Exposure to vaccines: The only vaccine proven related to ADEM is the Semple form of the rabies vaccine, but hepatitis B, pertussis, diphtheria, measles, mumps, rubella, pneumococcus, varicella, influenza, Japanese encephalitis, and polio vaccines have all been implicated. The majority of the studies that correlate vaccination with ADEM onset use small samples or case studies. Large scale epidemiological studies (e.g., of MMR vaccine or smallpox vaccine) do not show increased risk of ADEM following vaccination. An upper bound for the risk of ADEM from measles vaccination, if it exists, can be estimated to be 10 per million, which is far lower than the risk of developing ADEM from an actual measles infection, which is about 1 per 1,000 cases. For a rubella infection, the risk is 1 per 5,000 cases. Some early vaccines, later shown to have been contaminated with host animal CNS tissue, had ADEM incident rates as high as 1 in 600. In rare cases, ADEM seems to follow from organ transplantation. Diagnosis
ADEM term has been inconsistently used at different times. Currently, the commonly accepted international standard for the clinical case definition is the one published by the International Pediatric MS Study Group, revision 2007.Given that the definition is clinical, it is currently unknown if all the cases with ADEM are positive for anti-MOG autoantibody, but in any case, it seems strongly related to ADEM diagnosis. Differential diagnosis
Multiple sclerosis
While ADEM and MS both involve autoimmune demyelination, they differ in many clinical, genetic, imaging, and histopathological aspects.
When occurring between two parts of the intestine, it is known as an enteroenteral fistula, between the small intestine and the skin as an enterocutaneous fistula, and between the small intestine and the colon as a colocutaneous fistula.The following list is sorted by the International Statistical Classification of Diseases and Related Health Problems. H: Diseases of the eye, adnexa, ear, and mastoid process
(H04.6) Lacrimal fistula
(H05.81) Carotid cavernous fistula
(H70.1) Mastoid fistula
Craniosinus fistula: between the intracranial space and a paranasal sinus
(H83.1) Labyrinthine fistula
Perilymph fistula: tear between the membranes between the middle and inner ears
Preauricular fistula
Preauricular fistula: usually on the top of the cristae helicis of the ears

I: Diseases of the circulatory system
(I25.4) Coronary arteriovenous fistula, acquired
(I28.0) Arteriovenous fistula of pulmonary vessels
Pulmonary arteriovenous fistula: between an artery and vein of the lungs, resulting in shunting of blood. This results in improperly oxygenated blood. (I67.1) Cerebral arteriovenous fistula, acquired
(I77.0) Arteriovenous fistula, acquired
(I77.2) Fistula of artery

J: Diseases of the respiratory system
(J86.0) Pyothorax with fistula
(J95.0) Tracheoesophageal fistula, between the trachea and the esophagus. This may be congenital or acquired, for example as a complication of a tracheostomy. K: Diseases of the digestive system
(K11.4) Salivary gland fistula
(K31.6) Fistula of stomach and duodenum
(K31.6) Gastrocolic fistula
(K31.6) Gastrojejunocolic fistula – after a Billroth II a fistula forms between the transverse colon and the upper jejunum (which, post Billroth II, is attached to the remainder of the stomach). Fecal matter passes improperly from the colon to the stomach and causes halitosis.