Neonate with intractable seizures and metabolic acidosis: an unusual case of type-1 herpes simplex encephalitis- diagnostic and management challenges

Neonatal Herpes simplex virus (HSV) infection is usually caused by type 2 virus following maternal peripartum genital HSV infection. Type 1 HSV usually affects infants after 3 months of age. Neonatal HSV infection present as skin, eye and mouth disease (SEM disease); affect the central nervous system (CNS disease) or involve multiple organs (Disseminated disease). Illustrative case: A full term male baby; birth weight of 3.25 kg, born to a primiparous mother with uneventful intrapartum and postpartum period and normal physical examination. At 20 days of life, the neonate presented with lethargy, poor feeding and later developed generalized tonic-clonic seizures. Initial workup showed metabolic acidosis; neuro-sonogram showed diffuse cerebral edema. Seizures were not controlled initially with intravenous phenobarbitone, phenytoin and pyridoxine. On starting intravenous midazolam baby developed poor respiratory efforts and was intubated. Serum ammonia and lactate levels were mildly elevated. Lumbar puncture attempted after seizure control showed 93 WBCs, 90% lymphocytes, normal glucose and mildly elevated proteins. With possibility of viral encephalitis; intravenous acyclovir was started. EEG showed PLEDS and CSF HSV-PCR detected Type 1 HSV. This case illustrates the nonspecific presentation of HSV infection in the neonatal period without history of HSV in the mother and challenges faced during the management. Early initiation of acyclovir reduces HSV associated morbidity and mortality in neonates