Headache Impact Test (HIT-6). The HIT-6 data revealed that there was a highly statistically significant improvement pre- versus postoperatively (p < 0.001) overall and between groups, yet there are two patients who quantitatively became Class II and one patient remained a Class IV postoperatively. The remaining 11 patients became Class I. For the no-iOCD patients, the mean HIT-6 score was 74 (range, 68–78 [all Class IV], SD ± 4 preoperatively and 45.7 (range, 42–49 [all Class I], SD ± 3.14) postoperatively. This improvement was statistically significant (p < 0.001). For the both SCD and subsequent no-iOCD patients, the mean HIT-6 score was 69.3 (range, 57–78 [one Class III, three Class IV], SD ± 9.7 preoperatively and 46.8 (range, 36–53 [two Class II and two Class I], SD ± 8.10) postoperatively. This improvement was statistically significant (p < 0.001). For the SCD only patients, the mean HIT-6 score was 69.8 (range, 61–76 [all Class IV], SD ± 6.34 preoperatively and 44.5 (range, 36–61 [one Class IV and three Class I], SD ± 11.27) postoperatively. This improvement was statistically significant (p < 0.001). Both indicates SCD plugging, subsequent development of no-iOCD managed with RWR; no-iOCD, no imaging visible otic capsule dehiscence only managed with RWR; SCD, superior semicircular canal dehiscence only managed with middle cranial fossa approach and plugging. Copyright © Ear and Skull Base Center, used with permission.