A physician-validated, board-style question from the Active Transport QBank. Try it, then check the reasoning for every option.
A 75-year-old woman with hypertension presents to your office for a routine health exam. Her medications include hydrochlorothiazide and a multivitamin. She has been feeling well; however, she mentions that her family has been complaining about the volume of the television. She also reports difficulty hearing when others have called her name. On physical examination, her temperature is 99°F (37.2°C), blood pressure is 120/85 mmHg, pulse is 70/min, respirations are 17/min, and pulse oximetry is 99% on room air. The tympanic membrane is gray with no drainage or granulation tissue. Audiometry is consistent with high frequency sensorineural hearing loss. Which of the following is the most likely physiology behind this patient’s presentation?
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A
Increased endolymph productionIncorrect. Increased endolymph production describes Meniere disease, which causes episodic vertigo, tinnitus, and fluctuating low-frequency hearing loss, not gradual high-frequency loss.
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B
Destruction of cochlear hair cellsCorrect. Loss of cochlear outer hair cells (especially in the high-frequency-encoding basal turn) is the dominant mechanism of presbycusis.
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C
Abnormal skin growth in the middle earIncorrect. Abnormal skin growth in the middle ear describes cholesteatoma, which causes conductive hearing loss with otorrhea and an abnormal tympanic membrane - not the case here.
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D
Fixation of the stapes to the cochleaIncorrect. Stapes fixation describes otosclerosis, which produces CONDUCTIVE hearing loss (often low frequency initially) with a normal TM but abnormal tuning fork tests; her audiogram shows sensorineural loss.
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E
Demyelination of the cochlear nerveIncorrect. Cochlear-nerve demyelination describes acoustic neuroma (vestibular schwannoma), which causes unilateral hearing loss with tinnitus and disequilibrium, not symmetric high-frequency loss of presbycusis.
↑ Tap an answer to reveal the reasoning
Answer: B. An older adult with gradual, bilateral, high-frequency sensorineural hearing loss has presbycusis - age-related hearing loss. The dominant mechanism is loss of OUTER HAIR CELLS in the basal turn of the cochlea (which encodes high frequencies) and degeneration of stria vascularis and spiral ganglion neurons. This produces difficulty understanding speech, especially consonants like /s/, /f/, and /th/, and trouble hearing in noisy environments - which fits her complaints of needing higher TV volume and missing her name when called.
The gray, intact tympanic membrane and audiometry showing high-frequency SNHL distinguish this from conductive losses (otosclerosis, cholesteatoma, otitis media with effusion). Risk factors for accelerated presbycusis include noise exposure, ototoxic drugs (aminoglycosides, loop diuretics, cisplatin), smoking, diabetes, and genetic predisposition.
Management focuses on hearing aids, with cochlear implants reserved for severe-to-profound bilateral loss. Communication strategies and screening for social isolation and depression are important because presbycusis is strongly linked to cognitive decline and accelerated dementia.
**Why each option:**
**A.** Increased endolymph production describes Meniere disease, which causes episodic vertigo, tinnitus, and fluctuating low-frequency hearing loss, not gradual high-frequency loss.
**B.** Correct. Loss of cochlear outer hair cells (especially in the high-frequency-encoding basal turn) is the dominant mechanism of presbycusis.
**C.** Abnormal skin growth in the middle ear describes cholesteatoma, which causes conductive hearing loss with otorrhea and an abnormal tympanic membrane - not the case here.
**D.** Stapes fixation describes otosclerosis, which produces CONDUCTIVE hearing loss (often low frequency initially) with a normal TM but abnormal tuning fork tests; her audiogram shows sensorineural loss.