Contemporary review of the causes and differential diagnosis of sudden sensorineural hearing loss

Objectives: This article provides an overview of the causes and differential diagnosis of sudden deafness (SD) and sudden sensorineural hearing loss (SSHL). Design: Contemporary review. Study sample: This review is based on peer-reviewed articles published in those journals listed on journal of citation reports. Through the PubMed database of the US National Library of Medicine, Scopus, and Google Scholar using the keywords of "sudden deafness", "acute hearing loss", and "sudden sensorineural hearing loss", totally 1493 papers were considered and 166 relevant papers were selected. Results: Sensorineural hearing loss of sudden onset may be classified as primary SD and secondary SSHL. Proposed aetiologies of primary SD comprised viral infection, vascular insufficiency, autoimmune disorder and stress theory, while causes of secondary SSHL include neoplasm, stroke and irradiation. Conclusion: SD/SSHL is a syndrome that comprises various entities, and results from a variety of aetiologies. An inner ear test battery in SD/SSHL patients helps determine its aetiology, and provides comprehensive information on the affected territory. Identification of the cause and differential diagnosis of the different types of SD/SSHL may provide substantial benefits such as determining the prognosis, identifying associated risk factors and preventing further hearing loss.