Remyelination of acutely denuded axons is one mechanism by which relapse recovery may occur. Remyelination is suspected to occur via newly differentiated oligodendrocytes, which are derived from oligodendrocyte precursor cells (OPCs) in the CNS. However, despite the presence of this innate repair mechanism, many patients go on to develop progressive functional disability. This may be due to a failure of remyelination or because of progressive axonal injury. Chronic demyelinating lesions are surrounded by OPCs and premyelinating oligodendrocytes, which suggest that failed remyelination does occur and could be partially due to incomplete oligodendrocyte differentiation. Additionally, recent studies have highlighted the importance of mitochondrial dysfunction, perhaps related to oxidative stress or increased energy demands, in mediating MS disease progression. Mitochondrial dysfunction may drive axonal degeneration with resultant neurodegeneration and progressive neurological decline (progressive MS). While numerous immune modulating therapies exist, currently, there is an urgent need for novel therapies that have neuroreparative and neuroprotective properties.