What is the incidence of acute disseminated encephalomyelitis (ADEM) in North America?

Updated: Nov 08, 2018
  • Author: J Nicholas Brenton, MD; Chief Editor: Tarakad S Ramachandran, MBBS, MBA, MPH, FAAN, FACP, FAHA, FRCP, FRCPC, FRS, LRCP, MRCP, MRCS  more...
  • Print

The Canadian Pediatric Surveillance Program for acute demyelinating syndromes (ADS) in individuals younger than 18 years found that in 219 identified Canadian cases, ADEM represented 22% of diagnoses. This study generated an estimate of Canadian disease incidence of 0.9 per 100,000 for ADS, while cases of ADEM manifested an annual incidence of 0.2/100,000. [5] Higher incidence rates have been reported in San Diego County at 0.4/100,000 per year. [55]

Whether the increasing incidence of MS at increasing distance from the equator is also true of ADEM is unknown. The seasonal incidence of ADEM within North America peaks in the winter and spring months. [55, 54] Some severe forms of ADEM, such as those that occur in the wake of measles and the severe hemorrhagic variant called acute hemorrhagic leukoencephalopathy (AHLE) are probably less commonly encountered than they were prior to widespread immunization against measles and other formerly common and potentially serious illnesses that may serve as triggers for ADEM/AHLE.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!