Incidence of acute disseminated encephalomyelitis in the Jiangsu province of China, 2008–2011

Chen, Yong; Ma, Fubao; Xu, Yuanling; Chu, Xuhua; Zhang, Jinlin

Reportedly, ADEM can occur at any age, with higher frequency in children than adults. Predominant age of occurrence in children is 58 years, 6, 1417 or mainly in children and young people. 18 Pohl et al. reported that the incidence rate of ADEM was 0.09/ 100,000/year among children less than 10 years old and 0.03/100,000/year among children 1015 years old in Germany. 9 In Canada, children with ADEM were more likely to be younger than 10 years. 19 Previous studies on ADEM have focused on children but rarely on adults. Our study found that the highest incidence rate was among individuals 09 years old (0.77/100,000/year), and the incidence decreased with the increase of age among people less than 50 years old. But the incidence increased among people 5059 years old (0.45/100,000/year), followed by individuals 6069 years old (0.43/100,000/year). Senile ADEM, which attracts much of our attention, has rarely been reported. 20 It is probably due to: (1) differences between the elderly and young people in susceptibility or immune response to infectious agents, and (2) lack of sensitive tools to examine patients before the widespread use of MRI. 21 Some studies have reported no gender predominance in children. 10, 13, 22 Pohl et al. reported that the female-to-male ratio was balanced up to the age of 13 years, and more than twice as many girls than boys were reported in the 14-to 15-year-old group of children in Germany. 9 Our study found that males had an insignificantly higher risk of ADEM; the male/female ratio was 1.17. This frequency distribution has also been observed by others. 15, 23 A maleto-female incidence ratio that changes with advanced age may suggest differential referral, detection, or access to a neurologist. Generally, older women and men with neural disorders may be differentially referred from their households or homes to hospitals.