The investigators propose to use the novel SV2a-PET ligand, [F-18]SDM-8 to assess synaptic density in progressive MS (including primary progressive multiple sclerosis (PPMS) and secondary progressive multiple sclerosis (SPMS)) as compared to relapsing-remitting multiple sclerosis (RRMS) patients and healthy controls, given its improved imaging characteristics and potential for large scale applicability. The specific aims of the study are: Aim 1: To compare the cortical and subcortical grey matter synaptic density in progressive MS patients, patients with relapsing-remitting MS, and healthy subjects, using a novel [F-18] labeled synaptic density PET ligand, [F-18]SDM8, also known as [F-18]SynvesT-1. Aim 2: To compare the relationship of synaptic density PET and standard 3T MRI measures including global and regional brain atrophy and lesion load with clinical measures of physical disability, cognitive impairment, fatigue and depression in MS patients. Aim 3: To assess the relationship of synaptic density PET with serum neurofilament light chain (NfL) and with serum measurements of inflammatory markers, IL-1β, TNF-α, IL-6, MCP-1 (Monocyte Chemoattractant Protein-1) and MIF-1 (Macrophage Migration Inhibitory Factor-1).
Name: [F-18]SDM-8
Description: This will be calculated over whole brain, within white matter, within grey matter, and within MRI-visible lesions.
Measure: Tissue volume of Distribution (Vt) Time: Through study completion, an average of 1 yearDescription: SUV will be calculated based on standard procedures.
Measure: Standardized uptake values (SUV) Time: Through study completion, an average of 1 yearAllocation: N/A
Single Group Assignment
There is one SNP
Non Imaging Data MS subjects Expanded Disability Severity Scale (EDSS) Timed 25-feet walk (T25W) Modified Fatigue impact Scale Hamilton Depression Rating Scale Wechsler Logical Memory paragraph recall Healthy Controls Folstein Mini Mental Status Examination Hamilton Depression Rating Scale Wechsler Logical Memory paragraph recall --- T25W ---