title: Old microbleeds are a potential risk factor for cerebral bleeding after ischemic stroke: a gradient-echo T2*-weighted brain MRI study.
abstract: OBJECTIVE
  T2*-weighted gradient-echo MRI is known to detect old microbleeds (MBs), considered indicative of microangiopathy. MBs might be a potential risk factor for early cerebral bleeding (CB) after ischemic stroke. Therefore, we assessed the impact of MBs on the occurrence of CB after cerebral infarction.
  
  
  METHODS
  We included prospectively stroke patients who had documented ischemic damage. The imaging protocol involved baseline CT scan, T2*-weighted gradient-echo MRI, diffusion-weighted imaging, T2-weighted imaging, and magnetic resonance angiography and had to be performed within 24 hours after symptom onset. The assessment of CB with T2*-weighted gradient-echo sequence necessitated a focal area of signal loss either within the ischemic area revealed by diffusion-weighted imaging or remote from it. Old MBs were defined on T2*-weighted images as homogeneous rounded areas of signal loss without surrounding edema. CT scan was systematically repeated within the first week to verify CB as diagnosed by the T2* weighted sequence.
  
  
  RESULTS
  One hundred patients (mean age, 60 +/- 13 years; range, 19 to 83 years; 58 men, 42 women) met the inclusion criteria. MBs were seen in 20 patients on T2*-weighted imaging. Multivariate logistic regression analysis revealed that age, diabetes, previous use of antithrombotic drugs, evidence of an atherothrombotic source of stroke, and lacunar infarct were significantly associated with MBs (P<0.0001). CB was diagnosed in 26 patients: at the acute stage by T2*-gradient echo sequence in 18 patients and with CT scan performed within the first week in 8 patients. Multivariate logistic regression analysis showed that baseline National Institutes of Health Stroke Scale score, diabetes, and MBs were considered significant and independent predictors of CB (P<0.001).
  
  
  CONCLUSIONS
  Although the pathogenesis of CB after ischemic stroke is multifactorial, the increased observation of CB in patients with MBs suggests that the associated vascular vulnerability contributes to CB.
authors.affiliation: Cerebrovascular Disease Center, and CREATIS UMR CNRS 5515, Lyon, France. norbert.nighoghossian@chu-lyon.fr
authors.forename: N
authors.initials: N
authors.lastname: Nighoghossian
authors.forename: M
authors.initials: M
authors.lastname: Hermier
authors.forename: P
authors.initials: P
authors.lastname: Adeleine
authors.forename: K
authors.initials: K
authors.lastname: Blanc-Lasserre
authors.forename: L
authors.initials: L
authors.lastname: Derex
authors.forename: J
authors.initials: J
authors.lastname: Honnorat
authors.forename: F
authors.initials: F
authors.lastname: Philippeau
authors.forename: J F
authors.initials: JF
authors.lastname: Dugor
authors.forename: J C
authors.initials: JC
authors.lastname: Froment
authors.forename: P
authors.initials: P
authors.lastname: Trouillas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging; D002545:Brain Ischemia / Q000150:complications* / Q000175:diagnosis*; D002543:Cerebral Hemorrhage / Q000175:diagnosis* / Q000209:etiology*; D002560:Cerebrovascular Circulation; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D016015:Logistic Models; D018810:Magnetic Resonance Angiography; D008297:Male; D008833:Microcirculation / Q000000981:diagnostic imaging; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D014057:Tomography, X-Ray Computed