This study is a prospective observational clinical study, where the researchers will recruit adults with early MS (n=60) to complete a cognitive assessment and an optional gait assessment using Runscribe and G-sensor. Thirty-five [35] participants will also have a single 60-minute investigational MRI combined with 20 minutes of simultaneous tDCS. The MRI will repeat the protocol from the researchers' current study (ClinicalTrials.gov Identifier: NCT03564496, IRB i18-00548) using simultaneous transcranial direct current stimulation (tDCS) during the imaging acquisition.
The focus of this work is the evaluation of a measure of cognitive functioning- intra-individual variability (IIV) - derived from a computer-based continuous reaction time (RT) task (Cogstate) as an early marker of prodromal MS.