Labyrinthitis: The Daily PANCE Blueprint

The answer is C. Viral inflammation of both the vestibular and cochlear systems

This patient is presenting with classic signs and symptoms of acute labyrinthitis, an inflammatory condition of the inner ear labyrinth that affects both the vestibular (balance) and cochlear (hearing) components. The key diagnostic features are the acute and continuous onset of severe vertigo combined with unilateral sensorineural hearing loss and tinnitus. The etiology is most commonly idiopathic or presumed post-viral. The inflammation affects the entirety of the vestibulocochlear nerve (CN VIII), leading to both vestibular and auditory dysfunction. Treatment is typically supportive, including vestibular suppressants like meclizine or benzodiazepines for a short duration and antiemetics. Corticosteroids (e.g., prednisone) are often prescribed to reduce inflammation and hasten recovery.

Incorrect answer explanations:

• A. Viral inflammation limited to the vestibular nerve describes vestibular neuritis. While it also presents with acute, severe vertigo, it is distinguished from labyrinthitis by the absence of hearing loss or tinnitus.
• B. Bacterial infection of the middle ear extending into the labyrinth describes suppurative labyrinthitis, a rare and serious complication of untreated acute otitis media or meningitis. This patient’s normal otoscopic exam makes this unlikely.
• D. Episodic increases of endolymphatic fluid pressure is the proposed pathophysiology of Meniere’s disease. Meniere’s is characterized by episodic, not continuous, attacks of vertigo, tinnitus, and fluctuating hearing loss.
• E. Displacement of otoconia into a semicircular canal is the cause of Benign Paroxysmal Positional Vertigo (BPPV). BPPV causes brief, recurrent episodes of vertigo specifically triggered by changes in head position, not the continuous vertigo seen in this patient.