These results, therefore, should not be used to determine stroke risk, and repeated examinations Inhibitor Library order should be performed when the patient is stable. It is essential to use educational

intervention to target parents and caregivers as well as children about the importance of conducting systematic TCD examinations. The use of criteria other than ICA/MCA was analyzed in some studies; however, there is no consensus that allows us to recommend chronic transfusion. Nevertheless, we suggest attentiveness to changes in other arteries and a thorough understanding of “individual risk” thereby reducing the need for numerous exam repetitions. Children with abnormal ICA/MCA velocities and elevated anterior cerebral artery (ACA) velocities presented a risk of stroke more than twice that of those with abnormal ICA/MCA but normal ACA velocity [19]. There are similar findings with the basilar artery, vertebral, PCA and OA when compared with the ICA/MCA,

high throughput screening however, the recommendations must be more uniform. Although in the majority of cases, velocities could go back to a normal range (MCA TAMMX < 170 cm/s) after a period of 30 months or longer, discontinuation can result in a high rate of reversion to abnormal blood-flow velocities on the TCD or even in stroke. The STOP II study concluded that we must maintain chronic transfusion indefinitely [17] and [18]. Other treatment regimens are now being tested [20]. TCD screening rates in children with SCD have increased after the publication of the STOP trial, and medical providers may be targeting those children at the highest stroke risk. Prospective follow-up of a larger sample will be required to assess the impact of this screening on stroke rates. TCD screening

itself only stratifies stroke risk, but does not prevent stroke; stroke prevention depends on the implementation of Casein kinase 1 chronic transfusion therapy. However, access to vascular laboratories appears to be a barrier to the implementation of this highly effective stroke prevention strategy, even among children with comprehensive health insurance. The main problems are difficulties in performing the examination, differences in imaging and nonimaging techniques, and interpretation of guidelines. The identification of sickle cell vasculopathy by MRI, MRA, and MR diffusion imaging has increased our understanding of sickle cell lesions. Silent infarction incidence could be as high as 17% and carries a risk of future infarctions as well [21]. The etiology of silent infarctions, however, remains unresolved, and the implications for preventive therapy continue to be studied. At present, we should attempt to increase the availability of TCD screening by physician training and TCD machine access in the locations of disease prevalence.