Acute disseminated encephalomyelitis is a monophasic, immune-mediated disor
der that produces multifocal demyelinating lesions within the central nervo
us system. It is characterized clinically by the acute onset of neurologic
abnormalities, including varying degrees of mental state changes ranging fr
om drowsiness to coma, It is unusual for the illness to present as an isola
ted acute psychosis, The case of a 14-year-old female with biopsy-confirmed
acute disseminated encephalomyelitis, who was initially diagnosed with an
acute psychiatric disorder, is presented, and published reports on this unu
sual manifestation are reviewed. A Medline database search was performed fr
om 1965 to 1999, using the terms acute disseminated encephalomyelitis, post
vaccinal encephalomyelitis, postinfectious encephalomyelitis, and measles e
ncephalomyelitis, combined with the terms psychosis, psychiatric disorder,
and behavioral disorder, Selected cross-referenced reports were also review
ed, Nine patients were identified who presented with acute psychosis, We co
nclude that, although rare, acute disseminated encephalomyelitis can presen
t as an acute psychosis, This immune-mediated condition should be included
in the differential diagnosis of neurologic disorders presenting as a psych
iatric illness, (C) 2000 by Elsevier Science Inc. All rights reserved.