The correct answer is:

ocular nystagmus elicited by pneumatic otoscopy

Educational Objective:

Diagnose rupture of the round window in the inner ear.

Key Point:

Perilymph fistulas occur from rupture of the round or oval window in the inner ear and presents with vertigo and dizziness.

Explanation:

In light of his history, this patient's presentation is most consistent with rupture of the round or oval window in the inner ear, which creates an instant perilymph fistula.

Such a rupture permits the air pressure changes from the middle ear to now suddenly be transmitted to the vestibular apparatus, which can elicit vertigo that abruptly starts and stops with any pressure changes in the middle ear.

This direct pressure connection between the middle and inner ear can be documented with pneumatic otoscopy (Hennebert sign).

Rupture of the round or oval window with a resulting perilymph fistula can also be caused by the sudden changes in pressure associated with flying, scuba diving, coughing, or sneezing.

The vertigo subsides when there is no noise or other input to the middle ear. There is variable hearing loss associated with this condition; it may be fluctuating, complete, or intermittent. In any case, it is a sensorineural hearing loss (not conductive).

Tinnitus is not associated with perilymph fistulas.

Perilymph fistula can also occur in the context of temporal bone trauma, in which case pneumatic otoscopy should not be performed (due to possible concomitant rupture of the tympanic membrane and other structures, thereby leading to direct communication with cerebrospinal fluid).

In addition, using pneumatic otoscopy in a trauma patient might further displace tiny, fractured ear ossicles.