title: Clinical importance of microbleeds in patients receiving IV thrombolysis.
abstract: BACKGROUND
  Cerebral microbleeds (MBs) detected on gradient echo (GRE) imaging may be a risk factor for hemorrhagic complications in patients with stroke treated with IV tissue plasminogen activator (tPA).
  
  
  METHODS
  The authors prospectively evaluated patients with acute ischemic stroke treated with IV tPA between 3 and 6 hours of symptom onset. MRI scans, including GRE imaging, were performed prior to tPA treatment, 3 to 6 hours after treatment and at day 30. The authors compared the frequency of hemorrhagic complications after thrombolysis in patients with and without MBs on their baseline GRE imaging.
  
  
  RESULTS
  Seventy consecutive patients (mean age, 71 +/- 29 years; 31 men, 39 women) were included. MBs were identified in 11 patients (15.7%) on baseline GRE imaging. There was no significant difference in the frequency of either symptomatic or asymptomatic hemorrhagic complications after thrombolysis between patients with and without MBs at baseline. None of the 11 patients with MBs (0%) at baseline had a symptomatic intracerebral hemorrhage compared with 7 of 59 patients who did not have baseline MBs (11.9%). In addition, no patients with baseline MBs had asymptomatic hemorrhagic transformation observed at the site of any pre-treatment MB.
  
  
  CONCLUSIONS
  The presence of cerebral microbleeds on gradient echo imaging does not appear to substantially increase the risk of either symptomatic or asymptomatic brain hemorrhage following IV tissue plasminogen activator administered between 3 and 6 hours after stroke onset.
authors.affiliation: Stanford Stroke Center, Stanford University Medical Center, Palo Alto, CA, USA. wkakuda@stanford.edu
authors.forename: W
authors.initials: W
authors.lastname: Kakuda
authors.forename: V N
authors.initials: VN
authors.lastname: Thijs
authors.forename: M G
authors.initials: MG
authors.lastname: Lansberg
authors.forename: R
authors.initials: R
authors.lastname: Bammer
authors.forename: L
authors.initials: L
authors.lastname: Wechsler
authors.forename: S
authors.initials: S
authors.lastname: Kemp
authors.forename: M E
authors.initials: ME
authors.lastname: Moseley
authors.forename: M P
authors.initials: MP
authors.lastname: Marks
authors.forename: G W
authors.initials: GW
authors.lastname: Albers
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002536:Cerebral Arteries / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D002561:Cerebrovascular Disorders / Q000150:complications / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007049:Iatrogenic Disease / Q000517:prevention & control; D007260:Infusion Pumps / Q000009:adverse effects; D020300:Intracranial Hemorrhages / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008833:Microcirculation / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000150:complications / Q000188:drug therapy*; D015912:Thrombolytic Therapy / Q000009:adverse effects*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000009:adverse effects*
chemical_list: D010959:Tissue Plasminogen Activator