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Updated: Mar 17, 2026

Cochlear Implantation in the Guinea Pig
Published on: June 15, 2018
Extended use of systemic steroid is beneficial in preserving hearing in guinea pigs after cochlear implant
Yoon Chan Rah1,2, Min Young Lee1, Shin Hye Kim1
1a Department of Otorhinolaryngology-Head and Neck Surgery , Seoul National University College of Medicine , Seoul , Republic of Korea.
Conclusion:
Seven-day administration of systemic steroids was more effective in preserving hearing for 12 weeks after cochlear implantation (CI) than a 3-day delivery.
Objectives:
To determine the effectiveness of extended delivery of systemic steroids to preserve hearing in guinea pigs after CI.
Methods:
Dexamethasone (4 mg/ml) was delivered parenterally via a mini-osmotic pump for either 3 or 7 days. A dummy CI electrode was inserted via cochleostomy approach in 8-week-old guinea pigs. Auditory thresholds were assessed from tone burst auditory brainstem responses (2, 8, 16, 24, and 32 kHz) at 1 day prior to CI, and 1, 4, and 12 weeks after implantation. Histologic evaluation of the cochleae was carried out.
Results:
No differences were observed in hearing thresholds among groups before CI. Significant hearing preservation was achieved at 8, 16, 24, and 32 kHz only in the 7-day infusion group compared with the control group at 1 week after CI. The same trend was maintained at 4 weeks (16, 24 kHz) and 12 weeks (16, 24, and 32 kHz). Histologic review of the 7-day infusion group revealed less fibrosis and ossification in the scala tympani and the preservation of more spiral ganglion cells, compared with the control group.

