Prognosis and Therapy of Viral Encephalitis in Adults Wang Yiming PUMC 2001 Excerpt from NIAID-CASG (National Institute of Allergy and Infectious Diseases-Collaborative Antiviral Study group) recommendations and European consensus 2005

Prognosis Pathogen Immunological state Environmental factors Correct diagnosis and appropriate treatment

Pathogen Herpes simplex virus (HSV) Varicella-zoster virus (VZV) Epstein-Barr virus (EBV) Mumps Measles Enterovirus

Clues from Trails Of NIAID-CASG Major determinants of Prognosis: Age, duration of disease, level of consciousness < 30y with a normal level of consciousness GCS<6 (Whiley et al., 1986) Late death: severely impaired patients (not the persistent or reactivated HSV infection)

Age: Occurrence and Severity HSE % <20 20-50 >50 Age

PCR detection of viral DNA Diagnostic golden standard Sensitivity: 94%; Specificity: 98% (NIAID-CASG) HSV-DNA persists 1 week or more

Detection of HSV DNA

PCR detection of viral DNA Virus load in the CSF appears to correlate directly with outcome Quantity of virus (copies of viral DNA/mL) correlate statistically with: 1. Decreased level of consciousness, 2. Presence of a lesion detected by either CT or MRI, 3. Poor neurological outcome. Domingues et al., 1997,1998

Therapy Anti-viral therapy Corticosteroid Surgical intervention

Anti-viral therapy Acyclovir: 38% return to normal function. Ganciclovir Valciclovir (Biran and Steiner, 2002) Pleconaril: “broad spectrum” (Pevear et al., 1999)

Corticosteroid Large dose of corticosteroids as an adjunct treatment for acute viral encephalitis are not generally considered to be effective and their use is controversial.

Surgical Intervention Surgical decompression Improve outcome in HSE in individual cases (Yan, 2002)

PCR Monitoring of Therapy PCR of the CSF should be considered at completion of therapy for HSE to monitor treatment (category 2 recommendation)

PCR Monitoring of Therapy Aciclovir treatment of HSE mostly leads to a sharp decline of DNA copies. CSF-PCR should be performed upon completion of 10-14 days aciclovir therapy. Patients with detectable HSV DNA should receive an additional course of therapy. (Cinque P. et al., 1996)