Project Summary/Abstract
Sickle cell disease (SCD) is an inherited blood disorder with several neurological and developmental
complications. Young children with SCD between 2 and 5 years of age, in particular, have an increased risk for
ischemic stroke and silent cerebral infarctions (SCI). SCI are hyperintense T2 brain magnetic resonance
imaging (MRI) lesions with no accompanying acute neurological symptoms but with associated impaired
cognition and increased risk of future progressive or additional stroke/SCI. Neuroimaging and neurocognitive
profiles associated with SCI are well established in school-aged and adult SCD populations. This information is
largely unknown in young children under 6 years of age with SCD due to risk of sedation/anesthesia with MRI.
Our preliminary studies have shown that behavioral training can yield high quality neuroimaging data without
sedation in 3 to 4 years old children with SCD through a pilot study.
The long term goal of this application is to develop a diagnostic battery using a combination of
unsedated neuroimaging measures, neurocognitive testing, and plasma brain injury protein levels to identify
young children with SCD at risk for SCI. Through a prospective longitudinal case-control study, we will collect
medical history and clinical data and perform neurological examination and blood draws annually in 100
children with SCD from study entry to study exit. Participants will also undergo initial neuroimaging battery at 3
to 4 years of age with repeat neuroimaging at study exit as well as longitudinal neurocognitive testing at study
entry, with initial neuroimaging, and with exit neuroimaging. This multi-disciplinary and multi-modality proposal
has two Aims. Aim 1 will identify the cross-sectional neuroimaging and neurocognitive findings in 3 to 4 year-
old children with SCD and SCI on initial MRI by comparing their results to children with SCD without SCI. Aim
2 will compare longitudinal data from 6 year-old children with and without SCI on exit MRI. Exploratory aims
will explore differences in the neuroimaging measures in children on different disease-modifying treatments
(hydroxyurea) and plasma protein levels in children with and without SCI. The proposed work will determine
which neuroimaging measures and neurocognitive testing may predict SCI, leading to a multi-site study to
validate these findings in a larger regionally heterogenous SCD population. The study PI, a
neurodevelopmental physician, is an early stage investigator well suited to expand her existing study cohort
with support from a team of co-investigators, including a senior behavioral psychologist and neuroimaging
physicist, as well as existing collaborators and staff.