Evaluation of the Efficacy of Transcranial Direct Current Stimulation in Reducing Fatigue and Improving Quality of Life in Patients With Multiple Sclerosis: A Randomized Clinical Trial

The goal of this clinical trial is to evaluate whether the application of three 2-week cycles of tDCS combined with motor therapy is more effective in reducing fatigue in adult patients with multiple sclerosis, compared to the application of two cycles of the same treatment. The main questions aim to answer: * Is the application of three 2-week cycles of tDCS combined with motor therapy (experimental group) more effective for the recovery of fatigue in adult patients with multiple sclerosis compared to the application of two cycles of the same treatment (control group)? * Is tDCS combined with motor therapy effective in improving fatigue in adult patients with multiple sclerosis in both study arms, i.e., in the pre-post assessment of the experimental group and the pre-post assessment of the control group? Researchers will compare the application of three 2-week cycles of tDCS combined with motor therapy (experimental group) to the application of two cycles of the same treatment (control group) to see if the experimental group shows greater recovery of fatigue in adult patients with multiple sclerosis. Participants will: * Visit the clinic for two weeks to be evaluated (baseline measurement and first post-treatment assessment) and receive the first cycle of treatment from Monday to Friday. * Have a washout period of one month between the first and the second cycle. * Visit the clinic for two weeks to receive the second cycle of treatment and be evaluated (second post-treatment assessment). * Only participants in the experimental group will have another washout period of one month and visit the clinic to receive a third cycle of treatment and to be evaluated (third post-treatment assessment). * Only participants in the control group will visit the clinic one and a half months after completing their second cycle to be measured as a follow-up.