Integrating Metabolism, Connectivity, and Mesoscale Imaging at Ultra-high Field to Decipher Mechanisms of Resilience and Neurodegeneration in Neurological Diseases and Healthy Aging

The MESO7 study is a prospective observational research project designed to investigate the mechanisms of resilience and neurodegeneration in neurological diseases and healthy aging. It leverages advanced multiparametric brain and spinal cord imaging at high (3T) and ultra-high magnetic fields (7T) to assess structural, functional, metabolic, and mesoscale changes in the central nervous system (CNS). Particular emphasis is placed on sodium (23Na-MRI) and phosphorus (31P-MRI) imaging, along with layer-dependent brain connectivity analysis. The primary objective is to evaluate the impact of neuronal energy failure, measured via sodium concentration, on functional and structural reorganization in both healthy individuals and patients with various neurological conditions. Directed brain network models will be constructed from MRI data to quantify the connectivity strength (in- and out-degree) of cortical nodes. These connectivity metrics will be correlated with sodium concentrations to assess energy failure and its role in network reorganization. Longitudinal follow-up over two years is planned for subgroups with clinically progressive diseases. Secondary objectives include decoding metabolic, microstructural, and functional signatures of successful aging at the laminar level; characterizing disease-specific patterns of cortical and spinal microstructure associated with physical and cognitive dysfunction; describing longitudinal mesoscale and metabolic changes; and generating representative normative imaging datasets for the neuroscience community. The study plans to enroll a total of 540 patients across 9 neurological conditions:Multiple Sclerosis (MS), Neuromyelitis Optica Spectrum Disorders (NMOSD), MOG Antibody Disease (MOGAD), Alzheimer's disease, Parkinson's disease, Amyotrophic Lateral Sclerosis (ALS), temporal and non-temporal epilepsy, and mild traumatic brain injury (mTBI),in addition to 160 age- and sex-matched healthy controls, totaling 700 participants. Imaging and clinical assessments will be performed at the CEMEREM center at Timone University Hospital, AP-HM, Marseille, France. Each participant will undergo multiparametric brain and spinal cord MRI, including DTI, BOLD, MP2RAGE, SWI, quantitative sodium and phosphorus imaging, and functional assessments including neuropsychological testing, visual and motor function tests. Disease-specific assessments such as OCT, evoked potentials, and disability scores (e.g., EDSS for MS) will also be included when appropriate. The study is expected to improve understanding of CNS adaptation mechanisms and support the development of more accurate diagnostic and prognostic tools for neurodegenerative diseases