The proposed study is a double-blind, randomized controlled trial comparing donepezil with placebo in adult cochlear implant users.~Aim 1: Evaluate if six months of donepezil treatment improves speech recognition in cochlear implant users.~Aim 2: Evaluate if six months of donepezil treatment increases intramodal auditory cortex activity in cochlear implant users.~Aim 3: Evaluate if six months of donepezil treatment improves cognition in cochlear implant users.
Hearing loss is a major cause of disability that affects over 48 million Americans. There are currently no medications used to treat sensorineural hearing loss. Cochlear implants can significantly restore hearing in adults with moderate to profound sensorineural hearing loss, but their utility is limited by the wide variability in hearing outcomes. Differences in cochlear implant outcomes may be explained by neuroplasticity, as neural networks must reorganize to process the new auditory information provided by the implant. Therefore, the investigators predict that cholinergic enhancement with donepezil (an acetylcholinesterase inhibitor) may facilitate cortical reorganization after cochlear implantation, leading to functional improvements in speech recognition and cognition. In this randomized, double-blind controlled trial, the investigators aim to assess the effects of donepezil on speech recognition, cortical plasticity, and cognition. Participants will start daily treatment with either donepezil 5 mg or placebo at the time of cochlear implant activation. Participants will be followed longitudinally at 1 month, 3 months, and 6 months post-implantation. The findings from this study will provide important insight into the mechanisms of hearing restoration and could potentially improve hearing and cognitive outcomes for future cochlear implant users.