Virus-Induced Voracity: Uncovering Hyperphagia Post-Herpes Simplex Virus Type 1

Introduction: Herpes simplex virus type 1 (HSV-1) is the leading cause of sporadic fatal encephalitis, typically presenting with temporal lobe abnormalities. It usually manifests as fever, headache, seizure, altered sensorium, and focal neurological deficit. Hyperphagia as a sole complication of HSV-1 encephalitis is a rare presentation.

Case presentation: We report a 25-year-old woman with a 10-day history of fever, headache, and vomiting, progressing to confusion, visual hallucinations, and drowsiness. She had a history of meningoencephalitis at age 8 and well-controlled focal seizures. Upon admission, magnetic resonance imaging showed T2/fluid-attenuated inversion recovery hyperintensities in both temporal lobes with diffusion restriction. Electroencephalography indicated generalized slowing and cerebrospinal fluid (CSF) analysis revealed lymphocytic pleocytosis with elevated protein levels. Viral encephalitis was suspected, and intravenous acyclovir was initiated. CSF polymerase chain reaction (PCR) confirmed HSV-1. With treatment, she gradually improved but developed hyperphagia during hospital stay. Hyperphagia, a rare complication of herpes simplex virus (HSV) encephalitis, is a part of Kluver-Bucy syndrome typically associated with other cognitive dysfunctions. Despite early treatment, voracious appetite remained partially, emphasizing the need for rapid diagnosis and treatment to prevent severe outcomes.

Conclusion: The case highlights that acute onset hyperphagia can be an isolated complication of HSV encephalitis, requiring tailored therapeutic strategies. Follow-up showed significant weight gain with partial improvement in hyperphagia, underscoring the challenges in managing this condition.