Provided herein are methods of treating multiple sclerosis with a fumarate, wherein the fumarate is a dialkyl fumarate, a monoalkyl fumarate, a combination of a dialkyl fumarate and a monoalkyl fumarate, a prodrug of monoalkyl fumarate, a deuterated form of any of the foregoing, or a pharmaceutically acceptable salt, clathrate, solvate, tautomer, or stereoisomer of any of the foregoing, or a combination of any of the foregoing. The methods provided herein improve the safety of treatment by informing and monitoring patients undergoing treatment regarding progressive multifocal leukoencephalopathy, and/or by monitoring lymphocyte count.
