title: Cerebral microbleeds are a risk factor for warfarin-related intracerebral hemorrhage.
abstract: BACKGROUND
  Cerebral microbleeds are known to be indicative of bleeding-prone microangiopathy and may predict incident intracerebral hemorrhage (ICH). In this study, we investigated whether microbleeds are associated with the incidence of warfarin-related ICH.
  
  
  METHODS
  Twenty-four patients with ICH while on outpatient treatment with warfarin were selected from a consecutive cohort. Control, warfarin-using subjects with no history of ICH were randomly selected during the same time period (n = 48). We compared demographic factors, vascular risk factors, laboratory findings, and radiologic findings including microbleeds between the groups.
  
  
  RESULTS
  There were more cases of patients with microbleeds in the ICH than control group (79.2% vs 22.9%: p < 0.001), and the number of microbleeds was much higher for the ICH group (9.0 +/- 26.8 vs 0.5 +/- 1.03: p < 0.001). Moreover, the number of microbleeds was significantly correlated with the presence of warfarin-related ICH (r = 0.299; p < 0.001). Conditional logistic regression analysis showed that increased prothrombin time and the presence of microbleeds were independently related to the incidence of warfarin-related ICH (microbleeds: adjusted OR, 83.12).
  
  
  CONCLUSIONS
  This study suggests that underlying microbleeds are independently associated with an incidence of warfarin-related intracerebral hemorrhage. Future research should focus on elucidating the risks and benefits of warfarin medication in patients with microbleeds.
authors.affiliation: Department of Neurology, Seoul National University Hospital, Jongno-Gu, Seoul, Republic of Korea.
authors.forename: Seung-Hoon
authors.initials: SH
authors.lastname: Lee
authors.forename: Wi-Sun
authors.initials: WS
authors.lastname: Ryu
authors.forename: Jae-Kyu
authors.initials: JK
authors.lastname: Roh
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects*; D001160:Arterioles / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D001921:Brain / Q000098:blood supply / Q000473:pathology; D002536:Cerebral Arteries / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D002543:Cerebral Hemorrhage / Q000139:chemically induced* / Q000453:epidemiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D015994:Incidence; D020767:Intracranial Thrombosis / Q000188:drug therapy*; D008297:Male; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology; D008875:Middle Aged; D011517:Prothrombin Time; D012307:Risk Factors; D014859:Warfarin / Q000009:adverse effects*
chemical_list: D000925:Anticoagulants; D014859:Warfarin