title: Left-sided strokes are more often recognized than right-sided strokes: the Rotterdam study.
abstract: OBJECTIVE
  Left-sided strokes are reported to be more common than right-sided strokes, but it is unknown whether they occur more often or are simply recognized more easily by clinicians. In a large unselected community-dwelling population, we examined the frequency of clinical left- and right-sided strokes and transient ischemic attacks (TIAs) and compared it with the frequency of left- and right-sided infarcts on MRI.
  
  
  METHODS
  This study was conducted within the population-based Rotterdam Study. Between 1990 and 2012, 13 894 participants were followed up for first-ever stroke and TIA. MRI scans were performed within a random subgroup of 5081 persons and were rated for the presence of supratentorial cortical and lacunar infarcts. We compared frequencies of left- and right-sided strokes, TIAs, or MRI infarcts using binomial and Fisher exact tests.
  
  
  RESULTS
  After a mean follow-up of 9.6 (±6.0) years, 1252 patients had a stroke, of which 704 were ischemic, and 799 participants had a TIA. Within the subgroup with MRI, we identified 673 infarcts. Ischemic strokes were more frequently left-sided (57.7%; 95% confidence interval, 53.7-61.6) than right-sided, similar to TIAs (57.8% left-sided; 53.4-62.3). In contrast, we found no left-right difference in distribution of infarcts on MRI (51.9% left-sided; 48.1-55.6).
  
  
  CONCLUSIONS
  Clinical ischemic strokes and TIAs are more frequently left-sided than right-sided, whereas this difference is not present for infarcts on MRI. This suggests that left-sided strokes and TIAs are more easily recognized. Consequently, there should be more attention for symptoms of right-sided strokes and TIAs.
authors.affiliation: From the Department of Epidemiology (M.L.P.P., M.S., A.H., M.W.V., M.A.I.), Neurology (M.L.P.P., P.J.K., M.A.I.), Biomedical Engineering (M.S.), and Radiology (M.S., M.W.V.), Erasmus MC University Medical Center, Rotterdam, The Netherlands.
authors.forename: Marileen L P
authors.initials: ML
authors.lastname: Portegies
authors.affiliation: From the Department of Epidemiology (M.L.P.P., M.S., A.H., M.W.V., M.A.I.), Neurology (M.L.P.P., P.J.K., M.A.I.), Biomedical Engineering (M.S.), and Radiology (M.S., M.W.V.), Erasmus MC University Medical Center, Rotterdam, The Netherlands.
authors.forename: Mariana
authors.initials: M
authors.lastname: Selwaness
authors.affiliation: From the Department of Epidemiology (M.L.P.P., M.S., A.H., M.W.V., M.A.I.), Neurology (M.L.P.P., P.J.K., M.A.I.), Biomedical Engineering (M.S.), and Radiology (M.S., M.W.V.), Erasmus MC University Medical Center, Rotterdam, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: From the Department of Epidemiology (M.L.P.P., M.S., A.H., M.W.V., M.A.I.), Neurology (M.L.P.P., P.J.K., M.A.I.), Biomedical Engineering (M.S.), and Radiology (M.S., M.W.V.), Erasmus MC University Medical Center, Rotterdam, The Netherlands.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Koudstaal
authors.affiliation: From the Department of Epidemiology (M.L.P.P., M.S., A.H., M.W.V., M.A.I.), Neurology (M.L.P.P., P.J.K., M.A.I.), Biomedical Engineering (M.S.), and Radiology (M.S., M.W.V.), Erasmus MC University Medical Center, Rotterdam, The Netherlands.
authors.forename: Meike W
authors.initials: MW
authors.lastname: Vernooij
authors.affiliation: From the Department of Epidemiology (M.L.P.P., M.S., A.H., M.W.V., M.A.I.), Neurology (M.L.P.P., P.J.K., M.A.I.), Biomedical Engineering (M.S.), and Radiology (M.S., M.W.V.), Erasmus MC University Medical Center, Rotterdam, The Netherlands. m.a.ikram@erasmusmc.nl.
authors.forename: M Arfan
authors.initials: MA
authors.lastname: Ikram
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D002545:Brain Ischemia / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D007839:Functional Laterality; D006801:Humans; D002546:Ischemic Attack, Transient / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology
keywords: epidemiology; magnetic resonance imaging; stroke