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DOI: 10.1055/s-0038-1640248
Effects of locally applied GeranyGeranyLacetone (GGA) on electrode insertion trauma in cochlea implanted (CI) guinea pigs
Med El, Starnberg
Objective:
Cochlear implantation in patients with residual hearing can lead to hearing loss (HL) caused by e.g. inflammation. Preserving hearing is essential in patients who are candidates for combined electric and acoustic stimulation (EAS). Glucocorticoids are one possibility to counteract loss of residual hearing. GGA has been successfully tested to alleviate noise induced HL and age related HL. GGA is a non-toxic inducer of HSF1 which inhibits inflammatory cytokines.
Methods:
Two groups of hearing Guinea pigs were implanted with a custom-made electrode (MED-EL). GGA or ringer solution was infused via cochleostomy before using a micro-syringe pump. The second ear was treated likewise omitting implantation. HL was tested before and after application at day 0, 3 and 7 postop by measuring click evoked CAPs and frequency specific CAP audiograms via electrodes implanted near the round window. Additionally electrode impedances were determined for the implant contacts at each time point.
Results:
Differences found between GGA and control group were not statistically significant. However, there was one visible trend: CAP-thresholds were higher at all frequencies at day 0 in the GGA treated group but decreased to lower thresholds compared to controls at days 3 and 7. Similar results but with less HL were found at the control side. There was also a trend for lower impedances in the GGA group. HL at the implanted side of both groups showed a gradient from high (30 – 40dB) at the base to low frequencies (5 – 15 dB) at the apex.
Conclusions:
Although not significant, the slight decrease of CAP thresholds and impedances suggests that GGA might have the potential to preserve hearing after implantation. Higher dosage and/or sustained drug application could enhance the efficacy.
Mit freundlicher Unterstützung von Med El
Publication History
Publication Date:
18 April 2018 (online)
© 2018. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).
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