Article |
1 Vascular Laboratory, Kings College Hospital NHS Foundation Trust, London, UK
2 Department of Paediatric Haematology, Kings College London School of Medicine, Kings College Hospital NHS Foundation Trust, London, UK
3 Department of Paediatric Neurology, Evelina Childrens Hospital, Guys and StThomas NHS Foundation Trust, London, UK
4 Department of Neuroradiology, Kings College Hospital NHS Foundation Trust, London, UK
5 Department of Haematology, Kings College London School of Medicine, Kings College Hospital NHS Foundation Trust, London, UK
Correspondence: David Rees, Department of Paediatric Haematology, Kings College London School of Medicine, Kings College Hospital, Denmark Hill, London, SE5 9RS. Phone: international +44.203.2993242. Fax: international +44.203.2994068. E-mail: david.rees2{at}nhs.net
ABSTRACT
Background: Sickle cell anemia (SCA) 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 (ICA) disease.
Design and Method: Using Doppler ultrasound scanning, we assessed peak systolic blood velocity, tortuosity and stenosis in the extracranial ICAs of 236 children with SCA. 17 of the children had previously had a stroke. All measurements were performed as part of routine clinical care.
Results: The median extracranial ICA velocity in was 148cm/s (5th centile 84, 95th centile 236). Higher velocities were significantly correlated with younger age, higher white blood cell counts and higher rates of hemolysis. 14 (5.9%) had tortuous extracranial ICAs 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 ICA stenosis is strongly associated with stroke in children with SCA, and may explain some cases of stroke without overt intracranial vasculopathy. Doppler ultrasound scanning of extracranial ICAs 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 ICA scanning should be studied prospectively.