Unilateral Sensorineural Hearing Loss: A Retrospective Study

Abstract

Background: This retrospective study was carried out to know the characteristics of patients suffering from unilateral sensorineural hearing loss (USNHL) (type and degree). Aims and Objectives: (1) To know the incidence of pure USNHL (other ear being normal) in patients complaining of HL. (2) To establish the type and degree of USNHL in patients. Materials and Methods: This study was conducted over a period of more than 1 year to find out the pattern of pure USNHL (other ear being normal) in the patients attending ear, nose, and throat outpatient department (OPD) with a complaint of HL. Pure tone audiometry data of 1800 cases between August 2014 and December 2015 with HL were analyzed for this study. Demographic characteristics were compared with types and degrees of unilateral sensorineural hearing impairment. Results: A total of 1800 OPD patients who had a complaint of HL and had undergone pure tone audigram (PTA) in a period of more than 1 year in the Department of Otorhinolaryngology and Head and Neck Surgery were studied. SNHL type was the highest with 802 cases (44.55%). Out of 802 cases of SNHL, 257 (32.05%) were USNHL - out of which, only 155 patients (60.31%) had pure USNHL with other ear being normal; this constituted the study group, i.e., 155 patients (8.6%) out of 1800. Age of patients ranged from 9 years to 76 years (mean age - 41.5 years). Male:female ratio was 1.31:1. Both ears were almost equally involved. The highest numbers of USNHL patients were seen in the age group of 31-40 years (23.87%). Most cases presented with mild (34.2%), followed by profound (31.6%) USNHL. Conclusion: Our study concluded that SNHL type is the most common type (44.55%) of hearing impairment among patients complaining of HL. The incidence of pure USNHL (i.e. other ear being normal) was 60.31% (155/257) cases of USNHL, 19.32% (155/802) cases of SNHL, and 8.6% (155/1800) cases of PTA performed on patients complaining of HL. Limited work has been published on incidence, characteristics, and causes of pure USNHL. Further studies and researches are required in the field of USNHL to know the incidence, functional and psychological impact, and treatment options.