A 6 year old boy presented with meningoencephalitis and was found to h
ave serological evidence of acute human herpes virus-6 (HHV-6) infecti
on. He did not develop symptomatic seizures or the rash of exanthum su
bitum (roseola). His course was marked by severe spastic quadriparesis
associated with radiological evidence of basal ganglia infarction. HH
V-6 infection should be considered in any child with acute meningoence
phalitis.