Background: Herpes simplex encephalitis has an incidence of ~2000 cases in the US/yr, 90% of which are HSV-1 related. It needs to be rapidly distinguished from other conditions such as aseptic meningitis which is thought to be self-limiting. Papilledema is associated with 20% of cases with viral encephalitis and can act as a signal for treatment of ICP.
Case Report: A 62 y/o white male was dx with aseptic meningitis after presenting with severe headache, nausea, emesis, and confusion. The pt was afebrile with labs revealing mild leukocytosis, and a (-) brain MRI and CT. The pt was treated with IV acyclovir, rocephin, and vancomycin. Later, blood and CSF cultures were (-) for bacterial/viral growth, and PCR was (-) for HSV and other pathogens. The patient stabilized and was discharged with oral acyclovir. Soon after, the patient suffered hallucinations and confusion requiring restraints and sedatives. CSF analysis exhibited pleocytosis, mildly elevated proteins, and (+) HSV 1 IgG titers. The pt was dx with HSV-1 meningeal encephalitis and was restarted on IV acyclovir, and was discharged upon stabilization. Four wks from initial presentation, HA’s worsened with the development of vision loss and severely swollen ONH’s OU. Elevated ICP was confirmed by LP and the pt was restarted on IV acyclovir and decadron. Therapeutic spinals taps improved headache and visual symptoms, and were performed on an as needed basis. Resolution of the papilledema and vision loss took place over 6 mo. Exam findings 2.5 yrs later revealed atrophy of the papillomacular bundle and corresponding paracentral VF defects OU.
Conclusions: The pt’s clinical deterioration and development of elevated ICP was surprising to physicians as there was never significantly elevated proteins nor cells in the CSF that could cause obstruction of CSF outflow. Theories suggest that the development of elevated ICP in acute CNS infections may be due to inflammatory processes that result in dysfunctional absorption by the arachnoid granulations. Those with inflammatory CNS conditions should be monitored for papilledema and intracranial hypertension which can increase the risk for mortality.