Sudden Hearing Loss: Why It Is a Neurological Emergency That Must Be Treated Within 72 Hours

Sudden sensorineural hearing loss (SSNHL) — the rapid onset of hearing loss in one ear, developing over 72 hours or less — is a medical emergency. Yet most patients in India wait days to weeks before seeking help, often told by family that "it will come back on its own." For some, it does. For many, the delay means permanent hearing loss that could have been partially or fully restored with early treatment.

How It Presents

A person wakes up in the morning unable to hear in one ear — or notices over the course of a day that one ear progressively stops hearing. May be accompanied by: tinnitus (ringing) in the same ear; a feeling of fullness or pressure in the ear; mild dizziness or vertigo. There is no pain. The hearing loss is sensorineural — meaning it affects the inner ear (cochlea) or the auditory nerve, not the outer or middle ear.

Causes

In approximately 85–90% of cases, the cause is never identified — termed idiopathic SSNHL. Proposed mechanisms: viral infection of the cochlea (herpes viruses, mumps, cytomegalovirus); microvascular occlusion of the cochlear blood supply (the cochlea has no collateral circulation — even brief ischaemia causes irreversible hair cell death); autoimmune cochlear damage; labyrinthine membrane rupture.

The remaining 10–15% have identifiable causes: acoustic neuroma (vestibular schwannoma — a benign tumour compressing the auditory nerve — SSNHL is its presenting symptom in 1–2% of cases); multiple sclerosis lesion affecting the auditory pathway; Lyme disease; meningitis; perilymphatic fistula.

Why the 72-Hour Window Matters

The cochlear hair cells — once damaged — do not regenerate. The treatment window for meaningful recovery is 72 hours from onset — ideally within 24 hours. First-line treatment: high-dose oral prednisolone (1mg/kg/day for 7–14 days). Intratympanic steroid injection (directly into the middle ear through the eardrum): used if oral steroids fail or are contraindicated — delivers high local steroid concentration to the inner ear. Hyperbaric oxygen: adjunct treatment in some centres. Outcomes are significantly better with treatment initiated within 24 hours versus 48–72 hours.

If you or anyone you know experiences sudden hearing loss in one ear — even if it partially recovers — seek ENT or neurological evaluation the same day. Sri Anand CNC, Chanda Nagar, Hyderabad. Call +91 90633 66983.