Gaze Stability in Children with Hearing and Vestibular Loss
Kristen Janky, PhD
The consequences of vestibular loss in adults has been documented to include reduced visual acuity, increased falls, decreased quality of life and decreased social interactions; however, the extent to which vestibular loss affects children is unknown. In children with hearing loss, the presence of vestibular loss may result in gross motor developmental delay and reduced visual acuity, requiring additional habilitation. However, vestibular testing is not routine in the pediatric population, and vestibular habilitation is seldom considered for children with hearing loss. The long-term goal of this research program is to diagnose and then minimize the impact of vestibular loss in children with hearing loss. This project characterized vestibular loss in children with hearing loss and evaluated the effect of vestibular loss on static visual acuity and dynamic visual acuity in these children. We focused on children with hearing loss who use a cochlear implant, who had increased risk of vestibular loss due to implantation and etiology of hearing loss.
Children with cochlear implants were found to have a significantly higher prevalence of vestibular loss compared to children with normal hearing. Additionally, the relationship between severity of vestibular loss and gross motor performance was investigated. Children with cochlear implants who have vestibular loss performed significantly more poorly on gross motor performance outcomes compared to children with normal hearing. Moreover, significant vestibular loss could be predicted by performance on gross motor measures. Static visual acuity and dynamic visual acuity were assessed while sitting and under increasing demands of maintaining upright stance as well as increased optotype complexity. Children with cochlear implants with vestibular loss had significantly reduced dynamic visual acuity, but not static visual acuity, and children with cochlear implants who have vestibular loss had significantly reduced static visual acuity as optotype complexity increased. This work provided new knowledge regarding the prevalence of vestibular loss and the extent to which vestibular loss affects visual acuity in children with hearing loss. This work has further advanced our understanding of the natural compensation process of vestibular loss in children with hearing loss and has led to further investigations regarding the identification, implications, and habilitation of vestibular loss in children with hearing loss.