Clinical and evolutionary phenotype of severe herpes encephalitis

Abstract

Introduction: Herpes simplex virus type 1 (HSV-1) encephalitis is an important cause of severe infectious encephalitis in adults, characterized by a rapidly progressive clinical course and high morbidity and mortality even with timely antiviral treatment.
Objective: To describe the clinical features, diagnostic findings, management, and course of a case of severe herpes simplex virus type 1 encephalitis.
Clinical case: We present the case of a 53-year-old woman with a recent history of cold sores, who developed an acute episode of headache, followed by deterioration of consciousness and status epilepticus. Brain CT showed bilateral temporal hypodensities, and MRI revealed T2/FLAIR hyperintense lesions involving the mesial temporal region, insula, and frontobasal areas. Cerebrospinal fluid analysis showed lymphocytic pleocytosis and HSV-1 detection by meningeal panel. The patient received intravenous acyclovir, corticosteroids, and anticonvulsant therapy. Despite early treatment and intensive support, she required mechanical ventilation, tracheostomy, and gastrostomy, and was discharged in a minimally conscious state.
Conclusions: This case illustrates that HSV-1 herpes encephalitis can progress rapidly and result in significant neurological sequelae, even with timely diagnosis and early initiation of Acyclovir. It also highlights a particularly severe form, with bilateral temporal involvement and persistent epileptiform activity, emphasizing the need to maintain a high index of suspicion and provide prompt intensive management.