Discussion

The cell counts as reported are questionable; therefore, the next best step in treatment is to reanalyze the CSF tests. The patient should be treated with intravenous acyclovir for possible herpes zoster meningitis while awaiting CSF reanalysis.

Zoster, also known as shingles, typically presents with pain followed by a blistering rash. Most cases of shingles are not difficult to diagnose. However, one of the complications of shingles is meningitis, which may be more likely when the shingles occurs in the ophthalmic division of the trigeminal nerve, such as the case with this patient.    


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Varicella-zoster virus (VZV) meningitis, like herpes meningitis, can be difficult to diagnose, especially when there is no rash or the reactivation presents atypically.  VZV meningitis is not usually as destructive as herpes meningitis.  Typical presenting symptoms include headache, delirium, and/or fever.  The typical shingles rash is absent in approximately 50% of proven cases.

The diagnosis of VZV should be considered in any case of apparent viral meningitis with a WBC count >5×109/µL.  It is a myth that the RBC count is usually elevated in herpes or VZV meningitis; at times it can be, but it often is not.  Although polymerase chain reaction can be used to detect VZV, serum immunoglobulin M antibody is more sensitive.

VZV meningitis is treated with intravenous acyclovir 10 to 15 mg/kg 3 times per day for 2 to 3 weeks. Zoster can also cause local vasculitis that can lead to venous or arterial thrombosis.  Although it is unknown how commonly this occurs, both of the patients in whom the author diagnosed VZV meningitis developed cerebral venous thrombosis as a complication. Therefore, magnetic resonance venography should be considered in the setting of this diagnosis.

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Repeat CSF analysis found small lymphocytes that were initially counted as RBCs, increasing the WBC count to 140×109/µL. Magnetic resonance angiogram of the brain was normal. CSF was negative for herpes simplex virus and positive for VZV.

Despite treatment with acyclovir, the patient’s condition worsened. She underwent magnetic resonance venography, which demonstrated acute cerebral venous thrombosis. 

Reference

Pregerson DB. Emergency Medicine 1-Minute Consult Pocketbook. Emresource.org; 2017;5.