A 6-year old girl developed acquired aphasia with epilepsy and a parox
ysmal EEG (Landau-Kleffner syndrome). Isoelectric CSF focusing showed
oligoclonal IgG bands. Small lesions were visualized in periventricula
r left frontal white matter and right parietal lobe centrum semiovale
with magnetic resonance imaging (MRI). After a week of ACTH therapy, t
he EEG paroxysmal activity disappeared; during the next few months, th
e language disorder improved. Further MRI examination showed a decreas
e in size and signal of the left frontal lesions, with localized white
matter atrophy, dilatation of the subarachnoidal spaces, and disappea
rance of the right parietal lesion. The clinical and neuroradiologic f
eatures and the laboratory data suggest an acute disseminated encephal
omyelitis.