Prevalence of transcranial Doppler abnormalities in Nigerian children with sickle cell disease.

Transcranial Doppler (TCD) ultrasonography helps to identify children with sickle cell disease (SCD) who are at an increased risk of stroke,making primary stroke prevention a reality. A cross-sectional study of145 Nigerian children aged ≥3 years with SCD was carried out to describe the pattern of cerebral blood flow (CBF) abnormalities. The mean time-averaged mean velocity (TAMV) was 152 ±27.0 cm/sec and122 ±22.0 cm/sec in Hb SS and Hb S1C group, respectively. Abnormal velocities were recorded in six (4.7%) of the Hb SS patients and none of the Hb S1C while conditional risk (CR) velocities were recorded in 19.7% of Hb SS (low conditional 11.0%, high conditional 8.7%) and low conditional in 5.6% of Hb S1C cases. Cerebral flow velocities showed a negative correlation with age and hematocrit. Compared with African-American children, Nigerian children with Hb SS disease have a considerably higher prevalence of CR velocities.