Continuous video electroencephalogram for herpes simplex encephalitis: a case report and literature review

Wanhui Lin,Huapin Huang,Shenggen Chen,Hanbin Lin,Changyun Liu

doi:10.1186/s42494-020-00017-x

Wanhui Lin, Huapin Huang + Show 3 more

Open Access

https://doi.org/10.1186/s42494-020-00017-x

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Abstract

BackgroundElectroencephalogram (EEG) is an important tool for the diagnosis of herpes simplex virus encephalitis (HSE). However, the diagnosis of non-convulsive status epilepticus (NCSE) in HSE is challenging without the help of continuous video EEG (CVEEG), and whether EEG is a predictor of outcome remains controversial.Case presentationA 63-year-old woman presented with a 5 day history of fever, coma and seizures. Results of EEG, magnetic resonance imaging and polymerase chain reaction (PCR) in cerebrospinal fluid (CSF) were suggestive of herpes simplex encephalitis-1 (HSE-1). Preliminary EEG showed periodic discharges at the prefrontal and temporal lobes, which were particularly synchronized with intermittent lip smacking movements, and the discharges were terminated by diazepam. After 2-week treatment with acyclovir, high-dose hormone pulse therapy and high-dose immunoglobulin therapy, the CSF was improved, but the patient’s consciousness became worsen, consistent with the diffuse slow waves in the delta range and low voltage of EEG activity. In the following 1 month, the patient had non-responsiveness to pain and sound as shown by CVEEG with diffuse slow waves. Sometimes paroxysmal very slow waves (0.5–1 Hz) were synchronized with intermittent paroxysmal eye movements, pupil abnormality, and sweating in the frontal area. After 2 months of treatment, the EEG abnormalities improved to have alpha rhythm.ConclusionThe CVEEG not only helps identify NCSE but can also be used to monitor HSE progression.

Highlights

Electroencephalogram (EEG) is an important tool for the diagnosis of herpes simplex virus encephalitis (HSE)
Herpes simplex encephalitis (HSE) is the most common cause of sporadic fatal viral encephalitis [1], which has a mortality rate of ~ 70% in untreated patients and 19% in those treated with acyclovir
Brain magnetic resonance imaging (MRI) with contrast demonstrated increased cortical signal intensities in the bilateral frontal lobes and the bilateral temporal lobes, with associated diffusion restriction, indicating cytotoxic edema and enhancement of lesions and meninges, which were highly suggestive of HSE (Fig. 2)

Summary

Introduction

Electroencephalogram (EEG) is an important tool for the diagnosis of herpes simplex virus encephalitis (HSE). She had intermittent lip smacking movements, during which VEEG showed quasi-periodic discharges at the prefrontal and temporal lobes especially in the left hemisphere, suggesting focal seizure activity. 223 out of 245 (91%) HSE patients had abnormal EEG activity [10].

Results

Conclusion