Methods of treating neurological disorders, e.g., those characterized by demyelination and/or axonal loss (e.g., MS), are provided. The methods comprise administration of a therapeutically effective amount of at least one compound of Formula I: wherein R1 and R2 are independently selected from OH, O−, and (C1-6)alkoxy, or a pharmaceutically acceptable salt thereof; and either glatiramer acetate or interferon-beta.