Herpes Simplex Virus Meningitis Following Microvascular Decompression: A Rare Postoperative Complication Case Report and Literature Review

Introduction: Trigeminal neuralgia (TN) is a paroxysmal disorder characterized by debilitating facial pain caused by vascular compression of the trigeminal nerve. First-line treatment typically involves carbamazepine. When medical management fails, surgical interventions such as microvascular decompression (MVD) is the treatment of choice. We present a 26-year-old male who underwent MVD for trigeminal neuralgia (TN) and developed herpes simplex virus (HSV) meningitis. On post-op day (POD) 6, presented to ED with severe headache and an elevated WBC count. He underwent lumbar puncture and tested positive for HSV. He was started on IV acyclovir and had resolution of symptoms on POD-12.

Methods: Pubmed search to determine the content of literature, review papers, and report on outcomes, findings, and best practices in this rare post-operative complication.

Results: The overall prevalence of meningitis following microvascular decompression (MVD) is reported at 1.2%, with herpes simplex virus (HSV) accounting for 8.3% of these cases (Chojak et al., 2023). A review revealed that HSV reactivation occurs in approximately 10% of patients undergoing MVD for trigeminal neuralgia (Kikuchi et al., 2022). Although incidence of HSV reactivation is low, if left undiagnosed and untreated, it is associated with significant morbidity and mortality. In one study, 40 cases of HSV encephalitis were identified following craniotomy, with a 30% mortality rate due to the complication (McLaughlin et al., 2019). Undiagnosed HSV encephalitis often results in severe neurological impairments, including seizures, memory loss, mutism, language disorders, hemineglect, or aphasia (Chaudhuri & Kennedy, 2002). Early treatment of HSV meningitis with acyclovir significantly reduces mortality, from 70% to 30% (Kuhnt et al., 2012).

Conclusion : In patients who present with signs of meningitis after MVD that fail infectious work up, clinicians should have a high index of suspicion to test with lumbar puncture to assess for HSV. The role of empiric acyclovir in the early stages of diagnosis regardless of PCR should be assessed. Timely assessment and treatment significantly reduce mortality and morbidity. An important question to explore is whether perioperative administration of acyclovir could be beneficial.