Cochlear implantation (CI) has revolutionized the management of congenitally deaf children.[1] A growing body of evidence suggests that that performing CI as early as possible in congenitally deaf infants and toddlers results in the best outcome.[2, 3] However, auditory perception and language skills are difficult to assess accurately in infants.[4] Newborn hearing screening programs now in place in 38 states, are expected to identify 30-40 children per day nationally with congenital hearing loss, [6][7] precipitating the need for assessment and management strategies that utilize early windows of opportunity for interventions (such as a CI) by 12-18 months of age. Functional magnetic resonance imaging (fMRI), offers a novel tool for evaluation of central auditory processes in infants.[8-10] fMRI is non-invasive and presents no known biological risks, even for infants.[11] fMRI may permit differentiation of brain responses corresponding to auditory detection, speech perception and language processing in normal and hearing-impaired infants.[12] The ability of fMRI to demonstrate various levels of auditory and language processing in infants and toddlers can provide important data to clinicians that is not available by any other means in prelingual babies. The current proposal is designed to ascertain whether (H2) pre-implant cortical activation patterns revealed by fMRI during infancy will correlate with auditory performance two years after cochlear implantation and whether (H1)fMRI can reveal clinically relevant details about the central auditory system in infancy.
Three specific aims are designed to test these hypotheses. We plan to (S1) optimize a silent background, auditory stimulation fMRI method on a clinical 3T MRI system, (S2) acquire fMRI and hearing test data on normal hearing (n=30) and hearing impaired infants (n=60) and (S3) correlate central auditory activation pattems revealed by fMRI in hearing impaired infants at 1 year of age, with outcome measures 2 years after cochlear implantation. Our hope is that successful completion of the proposed study will provide clinicians with a new tool to guide optimal intervention strategies for hearing-impaired infants.
