Sudden Sensorineural Hearing loss (SNHL)

Glucocorticoids and antiviral drugs may also be helpful for patients with an idiopathic sudden sensorineural hearing loss though the evidence is lacking. Hyperbaric oxygen therapy may be of some benefit. Discuss with ENT.

About

• Hearing loss is a common condition.
• There are nearly 9 million people in the UK who are classified as either deaf or hard of hearing
• Of these 6 million are aged over 60 years.

Aetiology

• Malfunction of the inner ear and/or auditory (eighth cranial) nerve
• SNHL may be unilateral or bilateral, and onset can be sudden or progressive
• Speech may deteriorate over time because high-pitched speech sounds cannot be heard
• Patients may complain of tinnitus

Causes

• Idiopathic - 2/3rds improve
• Menieres syndrome: SNHL tinnitus, and episodic rotational vertigo
• Trauma - fracture or haemorrhage involving the cochlea
• Presbyacusis
• Perilymphatic fistula - classic history of explosive sound and nystagmus, vertigo and nausea and requires surgical correction. Confirmed by tympanometry and electronystagmography (ENG).
• Cogan's syndrome - autoimmune and responds to steroids
• Viral - mumps and measles
• Stroke - occlusion of the terminal branch of the anterior inferior cerebellar artery cause ischaemia of the 8th cranial nerve in rare cases
• Ototoxic drugs e.g. aminoglycosides
• Multiple sclerosis
• Acoustic neuroma

Investigations

• MRI CP angle if acoustic neuroma suspected
• Pure-tone audiometry (PTA)