A 72-year-old woman presents with bilateral progressive hearing loss for 10 years. She denies tinnitus or vertigo. Otoscopy is normal. Pure tone audiometry shows bilateral symmetrical sensorineural hearing loss that is worse at higher frequencies (8 kHz > 4 kHz > 2 kHz > 1 kHz > 500 Hz). Speech discrimination is mildly reduced. Bone conduction and air conduction thresholds are equally elevated. What is the most likely diagnosis?

## Diagnosis: Age-Related Hearing Loss (Presbycusis) **Key Point:** Presbycusis is characterized by a **gradual, downward-sloping high-frequency sensorineural hearing loss** that worsens with age. The loss is symmetrical and bilateral, with 8 kHz most severely affected. **High-Yield:** Presbycusis has these diagnostic hallmarks: - Bilateral, symmetrical sensorineural hearing loss - Progressive, gradual onset (years to decades) - High-frequency loss (8 kHz > 4 kHz > lower frequencies) - **No characteristic 4 kHz notch** (unlike NIHL) - Mildly reduced speech discrimination - Age >60 years - Equal air and bone conduction thresholds (sensorineural, not conductive) - No vertigo or tinnitus (distinguishes from Meniere's) **Clinical Pearl:** Presbycusis results from age-related degeneration of the cochlea, including loss of outer hair cells, strial atrophy, and neural degeneration. The basal turn (high-frequency region) is affected first because it has the highest metabolic demand. **Mnemonic:** **Presbycusis = Sloping High-Frequency Loss** — imagine the audiogram as a ski slope going downward from left (low frequency) to right (high frequency). ### Audiogram Pattern Comparison | Feature | Presbycusis | NIHL | Otosclerosis | Meniere's | | --- | --- | --- | --- | --- | | **Pattern** | Sloping (high-freq loss) | 4 kHz notch | Conductive or mixed | Variable, often low-freq | | **Symmetry** | Bilateral, symmetrical | Bilateral, symmetrical | Often unilateral | Often unilateral | | **Bone/Air** | Equal (SNHL) | Equal (SNHL) | Air > Bone (conductive) | Equal (SNHL) | | **Vertigo** | No | No | No | Yes | | **Tinnitus** | Mild/absent | Often present | No | Yes | | **Age of onset** | >60 years | Any (occupational) | 20–50 years | 20–50 years | ### Why This Patient Has Presbycusis - Age 72 (peak age for presbycusis) - 10-year gradual progressive history (not acute) - Bilateral symmetrical loss - High-frequency worse than low-frequency (8 kHz > 4 kHz > lower) - **No 4 kHz notch** (rules out NIHL) - No vertigo or tinnitus (rules out Meniere's) - Equal air and bone conduction (sensorineural, not conductive — rules out otosclerosis) - Mildly reduced speech discrimination (typical for presbycusis)