A 5-year-old male presents with irritability, ataxia, headaches, and progressive somnolence. His mother reports fevers after receiving his vaccinations for measles, mumps, and rubella, 3 weeks ago. The pediatrician is highly concerned for acute disseminated encephalomyelitis (ADEM). The mother believes that the recent vaccinations are the cause of the child’s symptoms.
Which of the following statements is LEAST true?
A. The disease is typically monophasicCorrect Answer: D
ADEM which affects 0.8 per 100 000 people can clinically appear similar to other demyelinating inflammatory conditions such as MS. It is however much more common in children ages 5 to 9 years old, is typically monophasic rather than having a relapsing and remitting course (although this has rarely been reported), and is usually temporally associated with a recent infection or up to 3 months following vaccination. Decreased level of consciousness with progression to coma and death is more a hallmark of ADEM than MS. MRI may demonstrate reversible ill-defined white matter lesions of the brain and spinal cord with frequent involvement of thalami and basal ganglia. CSF may have a mild pleocytosis and elevated protein but is usually negative for oligoclonal IgG bands. Measles vaccination has been linked to ADEM. However, the incidence of postimmunization ADEM for live measles vaccine is 1 to 2 cases per million vaccinations, which is much lower than the incidence of postinfectious ADEM caused by measles infection itself (1 in 1000). Since, there is no specific biomarker for ADEM, the diagnosis is usually one of exclusion. The treatment of choice is steroids. Plasmapheresis and cytotoxic medications are used as second-line therapy. Recovery has been reported in up to 75% of patients.
References: