Reduced sound-evoked and resting-state BOLD fMRI connectivity in tinnitus

Publication date: Available online 31 August 2018Source: NeuroImage: ClinicalAuthor(s): Benedikt Hofmeier, Stephan Wolpert, Ebrahim Saad Aldamer, Moritz Walter, John Thiericke, Christoph Braun, Dennis Zelle, Lukas Rüttiger, Uwe Klose, Marlies KnipperAbstractThe exact neurophysiological basis of chronic tinnitus, which affects 10–15% of the population, remains unknown and is controversial at many levels. It is an open question whether phantom sound perception results from increased central neural gain or not, a crucial question for any future therapeutic intervention strategies for tinnitus.We performed a comprehensive study of mild hearing-impaired participants with and without tinnitus, excluding participants with co-occurrences of hyperacusis. A right-hemisphere correlation between tinnitus loudness and auditory perceptual difficulty was observed in the tinnitus group, independent of differences in hearing thresholds. This correlation was linked to reduced and delayed sound-induced suprathreshold auditory brain responses (ABR wave V) in the tinnitus group, suggesting subsided rather than exaggerated central neural responsiveness. When anatomically predefined auditory regions of interest were analysed for altered sound-evoked BOLD fMRI activity, it became evident that subcortical and cortical auditory regions and regions involved in sound detection (posterior insula, hippocampus), responded with reduced BOLD activity in the tinnitus group, emphasizing reduced, rather than...
Source: NeuroImage: Clinical - Category: Radiology Source Type: research