[Long-term rehabilitation outcomes of prelingually deafened late-implanted patients with regular use]

Objectives: To evaluate the outcomes of cochlear implantation in prelingually deafened late-implanted patients with regular cochlear implant use and to analyze the influencing factors of rehabilitation effects. Methods: This before-after self-controlled study design included 60 subjects, comprising 36 males and 24 females, who had received cochlear implantation at Chinese PLA General Hospital. Post-implantation, all patients demonstrated continuous and regular use of cochlear implants (≥8 hours daily). Rehabilitation outcomes were evaluated by using the Categories of Auditory Performance scale (CAP), Meaningful Auditory Integration Scale (MAIS), Speech Intelligibility of Rating scale (SIR), Meaningful Use of Speech Scale (MUSS) and speech recognition score (SRS) in 2018 and 2023. 9 potential risk factors were analyzed by univariate analysis with SPSS 25.0. The influencing factors associated with outcomes were evaluated through multivariate logistic regression. Results: Longitudinal data of 60 participants followed-up in 2018 and 2023 were analyzed. The average duration of cochlear implant use for all patients was (11.3±3.0) years. The mean score of CAP, SIR and MUSS improved significantly over time. The mean CAP score before surgery was (1.0±0.9). From 2018 to 2023, the mean CAP score improved from (5.1±1.4) to (5.9±1.6), with a statistical significance (P<0.01); the mean SIR score before surgery was (1.3±0.5), and the mean SIR score improved from (2.7±1.1) to (3.2±1.3), with a statistical significance (P<0.01); the mean MUSS score increased from (16.8±9.7) to (21.1±10.9) between the two follow-ups, with a statistical significance (P<0.01); the MAIS was only initiated in the 2023 follow-up, with a mean score of (31.0±10.2). The speech recognition score for monosyllabic words increased from (23.9±16.0)% to (25.2±13.0)%, with no statistically significant difference (P=0.66). Preoperative residual hearing significantly predicted rehabilitation outcomes at univariate analysis (P<0.05), but the statistical significance was lost at multivariate analysis (P>0.05). Age at implantation was identified as an independent predictive factor by both univariate and multivariate analysis (Hazard Ratio, 0.88; 95% Confidence Interval 0.79-0.97; P=0.014). The cut-off point for predicting further rehabilitation effects was 19.2 years old. In the correlation analysis of different scales, the CAP score was positively correlated with the total score of MAIS. So were the SIR score and the total score of MUSS. Conclusions: For prelingually deafened late-implanted patients with regular CI use, there was still potential for further improvement of auditory and speech abilities even after 10 years post-implantation. Age at implantation was an independent predictive factor and the cut-off point was 19.2 years old.