Which are the causes of Acute Disseminated Encephalomyelitis?

Acute Disseminated Encephalomyelitis (ADEM) is an inflammatory condition of the central nervous system typically triggered by an immune response to a recent viral or bacterial infection. While the exact mechanism remains under investigation, it is characterized by the body’s immune system mistakenly attacking the protective myelin sheath surrounding nerve fibers in the brain and spinal cord.

What triggers Acute Disseminated Encephalomyelitis?

The primary cause of Acute Disseminated Encephalomyelitis is believed to be a process called "molecular mimicry." In this scenario, the immune system, while attempting to fight off a pathogen, accidentally targets proteins in the brain that look similar to the virus or bacteria. In approximately 75% of cases, patients report a preceding infectious illness, such as the flu, measles, or Epstein-Barr virus, occurring two to three weeks before the onset of neurological symptoms.

Is Acute Disseminated Encephalomyelitis hereditary?

Current medical literature does not classify Acute Disseminated Encephalomyelitis as a genetic or hereditary disease. There are no specific genes or mutations identified that cause the condition. Instead, researchers believe there may be a complex, yet-to-be-defined interaction between an individual’s immune system profile and specific environmental exposures that leads to the development of Acute Disseminated Encephalomyelitis in susceptible individuals.

What are the risk factors for this condition?

Distinguishing between causes and risk factors is important for understanding the disease. A cause is the direct trigger (the infection), while risk factors are variables that may increase the likelihood of the immune system overreacting. Known factors include:

• Age: It is most frequently diagnosed in children under the age of 10.


• Recent Infections: Recent exposure to common pathogens like Mycoplasma pneumoniae or respiratory viruses.


• Vaccination: Historically, rare cases have been linked to vaccinations, though the risk is significantly lower than the risk of developing neurological complications from the infections themselves.

How is research advancing our understanding?

Researchers are currently studying the specific biomarkers that differentiate Acute Disseminated Encephalomyelitis from other demyelinating diseases like Multiple Sclerosis. Our community of 80 people at DiseaseMaps.org continues to provide valuable insights into the patient experience, helping researchers map the long-term outcomes and potential triggers of Acute Disseminated Encephalomyelitis.

Next steps

• Consult a neurologist specializing in neuroimmunology for an accurate diagnosis.


• Keep a detailed log of any infections or vaccinations occurring in the month prior to symptom onset.


• Join the DiseaseMaps.org community to connect with others sharing their experiences with Acute Disseminated Encephalomyelitis.

Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Acute Disseminated Encephalomyelitis.


• Orphanet: Acute disseminated encephalomyelitis (ORPHA:2803).


• PubMed/NCBI: Clinical features and pathogenesis of ADEM.


• Multiple Sclerosis Society: Information on Acute Disseminated Encephalomyelitis.