Acute silent cerebral infarction in children with sickle cell anemia

Silent cerebral infarctions (SCI) occur in up to 35% of children with sickle cell anemia (HbSS) but are rarely recognized during the initial 10–14 days when diffusion weighted magnetic resonance imaging (MRI) can differentiate acute infarctions from remote events. We report acute SCI in seven children with HbSS who had areas of restricted diffusion on MRI without persistent focal neurologic deficits. Four had acute SCI identified following acute anemic events. Our observations suggest that SCI are detectible in the acute phase, present with subtle neurologic symptoms, result in permanent neurologic injury, and may be caused by acute anemic events. Pediatr Blood Cancer 2010;54:461–464. © 2009 Wiley‐Liss, Inc.     

Transcranial Doppler in hemoglobin SC disease

Background: Stroke is a severe clinical disorder in sickle cell disease (SCD), and few studies have evaluated transcranial Doppler (TCD) flow velocities in hemoglobin SC disease (HbSC). The guidelines for stroke risk are based on evaluations in sickle cell anemia (SCA) or HbS/β thalassemia. Procedure: In this study, we compare cerebral blood flow in patients with SCD stratified by genotypes. A total of 1,664 pediatric patients with SCD underwent TCD velocity screening, and the time‐averaged maximum mean velocity (TAMM) was determined in the middle cerebral artery (MCA), anterior cerebral artery (ACA), and distal intracranial internal carotid artery (ICA). Results: Abnormal velocities were not identified in the ACA; therefore, we only use ICA and MCA velocities. TAMM from the left and right in the ICA and MCA was 134.3 ± 32.0 and 134.4 ± 32.6 cm/s in patients with SCA, and 105.2 ± 20.6 and 104.7 ± 20.0 cm/s in the patients with HbSC, respectively. Mean TAMM between right and left ICA/MCA was 134.5 ± 30.5 cm/s in the SCA group, and 104.9 ± 19.3 cm/s in the HbSC group. Notably, our data show that TCD velocities were significantly lower among the patients with HbSC compared to SCA. TAMM was negatively correlated with hemoglobin and hematocrit in both genotypes. Conclusion: These results suggest that a different cut‐off value for abnormal TCD velocities could be considered for patients with HbSC. Additional studies are warranted to determine the actual risk of stroke in HbSC genotype associated with this possible TCD risk value.     

Advances in the management of sickle cell disease

This article summarizes my presentation at the Pediatric Hematology-Oncology Symposium in honor of Dr. Stephen A. Feig in April 2005. Areas highlighted reflect key topics whose evolution parallel and were impacted by Steve's exceptional academic career. It is by no means an exhaustive summation of all advances in the biology and treatment of sickle cell disease. The interested reader is encouraged to consider a number of well written recently published reviews that cover additional areas of scientific and medical advancement in the pathophysiology and care of sickle cell disease 1-5.     

Diverse manifestations of acute sickle cell hepatopathy in pediatric patients with sickle cell disease: A case series

The hepatic complications of sickle cell disease (SCD) are associated with increased morbidity and mortality in adults; children usually survive but may suffer significant sequelae. Few diagnostic tools differentiate the various hepatic manifestations of SCD. Why patients exhibit one hepatic pathology versus another is unclear. We report four pediatric patients with hemoglobin SS disease with diverse manifestations of acute hepatic involvement including acute sickle hepatic crisis, hepatic sequestration, sickle cell intrahepatic cholestasis, and a non‐SCD cause of hepatopathy in a patient with viral hepatitis. These complications require a systematic approach to extensive evaluation and coordinated multidisciplinary care.     

Cochlear implantation in children with sickle cell disease

Sickle cell disease (SCD) is associated with sensorineural hearing loss (SNHL). Although the hearing loss is usually mild, some develop severe‐to‐profound hearing loss, in whom cochlear implants (CI) may be an option. We present the cases of two children with SCD who developed bilateral severe‐to‐profound SNHL and underwent cochlear implantation. One patient became profoundly deaf after an acute episode of dizziness. Imaging indicated bilateral cochlear ossification, making subsequent cochlear implant surgery challenging. The second patient developed bilateral severe‐to‐profound SNHL following acute vaso‐occlusive crises. She went on to have uncomplicated cochlear implant surgery. These cases illustrate the variable manner in which children with SCD may develop SNHL, and the difficulties associated with managing such cases. We recommend that children with SCD should undergo regular audiological assessment. Furthermore, clinicians should be aware of the risk of cochlear fibrosis and ossification and ensure prompt assessment following an acute vaso‐occlusive crisis or unexplained vestibulocochlear event.