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Objective: To compare subjective and objective findings between patients with true dehiscence versus thin bone over the superior semicircular canal (SSC)., Study Design: Retrospective case series., Setting: Tertiary referral center., Patients: All patients from our institution with true dehiscence or thin bone over the SSC on computed tomography temporal bone (oblique view) from 2007 to 2013., Main Outcome Measures: Subjective test: Dizziness Handicap Inventory (DHI). Objective tests: Infrared video eye recording with varying stimuli (Tulio, Fistula, and Vibration); vestibular evoked myogenic potential (VEMP); electrocochleography; videonystagmography; pure-tone audiometry (i.e., air-bone gap)., Results: Fifty-four patients (64 ears) were reviewed. Thirty-nine patients (47 ears) had true dehiscence of the SSC on temporal bone computed tomography. Fifteen patients (17 ears) had thin bone over the SSC. There was no statistical difference in DHI scores for patients with true dehiscence versus those with thin bone over the SSC. Only cervical VEMP and air-bone gap via pure-tone audiometry revealed a significant difference between the two groups. The remaining vestibular assessments did not demonstrate any difference. No significant correlations were revealed between DHI and objective test findings across and within the two groups., Conclusion: Among the objective tests, cervical VEMP and pure-tone audiometry are the only tools to distinguish between true dehiscence and thin bone over the SSC. DHI does not differentiate between these two groups. Furthermore, no correlation exists between DHI and any objective finding. Further investigation is necessary to develop a validated subjective symptom index of patients with SSC syndrome.

Objective: To determine if age affects radiographic incidence of superior semicircular canal dehiscence (SSCD) in pediatric patients., Study Design: Retrospective case review., Setting: Tertiary children's hospital., Patients: Patients (0-18 yr) with high-resolution computed tomography (CT) temporal bone scans from April 2001 to February 2013., Interventions: Diagnostic high-resolution CT temporal bone scans., Main Outcome Measures: Findings of dehiscent, thin, or normal SSC on CT scans (including reconstructed Poschl views). Interobserver radiographic interpretation rate between neuroradiologist and otologist., Results: Seven-hundred CT scans (1,400 ears) were reviewed, and 1,188 ears were acceptable for analysis. Twenty-three ears (1.9%) had dehiscent SSC, 185 ears (15.6%) had thin SSC, and 980 ears (82.5%) had normal SSC. Median ages of dehiscent, thin, and normal canals were 5, 7, and 9 years, respectively ( p < 0.05). As age increased, the incidence of dehiscent and thin SCC cases decreased; for example, dehiscent or thin canal existed in 51.4% of children less than 12 months, 17.5% of children between 1 and 2 years, 18.5% of children between 3 and 10 years, and 10.9% of children between 11 and 18 years. The κ value of agreement between neuroradiologist and otologist was 0.814, demonstrating a high value of agreement (p < 0.05)., Conclusion: Radiographic SSCD, although uncommon, appears to be more prevalent in younger children, especially infants younger than 12 months. This suggests that the SSC may develop more bony covering with age.

Hypothesis: To determine the best method of removing hydroxyapatite cement from the temporal bone in the postoperative period., Background: The advent of hydroxyapatite cement in neurotologic surgery of the temporal bone has dramatically decreased the rate of postoperative cerebrospinal fluid leaks. However, there is no literature currently available on how to manage these patients in the setting of postoperative hematomas of the cerebellopontine angle., Methods: Nine cadaveric temporal bones were obtained that had previously undergone translabyrinthine approach drilling in an academic temporal bone lab. Fascia and adipose tissue were placed medial to the facial nerve and the temporal bone was then filled with hydroxyapatite cement to the level of the cortex. Removal of hydroxyapatite cement was undertaken using a Freer elevator, mastoid bone curette, and finally, a drill in sequential fashion. This occurred at 9 predetermined time intervals from 1 to 30 hours and was timed in each case., Results: Removal using the freer and curette failed in each case, and the drill was ultimately used to remove the hydroxyapatite cement in all cases. The time to reach the packed fascia and adipose tissue varied from 3 to 6 minutes, average time is 4.27 ± 0.84 minutes., Conclusion: Although hydroxyapatite cement has dramatically decreased the rate of postoperative cerebrospinal fluid leak in translabyrinthine surgery, its use has also brought a new set of considerations. This study suggests that hydroxyapatite cement removal in the setting of postoperative hematoma after translabyrinthine surgery would require drilling rather than bedside incisional opening alone. Like standard craniotomy approaches, postoperative hemorrhage management requires intraoperative drainage.