Transmastoid Occlusion Surgery for Superior Semicircular Canal Dehiscence Syndrome Improves Patient-Reported Quality-of-Life Measures and corrects cVEMP Thresholds and Amplitudes

Objective:To determine the pre-and postoperative clinical, audiological, vestibular, and patient-reported measures in patients undergoing transmastoid occlusion surgery for superior canal dehiscence syndrome (SCDS).Study Design:Retrospective case review.Setting:Tertiary referral centre, UK.Patients:All primary transmastoid occlusion surgeries for SCDS were included (tertiary centre, single-surgeon), January 2008 to July 2019.Interventions:Transmastoid superior canal occlusion surgery for SCDS.Main Outcome Measures:We collated audiological (pure tone audiogram), vestibular (cervical vestibular evoked myogenic potentials [cVEMPs]), and patient-reported outcome measures (Dizziness Handicap Inventory and subjective symptom grading).Results:Fifty-two patients (55 ears) met the inclusion criteria. Thirty-one (56%) were female. Mean age was 47years (range 29-63) and mean follow-up of 11.2months. Six patients had bilateral disease, four of whom underwent sequential, bilateral surgery.Autophony was the most frequent presenting symptom, improving in 92%.Significant improvements were self-reported in patients' autophony (p<0.0001), pressure-and noise-induced dizziness (p<0.0001 and p<0.0001), aural fullness (p=0.0159), pulsatile tinnitus (p<0.0001), perceived hearing loss (p=0.0058), and imbalance (p=0.0303).Overall Dizziness Handicap Inventory scores reduced from 45.9 to 27.4 (p<0.0001), and across all subgroups of functional (p=0.0003), emotional (p<0.0001), and physical handicap (p=0.0005).A 6.4-dB HL improvement in the air-bone gap (500-1000Hz) occurred (95% confidence intervals 3.3-9.4dB HL, p<0.0001). There were no dead ears. cVEMP thresholds, when recordable, normalized in all except two ears.Conclusions:Transmastoid occlusion is effective at improving patient-reported outcomes and normalizing cVEMP thresholds, though some symptoms, notably disequilibrium, persist to a variable degree.