Performance and self-perceived hearing impairment after cochlear implantation in Menière's disease.

OBJECTIVE: Evaluation of the self-perceived hearing impairment and performance after cochlear implantation in patients with definite Menière's disease (MD). PATIENTS AND METHODS: Seventeen unilaterally or bilaterally profoundly hearing-impaired patients suffering from MD who received a cochlear implantat (CI) were eligible for inclusion in this study. Their self-perceived hearing impairment using the short Speech Spatial and Qualities of Hearing Scale (SSQ12) as well as their performance in speech perception (German language Freiburger mono- and multisyllable test, Oldenburger sentence test) were compared with a best-matched control group of non-MD patients up to 24 months of follow-up. RESULTS: MD patients improved significantly in perception of monosyllables presented at 65 dBSPL, from preoperatively best aided 18.2% [2.4, 34.0] to 51.7% [39.4, 63.9] 1 year after cochlear implantation (mean [95% confidence interval]). Their performance approached the matched controls with 63.2% [55.7, 70.8]. Monosyllables presented at a lower intensity of 55 dBSPL revealed a significant underperformance of the MD patients (21.1% [12.6, 29.6]) in contrast to the non-MD controls (39.1% [30.9, 47.4]) 12 months post-CI. Self-assessed hearing disability was significantly more pronounced in MD patients with a mean total SSQ12 score of 3.6 [2.4, 4.9] in comparison to 6.1 [5.4, 6.8] of the matched non-MD controls after 12 months of cochlear implantation. CONCLUSION: Cochlear implantation substantially improves hearing capabilities in profoundly hearing-impaired patients with MD, but they tend to underperform in comparison to non-MD patients at least at lower sound pressure levels. This is likely one reason for the poorer self-assessed hearing function of cochlear implanted MD patients. LEVEL OF EVIDENCE: 3, retrospective, nonrandomized follow-up study.

Access to the Apical Cochlear Modiolus for Possible Stem Cell-based and Gene Therapy of the Auditory Nerve.

OBJECTIVE: Loss of spiral ganglion neurons (SGN) is permanent and responsible for a substantial number of patients suffering from hearing impairment. It can derive from the degeneration of SGNs due to the death of sensory hair cells as well as from auditory neuropathy. Utilizing stem cells to recover lost SGNs increasingly emerges as a possible therapeutic option, but access to human SGNs is difficult due to their protected location within the bony impacted cochlea. Aim of this study was to establish a reliable and practicable approach to access SGNs in the human temporal bone for possible stem cell and gene therapies. METHODS: In seven human temporal bone specimen a transcanal approach was used to carefully drill a cochleostomy in the lateral second turn followed by insertion of a tungsten needle into the apical modiolus to indicate the spot for intramodiolar injections. Subsequent cone beam computed tomography (CBCT) served as evaluation for positioning of the marker and cochleostomy size. RESULTS: The apical modiolus could be exposed in all cases by a cochleostomy (1.6 mm2, standard deviation ±0.23 mm2) in the lateral second turn. 3D reconstructions and analysis of CBCT revealed reliable positioning of the marker in the apical modiolus, deviating on average 0.9 mm (standard deviation ±0.49 mm) from the targeted center of the second cochlear turn. CONCLUSION: We established a reliable, minimally invasive, transcanal surgical approach to the apical cochlear modiolus in the human temporal bone in foresight to stem cell-based and gene therapy of the auditory nerve.