Interhemispheric auditory cortical relationships in asymmetric hearing loss

Abstract

Directional acoustic trauma, sudden hearing loss with incomplete recovery, Meniere’s disease, and cerebellopontine angle tumors are common clinical conditions that present with asymmetric hearing loss (ASL). Presentation of input signals from both ears for interhemispheric processing may be necessary to achieve the best hearing outcomes. To review temporal and spatial interhemispheric functional relationships revealed by microelectrode mapping studies in an animal model of ASL and by functional imaging studies in human single-sided deafness (SSD). Animal and human cohort comparison studies by investigators at the University of California. In animals with mild-to-moderate ASL, interaural temporal difference is a strong driver of cortical plastic change. Six months after hearing loss induction, the two cortices reorganize into a state of relative local hemispheric autonomy. In humans with SSD, temporal and spatial cortical plastic change is evidenced by reduced interhemispheric mean difference of the M100 p...