Faculty Collaboration Database

Indirect Structural Connectivity Identifies Changes in Brain Networks After Stroke. Brain Connect 2020 Oct;10(8):399-410

Date

08/01/2020

Pubmed ID

32731752

DOI

10.1089/brain.2019.0725

Scopus ID

2-s2.0-85094222419 (requires institutional sign-in at Scopus site)   11 Citations

Abstract

Background/Purpose: The purpose of this study was (1) to identify changes in structural connectivity after stroke and (2) to relate changes in indirect connectivity to post-stroke impairment. Methods: A novel measure of indirect connectivity was implemented to assess the impact of stroke on brain connectivity. Probabilistic tractography was performed on 13 chronic stroke and 16 control participants to estimate connectivity between gray matter (GM) regions. The Fugl-Meyer assessment of motor impairment was measured for stroke participants. Network measures of direct and indirect connectivity were calculated, and these measures were linearly combined with measures of white matter integrity to predict motor impairment. Results: We found significantly reduced indirect connectivity in the frontal and parietal lobes, ipsilesional subcortical regions, and bilateral cerebellum after stroke. When added to the regression analysis, the volume of GM with reduced indirect connectivity significantly improved the correlation between image parameters and upper extremity motor impairment (R² = 0.71, p < 0.05). Conclusion: This study provides evidence of changes in indirect connectivity in regions remote from the lesion, particularly in the cerebellum and regions in the fronto-parietal cortices, and these changes correlate with upper extremity motor impairment. These results highlight the value of using measures of indirect connectivity to identify the effect of stroke on brain networks. Impact statement Changes in indirect structural connectivity occur in regions distant from a lesion after stroke, highlighting the impact that stroke has on brain functional networks. Specifically, losses in indirect structural connectivity occur in hubs with high centrality, including the fronto-parietal cortices and cerebellum. These losses in indirect connectivity more accurately reflect motor impairments than measures of direct structural connectivity. As a consequence, indirect structural connectivity appears to be important to recovery after stroke and imaging biomarkers that incorporate indirect structural connectivity might improve prognostication of stroke outcomes.

Author List

Sotelo MR, Kalinosky BT, Goodfriend K, Hyngstrom AS, Schmit BD

Authors

Allison Hyngstrom PhD Associate Professor in the Physical Therapy department at Marquette University
Brian Schmit PhD Professor in the Biomedical Engineering department at Marquette University

MESH terms used to index this publication - Major topics in bold

Aged
Aged, 80 and over
Algorithms
Brain Mapping
Cerebellum
Diffusion Tensor Imaging
Female
Frontal Lobe
Gray Matter
Humans
Image Processing, Computer-Assisted
Magnetic Resonance Imaging
Male
Middle Aged
Movement Disorders
Nerve Net
Neural Pathways
Parietal Lobe
Stroke
White Matter