title: Tinnitus-related dissociation between cortical and subcortical neural activity in humans with mild to moderate sensorineural hearing loss.
abstract: Tinnitus is a phantom sound percept that is strongly associated with peripheral hearing loss. However, only a fraction of hearing-impaired subjects develops tinnitus. This may be based on differences in the function of the brain between those subjects that develop tinnitus and those that do not. In this study, cortical and sub-cortical sound-evoked brain responses in 34 hearing-impaired chronic tinnitus patients and 19 hearing level-matched controls were studied using 3-T functional magnetic resonance imaging (fMRI). Auditory stimuli were presented to either the left or the right ear at levels of 30-90 dB SPL. We extracted neural activation as a function of sound intensity in eight auditory regions (left and right auditory cortices, medial geniculate bodies, inferior colliculi and cochlear nuclei), the cerebellum and a cinguloparietal task-positive region. The activation correlated positively with the stimulus intensity, and negatively with the hearing threshold. We found no differences between both groups in terms of the magnitude and lateralization of the sound-evoked responses, except for the left medial geniculate body and right cochlear nucleus where activation levels were elevated in the tinnitus subjects. We observed significantly reduced functional connectivity between the inferior colliculi and the auditory cortices in tinnitus patients compared to controls. Our results indicate a failure of thalamic gating in the development of tinnitus.
authors.affiliation: Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, The Netherlands; Graduate School of Medical Sciences, Research School of Behavioural and Cognitive Neurosciences, University of Groningen, The Netherlands. Electronic address: k.boyen@umcg.nl.
authors.forename: Kris
authors.initials: K
authors.lastname: Boyen
authors.affiliation: Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, The Netherlands; Graduate School of Medical Sciences, Research School of Behavioural and Cognitive Neurosciences, University of Groningen, The Netherlands.
authors.forename: Emile
authors.initials: E
authors.lastname: de Kleine
authors.affiliation: Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, The Netherlands; Graduate School of Medical Sciences, Research School of Behavioural and Cognitive Neurosciences, University of Groningen, The Netherlands.
authors.forename: Pim
authors.initials: P
authors.lastname: van Dijk
authors.affiliation: Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, The Netherlands; Graduate School of Medical Sciences, Research School of Behavioural and Cognitive Neurosciences, University of Groningen, The Netherlands; National Institute for Health Research (NIHR), Nottingham Hearing Biomedical Research Unit, University of Nottingham, Nottingham, UK.
authors.forename: Dave R M
authors.initials: DR
authors.lastname: Langers
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001303:Auditory Cortex / Q000503:physiopathology; D001306:Auditory Pathways / Q000503:physiopathology*; D017626:Cochlear Nucleus / Q000503:physiopathology; D007839:Functional Laterality / Q000502:physiology; D005829:Geniculate Bodies / Q000503:physiopathology*; D006319:Hearing Loss, Sensorineural / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D012001:Hyperacusis / Q000503:physiopathology; D007245:Inferior Colliculi / Q000503:physiopathology; D016014:Linear Models; D008875:Middle Aged; D012720:Severity of Illness Index; D014012:Tinnitus / Q000150:complications / Q000503:physiopathology*