Intrinsic network changes associated with cognitive impairment in patients with hearing loss and tinnitus: a resting-state functional magnetic resonance imaging study

Background: Hearing loss and tinnitus often occur concurrently and play a vital role in the development and progression of cognitive impairment (CI). However, the exact mechanism remains unclear. This study aimed to investigate the changes in intrinsic brain connectivity in patients with hearing loss and tinnitus accompanied by CI. Methods: A total of 24 hearing loss and tinnitus patients with CI, 23 hearing loss and tinnitus patients with cognitive normality (CN), and 20 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging (rs-fMRI). Resting-state networks (RSNs) were identified and intrinsic functional connectivity (FC) values were measured using independent component analysis (ICA). FC values within the RSNs were measured and correlations between altered RSNs and clinical characteristics were evaluated using Pearson correlation analysis. Results: No significant difference was found in the disease duration or Tinnitus Handicap Inventory (THI) scores between the CI and CN groups. Eleven RSNs differed significantly among the 3 groups. Compared with the CN group, the CI group exhibited higher FC in the right supramarginal and left middle temporal gyri within the auditory network (AN), the left inferior parietal, but supramarginal and angular gyrus (IPL) gyrus within the right frontoparietal network (RFPN), the right middle occipital gyrus (R_MOG) and left superior frontal gyrus (L_SFG) within the dorsal attention network (DAN), the right middle frontal gyms (R_ MFG) within the executive control network (ECN), the right cuneus (R_cuneus) within the visual network (VN), and the left inferior frontal gyros within the salience network (SAN), as well as lower FC in the right superior temporal gyrus (R_STG) within the AN and the left FPN (LFPN) and the right superior frontal gyrus (R_SFG) within the LFPN. Montreal Cognitive Assessment (MoCA) scores were negatively correlated with the FC values of the R_MFG and positively correlated with the FC values of the R_STG and R_SFG. Conclusions: Aberrant intrinsic FC was observed in the R_MFG within the ECN, the R_STG within the AN, and the R_SFG within the LFPN in hearing loss and tinnitus patients, which may be a biomarker for the severity of CI in hearing loss and tinnitus patients.