Ventral attention and motor network connectivity is relevant to functional impairment in spatial neglect after right brain stroke

Abstract

Emerging research suggests spatial neglect after right stroke is linked to dysfunctional attention and motor networks. Advanced functional connectivity analysis clarified brain network recovery, however we need to know how networks participate in adaptive motor performance. We need to verify network changes associated with validated functional measures and spatial-motor performance in spatial neglect, especially in patients with large brain lesions and significant disability. This study tested whether disability-relevant spatial neglect associates with different patterns of resting state functional connectivity between motor, dorsal and ventral attention networks (MN, DAN and VAN). Right stroke patients had spatial neglect (n = 8) or not (n = 10) on the Behavioural Inattention Test-conventional. Spatial neglect patients had weaker intranetwork VAN connectivity, and reduced internetwork connectivity between VAN and left frontal eye field (DAN), and between VAN and the left primary motor area (MN). These network impairments might explain the co-occurrence of attention and motor deficits in spatial neglect, and open a path to assessing functional connectivity in clinical trials of combined spatial retraining and motor rehabilitation after stroke.

Keywords: Attention network connectivity; Machine learning; Motor network connectivity; Spatial neglect; Stroke.

Fig. 1.

Group lesion coverage map for all patients in the study (N=18). Hot color represents areas of stroke lesion overlap, with maximal overlap occurring in 13 participants. Right brain is on the right side of image. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 2.

Group average of functional connectivity FDR-corrected at p < 0.00005. Right brain is on the right side of image.

Fig. 3.

Regression plots showing significant relationship between BIT-c score and functional connectivity in the non-neglect group.

Fig. 4.

Hierarchical clustering of intra- and inter network functional connectivity in the motor, dorsal, and ventral attention networks labeled with each participant’s spatial neglect status as defined by the behavioral inattention test-conventional subtest (BIT-c) score and by the Kessler Foundation Neglect Assessment Process (KF-NAP).