The Epidemiology Study in Multiple Sclerosis - Relevance to Natural History

Multiple sclerosis (MS) is a chronic, demyelinating disease of the central nervous system white matter that has been extensively studied using the epidemiological approach, and yet an etiology for the disease remains elusive. This paper presents a review of past publications that have made suggestions toward the design of epidemiological studies in MS. A formal search strategy is described, and a short summary of these papers is provided. A natural history of MS based on previous studies is proposed as a framework for describing future directions in the neuroepidemiology of the disease, and categorization based on the clinical forms of MS is described. Within the context of a proposed natural history, suggestions are made on the use of sub-regionalization in cluster studies across different domains, as well as on the use of specific reference points in a patient's lifetime in the analysis of clusters.