Background. - Severe central nervous system diseases, such as encephalitis,
have been reported in association with Mycoplasma pneumoniae infections.
Case report. - After an ENT infection, a 9-year-old boy with Down's syndrom
e developed encephalitis revealed by an acute alteration in consciousness.
Head computed tomography showed, after 2 weeks, an infiltration in the basa
l ganglia region. The diagnosis of Mycoplasma pneumoniae encephalitis was m
ade; recovery was complete in a few weeks.
Conclusion.- Mycoplasma pneumoniae infection should be considered in all ca
ses of acute encephalopathy; yet the pathogenesis of the disorder is unknow
n and the treatment uncertain. (C) 1999 Elsevier, Paris.