title: Prevalence and risk factors for multiple simultaneous intracerebral hemorrhages.
abstract: BACKGROUND
  Multiple simultaneous intracerebral hemorrhages (MSICH) are rare. We aimed to describe the frequency and potential risk factors for MSICH.
  
  
  METHODS
  We reviewed 522 consecutive patients admitted to our institution with spontaneous ICH between August 1, 2006 and November 30, 2009. Patients with traumatic hemorrhages, predominantly subarachnoid or intraventricular hemorrhages, hemorrhagic transformation of ischemic infarcts, and hemorrhages due to cerebral venous thrombosis were excluded. We defined MSICH as spontaneous hemorrhages in 2 discrete areas with similar density profiles on initial CT imaging. We then classified MSICH as primary (spontaneous) or secondary (due to an underlying condition). In a 1:5 ratio case-control design study, we assessed risk factors for primary MSICH compared to solitary ICH using logistic regression. Values of p < 0.05 were considered significant in the final analyses.
  
  
  RESULTS
  Of 522 ICH patients, 29 met the criteria for MSICH (5.6%) with a mean age of 59 years. The mean systolic blood pressure at presentation was 176 mm Hg. Fifteen cases had secondary causes while 14 were considered as having primary MSICH. In a multivariable model comparing primary MSICH cases to 70 solitary ICH controls, the presence of >5 chronic microhemorrhages on gradient echo imaging (adjusted OR 9.8, 95% CI 2.0-49.3, p = 0.006) was the only independent predictor of primary MSICH.
  
  
  CONCLUSIONS
  In a single-center experience, we found that MSICH account for 5.6% of all spontaneous ICH. Prior microhemorrhage burden, perhaps due to severity of hypertension or cerebral amyloid angiopathy, may mark those at risk for primary MSICH occurrence.
authors.affiliation: Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Stemer
authors.forename: Bichun
authors.initials: B
authors.lastname: Ouyang
authors.forename: Vivien H
authors.initials: VH
authors.lastname: Lee
authors.forename: Shyam
authors.initials: S
authors.lastname: Prabhakaran
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D016657:Cerebral Amyloid Angiopathy / Q000150:complications; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D055815:Young Adult