Structural Brain Network Reorganization Following Anterior Callosotomy for Colloid Cysts: Connectometry and Graph Analysis Results

Marco Ciavarro; Eleonora Grande; Giuseppina Bevacqua; Roberta Morace; Ettore Ambrosini; Luigi Pavone; Giovanni Grillea; Tommaso Vangelista; Vincenzo Esposito

doi:10.3389/fneur.2022.894157

Structural Brain Network Reorganization Following Anterior Callosotomy for Colloid Cysts: Connectometry and Graph Analysis Results

Front Neurol. 2022 Jul 18:13:894157. doi: 10.3389/fneur.2022.894157. eCollection 2022.

Authors

Affiliations

¹ Mediterranean Neurological Institute Neuromed (IRCCS) Neuromed, Pozzilli, Italy.
² Department of Neuroscience, Imaging and Clinical Sciences, Gabriele d'Annunzio University, Chieti, Italy.
³ Department of Translational Medicine, Ferrara University, Ferrara, Italy.
⁴ Department of General Psychology, University of Padua, Padua, Italy.
⁵ Department of Neuroscience, University of Padua, Padua, Italy.
⁶ Padua Neuroscience Center, University of Padua, Padua, Italy.
⁷ Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy.

Abstract

Introduction: The plasticity of the neural circuits after injuries has been extensively investigated over the last decades. Transcallosal microsurgery for lesions affecting the third ventricle offers an interesting opportunity to investigate the whole-brain white matter reorganization occurring after a selective resection of the genu of the corpus callosum (CC).

Method: Diffusion MRI (dMRI) data and neuropsychological testing were collected pre- and postoperatively in six patients with colloid cysts, surgically treated with a transcallosal-transgenual approach. Longitudinal connectometry analysis on dMRI data and graph analysis on structural connectivity matrix were implemented to analyze how white matter pathways and structural network topology reorganize after surgery.

Results: Although a significant worsening in cognitive functions (e.g., executive and memory functioning) at early postoperative, a recovery to the preoperative status was observed at 6 months. Connectometry analysis, beyond the decrease of quantitative anisotropy (QA) near the resection cavity, showed an increase of QA in the body and forceps major CC subregions, as well as in the left intra-hemispheric corticocortical associative fibers. Accordingly, a reorganization of structural network topology was observed between centrality increasing in the left hemisphere nodes together with a rise in connectivity strength among mid and posterior CC subregions and cortical nodes.

Conclusion: A structural reorganization of intra- and inter-hemispheric connective fibers and structural network topology were observed following the resection of the genu of the CC. Beyond the postoperative transient cognitive impairment, it could be argued anterior CC resection does not preclude neural plasticity and may subserve the long-term postoperative cognitive recovery.

Keywords: anterior callosotomy; colloid cyst; diffusion MRI; graph analysis; network topology; structural connectivity; white matter.