Inner Ear Anomalies among Cochlear Implant Candidates in Erbil City, Iraq

Background and objective: To study the frequency of each type of inner ear abnormalities in cochlear implant candidates in Erbil city, Iraq. Methods: This is a case series study of high resolution computed tomography and magnetic resonance images of temporal bone in 111 candidates for cochlear implantation in Erbil city between June 2015 and December 2017; who had congenital bilateral profound hearing loss. Results: In total, 111 cases of congenital sensorineural hearing loss were included. Of these, 101 patients had a normal inner ear pattern. Ten patients identified to have inner ear anomalies (9%). unilateral anomaly seen in one child, so the total number of ears with inner ear anomalies was 19. Among these 19 abnormal ears, 7 were classified as incomplete partition type II (36.8%), 4 as incomplete partition type I (21.1%), 4 as a common cavity (21.1%), 2 as cochlear aplasia (10.5%), 1 as cochlear hypoplasia (5.3%) and 1 as Michel deformity (5.3%). Conclusions: The most common type of anomaly was incomplete partition type II “Mondini” deformity followed by common cavity and incomplete partition type I deformities. The incidence of congenital hearing loss with inner ear anomalies is similar to the results of such studies worldwide.