Using non-invasive brain stimulation to promote auditory neuroplasticity in the setting of hearing intervention: A scoping review.

Abstract

Cochlear implants (CI) have revolutionized our ability to treat severe sensorineural hearing loss (HL), yet there is substantial variability in speech perception outcomes. This may be due, in part, to the central nervous system's (CNS) response to HL, which is variable in extent and reversibility. Compensatory responses to HL mediated by neuroplasticity within the auditory CNS and other functional regions may interfere with perceptual, integrative and/or cognitive processes required to develop new listening skills with a CI. Non-invasive brain stimulation (NIBS) approaches offer a means to modulate the excitability of the brain and associated Hebbian processes that promote neuroplasticity. NIBS may therefore provide a means to increase gains in listening and communication function for individuals undergoing hearing rehabilitation. A narrative review is first performed to synthesize current evidence on CNS neuroplasticity associated with HL and intervention, and explores the conceptual rationale for applying NIBS to enhancing rehabilitation outcomes using contemporary hearing technology and auditory training. A formal scoping review was then done to identify studies that look at the use of NIBS in hearing rehabilitation in those with HL. Currently, clinical data for NIBS in patients with HL remain scarce. At present, conclusions regarding NIBS efficacy for improving hearing outcomes are premature; however, emerging findings provide a promising direction for future translational research. Limitations include the lack of standardized stimulation protocols and insufficient longitudinal data. Addressing these gaps will be essential to determine whether NIBS can safely and effectively enhance relevant neuroplasticity that improves rehabilitation outcomes for individuals with HL.