Reorganization of brain networks following carotid endarterectomy: an exploratory study using resting state functional connectivity with a focus on the changes in Default Mode Network connectivity

Michele Porcu; Davide Craboledda; Paolo Garofalo; Luigi Barberini; Roberto Sanfilippo; Fulvio Zaccagna; Max Wintermark; Roberto Montisci; Luca Saba

doi:10.1016/j.ejrad.2018.12.007

Reorganization of brain networks following carotid endarterectomy: an exploratory study using resting state functional connectivity with a focus on the changes in Default Mode Network connectivity

Eur J Radiol. 2019 Jan:110:233-241. doi: 10.1016/j.ejrad.2018.12.007. Epub 2018 Dec 6.

Authors

Michele Porcu¹, Davide Craboledda², Paolo Garofalo³, Luigi Barberini⁴, Roberto Sanfilippo², Fulvio Zaccagna⁵, Max Wintermark⁶, Roberto Montisci², Luca Saba³

Affiliations

¹ Department of Radiology, University Hospital of Cagliari, Italy. Electronic address: m.porcu@aoucagliari.it.
² Department of Vascular Surgery, University Hospital of Cagliari, Italy.
³ Department of Radiology, University Hospital of Cagliari, Italy.
⁴ Department of Medical Sciences and Public Health, University of Cagliari, Italy.
⁵ Department of Radiology, University of Cambridge School of Clinical Medicine, Cambridge, CB2 0QQ, UK.
⁶ Department of Radiology, Neuroradiology Division, Stanford University, Stanford, CA, USA.

PMID: 30599866
DOI: 10.1016/j.ejrad.2018.12.007

Abstract

Objectives: To assess whether there is mid-term reorganization in brain networks connectivity after Carotid Endarterectomy (CEA) using resting state functional connectivity Magnetic Resonance (fc-rsMR), with a special focus on the Default Mode Network (DMN).

Materials and methods: In this prospective exploratory study, 14 asymptomatic consecutive patients (10 males and 4 females, mean age 73.5) with unilateral, significant ICA stenosis eligible for CEA according to European Society for Vascular Surgery guidelines were prospectively recruited. The week before CEA procedure, each patient underwent both neurocognitive and rs-fcMR evaluations on the same day; the neurocognitive test consisted on a Mini Mental State Examination (MMSE). The same neurocognitive test and rs-fcMR examination were repeated on follow-up between 3-6 months after CEA. MMSE scores were compared using paired T-Student Test. Rs-fcMR Region Of Interest (ROI-to-ROI) and Seed-to-voxel group analysis were conducted using the CONN toolbox v18 and the SPM 12 software.

Results: Patients showed improvements in MMSE scores from before to after CEA (p-value = 0.0001). ROI-to-ROI analysis revealed several statistically significant connectivity changes following CEA, both in terms of positive and negative correlations; Seed-to-Voxel focusing on DMN revealed increased connectivity between medial prefrontal cortex (mPFC) and three different clusters of voxels.

Conclusions: CEA procedure is associated with an improvement in neurocognitive performance (according to MMSE testing) and reorganization of functional connectivity, including the DMN. These results represent a starting point in order to design further studies for a better understanding of the reorganization of brain networks following CEA, and to investigate the potential role of CEA as a therapeutic procedure for cognitive impairments in selected patients with critical ICA stenosis.

Keywords: Carotid endarterectomy; Default mode network; Resting-state functional connectivity MR.

MeSH terms

Aged
Aged, 80 and over
Brain / diagnostic imaging*
Brain / physiopathology*
Brain Mapping / methods*
Endarterectomy, Carotid / methods*
Female
Humans
Magnetic Resonance Imaging / methods*
Male
Middle Aged
Neuropsychological Tests
Prospective Studies