WITHDRAWN: Altered long- and short-range functional connectivity in patients with long-term unilateral hearing loss

Abstract

Functionally cross-modal reorganization in the sensory cortex and changes in cognitive processing areas of the brain have been described in patients with bilateral hearing impairments. However, it remains unclear whether long-term unilateral hearing loss (UHL) would similarly influence the higher-order functional networks in addition to the primary sensory networks. In this study, we collected restingstate fMRI data in 21 right-sided UHL patients caused by acoustic neuromas and 21 healthy controls. Whole-brain functional networks were constructed by measuring the temporal correlations of every pairs of brain voxels. We further computed wholerange, short-range and long-range normalized functional connectivity strength (nFCS) for each voxel in the brain. Nonparametric permutation tests were used to detect between-group differences in these nFCS metrics and to further systematically investigate the relationship between these differences and clinical variables in UHL patients. Compared to healthy controls, the UHL patients showed an increased nFCS mainly in anterior cingulate cortex and dorsal medial prefrontal cortex, and these changes resulted from both short-range and long-range nFCS. The UHL patients also showed decreased whole-range nFCS in visual cortex, resulting from short-range functional changes. Additionally, the UHL patients showed decreased long-range nFCS in the orbital frontal cortex. Together, we observed significantly altered nFCS mainly involving in the default-mode, ventral attention, limbic and visual networks. Our study provides empirical evidence for distance-dependent alteration of functional connectivity in long-term UHL, which may implicate the functionally cross-modal reorganization of the brain involving in primary sensory and higher-order functional networks in long-term UHL.