1 Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Canada. Electronic address: jonathan.dubois@biogen.com.
2 Translational Neuroimaging Laboratory, McGill Center for Studies in Aging, Douglas Mental Health University Institute, McGill University, Montreal, Canada.
3 Division of Nuclear Medicine and Molecular Imaging, Johns Hopkins University, Baltimore, United States.
4 Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Canada.
5 Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States; Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States.
6 Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Canada; Department of Pathology, McGill University, Montreal, Canada.
7 PET Unit, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, Canada; Bio-Imaging Group, PERFORM Centre, Concordia University, Montreal, Canada.
8 Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Canada; Translational Neuroimaging Laboratory, McGill Center for Studies in Aging, Douglas Mental Health University Institute, McGill University, Montreal, Canada; PET Unit, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, Canada.
9 Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Canada. Electronic address: eliane.kobayashi@mcgill.ca.

Large-scale mGluR5 network abnormalities linked to epilepsy duration in focal cortical dysplasia.

Neuroimage Clin. 2020 Dec 29; 29:102552

Authors: DuBois JM, Mathotaarachchi S, Rousset OG, Sziklas V, Sepulcre J, Guiot MC, Hall JA, Massarweh G, Soucy JP, Rosa-Neto P, Kobayashi E

Abstract

To determine the extent of metabotropic glutamate receptor type 5 (mGluR5) network abnormalities associated with focal cortical dysplasia (FCD), we performed graph theoretical analysis of [11C]ABP688 PET binding potentials (BPND), which allows for quantification of mGluR5 availability. Undirected graphs were constructed for the entire cortex in 17 FCD patients and 33 healthy controls using inter-regional similarity of [11C]ABP688 BPND. We assessed group differences in network integration between healthy controls and the ipsilateral and contralateral hemispheres of FCD patients. Compared to healthy controls, FCD patients showed reduced network efficiency and reduced small-world connectivity. The mGluR5 network of FCD patients was also less resilient to targeted removal of high centrality nodes, suggesting a less integrated network organization. In highly efficient hub nodes of FCD patients, we observed a significant negative correlation between local efficiency and duration of epilepsy only in the contralateral hemisphere, suggesting that some nodes may be more vulnerable to persistent epileptic activity. Our study provides the first in vivo evidence for a widespread reduction in cortical mGluR5 network integration in FCD patients. In addition, we find that ongoing epileptic activity may alter chemoarchitectural brain organization resulting in reduced efficiency in distant regions that are essential for network integration.

PMID: 33401137 [PubMed - as supplied by publisher]