Tone decay testing is performed on a patient with asymmetric sensorineural hearing loss. At 2000 Hz, the threshold shifts by 35 dB during one minute of continuous tone presentation. This degree of abnormal tone decay is most suggestive of:

• A Noise-induced cochlear damage
• B Retrocochlear pathology such as vestibular schwannoma ✓
• C Early otosclerosis
• D Normal adaptation, requiring no further workup

Explanation

Tone decay of up to 20 dB can occur normally or in mild cochlear disease. Decay exceeding 25 to 30 dB is pathological and points to a retrocochlear lesion such as an eighth nerve tumour, reflecting impaired neural encoding of sustained stimuli. Such a result warrants MRI of the internal auditory meatus to exclude vestibular schwannoma, especially with asymmetric loss.

Reference: Cummings Otolaryngology: Head and Neck Surgery, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.