Ismail Koubiyr1, Mathilde Deloire2, Pierre Besson3, Pierrick Coupé4, Cécile Dulau2, Jean Pelletier5, Thomas Tourdias6, Bertrand Audoin5, Bruno Brochet6, Jean-Philippe Ranjeva3, Aurélie Ruet6. 1. University of Bordeaux, Bordeaux, France/Inserm U1215, Neurocentre Magendie, Bordeaux, France. 2. CHU Pellegrin, CHU de Bordeaux, Bordeaux, France. 3. Aix-Marseille University, CNRS, CRMBM UMR, Marseille, France/Aix-Marseille University, APHM, Hopital la Timone, CEMEREM, Marseille, France. 4. Laboratoire Bordelais de Recherche en Informatique, Talence, France. 5. Aix-Marseille University, CNRS, CRMBM UMR, Marseille, France/Aix-Marseille University, APHM, Hopital la Timone, CEMEREM, Marseille, France/APHM, Hopital la Timone, service de Neurologie, Marseille, France. 6. University of Bordeaux, Bordeaux, France/Inserm U1215, Neurocentre Magendie, Bordeaux, France/CHU Pellegrin, CHU de Bordeaux, Bordeaux, France.
Abstract
BACKGROUND: There is a lack of longitudinal studies exploring the topological organization of functional brain networks at the early stages of multiple sclerosis (MS). OBJECTIVE: This study aims to assess potential brain functional reorganization at rest in patients with CIS (PwCIS) after 1 year of evolution and to characterize the dynamics of functional brain networks at the early stage of the disease. METHODS: We prospectively included 41 PwCIS and 19 matched healthy controls (HCs). They were scanned at baseline and after 1 year. Using graph theory, topological metrics were calculated for each region. Hub disruption index was computed for each metric. RESULTS: Hub disruption indexes of degree and betweenness centrality were negative at baseline in patients (p < 0.05), suggesting brain reorganization. After 1 year, hub disruption indexes for degree and betweenness centrality were still negative (p < 0.00001), but such reorganization appeared more pronounced than at baseline. Different brain regions were driving these alterations. No global efficiency differences were observed between PwCIS and HCs either at baseline or at 1 year. CONCLUSION: Dynamic changes in functional brain networks appear at the early stages of MS and are associated with the maintenance of normal global efficiency in the brain, suggesting a compensatory effect.
BACKGROUND: There is a lack of longitudinal studies exploring the topological organization of functional brain networks at the early stages of multiple sclerosis (MS). OBJECTIVE: This study aims to assess potential brain functional reorganization at rest in patients with CIS (PwCIS) after 1 year of evolution and to characterize the dynamics of functional brain networks at the early stage of the disease. METHODS: We prospectively included 41 PwCIS and 19 matched healthy controls (HCs). They were scanned at baseline and after 1 year. Using graph theory, topological metrics were calculated for each region. Hub disruption index was computed for each metric. RESULTS: Hub disruption indexes of degree and betweenness centrality were negative at baseline in patients (p < 0.05), suggesting brain reorganization. After 1 year, hub disruption indexes for degree and betweenness centrality were still negative (p < 0.00001), but such reorganization appeared more pronounced than at baseline. Different brain regions were driving these alterations. No global efficiency differences were observed between PwCIS and HCs either at baseline or at 1 year. CONCLUSION: Dynamic changes in functional brain networks appear at the early stages of MS and are associated with the maintenance of normal global efficiency in the brain, suggesting a compensatory effect.