Auditory Performance and Cortical Plasticity following Late Sequential Cochlear Implantation

Introduction: Bilateral cochlear implantation can be performed simultaneously or sequentially based on hearing loss and patient age, though global consensus on sequential implantation remains unresolved. Methods: Data of 27 individuals from this patient group were included in this study. The mean chronological age of the 27 individuals included in the study was 140.93 ± 41.51 months. The mean chronological age of the participants was 25.44 ± 9.25 months at the time of early unilateral cochlear implantation (CI 1). The implantation delay of late sequential cochlear implantation (CI 2) was 115.48 ± 41.45 months. Cortical auditory evoked potential P1 latency measurements were performed at 3, 6, 9, and 12 months. The change in performance over time was analyzed based on measurements at five different time points for CI 2. Results: There were substantial improvements in auditory perception and performance 3 months after CI 2 activation. CAEP analyses were indicative of improvements in cortical responses and positive effects of CI 2 on central auditory system plasticity. These results suggested that late second implantation might be associated with improved auditory outcomes. These improved from CAEP test P1 latency were statistically significant (p < 0.001). Conclusion: Late CI 2 can significantly improve auditory perception and promote adaptive plasticity in individuals with prior unilateral cochlear implants. These results suggest that even late consecutive cochlear implantations may provide clinical benefit.