Analysis of Inner Ear Abnormalities Using Temporal Bone Computed Tomography in Profound Hearing Loss Patients

Lee, Suk Woo; Lee, Ho Kyu; Kim, Chan Jong; Kim, Young Jin; Shin, Jung Eun; Chung, Jong Woo; Lee, Kwang Sun

Abstract

BACKGROUND AND OBJECTIVES: Many reports have been made on the associations between profound hearing loss and inner ear anomaly. The aim of this study is to evaluate and analyze the prevalence of the inner ear anomaly of profound hearing loss using temporal bone computed tomography (TBCT), and to find out the prognosis on the severity of the inner ear anomalies.
METHODS
The subjects on this study were 161 Korean patients (92 males and 69 females, aged 1 to 57, mean 20.2) diagnosed as having profound hearing loss. All patients received temporal bone computed tomography (TBCT), and their medical records were reviewed retrospectively. Dimensional reconstruction of temporal bone computed tomography was performed using the Surface Shaded Display method (SSD) for better visualization. The prevalence of inner ear anomalies was also evaluated on both prelingual and postlingual group.
RESULTS
The prevalence of inner ear anomaly in patients of profound hearing loss was 27% (N=43). The prevalence of inner ear anomaly in the prelingual deaf group was 22.6% (N=38), and the postlingual deaf group was 3.1% (N=5). The incomplete partition was the most common inner ear anomaly. There were 21 patients with incomplete partition (49%), followed by 8 patients (18%) with large vestibular aqueducts, 5 patients (12%) with cochlea hypoplasia, 4 patients (9.3%) with abnormal semicircular canal and/or large vestibule. 2 patients (5%) with internal auditory canal widening, and 1 patient (3%) with common cavity and cochlea aplasia, respectively.
CONCLUSION
Profound hearing loss patients had higher number of inner ear anomaly rate, especially in prelingual deaf patients. Among all the inner ear abnormalities, incomplete partition (Mondini dysplasia) showed the most prevalent in the profound hearing patients group. The otolaryngologist should carefully evaluate the severity of inner ear anomalies of young prelingual deafened patients using the temporal bone computed tomography (TBCT) for further treatments such as cochlear implantation.