Radiological Imaging Findings of Patients with Congenital Totally Hearing Loss

Abstract

OBJECTIVE:The aim of this study was to determine and classify inner ear abnormalities in patients who had cochlear implants because of congenital sensorineural hearing loss using preoperative temporal bone computed tomography and magnetic resonance imaging. MATERIALS and METHODS:Patients in the otolaryngology department who had cochlear implants because of congenital sensorineural hearing loss between January 2011 and December 2013 were included in the study. There were 167 male and 133 female patients, a total of 300. All of the patients were evaluated with 4-detector-row computed tomography and 1.5 Tesla magnetic resonance imaging. RESULTS:Inner ear abnormalities were found in 136 of 600 ears (20.3%). There were six ears with incomplete partition-II (4.4%), five ears with incomplete partition-I (3.6%), two ears with Michel deformity (1.4%), two ears with cochlear hypoplasia (1.4%), two ears with cochlear otosclerosis (1.4%), and one ear with common cavity deformity (0.7%). Dilatation of the internal acoustic canal was found in 42 ears (30.9%); also, 21 ears with cochlear nerve aplasia/hypoplasia (15.4%), 5 ears with internal acoustic canal aplasia, and 1 ear with internal acoustic canal hypoplasia (0.73%) were detected. There were 10 ears with posterior semicircular canal (7.3%), 10 ears with lateral semicircular canal (7.4%), 8 ears with superior semicircular canal aplasia/hypoplasia (5.9%), and 8 ears with lateral semicircular canal-vestibular dysplasia. An enlarged vestibular aqueduct was found in 16 ears (11.7%). High jugular bulbs were found in 21 ears; however, this variation was not considered to be an inner ear abnormality. CONCLUSION:Computed tomography and magnetic resonance imaging are essential for the evaluation, determination, and classification of inner ear abnormalities in patients with congenital sensorineural hearing loss who are candidates for cochlear implant operations. Also, these radiological instruments aid in determining contraindications and predicting intraoperative difficulties. Computed tomography and magnetic resonance imaging findings for these patients should be evaluated by an experienced radiologist before the operation.

Pre-Operative Evaluation of Petrous Temporal Bone Pathologies by CT and MRI in Cochlear Implant Candidates

“…In our study 74.2% and 94.6% cases revealed no ear deformity or abnormality on CT and MRI respectively. These figures correspond to a study conducted in 2015 in whichinner ear abnormalities were demonstrated to be 20% 17 . Cochlear aplasia or absence of the eighth nerve are absolute contraindicationsto cochlear implantation and puts a halt to the further process of cochlear implant if any of two is demonstrated 12 .…”

“…This condition requires slight change of procedure as either short array electrodes are used or incomplete insertion of electrodes is done is dysplastic cochlea.1.2 %of patientsshowed high jugular bulb which is included in vascular anomalies. Tomura et al showed percentage of 2.4% in a study conducted in 1995 18 and 3.5% in another study conducted in 2015 17 .…”

A Predictive Model for Cochlear Implant Outcome in Children with Cochlear Nerve Deficiency

“…It is found in approximately 25–48% of patients with unilateral hearing loss 4–6 . Moreover, bilateral CND is found in approximately 15.4% of patients with severe-to-profound bilateral hearing loss 7 . It has been reported that the hearing threshold and word recognition score of unilateral deafness may be related to the size of bony cochlear nerve canal, which is associated with CND 8,9 .…”

Epidemiologic, Imaging, Audiologic, Clinical, Surgical, and Prognostic Issues in Common Cavity Deformity

“…Abnormalities might encompass cochlear (about half of inner ear malformations) and/or labyrinthine bone structures, reflecting a developmental failure during early inner ear embryogenesis. The detection rate of common cavity deformity widely ranges between 0.7% and 26% of cochlear malformations. Such a wide incidence rate range likely reflects the differences in the study inclusion criteria, one of which might strictly consider ovoid cochlear-vestibular cysts centered by the IAC and another that might include a continuum of malformations that encompass cochlear aplasia and severe cases of incomplete partition type 1.…”