Superior semicircular canal dehiscence (SSCD) syndrome presents with which characteristic combination of symptoms?

• A Purely sensorineural hearing loss with absence of acoustic reflexes
• B Progressive bilateral sensorineural hearing loss with tinnitus and no vestibular symptoms
• C Purely conductive hearing loss with absent OAEs and flat tympanogram
• D Sound- or pressure-induced vertigo (Tullio phenomenon), autophony, and low-frequency conductive hearing loss with present acoustic reflexes ✓

Explanation

Superior semicircular canal dehiscence (SSCD) creates a 'third window' in the osseous labyrinth, causing characteristic features: (1) Tullio phenomenon — sound-induced oscillopsia and vertigo; (2) Hennebert sign — pressure-induced nystagmus; (3) autophony (hearing own heartbeat, eye movements, footsteps); and (4) an audiometric pattern of apparent low-frequency conductive hearing loss with present acoustic reflexes and OAEs — mimicking otosclerosis but with bone conduction thresholds better than 0 dB HL (negative BC thresholds). CT temporal bone confirms the dehiscence.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.