Sudden sensorineural hearing loss - A contemporary review of management issues

Abstract

Sudden sensorineural hearing loss (SSNHL) is an enigmatic entity, with obscure pathophysiology and debatable efficacy of the treatment agents used. An underlying cause is identified in only 10-15% of cases. The management of the remaining patients, classified as 'idiopathic', is empirical, and is conventionally with systemic steroids, vasodilator therapy, rheological agents, and antioxidants, to list a few amongst the host of the agents employed for the treatment. The availability of conflicting outcomes and lack of conclusive evidence has resulted in the propagation of consensus-based treatment protocols. In the present review, we discuss the various controversial issues and newer developments in the management of idiopathic SSNHL. The current review aims to present a narrative outlook of the updated evidence base available from PUBMED, augmented with relevant designated publications.

Keywords: Dexamethasone; Drug; Hearing loss; Instillation; Prognosis; Sensorineural; Sudden.

Fig. 1

Pure tone audiogram (left panel) of a patient who presented with sudden ear blockade sensation on left side without vestibular or focal neurological deficits. A Contrast Enhanced MRI brain (right panel) revealed a 1.5 × 1.1 cm (extrameatal part) intensely enhancing schwannoma involving the left internal acoustic canal and cerebellopontine angle with typical ice-cream cone appearance.

Fig. 2

Various routes of inner ear drug delivery. (ET-Eustachian Tube; RWM-Round Window Membrane; OW-Oval Window; RWN-Round Window Niche).

Fig. 3

Cadaveric temporal bone dissection showing the exposure of round window niche via posterior tympanotomy in a left sided temporal bone. (A) False round window membrane (black arrow) obscuring the view of true round window membrane. (B) Removal of false membrane reveals the true membrane (white arrow) located deep in the round window niche. (Inset shows the region of the dissected temporal bone {shaded rectangle} shown as magnified image in panel A and B; 1-Vertical part of facial nerve; 2-Chorda Tympani; 3-Pyramidal Process; original magnification X25).