Transcranial color Doppler in stroke-free adult patients with sickle cell disease

The threshold velocity ≥200 cm/s at transcranial Doppler (TCD) evaluation is a useful cut-off for preventing the stroke (STOP trial) in pediatric patients with sickle cell disease (SCD), term including different types of sickle genotypes. Scanty data are available for adult SCD patients. We compared intracranial blood flow velocities between adult SCD patients and controls using transcranial color Doppler (TCCD), measuring the peak of systolic velocity (PSV) with the insonation angle correction and the pulsatility index (PI), an indicator of endothelial elasticity. Fifty-three adult SCD patients (aged >18 years) were enrolled (15 sickle cell anemia, 26 sickle cell thalassemia, and 12 HbS/HbC). None of the patients presented neurological signs. PSVs in middle cerebral artery (MCA) were higher in SCD patients than in controls (p = 0.001). In sickle cell anemia patients, PSVs were higher when compared to HbS/βThal (p < 0.0060) and HbS/HbC patients (p < 0.0139). PI was within the lower range of normality in SCD patients compared to controls. Moreover, MCA-PSV was higher with lower Hb levels and higher HbS%; PI did not change with variation of Hb levels and HbS%.

PSV and PI in SCD adult patients could be a relevant index to indicate the abnormal cerebral blood flow and to detect the sickle endothelial damage, in order to prevent cerebrovascular accidents.