Superior Canal Dehiscence Plugging Reduces Dizziness Handicap

Objectives/Hypothesis,: To compare dizziness handicap inventory (DHI) scores before and after surgery for plugging of superior canal dehiscence (SCD). The size of the dehiscence as measured during surgery, subject age, vestibular-evoked myogenic potentials threshold, and degree of conductive hearing loss (CBL) were also considered. Study Design: Retrospective. Methods: Nineteen adults with SCD who underwent surgery to plug the SCD via middle fossa approach were studied. Pre- and postoperative DHI scores were compared, and correlations between DHI scores and other clinical measures were assessed. Results: Average preoperative DHI score was 44 +/- 24 (mean +/- SD). Postoperative DHI score was significantly lower at 18 +/- 15 (P <.01). Only two subjects had a higher DHI score after surgery. Subjects who had a preoperative DHI score below 30 did not have any significant change in their DHI score after surgery, whereas those with a preoperative DHI score >= 30 had an improvement by an average of 39 +/- 16 after surgery. There were no correlations between either preoperative DHI score or the change in DHI score after surgery and HL, age, vestibular-evoked myogenic potentials threshold, or dehiscence size. Conclusions: DHI scores significantly decreased after SCD plugging. Subjects who had the largest decrease in DHI scores were those with high preoperative DHI scores. Subjects who chose to undergo SCD plugging because of nonvestibular symptoms such as conductive HL, tinnitus, or autophony generally had lower preoperative DHI scores and did not experience large improvements in DHI scores. The SCD plugging procedure offers an improvement in DHI score that is comparable with that of other procedures for peripheral vestibular dysfunction.