Variations in the cochlear implant experience in children with enlarged vestibular aqueduct.

OBJECTIVES/HYPOTHESIS To describe the clinical experience and characterize the outcomes of cochlear implantation (CI) in children with isolated enlarged vestibular aqueduct (IEVA) as compared to children with enlarged vestibular aqueduct (EVA) associated with other bony labyrinth abnormalities. STUDY DESIGN Single, tertiary care, institutional retrospective review over 2 decades. METHODS The clinical course and outcomes of 55 children with EVA undergoing CI between 1991 and 2013 were reviewed. Test measures included open and closed set speech perception tests, and various speech and language measures. RESULTS In 18 children (32.7%), IEVA was the only defect present. In 33 children (60%), EVA occurred concomitantly with incomplete partition type 2 (IP 2) bilaterally, and three children with incomplete partition type 1 bilaterally. Ninety-two percent (51 of 55) occurred bilaterally and had matching bony defects. Mean age of CI was 73.4 months. A statistically significant defect-related and linguistic-status pattern was noted, impacting the timing of implantation: IEVA = 112.8 months, IP 2 = 58.4 months (P < .001), prelingual deafness = 53.8 months, postlingual deafness = 110.8 months (P < .001). Controlling for implant age and hearing loss severity, IEVA children demonstrated superior performance on speech perception tests (8.2 to 20.3 point differences), though statistical significance was inconsistent (P = .01-.40. Performance was also superior in speech and language tests, though statistical significance was never reached (2.9-13.9 point differences; P = .14-.69). CONCLUSIONS Children with hearing loss secondary to EVA respond meaningfully to cochlear implantation. However, the severity of temporal bone anomalies in these children has clinical relevance. LEVEL OF EVIDENCE 4.