100 Section - Altered Temporal Variability Functional Reorganization in Brain Network Predict Motor Outcome in Stroke

This study aimed to investigate functional reorganization in chronic subcortical stroke patients using temporal variability (TV) analysis of brain networks.

Design:

Thirty-three left subcortical stroke (LSS) and thirty right subcortical stroke (RSS) patients at the chronic stage underwent both resting fMRI scans and Fugl-meyer Motor Assessment for Upper Extremities (UE-FMA) evaluation at first and second observation. Fifty-six age- and sex-matched healthy individuals were enrolled. Then, TV was calculated to assess dynamic functional connectivity changes across regional and network levels. One way ANCOVA analysis was used compared TV differences among three groups, followed by post hoc tests. The linear regression was used to evaluate relationship between TV and UE-FMA.



Results:

Compared to HCs, LSS and RSS demonstrated significant decreased TV in the right opercular part of inferior frontal gyrus (IFGoperc), supplemental motor area, anterior cingulate cortex and paracingulate gyrus, somatomotor hand network (SSH) and between SSH and other networks (e.g., ventral attention and executive control networks), and increased in the left postcentral gyrus and inferior frontal gyrus, cerebellar network (CEN) and somatomotor mouth networks. Additionally, RSS showed TV reductions in the right middle occipital gyrus and orbital part of middle frontal gyrus, and in default mode network (DMN) and between DMN and other networks (e.g., attention and executive control networks) when compared to LSS and HCs. Moreover, the TV in the right IFGoperc and CEN at the baseline positively correlated with UE-FMA scores after treatment, associating with the location of stroke lesion.

Conclusion: TV reveals widespread functional reorganization in chronic stroke, involving motor, cognitive and sensory networks, which are influenced by lesion location, and may predict motor recovery after stroke as a potential biomarker.