OBJECTIVE: To monitor cochlear function by extra- and intra-cochlear electrocochleography (ECoG) during and after cochlear implantation and thereby to enhance the understanding of changes in cochlear function following cochlear implantation surgery. METHODS: ECoG responses to acoustic stimuli of 250, 500 and 1,000 Hz were recorded in 9 cochlear implant recipients with presurgical residual hearing. During surgery extracochlear ECoG recordings were performed before and after insertion of the cochlear implant electrode array. After insertion of the electrode array, intracochlear ECoG recordings were conducted using intracochlear electrode contacts as recording electrodes. Intracochlear ECoG recordings were performed up to 6 months after implantation.ECoG findings were correlated with findings from audiometric tests. RESULTS: Extra- and intracochlear ECoG responses could be recorded in all subjects. Extracochlear ECoG recordings during surgery showed moderate changes.Loss or reduction of the ECoG signal at all three frequencies did not occur during cochlear implantation. During the first week following surgery, conductive hearing loss, due to middle ear effusion, led to a decrease in intracochlear ECoG signal amplitudes. This was not attributable to changes of cochlear function. All persistent reductions in ECoG response magnitude after normalization of the tympanogram occurred during the first week following implantation. Thresholds of ECoG signals were at or below hearing thresholds in all cases. CONCLUSION: Gross intracochlear trauma during surgery appears to be rare. In the early postoperative phase the ability to assess cochlear status by ECoG recordings was limited due to the regular occurrence of middle ear effusion.Still, intracochlear ECoG along with tympanogram recordings suggests that any changes of low-frequency cochlear function occur mainly during the first week after cochlear implantation. ECoG seems to be a promising tool to objectively assess changes in cochlear function in cochlear implant recipients and may allow further insight into the mechanisms underlying the loss of residual hearing.
OBJECTIVE: To monitor cochlear function by extra- and intra-cochlear electrocochleography (ECoG) during and after cochlear implantation and thereby to enhance the understanding of changes in cochlear function following cochlear implantation surgery. METHODS: ECoG responses to acoustic stimuli of 250, 500 and 1,000 Hz were recorded in 9 cochlear implant recipients with presurgical residual hearing. During surgery extracochlear ECoG recordings were performed before and after insertion of the cochlear implant electrode array. After insertion of the electrode array, intracochlear ECoG recordings were conducted using intracochlear electrode contacts as recording electrodes. Intracochlear ECoG recordings were performed up to 6 months after implantation.ECoG findings were correlated with findings from audiometric tests. RESULTS: Extra- and intracochlear ECoG responses could be recorded in all subjects. Extracochlear ECoG recordings during surgery showed moderate changes.Loss or reduction of the ECoG signal at all three frequencies did not occur during cochlear implantation. During the first week following surgery, conductive hearing loss, due to middle ear effusion, led to a decrease in intracochlear ECoG signal amplitudes. This was not attributable to changes of cochlear function. All persistent reductions in ECoG response magnitude after normalization of the tympanogram occurred during the first week following implantation. Thresholds of ECoG signals were at or below hearing thresholds in all cases. CONCLUSION: Gross intracochlear trauma during surgery appears to be rare. In the early postoperative phase the ability to assess cochlear status by ECoG recordings was limited due to the regular occurrence of middle ear effusion.Still, intracochlear ECoG along with tympanogram recordings suggests that any changes of low-frequency cochlear function occur mainly during the first week after cochlear implantation. ECoG seems to be a promising tool to objectively assess changes in cochlear function in cochlear implant recipients and may allow further insight into the mechanisms underlying the loss of residual hearing.
Authors: Artur Lorens; Adam Walkowiak; Marek Polak; Aleksandra Kowalczuk; Mariusz Furmanek; Henryk Skarzynski; Anita Obrycka Journal: J Int Adv Otol Date: 2019-12 Impact factor: 1.017
Authors: William J Riggs; Robert T Dwyer; Jourdan T Holder; Jameson K Mattingly; Amanda Ortmann; Jack H Noble; Benoit M Dawant; Carla V Valenzuela; Brendan P O'Connell; Michael S Harris; Leonid M Litvak; Kanthaiah Koka; Craig A Buchman; Robert F Labadie; Oliver F Adunka Journal: Otol Neurotol Date: 2019-06 Impact factor: 2.311
Authors: Thomas Lenarz; Andreas Buechner; Bruce Gantz; Marlan Hansen; Viral D Tejani; Robert Labadie; Brendan O'Connell; Craig Alan Buchman; Carla V Valenzuela; Oliver F Adunka; Michael S Harris; William J Riggs; Douglas Fitzpatrick; Kanthaiah Koka Journal: Otol Neurotol Date: 2022-01-01 Impact factor: 2.311
Authors: Christopher K Giardina; Tatyana E Khan; Stephen H Pulver; Oliver F Adunka; Craig A Buchman; Kevin D Brown; Harold C Pillsbury; Douglas C Fitzpatrick Journal: Ear Hear Date: 2018 Nov/Dec Impact factor: 3.570
Authors: Christopher K Giardina; Kevin D Brown; Oliver F Adunka; Craig A Buchman; Kendall A Hutson; Harold C Pillsbury; Douglas C Fitzpatrick Journal: Ear Hear Date: 2019 Jul/Aug Impact factor: 3.570
Authors: Tatyana Elizabeth Fontenot; Christopher Kenneth Giardina; Margaret Dillon; Meredith A Rooth; Holly F Teagle; Lisa R Park; Kevin David Brown; Oliver F Adunka; Craig A Buchman; Harold C Pillsbury; Douglas C Fitzpatrick Journal: Ear Hear Date: 2019 May/Jun Impact factor: 3.570