TY - JOUR
T1 - Intraoperative electrocochleographic characteristics of auditory neuropathy spectrum disorder in cochlear implant subjects
AU - Riggs, William J.
AU - Roche, Joseph P.
AU - Giardina, Christopher K.
AU - Harris, Michael S.
AU - Bastian, Zachary J.
AU - Fontenot, Tatyana E.
AU - Buchman, Craig A.
AU - Brown, Kevin D.
AU - Adunka, Oliver F.
AU - Fitzpatrick, Douglas C.
N1 - Publisher Copyright:
© 2017 Riggs, Roche, Giardina, Harris, Bastian, Fontenot, Buchman, Brown, Adunka and Fitzpatrick.
PY - 2017/7/19
Y1 - 2017/7/19
N2 - Auditory neuropathy spectrum disorder (ANSD) is characterized by an apparent discrepancy between measures of cochlear and neural function based on auditory brainstem response (ABR) testing. Clinical indicators of ANSD are a present cochlear microphonic (CM) with small or absent wave V. Many identified ANSD patients have speech impairment severe enough that cochlear implantation (CI) is indicated. To better understand the cochleae identified with ANSD that lead to a CI, we performed intraoperative round window electrocochleography (ECochG) to tone bursts in children (n = 167) and adults (n = 163). Magnitudes of the responses to tones of different frequencies were summed to measure the "total response" (ECochG-TR), a metric often dominated by hair cell activity, and auditory nerve activity was estimated visually from the compound action potential (CAP) and auditory nerve neurophonic (ANN) as a ranked "Nerve Score". Subjects identified as ANSD (45 ears in children, 3 in adults) had higher values of ECochG-TR than adult and pediatric subjects also receiving CIs not identified as ANSD. However, nerve scores of the ANSD group were similar to the other cohorts, although dominated by the ANN to low frequencies more than in the non-ANSD groups. To high frequencies, the common morphology of ANSD cases was a large CM and summating potential, and small or absent CAP. Common morphologies in other groups were either only a CM, or a combination of CM and CAP. These results indicate that responses to high frequencies, derived primarily from hair cells, are the main source of the CM used to evaluate ANSD in the clinical setting. However, the clinical tests do not capture the wide range of neural activity seen to low frequency sounds.
AB - Auditory neuropathy spectrum disorder (ANSD) is characterized by an apparent discrepancy between measures of cochlear and neural function based on auditory brainstem response (ABR) testing. Clinical indicators of ANSD are a present cochlear microphonic (CM) with small or absent wave V. Many identified ANSD patients have speech impairment severe enough that cochlear implantation (CI) is indicated. To better understand the cochleae identified with ANSD that lead to a CI, we performed intraoperative round window electrocochleography (ECochG) to tone bursts in children (n = 167) and adults (n = 163). Magnitudes of the responses to tones of different frequencies were summed to measure the "total response" (ECochG-TR), a metric often dominated by hair cell activity, and auditory nerve activity was estimated visually from the compound action potential (CAP) and auditory nerve neurophonic (ANN) as a ranked "Nerve Score". Subjects identified as ANSD (45 ears in children, 3 in adults) had higher values of ECochG-TR than adult and pediatric subjects also receiving CIs not identified as ANSD. However, nerve scores of the ANSD group were similar to the other cohorts, although dominated by the ANN to low frequencies more than in the non-ANSD groups. To high frequencies, the common morphology of ANSD cases was a large CM and summating potential, and small or absent CAP. Common morphologies in other groups were either only a CM, or a combination of CM and CAP. These results indicate that responses to high frequencies, derived primarily from hair cells, are the main source of the CM used to evaluate ANSD in the clinical setting. However, the clinical tests do not capture the wide range of neural activity seen to low frequency sounds.
KW - Auditory neuropathy spectrum disorder
KW - Cochlear implants
KW - Cochlear microphonic
KW - Electrocochleography
KW - Intraoperative
KW - Pediatrics
UR - http://www.scopus.com/inward/record.url?scp=85025690982&partnerID=8YFLogxK
U2 - 10.3389/fnins.2017.00416
DO - 10.3389/fnins.2017.00416
M3 - Article
C2 - 28769753
AN - SCOPUS:85025690982
SN - 1662-4548
VL - 11
JO - Frontiers in Neuroscience
JF - Frontiers in Neuroscience
IS - JUL
M1 - 416
ER -