Patient with Suspected Meningitis Age > 56 days — HSV Encephalitis Considerations — Clinical Pathway: Emergency, Inpatient

Suspected Meningitis Age > 56 days Clinical Pathway — Emergency Department, Inpatient and ICU

HSV Encephalitis Considerations

  • The following symptoms can be seen with HSV encephalitis:
    • Fever
    • Altered mental status (confusion, lethargy, decreased consciousness)
    • Headache
    • Seizures
    • Aphasia
    • Increased numbers of CSF RBCs*
  • Younger children and immunocompromised patients may present with mild or atypical symptoms
  • EEG and MRI imaging may show frontotemporal lobe abnormalities
  • CSF HSV PCR is > 95% sensitive, but may be falsely negative if obtained too early (first 4 days of symptoms) or when there are elevated numbers of CSF RBCs
  • When HSV encephalitis is suspected, obtaining a CSF HSV PCR and administration of acyclovir are recommended. If CSF cannot be obtained, empiric administration of acyclovir is recommended.

*Increased number of CSF RBCs should raise suspicion for HSV encephalitis, but this is typically a late finding. The absence of RBCs in CSF should not exclude this diagnosis.