[Acute disseminated encephalomyelitis associated with herpes virus infection: a case report].

Acute disseminated encephalomyelitis (ADEM) is a demyelinating disease of the central nervous system, also called post-infectious encephalitis; it is triggered by an autoimmune mechanism and follows an infection or a vaccination after a free interval of 2 to 30 days. We report a case of ADEM in a 4-year-old girl, who was diagnosed based on the data from a brain MRI, which revealed multiple demyelinization foci in the periventricular white matter, the semi-oval centers, and the thalamic regions, both bilaterally and symmetrically. The clinical course was characterized by complete recovery 10 days after steroid therapy. In the literature, more than the half of the patients treated for ADEM had a good prognosis, with recovery and no sequelae. Clinical improvement is generally noted in the hours or days following the initiation of treatment. However, in the most severe cases of ADEM, the most frequent neurological sequelae consist in focal deficiencies of the limbs and ataxia or visual disorders. Cognitive and behavioral disorders are noted in 6 to 50% of pediatric patients.