A patient with a confirmed vestibular schwannoma of the left internal auditory canal is likely to show which earliest vestibular test abnormality?

• A Absent cervical VEMP bilaterally
• B Reduced caloric response on the left side ✓
• C Directional preponderance to the left on calorics
• D Hyperactive caloric response on the right side

Explanation

Tumours of the internal auditory canal compress the superior vestibular nerve first, so unilateral caloric hypofunction (canal paresis) on the tumour side is the earliest and most consistent vestibular test abnormality in vestibular schwannoma. Directional preponderance reflects asymmetry of spontaneous nystagmus rather than a focal lesion and is not the characteristic finding here, killing option C. cVEMP abnormalities occur later and are typically unilateral, not bilateral, killing option A.

Reference: Scott-Brown's Otorhinolaryngology Head and Neck Surgery, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.