Memantine is an NMDA (N-methyl D-aspartate) receptor antagonist currently used in the treatment of Alzheimer’s disease. NMDA receptors appear to mediate oligodendrocyte injury and damage to the myelin sheath, and Canadian researchers have speculated that blocking these receptors may be clinically useful in MS (Stys & Lipson. Trends Pharmacol Sci 2007; 28: 561-566).