title: Timing of Incident Stroke Risk After Cervical Artery Dissection Presenting Without Ischemia.
abstract: Cervical artery dissection is a common cause of stroke in young people. The temporal profile of stroke risk after cervical artery dissection presenting without ischemia remains uncertain.
  
  
  
  We performed a crossover cohort study using administrative claims data on all emergency department visits and acute care hospitalizations from 2005 to 2011 in CA, 2006 to 2013 in NY, and 2005 to 2013 in FL. Using previously validatedInternational Classification of Diseases, Ninth Revision, Clinical Modificationcodes, we identified patients with a cervical artery dissection and no previous or concurrent stroke or transient ischemic attack diagnosis. We compared the risk of stroke in successive 2-week periods during the 12 weeks after dissection versus the corresponding 2-week period 1 year later. Absolute risk increases were calculated using McNemar test for matched data. In a sensitivity analysis, we limited our population to patients presenting with typical symptoms of cervical artery dissection.
  
  
  
  We identified 2791 patients with dissection without ischemia. The absolute increase in stroke risk was 1.25% (95% confidence interval, 0.84-1.67%) in the first 2 weeks after dissection compared with the same time period 1 year later. The absolute risk increase was 0.18% (95% confidence interval, 0.02-0.34%) during weeks 3 to 4 and was no longer significant during the remainder of the 12-week postdissection period. Our findings were similar in a sensitivity analysis identifying patients who presented with typical symptoms of acute dissection.
  
  
  
  The risk of stroke after cervical artery dissection unaccompanied by ischemia at time of diagnosis seems to be limited to the first 2 weeks.
authors.affiliation: From the Clinical and Translational Neuroscience Unit, Feil Family Brain and Mind Research Institute (N.A.M., A.E.M., G.G., H.K.) and Department of Neurology (A.E.M., H.K.), Weill Cornell Medicine, New York, NY; and Department of Neurology, Columbia University Medical Center, New York, NY (N.A.M.).
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Morris
authors.affiliation: From the Clinical and Translational Neuroscience Unit, Feil Family Brain and Mind Research Institute (N.A.M., A.E.M., G.G., H.K.) and Department of Neurology (A.E.M., H.K.), Weill Cornell Medicine, New York, NY; and Department of Neurology, Columbia University Medical Center, New York, NY (N.A.M.). alm9097@med.cornell.edu.
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Merkler
authors.affiliation: From the Clinical and Translational Neuroscience Unit, Feil Family Brain and Mind Research Institute (N.A.M., A.E.M., G.G., H.K.) and Department of Neurology (A.E.M., H.K.), Weill Cornell Medicine, New York, NY; and Department of Neurology, Columbia University Medical Center, New York, NY (N.A.M.).
authors.forename: Gino
authors.initials: G
authors.lastname: Gialdini
authors.affiliation: From the Clinical and Translational Neuroscience Unit, Feil Family Brain and Mind Research Institute (N.A.M., A.E.M., G.G., H.K.) and Department of Neurology (A.E.M., H.K.), Weill Cornell Medicine, New York, NY; and Department of Neurology, Columbia University Medical Center, New York, NY (N.A.M.).
authors.forename: Hooman
authors.initials: H
authors.lastname: Kamel
mesh_terms: D000328:Adult; D000368:Aged; D020215:Carotid Artery, Internal, Dissection / Q000453:epidemiology*; D015331:Cohort Studies; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012306:Risk; D020521:Stroke / Q000453:epidemiology*; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D020217:Vertebral Artery Dissection / Q000453:epidemiology*
keywords: dissection; hospitalization; risk; stroke; vertebral artery dissection