title: Stroke risk of asymptomatic intra- and extracranial large-artery disease in apparently healthy adults.
abstract: BACKGROUND
  The predictive value of asymptomatic intracranial artery stenosis for future stroke remains uncertain. The aim of this study is to assess the stroke risk of asymptomatic intracranial artery stenosis and to compare it with that of extracranial artery disease.
  
  
  METHODS
  The study subjects were 2,924 participants (mean age 55 years) without any history of stroke. We examined the relation between intra- or extracranial large-artery disease and subsequent cerebrovascular events (mean follow-up 63 months).
  
  
  RESULTS
  The incidence rate of total cerebrovascular events in persons with intracranial artery stenosis was 1.3% per year. In the group without plaque in the extracranial carotid arteries, the annual rate of total cerebrovascular events was only 0.6%, but in the group with plaque, the rate was 3.6%. Kaplan-Meier analysis of total events showed a significant difference between the 2 groups (p = 0.002).
  
  
  CONCLUSIONS
  The stroke risk in subjects with asymptomatic extracranial artery disease is markedly increased if intracranial artery stenosis is also present.
authors.affiliation: Department of Neurology, Tokai University School of Medicine, Kanagawa, Japan. kawasi29@is.icc.u-tokai.ac.jp
authors.forename: Wakoh
authors.initials: W
authors.lastname: Takahashi
authors.forename: Tomohide
authors.initials: T
authors.lastname: Ohnuki
authors.forename: Michiru
authors.initials: M
authors.lastname: Ide
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Takagi
authors.forename: Yukito
authors.initials: Y
authors.lastname: Shinohara
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D002342:Carotid Artery, External / Q000000981:diagnostic imaging*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D020765:Intracranial Arterial Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D020521:Stroke / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D014463:Ultrasonography