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Updated: Mar 18, 2026
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Transcranial Doppler Screening in a Regional Care Network for Sickle Cell Disease in the United Kingdom
Paul Telfer1, Kerry Dwan, Andrea Simmons
1*Center for Genomics and Child Health, Barts and The London School of Medicine, London †Liverpool Reviews and Implementation Group, University of Liverpool, Liverpool Departments of ‡Pediatrics §Neuroradiology, Royal London Hospital, Barts Health NHS Trust, London ∥Department of Pediatrics, Newham University Hospital, Barts Health NHS Trust, London ¶Newham Sickle Cell and Thalassemia Community Centre, London #Department of Pediatrics, Whipps Cross University Hospital, Barts Health NHS Trust, London **Department of Pediatrics, Basildon University Hospital NHS Trust, Basildon, Essex ††Department of Hematology, Queens Hospital, Romford NHS Trust, Romford, Essex, UK.
Insights
Transcranial Doppler ultrasound screening identifies a higher proportion of children at high risk for stroke than previously estimated. This screening can help identify children who may benefit from early intervention to prevent acute ischemic stroke.
Area of Science:
- Pediatric Neurology
- Neuroimaging
- Cerebrovascular Disease
Background:
- The prevalence and risk of stroke in children undergoing transcranial Doppler (TCD) ultrasound screening in the UK remain largely unknown.
- Previous stroke risk assessment protocols may not fully capture the spectrum of risk in pediatric populations.
- Accurate identification of high-risk children is crucial for timely intervention and stroke prevention.
Purpose of the Study:
- To evaluate a clinician-led TCD ultrasound screening program in children using a modified STOP protocol.
- To determine the proportion of children classified as high-risk for stroke based on specific velocity criteria.
- To estimate the incidence of acute ischemic stroke (AIS) and acute hemorrhagic stroke in the screened cohort.
Main Methods:
- A cohort of 542 children underwent 1653 TCD ultrasound scans over 2235 patient-years.
- A modified STOP protocol was used for risk assessment, including abnormal velocities in the anterior cerebral artery and specific criteria for high-risk classification.
- Follow-up data were collected to identify stroke events.
Main Results:
- Fifty-eight children (10.7%) were identified as high-risk, with a significant proportion having high abnormal velocities or prior conditional scans.
- Abnormal velocities were occasionally restricted to the anterior cerebral artery.
- The incidence rates for all stroke, AIS, and acute hemorrhagic stroke were 0.27, 0.18, and 0.09 per 100 patient-years, respectively. Approximately 2 children per 1000 screened developed AIS.
Conclusions:
- The modified risk assessment identified a higher proportion of high-risk children compared to previous estimates.
- TCD ultrasound screening, particularly in children under six, can identify a substantial number of high-risk individuals.
- The findings support the utility of TCD ultrasound screening in pediatric stroke prevention, with a low incidence of AIS in the screened population.
Abstract:
The risk of stroke in children screened with transcranial Doppler ultrasound in the United Kingdom is not known. We evaluated a clinician-led program using a risk assessment modified from the STOP protocol. High-risk classification included abnormal velocities in the anterior cerebral artery, and single abnormal scan if initial velocity >220 cm/s (high abnormal) or if preceded by at least 2 conditional scans. In total, 1653 scans were performed in 542 children, followed for 2235 patient-years. Fifty-eight (10.7%) high-risk subjects were identified, including 18 (31%) with high abnormal, and 15 (26%) with previous conditional scans. In 2 (3%), abnormal velocity was restricted to the anterior cerebral artery. The estimated proportion of children at high risk, scanned before 6 years of age was >20%. There were 4 cases of acute ischemic stroke (AIS) and 2 of acute hemorrhagic stroke. The incidence of all stroke, AIS, and acute hemorrhagic stroke were 0.27, 0.18, and 0.09 per 100 patient-years, respectively. The proportion of children at high risk is higher than most previous estimates, partly as a result of our modified risk assessment. About 2 children per 1000 screened with transcranial Doppler ultrasound progress to AIS.
