A Systematic Review to Define the Speech and Language Benefit of Early (<12 Months) Pediatric Cochlear Implantation

Abstract

Objective: This review aimed to evaluate the additional benefit of pediatric cochlear implantation before 12 months of age considering improved speech and language development and auditory performance. Materials and Methods: We conducted a search in PubMed, EMBASE and CINAHL databases and included studies comparing groups with different ages at implantation and assessing speech perception and speech production, receptive language and/or auditory performance. We included studies with a high directness of evidence (DoE). Results: We retrieved 3,360 articles. Ten studies with a high DoE were included. Four articles with medium DoE were discussed in addition. Six studies compared infants implanted before 12 months with children implanted between 12 and 24 months. Follow-up ranged from 6 months to 9 years. Cochlear implantation before the age of 2 years is beneficial according to one speech perception score (phonetically balanced kindergarten combined with consonant-nucleus-consonant) but not on Glendonald auditory screening procedure scores. Implantation before 12 months resulted in better speech production (diagnostic evaluation of articulation and phonology and infant-toddler meaningful auditory integration scale), auditory performance (Categories of Auditory Performance-II score) and receptive language scores (2 out of 5; Preschool Language Scale combined with oral and written language skills and Peabody Picture Vocabulary Test). Conclusions: The current best evidence lacks level 1 evidence studies and consists mainly of cohort studies with a moderate to high risk of bias. Included studies showed consistent evidence that cochlear implantation should be performed early in life, but evidence is inconsistent on all speech and language outcome measures regarding the additional benefit of implantation before the age of 12 months. Long-term follow-up studies are necessary to provide insight on additional benefits of early pediatric cochlear implantation.