The pathogenesis of multiple sclerosis: Relating human pathology to experimental studies

Multiple sclerosis (MS) is a complex disease of unknown etiology. A careful study of the pathology of its component elements in relation to relevant experimental models has helped to understand some of the mechanisms that might be present in the disease. However, the autoimmune nature of the disease has recently come under question and there is a growing recognition of the importance of axonal, cortical, and white matter changes in the genesis and evolution of the lesions, their clinical diagnostic characteristics, and their response to treatment. This review highlights the emerging issues in MS from experimental, imaging and clinical perspectives.