Two cases of acute meningoencephalitis, presumably viral in origin, with brainstem involvement are reported. Common to both patients during the course of their illness was coma, downbeat nystagmus, and ataxia. Although both reached what appeared to be a terminal state, recovery began following treatment with corticosteroids. The significance of the neurologic signs, particularly the unusual occurrence of downbeat nystagmus, is discussed, as is the appropriate management of the disorder.