Makindo Medical Notes

Related Subjects: |Assessing Hearing Loss |Benign Paroxysmal Positional Vertigo (BPPV) |Cholesteatoma |Epistaxis (Nosebleeds) |Acute Mastoiditis |Nasal polyps |Acute Sinusitis |Sudden Sensorineural Hearing loss (SNHL) |Causes of Vertigo

Glucocorticoids and antiviral drugs may be helpful for patients with idiopathic sudden sensorineural hearing loss (SNHL), though evidence for their efficacy is limited. Hyperbaric oxygen therapy may also offer some benefit. For further management and treatment options, consult with an ENT specialist.

About

• Hearing loss is a widespread condition, affecting millions of people worldwide.
• Nearly 9 million people in the UK are classified as either deaf or hard of hearing.
• Of these, 6 million are over the age of 60, highlighting its prevalence in the elderly population.

Aetiology

• Sensorineural hearing loss (SNHL) is due to malfunction of the inner ear or the auditory (eighth cranial) nerve.
• SNHL may present as unilateral or bilateral hearing loss, with an onset that can be either sudden or progressive.
• As hearing deteriorates, patients may experience difficulties with speech comprehension, especially high-pitched sounds.
• Tinnitus is a common symptom reported by patients with SNHL.

Causes

• Idiopathic: Approximately two-thirds of idiopathic SNHL cases improve spontaneously.
• Meniere's Syndrome: Characterized by SNHL, tinnitus, and episodic rotational vertigo.
• Trauma: Injury to the cochlea through fracture or haemorrhage can lead to SNHL.
• Presbyacusis: Age-related hearing loss, commonly seen in older adults.
• Perilymphatic Fistula: Often presents after an explosive sound with symptoms like nystagmus, vertigo, and nausea, requiring surgical intervention. Confirmed with tympanometry and electronystagmography (ENG).
• Cogan's Syndrome: An autoimmune condition responsive to steroid treatment.
• Viral Infections: Mumps and measles are known viral causes.
• Stroke: In rare cases, occlusion of the terminal branch of the anterior inferior cerebellar artery leads to ischaemia of the eighth cranial nerve.
• Ototoxic Drugs: Medications like aminoglycosides can damage hearing.
• Multiple Sclerosis (MS): Neurological disorders like MS can impact the auditory nerve.
• Acoustic Neuroma: A benign tumor affecting the auditory nerve, which can lead to progressive SNHL and tinnitus.

Investigations

• MRI of the Cerebellopontine (CP) Angle: Recommended if an acoustic neuroma is suspected to visualize the tumor.
• Pure-Tone Audiometry (PTA): Assesses hearing thresholds at various frequencies and helps in determining the extent and type of hearing loss.

Management

• Glucocorticoids: Steroids may be administered in cases of sudden SNHL to reduce inflammation.
• Antiviral Therapy: Considered in idiopathic cases, especially if a viral cause is suspected.
• Hyperbaric Oxygen Therapy: May provide some benefit in acute SNHL, though evidence is limited.
• Referral to ENT: Essential for further assessment and treatment, particularly in cases of sudden, severe, or progressive hearing loss.
• Hearing Aids: Commonly recommended for patients with persistent SNHL, especially in age-related or irreversible cases.
• Cochlear Implants: Considered in cases of severe-to-profound SNHL unresponsive to hearing aids.

Prognosis and Follow-Up

• Early treatment in sudden SNHL may improve outcomes, particularly with steroid therapy.
• Regular follow-up is recommended to monitor for progression or recurrence, especially in cases of Meniere's or autoimmune-related hearing loss.

References

• Sensorineural Hearing Loss Management