Varicella-zoster meningoencephalitis — Case report

Abstract

Introduction: Encephalitis is defined as inflammation of the brain parenchyma and meningoencephalitis when there is meningeal involvement. A viral etiology is the most common and the diagnostic method of choice is the polymerase chain reaction (PCR) of viral nucleic acids in cerebrospinal fluid (CSF). Herpes simplex virus is the leading cause of encephalitis and varicella-zoster virus (VZV) a less common cause, particularly in immunocompetent individuals. Case report: Woman, 67 years old, retired nurse, brought to the emergency room by disorientation. Physical examination: slowed, disoriented, incoherent and repetitive speech; subfebrile (T-37, 2 °C); no meningeal signs or skin lesions were identified. Laboratory tests revealed leukocytosis (10.5 × 10 ^9/L) with neutrophilia (86.9%). Computed tomography and magnetic resonance imaging (MRI) of the brain were performed and there were no lesions on brain parenchyma. Lumbar puncture (LP): 5 leukocytes/mm3; erythrocytes 2327/mm3; glucose: 80 mg/dl, and protein 26.7 mg/dl. Blood, cerebrospinal fluid cultures and capsular antigens were collected. The patient had clinical worsening at 48 h with fever (T-38, 7 °C), agitation, seizures, left hemiparesis and meningeal signs. LP was repeated: leukocytes 40/mm (98% of polymorphonuclear cells), glucose: 113 mg/dl, and protein: 30.4 mg/dl. CSF cultures were repeated and viral PCR in cerebrospinal fluid was requested. Human immunodeficiency virus testing was negative. Empirically ceftriaxone, ampicillin and acyclovir 10 mg/Kg ev, 8/8 h was established. Electroencephalography revealed severe cortical structural damage in the left hemisphere. MRI of the brain was repeated and showed no lesions. Microbiological study was negative and VZV PCR in CSF was positive. She completed 21 days of acyclovir. The patient had a good clinical and neurologic outcome with resolution of all the symptoms. Conclusion: VZV meningoencephalitis. The case stands out for infection of the central nervous system by VZV in an immunocompetent patient, along with the importance of a high clinical suspicion of viral encephalitis even in the presence of pleocytosis with a predominance of polymorphonuclear cells in the early phase of infection. The suspicion of encephalitis is critical in the decision of early antiviral therapy to prevent neurological sequelae.