Transcranial Doppler Ultrasonography in Sickle Cell Disease

Abstract

Changes on Transcranial Doppler (TCD) ultrasonography have been proposed as significant predictors of cerebrovascular complications in sickle cell disease (SCD). However, consensus with regards to the TCD criteria to recognize abnormalities in cerebral vasculature is lacking. We studied the TCD characteristics of cerebral arteries among Omani patients with SCD and correlated them with cerebrovascular events. TCD was performed through the temporal and suboccipital windows using a 2 MHz probe (DWL). Thirty-three of 59 patients (56%) with SCD had neurological symptoms including stroke--12 (20%) and epilepsy--7. Fifteen patients (25%) had significant TCD abnormalities including: markedly increased velocities--11 (3 with stroke); turbulent flow--2; and reversal of flow--2. No patient had a time averaged maximum mean velocity of >200 cm/s in anterior circulation. On applying a modified definition of "abnormal TCD" to anterior and posterior circulation studies, increased TCD velocities in posterior circulation correlated with history of stroke (P < 0.05). TCD velocities in the 18 adult patients ( older than 15 y) were significantly lower than in children. Logistic regression analysis revealed abnormal TCD in the left posterior cerebral artery to be an independent predictor of stroke in this cohort (P = 0.035).

Transcranial Doppler Ultrasound in Peninsular Arab Patients With Sickle Cell Disease

“…This finding was consistent with the reported figures of approximately 1.0% for childhood stroke among patients with SCD and the AI haplotype . A previous study, from Oman, which included adult patients, reported stroke prevalence of 20% among its patients but did not indicate how many had the AI haplotype …”

“…Table shows reported transcranial Doppler values from the United States, France, Brazil, Tanzania, Nigeria, and Iran in which the proportions with abnormal values ranged from 1.6% to 20.7%. However, the 2 studies from the Arabian Peninsula (Oman and Kuwait) did not record any abnormal values, whereas the study from Iran reported 3% . The question therefore arises of whether the results from these countries could be reproduced among other Peninsular Arabs, and whether this variation is related to the β S haplotypes, HbF level, and hydroxyurea therapy or race/ethnicity.…”

Repeat transcranial Doppler ultrasound imaging in Kuwaiti children with sickle cell disease after a 10-year interval

“…This suggests low progression of cerebral vasculopathy among these patients. Interestingly, however, this sparing of the cerebral vessels is not only limited to patients with the AI haplotype, as reports from Oman 17,18 , Iran 15 and Iraq 16,19 , where this haplotype is not particularly common, also report relatively normal TCDI indices. Therefore, there may be other obscure factors in this population that protect them from neurological events.…”

Updating the role of transcranial Doppler in prediction and prevention of stroke in correlation to the regularity of blood transfusion in Egyptian children with sickle cell anemia

“…According to the frequency of blood transfusion, the right MCA (PSV), left DICA (PSV) & both DICA (TAmax) had a significant correlation with the frequency of blood transfusion, and this finding is in accordance with prior research. Abd-Allah et al [36] which showed that the annual frequency of blood transfusion and HU dose was associated with a decreased frequency of abnormal TCD findings, but is opposite to Bowman et al [37]; Gujjar et al [38] that had reported that The differences in Doppler velocities noted were not significantly different between patients who had been transfused within 3 months of examination, and those who had not received transfusions.…”