title: Extracranial internal carotid arterial disease in children with sickle cell anemia.
abstract: BACKGROUND
  Sickle cell anemia is one of the commonest causes of stroke in children. It is usually, but not always, associated with intracranial vasculopathy. We have assessed the value of ultrasound screening for extracranial internal carotid artery disease.
  
  
  METHODS
  Using Doppler ultrasound scanning, we assessed peak systolic blood velocity, tortuosity and stenosis in the extracranial internal carotid arteries of 236 children with sickle cell anemia. Seventeen of the children had previously had a stroke. All measurements were performed as part of routine clinical care.
  
  
  RESULTS
  The median extracranial internal carotid artery velocity was 148cm/s (5(th) centile 84, 95(th) centile 236). Higher velocities were significantly correlated with younger age, higher white blood cell counts and higher rates of hemolysis. Fourteen (5.9%) had tortuous extracranial internal carotid arteries and 13 (5.4%) had stenosis or occlusion. None of the children with tortuous vessels but 8 of those with stenosis had previously had a stroke; the presence of stenosis was strongly associated with overt clinical stroke (OR 35.9, 95% C.I. 9.77-132, P<0.001). In 6 children, extracranial stenosis was part of extensive intracranial vasculopathy, but in 2 there was no evidence of intracranial disease. Stenosis seemed to be more common in older children.
  
  
  CONCLUSIONS
  Extracranial internal carotid artery stenosis is strongly associated with stroke in children with sickle cell anemia, and may explain some cases of stroke without overt intracranial vasculopathy. Doppler ultrasound scanning of extracranial internal carotid arteries is non-invasive and fairly quick to perform and may identify children at increased risk of stroke who would otherwise be missed. The value of extracranial internal carotid artery scanning should be studied prospectively.
authors.affiliation: Department of Paediatric Haematology, King's College London, School of Medicine, King's College Hospital, Denmark Hill, London SE5 9RS, UK.
authors.forename: Colin R
authors.initials: CR
authors.lastname: Deane
authors.forename: David
authors.initials: D
authors.lastname: Goss
authors.forename: Jack
authors.initials: J
authors.lastname: Bartram
authors.forename: Keith R E
authors.initials: KR
authors.lastname: Pohl
authors.forename: Susan E
authors.initials: SE
authors.lastname: Height
authors.forename: Naomi
authors.initials: N
authors.lastname: Sibtain
authors.forename: Jozef
authors.initials: J
authors.lastname: Jarosz
authors.forename: Swee Lay
authors.initials: SL
authors.lastname: Thein
authors.forename: David C
authors.initials: DC
authors.lastname: Rees
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000150:complications*; D001783:Blood Flow Velocity; D002340:Carotid Artery Diseases / Q000150:complications / Q000175:diagnosis*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016893:Carotid Stenosis / Q000150:complications / Q000175:diagnosis; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D020521:Stroke / Q000150:complications; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*