Indirect Structural Connectivity Identifies Changes in Brain Networks After Stroke. Brain Connect 2020 Oct;10(8):399-410
Date
08/01/2020Pubmed ID
32731752DOI
10.1089/brain.2019.0725Scopus ID
2-s2.0-85094222419 (requires institutional sign-in at Scopus site) 11 CitationsAbstract
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 BDAuthors
Karin Goodfriend MD Associate Professor in the Physical Medicine and Rehabilitation department at Medical College of WisconsinAllison 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
AgedAged, 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