TY - JOUR
T1 - The association between subcortical and cortical fMRI and lifetime noise exposure in listeners with normal hearing thresholds
AU - Dewey, Rebecca S.
AU - Francis, Susan T.
AU - Guest, Hannah
AU - Prendergast, Garreth
AU - Millman, Rebecca E.
AU - Plack, Christopher J.
AU - Hall, Deborah A.
N1 - Funding Information:
Professor Deborah Hall is an NIHR Senior Investigator and this research was supported by the NIHR Manchester Biomedical Research Centre and NIHR Nottingham Biomedical Research Centre . This work is supported by a Medical Research Council grant [ MR/L003589/1 ] awarded to the University of Manchester .
Funding Information:
Professor Deborah Hall is an NIHR Senior Investigator and this research was supported by the NIHR Manchester Biomedical Research Centre and NIHR Nottingham Biomedical Research Centre. This work is supported by a Medical Research Council grant [MR/L003589/1] awarded to the University of Manchester.
Publisher Copyright:
© 2019
PY - 2020/1/1
Y1 - 2020/1/1
N2 - In animal models, exposure to high noise levels can cause permanent damage to hair-cell synapses (cochlear synaptopathy) for high-threshold auditory nerve fibers without affecting sensitivity to quiet sounds. This has been confirmed in several mammalian species, but the hypothesis that lifetime noise exposure affects auditory function in humans with normal audiometric thresholds remains unconfirmed and current evidence from human electrophysiology is contradictory. Here we report the auditory brainstem response (ABR), and both transient (stimulus onset and offset) and sustained functional magnetic resonance imaging (fMRI) responses throughout the human central auditory pathway across lifetime noise exposure. Healthy young individuals aged 25–40 years were recruited into high (n = 32) and low (n = 30) lifetime noise exposure groups, stratified for age, and balanced for audiometric threshold up to 16 kHz fMRI demonstrated robust broadband noise-related activity throughout the auditory pathway (cochlear nucleus, superior olivary complex, nucleus of the lateral lemniscus, inferior colliculus, medial geniculate body and auditory cortex). fMRI responses in the auditory pathway to broadband noise onset were significantly enhanced in the high noise exposure group relative to the low exposure group, differences in sustained fMRI responses did not reach significance, and no significant group differences were found in the click-evoked ABR. Exploratory analyses found no significant relationships between the neural responses and self-reported tinnitus or reduced sound-level tolerance (symptoms associated with synaptopathy). In summary, although a small effect, these fMRI results suggest that lifetime noise exposure may be associated with central hyperactivity in young adults with normal hearing thresholds.
AB - In animal models, exposure to high noise levels can cause permanent damage to hair-cell synapses (cochlear synaptopathy) for high-threshold auditory nerve fibers without affecting sensitivity to quiet sounds. This has been confirmed in several mammalian species, but the hypothesis that lifetime noise exposure affects auditory function in humans with normal audiometric thresholds remains unconfirmed and current evidence from human electrophysiology is contradictory. Here we report the auditory brainstem response (ABR), and both transient (stimulus onset and offset) and sustained functional magnetic resonance imaging (fMRI) responses throughout the human central auditory pathway across lifetime noise exposure. Healthy young individuals aged 25–40 years were recruited into high (n = 32) and low (n = 30) lifetime noise exposure groups, stratified for age, and balanced for audiometric threshold up to 16 kHz fMRI demonstrated robust broadband noise-related activity throughout the auditory pathway (cochlear nucleus, superior olivary complex, nucleus of the lateral lemniscus, inferior colliculus, medial geniculate body and auditory cortex). fMRI responses in the auditory pathway to broadband noise onset were significantly enhanced in the high noise exposure group relative to the low exposure group, differences in sustained fMRI responses did not reach significance, and no significant group differences were found in the click-evoked ABR. Exploratory analyses found no significant relationships between the neural responses and self-reported tinnitus or reduced sound-level tolerance (symptoms associated with synaptopathy). In summary, although a small effect, these fMRI results suggest that lifetime noise exposure may be associated with central hyperactivity in young adults with normal hearing thresholds.
KW - Auditory brainstem response
KW - Auditory pathways
KW - Functional magnetic resonance imaging
KW - Noise induced hearing loss
UR - http://www.scopus.com/inward/record.url?scp=85073064573&partnerID=8YFLogxK
U2 - 10.1016/j.neuroimage.2019.116239
DO - 10.1016/j.neuroimage.2019.116239
M3 - Article
C2 - 31586673
AN - SCOPUS:85073064573
SN - 1053-8119
VL - 204
JO - NeuroImage
JF - NeuroImage
M1 - 116239
ER -