Intrinsic network activity in tinnitus investigated using functional MRI.
Tinnitus is an increasingly common disorder in which patients experience phantom auditory sensations, usually ringing or buzzing in the ear. Tinnitus pathophysiology has been repeatedly shown to involve both auditory and non-auditory brain structures, making network-level studies of tinnitus critical. In this magnetic resonance imaging (MRI) study, two resting-state functional connectivity (RSFC) approaches were used to better understand functional network disturbances in tinnitus. First, we demonstrated tinnitus-related reductions in RSFC between specific brain regions and resting-state networks (RSNs), defined by independent components analysis (ICA) and chosen for their overlap with structures known to be affected in tinnitus. Then, we restricted ICA to data from tinnitus patients, and identified one RSN not apparent in control data. This tinnitus RSN included auditory-sensory regions like inferior colliculus and medial Heschl's gyrus, as well as classically non-auditory regions like the mediodorsal nucleus of the thalamus, striatum, lateral prefrontal, and orbitofrontal cortex. Notably, patients' reported tinnitus loudness was positively correlated with RSFC between the mediodorsal nucleus and the tinnitus RSN, indicating that this network may underlie the auditory-sensory experience of tinnitus. These data support the idea that tinnitus involves network dysfunction, and further stress the importance of communication between auditory-sensory and fronto-striatal circuits in tinnitus pathophysiology. Hum Brain Mapp 37:2717-2735, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia.|Department of Neurology, University of California Los Angeles, Los Angeles, California.
Amber M
AM
Leaver
Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia.
Ted K
TK
Turesky
Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia.
Anna
A
Seydell-Greenwald
Division of Audiology, Medstar Georgetown University Hospital, Washington, District of Columbia.
Susan
S
Morgan
Department of Otolaryngology, Medstar Georgetown University Hospital, Washington, District of Columbia.
Hung J
HJ
Kim
Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia.|Institute for Advanced Study, TU Munich, Germany.
Josef P
JP
Rauschecker
D000328:Adult; D000368:Aged; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology*; D014012:Tinnitus / Q000503:physiopathology*
auditory; fMRI; functional connectivity; hearing loss; striatum; thalamus