Objectives-1) Investigate the impact of electrode type and surgical approach on scalar electrode location in a large patient cohort; and 2) examine the relation between electrode location and postoperative audiologic performance. Setting-Tertiary academic hospital. Patients-220 post-lingually deafened adults undergoing cochlear implant (CI).Main Outcome Measures-Primary outcome measures of interest were scalar electrode location and postoperative audiologic performance.Results-In 68% of implants, electrodes were observed to be located solely in the scala tympani (ST). Multivariate analysis demonstrated perimodiolar(PM) and Mid-scala(MS) electrodes were p<0.001) times more likely to have at least one electrode in the scala vestibuli (SV) compared to lateral wall(LW) electrodes, respectively. Compared to cochleostomy(C), round window(RW) and extended round window(ERW) approaches demonstrated 70% reduction in SV insertion (OR 0.28,95%CI:0.1-0.8, p=0.01; ERW (OR O.28,95%CI:0.1-0.7, p=0.005). Examining postoperative audiometric performance, CNC score increased 0.6% with every 10° increase in angular insertion depth beyond the group minimum of 208° (Coefficient 0.0006,95%CI:0.0001-0.001, p=0.03). SV insertion was associated with a 12% decrease in CNC score (Coefficient -0.12,95%CI:-0.22--0.02, p=0.02). CNC score decreased 0.3% for every 1 year increase in age (Coefficient -0.003,95%CI:-0.006--0.0006), p=0.02). HHS Public Access Author Manuscript Author ManuscriptAuthor Manuscript Author ManuscriptConclusions-Electrode design and surgical approach were predictors of scalar electrode location. Specifically, LW electrodes showed higher rates of ST insertion compared to PM or MS. RW and ERW approaches showed higher rates of ST insertion when compared to C. In regards to performance, ST insertion, younger age, and greater angular insertion depth were predictors of improved CNC scores.

No abstract

Objectives To determine whether cervical vestibular evoked myogenic potential (cVEMP) thresholds or ocular VEMP amplitudes are more sensitive and specific in the diagnosis of superior semicircular canal dehiscence syndrome (SCDS). Study design Prospective case-control study Setting Tertiary referral center Subjects and Methods 29 patients with SCDS (mean age 48y; range 31–66y) and 25 age-matched controls (mean age 48y; range 30–66y). Intervention(s) cVEMP and oVEMP in response to air-conducted sound (ACS). All patients underwent surgery for repair of SCDS. Main outcome measure(s) cVEMP thresholds; oVEMP n10 and peak-to-peak amplitudes. Results cVEMP threshold results showed sensitivity and specificity ranging from 80–100% for the diagnosis of SCDS. In contrast, oVEMP amplitudes demonstrated sensitivity and specificity >90%. Conclusions oVEMP amplitudes are superior to cVEMP thresholds in the diagnosis of SCDS.

Objective To describe the incidence, clinical presentation, and performance of cochlear implant (CI) recipients with tip fold-over. Study design Retrospective case series. Setting Tertiary referral center. Patients CI recipients who underwent postoperative CT scanning. Intervention(s) Tip fold-over was identified tomographically using previously-validated software that identifies the electrode array. Electrophysiologic testing including spread of excitation (SOE) or electric field imaging (EFI) was measured on those with fold-over. Main outcome measure(s) Location of the fold-over; audiological performance pre and post selective deactivation of fold-over electrodes. Results 303 ears of 235 CI recipients had postoperative CTs available for review. Six (1.98%) had tip fold-over with 5/6 right-sided ears. Tip fold-over occurred predominantly at 270° and was associated with pre-curved electrodes (5/6). Patients did not report audiological complaints during initial activation. In one patient, the electrode array remained within the scala tympani with preserved residual hearing despite the fold-over. SOE supported tip fold-over, but the predictive value was not clear. EFI predicted location of the fold-over with clear predictive value in one patient. At an average follow-up of 11 months, three subjects underwent deactivation of the overlapping electrodes with two of them showing marked audiological improvement. Conclusions In a large academic center with experienced surgeons, tip fold-over occurred at a rate of 1.98% but was not immediately identifiable clinically. CT imaging definitively showed tip fold-over. Deactivating involved electrodes may improve performance possibly avoiding revision surgery. EFI may be highly predictive of tip fold-over and can be run intraoperatively, potentially obviating the need for intra-op fluoroscopy.

No abstract