title: Cannabis, ischemic stroke, and transient ischemic attack: a case-control study.
abstract: OBJECTIVE
  There is a temporal relationship between cannabis use and stroke in case series and population-based studies.
  
  
  METHODS
  Consecutive stroke patients, aged 18 to 55 years, who had urine screens for cannabis were compared with a cohort of control patients admitted to hospital without cardiovascular or neurological diagnoses.
  
  
  RESULTS
  One hundred sixty of 218 (73%) ischemic stroke/transient ischemic attack patients had urine drug screens (100 men; mean [SD] age, 44.8 [8.7] years). Twenty-five (15.6%) patients had positive cannabis drug screens. These patients were more likely to be men (84% versus 59%; χ2: P=0.016) and tobacco smokers (88% versus 28%; χ2: P<0.001). Control urine samples were obtained from 160 patients matched for age, sex, and ethnicity. Thirteen (8.1%) control participants tested positive for cannabis. In a logistic regression analysis adjusted for age, sex, and ethnicity, cannabis use was associated with increased risk of ischemic stroke/transient ischemic attack (odds ratio, 2.30; 95% confidence interval, 1.08-5.08). However after adjusting for tobacco use, an association independent of tobacco could not be confirmed (odds ratio, 1.59; 95% confidence interval, 0.71-3.70).
  
  
  CONCLUSIONS
  This study provides evidence of an association between a cannabis lifestyle that includes tobacco and ischemic stroke. Further research is required to clarify whether there is an association between cannabis and stroke independent of tobacco.
  
  
  BACKGROUND
  http://www.anzctr.org.au. Unique identifier: ACTRN12610000198022.
authors.affiliation: Department of Neurology, Auckland City Hospital, Auckland, New Zealand. a.barber@auckland.ac.nz
authors.forename: Peter Alan
authors.initials: PA
authors.lastname: Barber
authors.forename: Heidi M
authors.initials: HM
authors.lastname: Pridmore
authors.forename: Venkatesh
authors.initials: V
authors.lastname: Krishnamurthy
authors.forename: Sally
authors.initials: S
authors.lastname: Roberts
authors.forename: David A
authors.initials: DA
authors.lastname: Spriggs
authors.forename: Kristie N
authors.initials: KN
authors.lastname: Carter
authors.forename: Neil E
authors.initials: NE
authors.lastname: Anderson
mesh_terms: D000293:Adolescent; D000328:Adult; D002545:Brain Ischemia / Q000453:epidemiology* / Q000652:urine; D002188:Cannabis / Q000009:adverse effects*; D016022:Case-Control Studies; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000453:epidemiology / Q000652:urine; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D020521:Stroke / Q000453:epidemiology* / Q000652:urine; D019966:Substance-Related Disorders / Q000453:epidemiology* / Q000652:urine; D055815:Young Adult; D062789:Tobacco Products
keywords: cannabis; drug abuse; ischemic stroke; transient ischemic attack