Diagnosis of Herpes Simplex Encephalitis: Application of Polymerase Chain Reaction to Cerebrospinal Fluid from Brain-Biopsied Patients and Correlation with Disease

TLDR

Isolation of HSV from brain tissue after biopsy has been considered the reference standard for diagnosing herpes simplex encephalitis (HSE). CSF was collected from clinically suspected HSE patients undergoing brain biopsy to evaluate antiviral treatment. PCR detected HSV DNA in CSF of 98 % of biopsy‑confirmed HSE patients, including all pre‑biopsy samples, remained positive in 4 of 19 specimens after two weeks of therapy, was positive in 3 of 47 culture‑negative cases, and correlated with age and focal imaging, supporting PCR as the diagnostic standard.

Abstract

Isolation of herpes simplex virus (HSV) from brain tissue after biopsy has been considered the reference standard for the diagnosis of herpes simplex encephalitis (HSE). During the evaluation of antiviral treatment of HSE, cerebrospinal fluid (CSF) was obtained from patients with clinical disease indicative of HSE who underwent diagnostic brain biopsy. HSV DNA was detected by polymerase chain reaction (PCR) in CSF of 53 (98%) of 54 patients with biopsy-proven HSE and was detected in all 18 CSF specimens obtained before brain biopsy from patients with proven HSE. Four of 19 CSF specimens were positive after 2 weeks of antiviral therapy. Positive results were found in 3 (6%) of 47 patients whose brain tissue was culture-negative. Detection ofHSV DNA in the CSF correlated significantly with age and focal radiographic findings. Thus, PCR detection of HSV DNA should be the standard for diagnosis of HSE.