Congenital conductive hearing loss: Imaging and treatment

Abstract

Objectives: Conductive hearing loss in children is most often due to nonossicular problems, such as middle ear fluid or cholesteatoma. Hearing loss, however, can also be caused by congenital abnormalities of the conductive mechanism. This study evaluates the operative findings, results, and the role of imaging in children with congenital conductive hearing loss. Methods: A retrospective case review was performed at an academic medical center. Children with hearing loss due to trauma, chronic infections, or external auditory canal malformations were excluded. Twenty-five cases were included. Preoperative air and bone pure tone and speech thresholds were compared with 1-year postoperative hearing results. All preoperative computed tomography (CT) scans were reviewed, and the incidence of preoperative CT defined abnormalities was reported. Results: The most common causes of conductive hearing loss were malleus fixation (33%) and stapes fixation (33%). Fifty percent of abnormalities were identified on preoperative CT scan. Postoperative hearing results were mixed with only 30% of cases achieving a PTA of less than 30 dB. Fifty-five percent of cases had an improvement in postoperative air bone gap by 10 dB from preoperative levels. Cases of malleus fixation had better results overall, with 60% of these achieving a postoperative PTA of less than 30 dB and 60% improving by greater than 10 dB in postoperative air bone gap. Conclusions: CT scan is a useful diagnostic test in children with congenital conductive hearing loss. While surgical intervention overall has mixed results, isolated malleus fixation has the best prognosis for hearing improvement.