Effect of Cerebral Visual Impairment on Functional-Structural Coupling of the Attention Networks

Visual attentional processes, including selective attention, are often impaired in individuals with Cerebral Visual Impairment (CVI) [1]. Yet, the underlying neural correlates thereof remain unclear. This study investigated potential differences in the relationship between white matter integrity and resting state functional connectivity (rsFC) of the dorsal (DAN) and ventral (VAN) attention networks underlying visual attention [2] in individuals with CVI compared to controls. Resting-state fMRI, diffusion, and METRICS [3] data were collected on a 3T Philips scanner for 25 participants (16 control, 9 CVI). Average rsFC was calculated within the DAN and VAN, and also between the DAN, VAN, thalamus, and early visual regions. Tract volume, fractional anisotropy (FA), radial/axial diffusivity (RD/AD), and myelin water fraction (MWF) and intra-extracellular T2 (IET2) [4] were calculated for the superior longitudinal fasciculus (SLF) (divisions I, II, and III), inferior longitudinal fasciculus (ILF), inferior fronto-occipital fasciculus (IFOF), and the anterior (ATR), superior (STR), and posterior (PTR) thalamocortical radiations. Spearman partial correlations within each group (adjusting for age) followed by FDR correction for multiple comparisons were used to investigate the functional-structural coupling of the attention networks. In the control group, within-network rsFC for the DAN was positively correlated with FA of the SLF I. Between-network connectivity of the DAN was significantly positively correlated with FA and negatively correlated with RD of the left ILF and FA of the bilateral IFOF. Between-network connectivity of the VAN was significantly positively correlated with FA of the left ILF and IFOF. Functional connectivity between the thalamus and VAN was significantly negatively associated with PTR IET2. No significant associations were observed in the CVI group. Overall, the results suggest that CVI may be associated with aberrant functional-structural coupling of the attention networks. The relationship with the previously observed selective attention deficits in individuals with CVI needs to be further investigated.