title: Preexisting cerebral microbleeds on susceptibility-weighted magnetic resonance imaging and post-thrombolysis bleeding risk in 392 patients.
abstract: OBJECTIVE
  The question whether cerebral microbleeds (CMBs) visible on MRI in acute stroke increase the risk for intracerebral hemorrhages (ICHs) or worse outcome after thrombolysis is unresolved. The aim of this study was to analyze the impact of CMB detected with pretreatment susceptibility-weighted MRI on ICH occurrence and outcome.
  
  
  METHODS
  From 2010 to 2013 we treated 724 patients with intravenous thrombolysis, endovascular therapy, or intravenous thrombolysis followed by endovascular therapy. A total of 392 of the 724 patients were examined with susceptibility-weighted MRI before treatment. CMBs were rated retrospectively. Multivariable regression analysis was used to determine the impact of CMB on ICH and outcome.
  
  
  RESULTS
  Of 392 patients, 174 were treated with intravenous thrombolysis, 150 with endovascular therapy, and 68 with intravenous thrombolysis followed by endovascular therapy. CMBs were detected in 79 (20.2%) patients. Symptomatic ICH occurred in 21 (5.4%) and asymptomatic in 75 (19.1%) patients, thereof 61 (15.6%) bleedings within and 35 (8.9%) outside the infarct. Neither the existence of CMB, their burden, predominant location nor their presumed pathogenesis influenced the risk for symptomatic or asymptomatic ICH. A higher CMB burden marginally increased the risk for ICH outside the infarct (P=0.048; odds ratio, 1.004; 95% confidence interval, 1.000-1.008).
  
  
  CONCLUSIONS
  CMB detected on pretreatment susceptibility-weighted MRI did not increase the risk for ICH or worsen outcome, even when CMB burden, predominant location, or presumed pathogenesis was considered. There was only a small increased risk for ICH outside the infarct with increasing CMB burden that does not advise against thrombolysis in such patients.
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
authors.forename: Pascal P
authors.initials: PP
authors.lastname: Gratz
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
authors.forename: Marwan
authors.initials: M
authors.lastname: El-Koussy
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
authors.forename: Kety
authors.initials: K
authors.lastname: Hsieh
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: von Arx
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
authors.forename: Marie-Luise
authors.initials: ML
authors.lastname: Mono
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
authors.forename: Mirjam Rachel
authors.initials: MR
authors.lastname: Heldner
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
authors.forename: Urs
authors.initials: U
authors.lastname: Fischer
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland. heinrich.mattle@insel.ch.
authors.forename: Heinrich P
authors.initials: HP
authors.lastname: Mattle
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Zubler
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schroth
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
authors.forename: Jan
authors.initials: J
authors.lastname: Gralla
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
authors.forename: Marcel
authors.initials: M
authors.lastname: Arnold
authors.affiliation: From the Department of Diagnostic and Interventional Neuroradiology (P.P.G., M.E.-K., K.H., C.Z., G.S., J.G., S.J.) and Department of Neurology (S.v.A., M.-L.M., M.R.H., U.F., H.P.M., M.A., S.J.), Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Jung
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000628:therapy; D015912:Thrombolytic Therapy / Q000009:adverse effects*
keywords: mechanical thrombolysis; outcome assessment