Altered Dynamic Resting State Functional Connectivity Associated With Somatosensory Impairments in the Upper Limb in the Early Sub-Acute Phase Post-Stroke

Background. Altered dynamic functional connectivity has been associated with motor impairments in the acute phase post-stroke. Its association with somatosensory impairments in the early sub-acute phase remains unexplored. Objective. To investigate altered dynamic functional connectivity associated with somatosensory impairments in the early sub-acute phase post-stroke. Methods. We collected resting state magnetic resonance imaging and clinical somatosensory function of the upper limb of 20 subacute stroke patients and 16 healthy controls (HC). A sliding-window approach was used to identify 3 connectivity states based on the estimated dynamic functional connectivity of sensorimotor related networks. Network components were subdivided into 3 domains: cortical and subcortical sensorimotor, as well as cognitive control network. Between-group differences were investigated using independent t-tests and Mann-Whitney-U tests. Analyzes were performed with correction for age, head motion and time post-stroke and corrected for multiple comparisons. Results. Stroke patients spent significantly less time in a weakly connected network state (state 3; dwell time: p(state3) = 0.003, mean(stroke) = 53.02, SDstroke = 53.13; mean(HC) = 118.92, SDHC = 72.84), and stayed shorter but more time intervals in a highly connected intra-domain network state (state 1; fraction time: p(state 1) < 0.001, mean(stroke) = 0.46, SDstroke = 0.26; mean(HC) = 0.26, SDHC = 0.21) compared to HC. After 8 weeks of therapy, improvements in wrist proprioception were moderately associated with decreases in dwell and fraction times toward a more normalized pattern. Conclusion. Changes in temporal properties of large-scale network interactions are present in the early rehabilitation phase post-stroke and could indicate enhanced neural plasticity. These findings could augment the understanding of cerebral reorganization after loss of neural tissue specialized in somatosensory functions.

Automated summary

This study investigated the altered dynamic functional connectivity associated with somatosensory impairments in the early sub-acute phase post-stroke. The results showed that stroke patients spent less time in a weakly connected network state and had shorter but more time intervals in a highly connected intra-domain network state compared to healthy controls. After 8 weeks of therapy, improvements in wrist proprioception were moderately associated with decreases in dwell and fraction times toward a more normalized pattern.