# A Rare Case of Human Herpesvirus 6 Meningitis in an Immunocompetent Adult Presenting With Recurrent Encephalopathy: Could Prior Head Trauma or an Incidental Cerebral Cavernous Malformation Be a Predisposing Factor?

## TL;DR

A rare case of HHV-6 meningitis in an immunocompetent adult is linked to prior head trauma and a brain malformation, suggesting these factors may allow the virus to invade the brain.

## Contribution

This case report highlights structural brain abnormalities and prior trauma as potential predisposing factors for HHV-6 CNS infection in immunocompetent individuals.

## Key findings

- HHV-6 infection was confirmed in an immunocompetent adult with a history of TBI and a cerebral cavernous malformation.
- Neuroimaging showed leptomeningeal enhancement, suggesting BBB disruption may facilitate HHV-6 neuroinvasion.
- The case implies that BBB dysfunction from structural brain issues could enable CNS infection without immunosuppression.

## Abstract

Human herpesvirus 6 (HHV-6) meningitis/encephalitis is typically seen in immunocompromised patients, with rare reports in immunocompetent adults. We present the case of a 52-year-old immunocompetent man with recurrent acute encephalopathy and incidental cerebral cavernous malformation (CCM), alongside a remote history of traumatic brain injury (TBI). Cerebrospinal fluid (CSF) analysis and multiplex polymerase chain reaction (PCR) test confirmed HHV-6 infection, with neuroimaging showing leptomeningeal enhancement. This case suggests that structural brain abnormalities such as CCM and prior TBI may cause chronic blood-brain barrier (BBB) disruption, facilitating HHV-6 neuroinvasion even in the absence of immunosuppression. Awareness of such predisposing factors is crucial for the timely diagnosis and treatment of HHV-6 meningitis/encephalitis in immunocompetent individuals. Further research is needed to clarify the pathophysiological link between BBB dysfunction and HHV-6 central nervous system (CNS) infection.