Variations in transcranial doppler among pediatric patients with sickle cell disease in the Brazilian Northeast: a cross-sectional study

BACKGROUND: Stroke, the most severe neurological complication of sickle cell disease, can result in irreversible sequelae and death. Transcranial Doppler combined with periodic blood transfusions reduces the chances of stroke by 90 %. In Brazil, transcranial Doppler coverage for children is low (around 20 %). This study aimed to analyze the velocity of cerebral blood flow in pediatric patients using transcranial Doppler. METHODS: This cross-sectional study analyzed 42 patients with sickle cell disease aged between 2 and 18 years who underwent transcranial Doppler following the Stroke Prevention Trial in Sickle Cell Anemia protocol. The time-averaged maximum mean velocities of the internal carotid and middle cerebral arteries were analyzed, considering biological, sociodemographic, and clinical factors. RESULTS: The predominant genotype was hemoglobin SS, and the median age was 10 years (interquartile range: 7-13). Of the total, 42.9 % had never undergone the exam; 7.1 % had a history of stroke with a 66.7 % recurrence rate. Regarding transcranial Doppler, 83 % of patients had normal velocity, 2.4 % abnormal, 2.4 % conditional, 9.5 % low, and 2.4 % had inconclusive results. Higher time-averaged maximum mean velocities were observed in younger patients (r = -0.48; p-value = 0.001), in those with lower levels of hemoglobin (r = -0.37; p-value = 0.024), and with higher leukocyte counts (r = 0.33; p-value = 0.050). Stroke was associated with abnormal transcranial Doppler results (p-value < 0.001). CONCLUSION: Despite recommendations, primary stroke prevention is not yet effectively implemented in the northeast of Brazil, as evidenced by low transcranial Doppler screening rates and the high incidence of stroke in the study population.