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Herpes simplex virus encephalitis despite normal cell count in the cerebrospinal fluid
Nurith J Jakob1, Thorsten Lenhard, Paul Schnitzler
1Department of Neurology, University Hospital Heidelberg, Heidelberg, Germany. jakob@urz.uni-hd.de
Critical Care Medicine
|November 10, 2011
Summary
Herpes simplex virus encephalitis can occur in cancer patients after brain radiation, even with normal spinal fluid cell counts. Early PCR testing for herpes simplex virus is crucial for timely diagnosis and treatment.
Area of Science:
- Neurology
- Infectious Diseases
- Oncology
Background:
- Whole brain irradiation is a common treatment for various malignancies.
- Herpes simplex virus encephalitis (HSVE) typically presents with abnormal cerebrospinal fluid (CSF) cell counts.
Observation:
- This study describes five patients with malignancy and recent whole-brain irradiation who presented with impaired consciousness and/or seizures.
- Despite normal CSF cell counts, all patients tested positive for herpes simplex virus DNA via PCR.
Findings:
- Atypical, anergic HSVE should be suspected in immunocompromised patients with neurological symptoms post-brain irradiation and normal CSF.
- Polymerase chain reaction (PCR) for herpes simplex virus is more sensitive than routine CSF analysis for early HSVE detection.
Implications:
- Early initiation of antiviral therapy is critical, even with mild suspicion, until HSVE is definitively ruled out.
- This highlights the importance of considering HSVE in the differential diagnosis of neurological decline in irradiated cancer patients.
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