.lastname: Pamir
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis / Q000473:pathology / Q000628:therapy; D002533:Cerebral Angiography; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D018810:Magnetic Resonance Angiography; D008297:Male; D009044:Motor Cortex / Q000473:pathology*; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis* / Q000473:pathology* / Q000628:therapy; D016896:Treatment Outcome