|Children with unilateral sensorineural hearing loss (SNHL) often present with abnormal inner ear anatomy on the affected side, either with malformed bony structures and/or aplastic/hypoplastic 8th cranial nerve (CN). Clinically, it is believed that the good ear is adequate to support the development of typical motor and cognitive functions, despite abnormalities on the affected side. However, recent research suggests that abnormal anatomy in the inner ear may result in diminished or absent auditory and vestibular sensory input to higher cortical areas, thereby significantly impeding optimal growth, despite an otherwise good ear. Research in children with unilateral SNHL has historically faced several challenges including: 1) inadequate neuroimaging protocols to assess 8th CN integrity within the internal auditory canal (IAC); 2) imprecise measures to aid in clinical decision making in the use of cochlear implants; and 3) lack of routine and consistent measurement of vestibular and motor functions.
To advance our understanding of the relationship between abnormal inner ear anatomy in children with unilateral SNHL and the impact on development, our transdisciplinary team is proposing a research study using a novel magnetic resonance imaging (MRI) acquisition protocol and diffusion tensor imaging (DTI) analyses for measuring 8th CN integrity, combined with behavioral measures of vestibular and motor functions. In this study, twenty children aged 5-13 years with/without SNHL, will receive behavioral testing of vestibular and motor functions using standardized, norm-referenced measures, and one 60-minute unsedated MRI. We will assess the structural integrity of the inner ear in our sample, and the subsequent differences in vestibular and motor functions. The results will provide pilot data to seed a larger, more comprehensive study that could lead to improved clinical management of children with unilateral SNHL by augmenting neuroimaging protocols for better 8th CN integrity analyses and routine testing of vestibular and motor functions.