A 52-year-old man reports one year of right-sided tinnitus and hearing loss. Pure tone audiogram shows right high-frequency sensorineural loss with average threshold 35 dB, but his speech discrimination score in that ear is only 44 percent, markedly worse than expected for the degree of loss. Caloric test shows mild right canal paresis. The next most appropriate investigation is:
- A Repeat pure tone audiometry in six months
- B Gadolinium-enhanced MRI of the internal auditory meatus ✓
- C Tympanometry with reflex decay
- D Electrocochleography
Correct answer: B. Gadolinium-enhanced MRI of the internal auditory meatus
Explanation
Asymmetric SNHL with disproportionately poor speech discrimination and unilateral canal paresis strongly suggests a vestibular schwannoma compressing the eighth nerve, since tumour damage impairs speech understanding out of proportion to pure tone thresholds. Contrast-enhanced MRI of the IAM is the definitive test. Waiting risks tumour growth, and electrocochleography is used in Meniere disease, not for retrocochlear diagnosis.
Reference: Dhingra's Diseases of Ear, Nose and Throat, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.