An up-to-date review of the most common neurological disorders in the United States was published in the January 30th issue of Neurology [1]. Researchers reviewed nearly 500 articles published between 1990 and 2005 to determine the rates of prevalence (meaning the total number of cases of a disease in a given population at a specific time; does not convey information about risk) or incidence (meaning the rate of occurrence of new cases of a particular disease in a given population; measures the risk of a disease) for 12 neurological disorders.