Pediatric Herpes Simplex Virus Encephalitis

Knowledge on pediatric herpes simplex virus encephalitis is limited. Here we summarize 6 neonates and 32 children diagnosed by polymerase chain reaction (n = 37) or serological studies (n = 1), respectively. Diagnosis was difficult, as only 15 patients presented neurologic symptoms. Moreover, cerebrospinal fluid glucose, protein, and leukocytes were normal in 6 patients. Subsequently, all but 2 showed neurologic symptoms. Diffusion-weighted neuroimaging was the most sensitive early imaging method. Despite acyclovir treatment, 8 patients experienced early relapses, showing movement abnormalities, impaired vigilance, and seizures. Diffuse white matter changes, found in 3 of 5 relapse patients on neuroimaging, and a negative cerebrospinal fluid herpes simplex virus polymerase chain reaction suggested inflammatory processes. All relapse patients were again treated with acyclovir, and 3 responded to additional corticosteroid treatment. Whereas outcome after relapses was poor, overall outcome was good. No child died; 14 were asymptomatic at discharge, and neuroimaging remained normal in 7 of 30 patients studied.