Objective: To present two cases of post-infectious encephalitis of the brain stem (ETC) in infancy, which is very infrequent at this age.
Clinical cases: Two patients aged 4 months and 9 months respectively had a previous history of a catarrhal illness a few days before the onset of encephalitis. The clinical condition was of subacute onset and torpid course, characterized by ataxia, reduced level of consciousness, involvement of the pyramidal tracts and paralysis of the cranial nerves. No significant information for the diagnosis of either case was obtained from CT. MR showed lesions at the level of the pons. However, the MR image did not correspond in seventy to the clinical condition. The clinical courses of the two patients were different. One case recovered with no sequelae. In the other case the cranial nerves and gait did not return to normal.
Conclusions: In our experience, ETC is rarely seen in infancy. A high degree of suspicion and early treatment of ETC caused by the herpes simplex virus is necessary, since there is usually a high mortality or serious neurological sequelae.