A 52-year-old man from rural Maharashtra presents with progressive bilateral hearing loss over 8 years. He reports difficulty hearing high-pitched sounds initially, which has now progressed to affect all frequencies. On examination, Weber test shows lateralization to the right ear, and Rinne test reveals bone conduction better than air conduction bilaterally. Otoscopy is normal. Audiometry shows a bilateral high-frequency sensorineural hearing loss with an air-bone gap of 2 dB. Which of the following is the most likely diagnosis?

Explanation

## Clinical Analysis **Key Point:** Presbycusis is age-related sensorineural hearing loss, the most common cause of SNHL in adults over 50 years. ### Audiometric Pattern Recognition | Feature | Presbycusis | Otosclerosis | CSOM | Viral SNHL | |---------|-------------|--------------|------|------------| | **Type** | SNHL | Conductive/Mixed | Conductive | SNHL | | **Frequency** | High-frequency first | All frequencies | All frequencies | Variable | | **Progression** | Gradual (years) | Gradual (months–years) | Gradual with exacerbations | Sudden (hours–days) | | **Bilaterality** | Bilateral, symmetric | Often unilateral initially | Often unilateral | Often unilateral | | **Air-bone gap** | Absent (<5 dB) | Present (20–50 dB) | Present (30–40 dB) | Absent | | **Otoscopy** | Normal | Normal | Perforation/discharge | Normal | ### Why This Patient Has Presbycusis 1. **Age and timeline:** 52-year-old with 8-year progressive history fits the typical presbycusis presentation (usually >50 years). 2. **High-frequency loss first:** Classic pattern—cochlear hair cell loss begins at the basal turn (high frequencies). 3. **Pure SNHL:** Air-bone gap of 2 dB (normal) confirms sensorineural origin; no ossicular pathology. 4. **Bilateral and symmetric:** Presbycusis affects both ears equally due to age-related degeneration. 5. **Normal otoscopy:** Rules out middle ear disease. **High-Yield:** Presbycusis is **bilateral, symmetric, high-frequency SNHL** with **gradual onset over years** and **normal air-bone gap**. ### Pathophysiology Presbycusis results from cumulative cochlear hair cell loss, strial atrophy, and neural degeneration due to aging. The basal turn (high-frequency region) degenerates first, explaining the characteristic high-frequency notch on audiometry. **Clinical Pearl:** Presbycusis often coexists with tinnitus and balance problems (presbystasis) in older adults. ### Differential Exclusions - **Otosclerosis:** Would show conductive or mixed hearing loss with significant air-bone gap (20–50 dB); may be unilateral initially. - **CSOM with ossicular erosion:** Would show conductive loss with otoscopic findings (perforation, discharge) or ossicular discontinuity on imaging. - **Viral SNHL:** Sudden onset (hours–days), not gradual; often unilateral; may have vertigo.