A Study of Aetiological Profile of Unilateral Sensorineural Hearing Loss

Abstract

Introduction: It is necessary to identify the aetiology of sudden sensorineural hearing loss for proper management. Despite advancement in the field of diagnostic radiology, immunochemistry and genetic studies, there are still many cases of USNHL where a definite cause cannot be identified. In this study, an attempt has been made to identify the aetiological factors responsible for unilateral sensorineural hearing loss (USNHL).. 
 Materials and Methods: Seventyfive patients with acquired unilateral sensorineural hearing loss without chronic otitis media were included in the study. Hearing was assessed by tuning fork test and pure tone audiometry. Special tests were done to differentiate between cochlear and retrocochlear pathology, to objectively assess hearing loss and to diagnose nonorganic hearing loss. Radio-imaging was done to diagnose skull bone fractures, space occupying lesions in internal auditory meatus and cerebellopontine angle or intracranial pathologies. Biochemical analysis of blood, immunoglobulin and serological assay were done to rule out specific causes.
 Results: Majority of patients were within 21-30 years of age. 37 patients presented with sudden and remaining with progressive hearing loss. Majority (57.3%) were found to have idiopathic cochlear pathology. Amongst the remaining, there were 8 cases of acoustic trauma, 4 each of Meniere’s disease and cerebellopontine angle tumour and 3 each of Noise-induced hearing loss, labyrinthitis and Non-organic hearing loss. There were 2 cases of meningitis and 1 each of barotrauma, connective tissue disorder, iatrogenic trauma, fracture of petrous bone and cerebrovascular accident. 
 Conclusion: Most of the studies have been done on sudden sensorineural hearing loss. Current study, including sudden and progressive cases, is hence an attempt to ascertain aetiological profile of unilateral SNHL.