UNUSUAL COURSE OF HERPES-SIMPLEX VIRUS ENCEPHALITIS AFTER ACYCLOVIR THERAPY

This is a report on a case of herpes simplex encephalitis (HSE) taking an unusual course after initially successful acyclovir therapy. The e tiology of HSE was proven serologically, by repeated detection of herp es simplex virus (HSV)-specific DNA sequences in cerebrospinal fluid ( CSF) with polymerase chain reaction (PCR) and was supported by cerebra l imaging, After both the neurological symptoms and laboratory finding s had improved initially under acyclovir therapy, the patient's clinic al condition deteriorated accompanied by a renewed increase in CSF ple ocytosis and protein content, Nuclear magnetic resonance (NMR) imaging confirmed the finding of bilateral, mainly temporal lesions compatibl e with a diagnosis of relapsing HSE, The patient responded well to a s econd cycle of antiviral therapy but required a third treatment cycle due to renewed deterioration later on, HSV-specific DNA sequences coul d not be demonstrated in several consecutive CSF samples taken after t he first week of illness but increased inflammatory changes typical of HSE were seen on NMR during phases of deterioration, IgM-class antibo dies against HSV were detected in CSF 4 weeks after onset of symptoms and stayed positive for at least 7 weeks. Reasons for the repeated det erioration and possible explanations for the absence of HSV DNA in spi te of what could be seen as relapses are discussed.