Hearing and vestibular functions after plugging surgery for the posterior semicircular canal.

CONCLUSIONS: Results of audiometry, caloric testing and vestibular evoked myogenic potential (VEMP) testing were hardly influenced by plugging surgery.

OBJECTIVE: To evaluate the influence of surgical plugging of the posterior semicircular canal on inner ear function in patients with benign paroxysmal positional vertigo (BPPV).

SUBJECTS AND METHODS: The subjects were five consecutive patients with intractable BPPV who underwent plugging surgery. The following functions of the inner ear were examined before and 6 months after surgery. Cochlea function was evaluated by the average hearing level of three frequencies (500, 1000 and 2000 Hz), that of the semicircular canal by canal paresis percent (CP%) in caloric testing and that of the otolith by the left-right difference ratio on VEMP testing.

RESULTS: Positional vertigo was resolved in all patients. One subject was completely deaf before and after surgery. The average hearing level did not change more than 10 dB after surgery in the other four cases. CP% did not worsen more than 10% in any case. The VEMP results after surgery did not change more than 10% from before surgery in any case.