Bilateral hippocampal encephalitis caused by enteroviral infection

Nonpolio enteroviral encephalitis usually presents as a diffuse, generalize d encephalitis. Focal cerebral involvement by nonpolioviruses is uncommon, and neuroradiologic studies in these cases are usually normal. The authors present a case of a 5-year-old male with an acute encephalitic illness and bilateral lesions of the hippocampi on magnetic resonance imaging. Enterovi ral nucleic acids were detected in the cerebrospinal fluid by the reverse t ranscription polymerase chain reaction. The findings suggest that enterovir al infection should be considered in the differential diagnosis of acute bi lateral hippocampal encephalitis in patients in whom polymerase chain react ion fails to demonstrate the presence of herpes simplex virus. (C) 1999 by Elsevier Science Inc. All rights reserved.