Transcranial Doppler Findings Among Gulf Arabs

Background: Transcranial Doppler (TCD) is used to identify patients with sickle cell disease (SCD) at risk for stroke. We have carried out TCD studies in patients from 4 countries in the Arabian Peninsula (Kuwait, Oman, Southern Iraq and UAE) to document the prevalence of abnormal TCD findings.

Methodology: The patients were recruited from outpatient clinics and studied in steady state. TCD was performed using standard equipment with experienced operators. Time-averaged mean of maximum velocity (TAMMV) was documented in the arteries of the Circle of Willis. The hemoglobin (Hb) genotype was confirmed and the fetal Hb (HbF) level and complete blood counts were determined.

Results: There were 415 patients in the study, aged 2 to 18 years (mean of 8.6±3.5). None of the patients had abnormal TAMMV (i.e. >200 cm/sec), while only 13 (3.1%), all from Iraq had conditional values in the right middle cerebral artery (MCA) and 7 (1.7%) in the left MCA. There were no significant gender differences, and both the Hb genotype (SS, Sβ⁰thal or SD) and the use of hydroxyurea did not show consistent influence on TAMMV. Total hemoglobin, reticulocyte count, serum bilirubin and HbF showed varying degrees of association with TAMMV in the different vessels.

Conclusions: This study has demonstrated the rarity of abnormal TCD findings among Peninsular Arab patients with SCD. This might be related to the haplotype, elevated HbF or may represent a racial variation. The guidelines for TCD screening in this population need further studies and recommendations.