DIAGNOSIS OF HERPES-SIMPLEX ENCEPHALITIS BY MAGNETIC-RESONANCE-IMAGING AND POLYMERASE-CHAIN-REACTION ASSAY OF CEREBROSPINAL-FLUID

The early diagnosis of herpes simplex encephalitis (HSE) is essential because early introduction of antiviral therapy can significantly redu ce the mortality of this disease. Herpes simplex virus (HSV) DNA detec tion in cerebrospinal fluid (CSF) samples is a rapid, noninvasive, spe cific, and highly sensitive method for HSE diagnosis. Neurodiagnostic methods have also been studied for noninvasive diagnosis of HSE. Magne tic resonance imaging (MRI) seems to be the most sensitive of them but it has not been compared to PCR in terms of efficacy for HSE diagnosi s. In this study, 17 patients with focal encephalitis were prospective ly evaluated by PCR analysis of CSF samples and MRI examination. MRI l esions involving the inferomedial region of one or both temporal lobes were observed in all PCR-positive patients but one. No PCR-negative p atient presented with the same pattern of MRI lesions. MRI was also im portant for the establishment of an alternative diagnosis in three of eight PCR-negative patients. Both methods should be routinely applied in the evaluation of presumed HSE cases. (C) 1998 Elsevier Science B.V .