TM has a conservatively estimated incidence of between 1 and 8 new cases per million per year, or approximately 1400 new cases each year in the US. Although this disease affects people of all ages, with a range of six months to 88 years, there are bimodal peaks between the ages of 10 to 19 years and 30 to 39 years. In addition, approximately 25% of cases are in children. There is no gender or familial association with TM. In 75-90% of cases transverse myelitis is monophasic, yet a small percentage experience recurrent disease especially if there is a predisposing underlying illness.