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

Abstract

Objectives

To conduct critical assessment of the literature on the effects of cochlear implantation on adults’ cognitive abilities.

Design

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.

Study sample

Out of 1830 studies, 16 met the inclusion criteria.

Results

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%].

Conclusion

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.

Keywords:

• Cochlear implant
• ageing
• hearing loss
• cognition

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Disclosure statement

The authors declare no conflict of interest.

Informed consent

For this type of study, formal consent is not required.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.