title: Diabetes, intracranial stenosis and microemboli in asymptomatic carotid stenosis.
abstract: BACKGROUND
  The risk of stroke in patients with asymptomatic carotid stenosis (ACS) is now so low that it is important to have methods to identify those patients most likely to benefit from intervention, or who may require special consideration in choice of medical therapy. We studied the prediction of stroke, death or transient ischemic attacks (stroke/death/TIA) in patients with ACS by intracranial arterial stenosis, and microemboli on transcranial Doppler (TCD), and the effect of diabetes mellitus on microemboli, intracranial stenosis and risk of events.
  
  
  METHODS
  Patients with ACS > 60% by Doppler ultrasound were recruited from the Stroke Prevention Clinic of University Hospital, London, Canada. All 339 participants underwent TCD for detection of intracranial stenosis and detection of microemboli, and carotid ultrasound to measure extracranial stenosis and total carotid plaque area. Participants were followed for three years, to determine the risk of stroke/death/TIA.
  
  
  RESULTS
  Stroke/death/TIA occurred in 38% of patients with microemboli versus 10% without (p=0.0001), and in 18% of patients with intracranial stenosis, versus 10% without (p=0.042). Diabetics were significantly more likely to have intracranial stenosis (45% vs. 29%, p =0.014), microemboli (38% vs. 10%, p <0.0001), and had significantly higher risk of stroke/death/TIA over three years (21% vs. 11% without; p=0.024). Survival free of stroke, TIA or death was significantly better without microemboli or intracranial stenosis (p<0.0001).
  
  
  CONCLUSIONS
  Diabetes, microemboli and intracranial stenosis predicted higher risk of stroke, death or TIA than did extracranial stenosis or total plaque area; diabetics may need more intensive therapy.
authors: Schulich School of Medicine and Dentistry, Stroke Prevention and Atherosclerosis Research Centre, University of Western Ontario, London, Canada.
authors: Thach D
authors: TD
authors: Lam
authors: Stephanie
authors: S
authors: Lammers
authors: Claudio
authors: C
authors: Munoz
authors: Arturo
authors: A
authors: Tamayo
authors: J David
authors: JD
authors: Spence
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D058070:Asymptomatic Diseases; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000401:mortality; D003251:Constriction, Pathologic / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000453:epidemiology; D003920:Diabetes Mellitus / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D004617:Embolism / Q000000981:diagnostic imaging / Q000453:epidemiology*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D017585:Ultrasonography, Doppler, Transcranial