A 50-year-old woman has episodic attacks of true rotatory vertigo lasting 20-30 minutes, fluctuating low-frequency sensorineural hearing loss, tinnitus, and aural fullness in the left ear. Glycerol dehydration test improves her hearing thresholds by 15 dB. Electrocochleography shows an elevated summating potential to action potential (SP/AP) ratio. What is the diagnosis?
- A Vestibular migraine
- B Perilymph fistula
- C Meniere's disease (endolymphatic hydrops) ✓
- D Superior semicircular canal dehiscence
Correct answer: C. Meniere's disease (endolymphatic hydrops)
Explanation
Meniere's disease is caused by endolymphatic hydrops — excess endolymph in the membranous labyrinth. The diagnostic tetrad is episodic vertigo (minutes to hours), fluctuating low-frequency sensorineural hearing loss, tinnitus, and aural fullness. The glycerol dehydration test improves hearing by reducing endolymph volume, confirming the diagnosis. An elevated SP/AP ratio on electrocochleography (>0.4) reflects distortion of the basilar membrane by hydrops. It is typically unilateral initially.
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.