Acute silent cerebral ischemia and infarction during acute anemia in children with and without sickle cell disease

Abstract

We hypothesized that the silent cerebral infarcts (SCI), which affect up to 40% of children with sickle cell disease (SCD), could occur in the setting of acute anemic events. In a prospective observational study of children with and without SCD hospitalized for an illness associated with acute anemia, we identified acute silent cerebral ischemic events (ASCIE) in 4 (18.2%) of 22 with SCD and in 2 (6.7%) of 30 without SCD, using diffusion-weighted magnetic resonance imaging. Children with ASCIE had lower hemoglobin concentration than those without (median 3.1 vs 4.4 g/dL, P = .003). The unique temporal features of stroke on diffusion-weighted magnetic resonance imaging permit estimation of incidence rates for ASCIE of 421 (95% confidence interval, 155-920) per 100 patient-years during acute anemic events for all patients. For children with SCD, the estimated incidence was 663 (95% confidence interval, 182-1707) which is much higher than previously reported. Acute anemic events are common in children with SCD and prevalence could partially account for the high SCI. Some ASCIE (1 of 4 in our study) may be reversible. Alterations in management may be warranted for children with severe anemia to identify unrecognized ischemic brain injury that may have permanent neurocognitive sequelae.

Figure 1

Axial MRI images of case 3. A 10-year-old girl with SCD and parvovirus infection with hgb = 2.9 g/dL showing (left, arrow) an area of restricted diffusion on DWI images with an ACD correlate (middle). Follow-up FLAIR MRI 7 months later (right) shows a lesion corresponding to the affected area on the DWI.

Figure 2

Axial MRI images of case 4. A 6-year-old boy with SCD and acute chest syndrome with hgb = 4.1 g/dL showing (left, arrow) an area of restricted diffusion on DWI images with an ADC correlate (middle). Follow-up FLAIR MRI 4 months later (right) shows a lesion corresponding to the affected area on the DWI.