Acute disseminated encephalomyelitis
Evidence: Antibody
Names
Acute disseminated encephalomyelitis
ADEM
Description
Acute disseminated encephalomyelitis (ADEM) is caused when inflammation stemming from fever or immunization damages the myelin sheaths of nerves in the brain, spinal cord, and occasionally the optic nerves, leading to abnormal nerve function. Onset is brief but intense and occurs predominantly in children. Patients often experience complete recovery within 6 months and do not experience relapses. The risk of developing ADEM depends on several factors, including genetics, exposure to infectious organisms, immunization exposure, and lighter skin pigmentation. ADEM can affect people of all ethnic backgrounds globally. Between 50% to 85% of ADEM cases are linked to a prior infection or vaccination, with many following a viral or bacterial infection. Nonetheless, the specific pathogen causing ADEM is often unknown.
Prevalence
US Incidence: 300 - 2000 cases per year [Filippi and Rocca 2020]
Note: ADEM is episodic rather than chronic. Patients experience a full recovery from the disease, which often occurs following an infection or vaccination. We report incidence rather than prevalence for these diseases.
Typical Age of
onset
5-8 years of age in children; 33-41 years of age in adults [Filippi and Rocca 2020]
Symptoms
Confusion
Drowsiness
Unsteadiness
Falling
Blurred vision
Double vision
Difficulty swallowing
Weakness in arms
Weakness in legs
Seizures
Source: Cleveland Clinic
