HYPOTHESIS: Acoustically evoked neural and hair cell potentials can be measured from the round window (RW) intraoperatively in the general population of cochlear implant recipients. BACKGROUND: Cochlear implant performance varies greatly among patients. Improved methods to assess and monitor functional hair cell and neural substrate before and during implantation could potentially aid in enhanced nontraumatic intracochlear electrode placement and subsequent improved outcomes. METHODS: Subjects (1-80 yr) undergoing cochlear implantation were included. A monopolar probe was placed at the RW after surgical access was obtained. The cochlear microphonic (CM), summating potential (SP), compound action potential (CAP), and auditory nerve neurophonic (ANN) were recorded in response to tone bursts at frequencies of 0.25 to 4 kHz at various levels. RESULTS: Measurable hair cell/neural potentials were detected to 1 or more frequencies in 23 of 25 subjects. The greatest proportion and magnitude of cochlear responses were to low frequencies (<1,000 Hz). At these low frequencies, the ANN, when present, contributed to the ongoing response at the stimulus frequency. In many subjects, the ANN was small or absent, whereas hair cell responses remained. CONCLUSION: In cochlear implant recipients, acoustically evoked cochlear potentials are detectable even if hearing is extremely limited. Sensitive measures of cochlear and neural status can characterize the state of hair cell and neural function before implantation. Whether this information correlates with speech performance outcomes or can help in tailoring electrode type, placement or audiometric fitting, can be determined in future studies.
HYPOTHESIS: Acoustically evoked neural and hair cell potentials can be measured from the round window (RW) intraoperatively in the general population of cochlear implant recipients. BACKGROUND: Cochlear implant performance varies greatly among patients. Improved methods to assess and monitor functional hair cell and neural substrate before and during implantation could potentially aid in enhanced nontraumatic intracochlear electrode placement and subsequent improved outcomes. METHODS: Subjects (1-80 yr) undergoing cochlear implantation were included. A monopolar probe was placed at the RW after surgical access was obtained. The cochlear microphonic (CM), summating potential (SP), compound action potential (CAP), and auditory nerve neurophonic (ANN) were recorded in response to tone bursts at frequencies of 0.25 to 4 kHz at various levels. RESULTS: Measurable hair cell/neural potentials were detected to 1 or more frequencies in 23 of 25 subjects. The greatest proportion and magnitude of cochlear responses were to low frequencies (<1,000 Hz). At these low frequencies, the ANN, when present, contributed to the ongoing response at the stimulus frequency. In many subjects, the ANN was small or absent, whereas hair cell responses remained. CONCLUSION: In cochlear implant recipients, acoustically evoked cochlear potentials are detectable even if hearing is extremely limited. Sensitive measures of cochlear and neural status can characterize the state of hair cell and neural function before implantation. Whether this information correlates with speech performance outcomes or can help in tailoring electrode type, placement or audiometric fitting, can be determined in future studies.
Authors: P Blamey; P Arndt; F Bergeron; G Bredberg; J Brimacombe; G Facer; J Larky; B Lindström; J Nedzelski; A Peterson; D Shipp; S Staller; L Whitford Journal: Audiol Neurootol Date: 1996 Sep-Oct Impact factor: 1.854
Authors: Michael S Harris; William J Riggs; Christopher K Giardina; Brendan P O'Connell; Jourdan T Holder; Robert T Dwyer; Kanthaiah Koka; Robert F Labadie; Douglas C Fitzpatrick; Oliver F Adunka Journal: Otol Neurotol Date: 2017-12 Impact factor: 2.311
Authors: Andrew K Pappa; Kendall A Hutson; William C Scott; J David Wilson; Kevin E Fox; Maheer M Masood; Christopher K Giardina; Stephen H Pulver; Gilberto D Grana; Charles Askew; Douglas C Fitzpatrick Journal: J Neurophysiol Date: 2019-04-03 Impact factor: 2.714
Authors: William C Scott; Christopher K Giardina; Andrew K Pappa; Tatyana E Fontenot; Meredith L Anderson; Margaret T Dillon; Kevin D Brown; Harold C Pillsbury; Oliver F Adunka; Craig A Buchman; Douglas C Fitzpatrick Journal: Otol Neurotol Date: 2016-12 Impact factor: 2.311
Authors: Douglas C Fitzpatrick; Adam P Campbell; Adam T Campbell; Baishakhi Choudhury; Margaret T Dillon; Margaret P Dillon; Mathieu Forgues; Craig A Buchman; Oliver F Adunka Journal: Otol Neurotol Date: 2014-01 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: Oliver F Adunka; Christopher K Giardina; Eric J Formeister; Baishakhi Choudhury; Craig A Buchman; Douglas C Fitzpatrick Journal: Laryngoscope Date: 2015-09-11 Impact factor: 3.325
Authors: Baishakhi Choudhury; Oliver Franz Adunka; Omar Awan; John Maxwell Pike; Craig A Buchman; Douglas C Fitzpatrick Journal: Otol Neurotol Date: 2014-03 Impact factor: 2.311