This is a pragmatic clinical trial that aims to determine the effect of tDCS on symptomatic fatigue in Multiple Sclerosis (MS) patients. This is a randomized, blinded, sham-controlled study design to determine the effect of Transcranial Direct Current Stimulation (tDCS) on MS participants to reduce feelings of fatigue.120 participants with MS and clinically-significant fatigue (as defined by a score of >36 on the Fatigue Severity Scale) will be recruited to participate in either an active or sham treatment condition.

Inclusion Criteria:

• Definite MS diagnosis, all subtypes
• Fatigue Severity Scale score of 36 or greater
• Score of 7.5 or less on the Expanded Disability Status Scale (EDSS) (with caregiver proxy required for those with scores of 7.5 or greater)
• Ability to understand the informed consent process and provide consent to participate in the study

Exclusion Criteria:

• Primary neurologic, psychiatric or other medical disorder other than MS
• History of seizures or seizure disorder
• History of head trauma or medical device in head or neck
• Clinically significant abnormality on EKG
• Current symptomatic treatment for fatigue
• Symbol Digit Modalities Test or SDMT score≥3.0 SD from published norms
• WRAT-4 reading level below average (<85) (estimated general intellectual function)
• Beck Depression Inventory-Fast Screen (BDI- FS) score ≥10
• Current chronic headaches or migraines
• Skin disorder/sensitive near stimulation locations

Individual participant data that underlie the results reported in this article, after deidentification (text, tables, figures, and appendices).

Beginning 9 months and ending 36 months following article publication.

For individual participant data meta-analysis. Investigators whose proposed use of the data has been approved by an independent review committee ("learned intermediary") identified for this purpose.