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Stroke prevention in sickle cell disease (STOP) study guidelines for transcranial Doppler testing
F T Nichols1, A M Jones, R J Adams
1Department of Neurology/BP 3147, Medical College of Georgia, Augusta, GA 30912, USA. fnichols@neuro.mcg.edu
Insights
The Stroke Prevention in Sickle Cell Disease (STOP) trial demonstrated that transcranial Doppler (TCD) screening identified children with sickle cell disease at high risk for stroke. Transfusion significantly reduced stroke incidence compared to standard care.
Area of Science:
- Neurology
- Pediatrics
- Hematology
Background:
- Sickle cell disease (SCD) is a genetic blood disorder associated with a high risk of stroke in children.
- Transcranial Doppler (TCD) ultrasound is a non-invasive tool used to assess cerebral blood flow velocities.
- The Stroke Prevention in Sickle Cell Disease (STOP) trial investigated the efficacy of TCD screening in preventing strokes.
Purpose of the Study:
- To detail the TCD scanning and reading protocols used in the STOP trial.
- To explain the measurement and significance of time-averaged mean of the maximum (TAMM) velocities.
- To provide guidance for appropriate application of STOP TCD data.
Main Methods:
- Children with SCD and no history of stroke underwent TCD screening.
- Children with elevated TAMM velocities in specific cerebral arteries were randomized to either transfusion or standard care.
- Follow-up data on stroke incidence were collected and analyzed.
Main Results:
- The standard care arm experienced 11 strokes over an average follow-up of 20 months.
- The transfusion arm experienced only 1 stroke during the same period.
- This highlights a significant reduction in stroke risk with transfusion therapy.
Conclusions:
- TCD screening is effective in identifying children with SCD at high risk for stroke.
- Prophylactic transfusions significantly decrease stroke incidence in these high-risk children.
- Understanding the STOP TCD methodology is crucial for accurate interpretation and application of screening results.
Abstract:
The Stroke Prevention in Sickle Cell Disease (STOP) trial used transcranial Doppler (TCD) to screen children with sickle cell disease with no history of stroke. Children (who consented) who had time-averaged mean of the maximum (TAMM) velocities in the middle cerebral artery and/or distal internal carotid artery were randomized to transfusion or standard. Over a slightly more than 20-month average follow-up, there were 11 strokes in the standard care arm and 1 stroke in the transfusion arm. This study has caused a great deal of interest in using TCD to screen children with sickle cell disease. For the STOP TCD data to be applied appropriately, it is necessary for users of TCD to understand how the STOP TCD examinations were performed, how the TCD velocities were measured, and which velocities were used. This article will review the STOP TCD scanning protocol and the reading protocol and review the TAMM velocity and how it differs from other velocity measurements.
