Herpes Simplex Encephalitis: Need for Accurate Diagnosis

Abstract

The introduction of vidarabine for the treatment of herpes simplex viral encephalitis (HSE) has produced a major diagnostic dilemma for the medical profession. This antiviral agent is specific for herpes simplex virus but is not an effective therapeutic agent for other organisms that cause focal encephalitis and that can clinically mimic HSE. In fact, in previous and ongoing large-scale collaborative studies, only 50% of the 208 cases thus far examined for evidence of virus in brain biopsy specimens was proved to be HSE. 1 In the case presented by Bia et al (p 367), western encephalitis emerged as the primary diagnosis after proper virological examinations, including study of brain biopsy material, even though herpes simplex virus had been presumed to be responsible for the clinical findings. Other diseases that cause focal brain pathological conditions have been confused with HSE. Such processes include cryptococcal and tuberculous infections, malignant neoplasms, and arteriovenous