Tumor lesions in the supplementary motor area may induce large-scale sensorimotor and cognitive network alterations— A functional and structural connectivity analysis
5 affiliations
- 1Department of Neurosurgery, RWTH Aachen University
- 2Center for Integrated Oncology Aachen, Bonn, Cologne, Düsseldorf (CIO ABCD)
- 3Brain Imaging Facility, Interdisciplinary Center for Clinical Research (IZKF), RWTH Aachen University
- 4Department of Diagnostic and Interventional Neuroradiology, RWTH Aachen University
- 5Department of Neurosurgery, University of Erlangen
Abstract
Background: Patients with brain tumors involving the SMA often develop postoperatively a mostly transient contralateral akinesia (‘SMA-syndrome'), which may primarily be a cognitive disorder of executive functions. However, the neurophysiological correlates are unclear. Considering the SMA as a gateway between motor and cognitive control functions, we explored structural SMA-connectivity (SC), and functional connectivity (FC) of the sensorimotor (SMN), and of cognitive networks in SMA-tumor patients.
Methods: 13 SMA-tumor patients and 13 matched healthy controls underwent diffusion-tensor-imaging (DTI) and resting-state-fMRI preoperatively. Intra- (Frontal Aslant Tract) and interhemispheric SC of the SMA (SMA-SMA, SMA-M1) was compared between groups. FC-networks were established by group Independent Component Analysis (ICA), and subjected to a second-level ROI-to-ROI (region-of-interest) analysis to investigate between-group differences.
Results: DTI revealed microstructural white-matter disintegration and smaller tract volumes of SMA-M1 connectivity ( p < 0.005), and by trend of the FAT ( p < 0.06), with differing SMA-M1 fiber-length in patients ( p < 0.026). SMA-SMA SC was not reduced, but showed greater variance in patients. While FC was significantly decreased within different cognitive networks, FC was increased within the SMN, as well as between the SMA and the contralesional frontoparietal network ( p < 0.046) in patients.
Conclusions: In this exploratory study, we found sensorimotor- as well as large-scale cognitive network alterations prior to therapeutic intervention, suggesting tumor-associated SC disintegration to be accompanied by in- and decreases of FC within and across different networks. Future studies incorporating neuropsychological-testing are required to characterize pretherapeutic connectivity alterations with regard to their behavioral significance, and to determine whether they may impact the postoperative functional outcome.
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BibTeX
@article{na2026tumor,
title = {{Tumor lesions in the supplementary motor area may induce large-scale sensorimotor and cognitive network alterations— A functional and structural connectivity analysis}},
author = {Chuh-Hyoun Na and Rik Sijben and Oleg Posnansky and Martin Wiesmann and Hans Clusmann and Daniel Delev and Rea Rodriguez-Raecke},
journal = {Frontiers in Neurology},
year = {2026},
month = oct,
doi = {10.3389/fneur.2026.1878278},
url = {https://www.frontiersin.org/articles/10.3389/fneur.2026.1878278/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Tumor lesions in the supplementary motor area may induce large-scale sensorimotor and cognitive network alterations— A functional and structural connectivity analysis
AU - Chuh-Hyoun Na
AU - Rik Sijben
AU - Oleg Posnansky
AU - Martin Wiesmann
AU - Hans Clusmann
AU - Daniel Delev
AU - Rea Rodriguez-Raecke
PY - 2026
DA - 2026/10/21
JO - Frontiers in Neurology
DO - 10.3389/fneur.2026.1878278
UR - https://www.frontiersin.org/articles/10.3389/fneur.2026.1878278/full
AB - Background: Patients with brain tumors involving the SMA often develop postoperatively a mostly transient contralateral akinesia (‘SMA-syndrome'), which may primarily be a cognitive disorder of executive functions. However, the neurophysiological correlates are unclear. Considering the SMA as a gateway between motor and cognitive control functions, we explored structural SMA-connectivity (SC), and functional connectivity (FC) of the sensorimotor (SMN), and of cognitive networks in SMA-tumor patients. Methods: 13 SMA-tumor patients and 13 matched healthy controls underwent diffusion-tensor-imaging (DTI) and resting-state-fMRI preoperatively. Intra- (Frontal Aslant Tract) and interhemispheric SC of the SMA (SMA-SMA, SMA-M1) was compared between groups. FC-networks were established by group Independent Component Analysis (ICA), and subjected to a second-level ROI-to-ROI (region-of-interest) analysis to investigate between-group differences. Results: DTI revealed microstructural white-matter disintegration and smaller tract volumes of SMA-M1 connectivity ( p < 0.005), and by trend of the FAT ( p < 0.06), with differing SMA-M1 fiber-length in patients ( p < 0.026). SMA-SMA SC was not reduced, but showed greater variance in patients. While FC was significantly decreased within different cognitive networks, FC was increased within the SMN, as well as between the SMA and the contralesional frontoparietal network ( p < 0.046) in patients. Conclusions: In this exploratory study, we found sensorimotor- as well as large-scale cognitive network alterations prior to therapeutic intervention, suggesting tumor-associated SC disintegration to be accompanied by in- and decreases of FC within and across different networks. Future studies incorporating neuropsychological-testing are required to characterize pretherapeutic connectivity alterations with regard to their behavioral significance, and to determine whether they may impact the postoperative functional outcome.
SN - 1664-2295
ER -