Changes in cognitive performance after cochlear implantation in adults and older adults: a systematic review and meta-analysis

To conduct critical assessment of the literature on the effects of cochlear implantation on adults’ cognitive abilities. PubMed, Scopus, Lilacs, Web of Science, Livivo, Cochrane, Embase, PsycInfo, and grey literature were searched. Eligibility criteria: age 18 or over with severe-to-profound bilateral hearing loss, cochlear implantation, cognitive test before and after implantation. Risk of bias was assessed using ROB, ROBINS-I and MASTARI tools. Meta-analysis was performed. Out of 1830 studies, 16 met the inclusion criteria. On AlaCog test, significant improvement was found after implantation [MD = −46.64; CI95% = −69.96 to −23.33; I2 = 71%]. No significant differences were found on the Flanker, Recall, Trail A and n-back tests (p > 0.05). For MMSE, no significance was found [MD 0.63; CI 95% = −2.19 to 3.45; I2 = 88%]. On TMT, an overall significant effect with a 9-second decrease in processing speed post-implantation [MD = −9.43; CI95% = −15.42 to −3.44; I2 = 0%]. Cognitive improvements after cochlear implantation may depend on time and the cognitive task evaluated. Well-designed studies with longer follow-up are necessary to examine whether cochlear implantation has a positive influence on cognitive abilities. Development of cognitive assessment tools to hearing-impaired individuals is needed.本研究旨在对关于人工耳蜗植入对成年人认知能力影响的相关文献开展批判性评估。研究检索了PubMed、Scopus、Lilacs、Web of Science、Livivo、Cochrane、Embase、PsycInfo及灰色文献资源。纳入标准为：年龄18岁及以上，患有重度至极重度双侧听力损失，接受人工耳蜗植入，且在植入前后均接受了认知功能测试。本研究采用ROB、ROBINS-I及MASTARI工具对偏倚风险进行评估，并开展了荟萃分析。在检索得到的1830项研究中，共16项符合纳入标准。在AlaCog测试中，植入后受试者的认知能力出现显著改善[均差(MD) = -46.64；95%置信区间(CI95%) = -69.96至-23.33；异质性指数I²=71%]。在Flanker任务、回忆测试、Trail A及n-back测试中均未发现显著差异（p>0.05）。对于简易精神状态检查表(MMSE)，未发现显著差异[MD=0.63；95%CI=-2.19至3.45；I²=88%]。在连线测验(TMT)中，整体效应显著，植入后信息处理速度提升9秒[MD=-9.43；95%CI=-15.42至-3.44；I²=0%]。人工耳蜗植入后的认知改善效果可能受评估时机与认知任务类型的影响。未来需开展设计更严谨、随访周期更长的研究，以验证人工耳蜗植入是否对认知能力存在积极影响。此外，还需针对听障人群开发专用的认知评估工具。