Herpes Simplex Encephalitis (HSV)

FACTS

  • HSV-1 most common cause of sporadic fatal viral encephalitis in adults
 

HPI

universal ROS
  • memory loss (affects medial temporal lobe)

PHYSICAL EXAM

universal exam
  • nuchal rigidity

IMAGING

MRI w/wo to r/o abscess/meningitis in this setting
  • on non-con, will see Temporal-lobe predominant T2/FLAIR hyperintensity ± hemorrhage
A/P
  • Start IV acyclovir as soon as HSV encephalitis is suspected — do not delay for imaging or LP results.
    • Acyclovir 10 mg/kg IV every 8 hours
    • duration: 14-21 days
    • maintain hydration (acyclovir-induced nephrotoxicity)
  • LP and send CSF PCR for HSV-1 or HSV-2 (gold standard) to prove diagnosis
  • cEEG +/- AEDs: high risk of seizures given location