Herpes Simplex Encephalitis

Abstract

Continuing evaluations of antiviral agents for treatment of herpes simplex encephalitis (HSE) provided an opportunity to collect clinical data from 113 patients in whom the diagnosis was proved by viral isolation. Occurrence of HSE was in all ages and in both sexes and was nonseasonal. Characteristically, patients had behavioral changes, fever, confusion, speech disturbances, and, less frequently, seizures. The EEG was the most useful neurodiagnostic aid followed by technetium and computed axial tomographic scans. Employing a logistic regression model for variable selection, the diagnosis could be predicted by clinical findings and neurodiagnostic tests in 83% of the proved cases, but the evidence in 25% was falsely positive. There was evidence of localization by either clinical or neurodiagnostic assessment in all patients with proved disease. Among patients wtih negative findings for HSE, similar focal findings predominated in all but a few. The CSF and brain scans were normal in many patients with proved HSE. This extensive clinical experience in patients wtih diagnosis proved by viral isolation shows that diagnosis cna be confirmed only by brain biopsy.

Herpes PCR Testing and Empiric Acyclovir Use Beyond the Neonatal Period

“…In a series of 113 children and adults with HSV encephalitis before the introduction of PCR-based diagnostics, a prodrome of malaise, headache, and nausea/vomiting was typical, and fever occurred in 90% of subjects. 7 Progressive alteration in mentation occurred in 71% and seizure activity occurred in 67%; all cases had identifiable focal abnormalities on clinical, computed tomography, or EEG findings. The introduction of CSF PCR led to the understanding that less-severe forms of HSV CNS disease do exist, although these cases typically lack only the classic severe focal encephalitis syndrome: fever (94% to 96% of cases) and altered mental status to some degree remain near universal findings in reports of "milder" disease.…”

Viral encephalitis in travellers

“…It should be noted that a history of recurrent labial or genital herpes simplex infection occurs no more commonly in patients with HSE than controls. 9 Reports of noting strange smells may indicate olfactory hallucinations from frontotemporal involvement in HSE. 4 Symptoms of parotitis, testicular pain or abdominal pain from pancreatitis may be suggestive of mumps virus as the causative agent.…”

Clinical Spectrum of the Herpes Simplex Encephalitis in Children: Clinical Features, Neuroimaging, Treatment, and Outcomes

“…As noted in previous series and case reports (1-4,10), most children with HSE, as it was the case in our study, suffer from seizures and fever as the most common presenting clinical symptom. The cerebrospinal fluid findings of patients with HSE are abnormal in majority of cases, typically with a predominance of lymphocytes as well as increased protein concentration and high red blood cell count indicating a hemorrhagic process (3,(11)(12). This typical abnormal CSF findings are highly suggestive of HSV, but lumbar puncture early in the illness may be normal and the normal feature of CSF does not rule out a diagnosis of HSE.…”