Altered Spatial and Temporal Brain Connectivity in the Salience Network of Sensorineural Hearing Loss and Tinnitus

• Published in: Frontiers in neuroscience Vol. 13; p. 246
• Main Authors: Xu, Xiao-Min, Jiao, Yun, Tang, Tian-Yu, Lu, Chun-Qiang, Zhang, Jian, Salvi, Richard, Teng, Gao-Jun
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Research Foundation 19.03.2019; Frontiers Media S.A
• Subjects: Anxiety; Auditory deprivation; Brain; Brain mapping; Cerebellum; Cognition; Cognition & reasoning; Correlation analysis; Cortex (cingulate); Cortex (frontal); Ears & hearing; effective connectivity; Frontal gyrus; functional connectivity; Functional magnetic resonance imaging; Hearing loss; Hospitals; Mental depression; Neural networks; Neuroscience; non-auditory symptom; Precentral gyrus; salience network; sensorineural hearing loss; Sensory integration; Somatosensory cortex; Supplementary motor area; Temporal cortex; Temporal gyrus; Tinnitus; China; sensorineural hearing loss; functional connectivity; salience network; tinnitus; non-auditory symptom; effective connectivity
• ISSN: 1662-4548; 1662-453X; 1662-453X
• DOI: 10.3389/fnins.2019.00246

Sensorineural hearing loss (SNHL), sometimes accompanied with tinnitus, is associated with dysfunctions within and outside the classical auditory pathway. The salience network, which is anchored in bilateral anterior insula and dorsal anterior cingulate cortex, has been implicated in sensory integration. Partial auditory deprivation could alter the characteristics of the salience network and other related brain areas, thereby contributing to hearing impairments-induced neuropsychiatric symptoms. To test this hypothesis, we performed fMRI scanning and neuropsychological tests on 32 subjects with long-term bilateral hearing impairment and 30 well-matched Controls. Non-directional functional connectivity and directional Granger causality analysis were used to identify aberrant spatial and temporal patterns of connections targeting bilateral anterior insula and dorsal anterior cingulate cortex. We found that the left anterior insula showed decreased connectivity with right precentral gyrus and superior frontal gyrus. The connections between the dorsal anterior cingulate cortex and middle frontal gyrus, superior parietal gyrus and supplementary motor area (SMA) were also reduced. Relative to Controls, SNHL patients showed abnormal effective connectivity of the salience network, including inferior temporal gyrus, cerebellum lobule VI, lobule VIII, precentral gyrus, middle frontal gyrus and SMA. Furthermore, correlation analysis demonstrated that some of these atypical connectivity measures were correlated with performance of neuropsychiatric tests. These findings suggest that the inefficient modulation of the salience network might contribute to the neural basis of SNHL and tinnitus, as well as associated cognition and emotion deficits.