Related Experiment Video
Updated: May 22, 2026
Analysis of Cerebral Vasospasm in a Murine Model of Subarachnoid Hemorrhage with High Frequency Transcranial Duplex Ultrasound
Published on: June 3, 2021
Transcranial Doppler Ultrasound Velocity Measurements in Children With Sickle Cell Disease in Kenya
Catherine Mwalimu1,2, Oscar Odhiambo3,4, Elaine Mashisia3
1Department of Paediatrics and Child Health Aga Khan University Hospital Nairobi Kenya.
Insights
Sickle cell disease (SCD) screening using transcranial Doppler (TCD) showed low abnormal velocities in children on hydroxyurea. Normal TCD values in healthy children provide local reference data for stroke risk assessment.
Area of Science:
- Neurology
- Pediatrics
- Hematology
Background:
- Sickle cell disease (SCD) is a prevalent inherited blood disorder in Sub-Saharan Africa.
- Children with SCD face a high risk of ischemic stroke.
- Transcranial Doppler (TCD) ultrasonography is crucial for identifying children at elevated stroke risk.
Purpose of the Study:
- To determine the prevalence of abnormal cerebral blood flow velocity (CBFV) in children with SCD.
- To describe CBFV in children without SCD for comparison.
Main Methods:
- A two-component study involving retrospective TCD data review and a cross-sectional assessment.
- TCD measurements were analyzed in 143 children with SCD (aged 2-16) and 17 children without SCD (aged 3-11).
- Standardized middle cerebral artery (MCA) TCD assessments were performed and velocities categorized.
Main Results:
- Among 143 children with SCD on hydroxyurea, 1.4% had high TCD velocities (≥200 cm/s) and 4.9% had low velocities (<50 cm/s).
- TCD velocities showed no association with demographic, clinical characteristics, or hemoglobin levels.
- In children without SCD, MCA velocities were normal (50-149 cm/s), age-dependent, and symmetrical.
Conclusions:
- Abnormal TCD velocities were infrequent in children with SCD receiving hydroxyurea.
- Normal MCA velocities in children without SCD establish local reference values.
- CBFV variability underscores the need for continued annual TCD screening for accurate stroke-risk classification.
Background:
Sickle cell disease (SCD) is the most common inherited haemoglobinopathy and poses a high public health burden in Sub-Saharan Africa. Children with sickle cell anaemia are at a highrisk of ischemic stroke, and transcranial Doppler (TCD) ultrasonography helps identify those at highest risk for primary stroke prevention.
Objective:
To determine the prevalence of abnormal cerebral blood flow velocity (CBFV) in children with SCD and describe CBFV in children without SCD.
Methods:
We conducted a two-component study comprising a retrospective review and a cross-sectional assessment. TCD measurements from 143 children with confirmed SCD aged 2-16 years were reviewed. In a cross-sectional arm, children without SCD aged 3-11 years (n = 17) underwent standardized middle cerebral artery (MCA) TCD assessment. TCD velocities were categorized using standard criteria and analysed descriptively.
Results:
Among 143 children screened, all of whom were receiving hydroxyurea, 1.4% had high TCD velocities (≥ 200 cm/s), while 4.9% had low velocities (< 50 cm/s). TCD velocities were not associated with demographic/clinical characteristics or haemoglobin levels. Symmetric MCA flows with wide depth and velocity range variability were observed. In children without SCD, all MCA velocities were within the normal range (50-149 cm/s), showed right-left symmetry, declined with age, and were broadly similar by gender.
Conclusion:
The prevalence of abnormal TCD velocities was low in children with SCD receiving universal hydroxyurea. In children without SCD, MCA velocities were normal and declined with age, providing local reference values. The observed variability in CBFV supports continued annual TCD screening and repeat scans to confirm stroke-risk classification.
Trial Registration:
The authors have confirmed clinical trial registration is not needed for this submission.
