Varicella-zoster virus CNS disease--viral load, clinical manifestations and sequels

Abstract

Background: Real-time polymerase chain reaction (PCR) analysis of cerebrospinal fluid (CSF) samples has improved the diagnosis of varicella-zoster virus (VZV) infection of the central nervous system (CNS). The VZV viral load in the CSF obtained from VZV-related neurological syndromes is not known.

Objectives: To investigate VZV viral loads associated with VZV-related neurological syndromes, and to describe the clinical manifestations and sequels in patients with VZV DNA in the CSF.

Study design: Patients in the Western Gotaland region of Sweden with CNS symptoms and VZV DNA in the CSF, during 1995-2006 were retrospectively identified. The diagnoses, laboratory tests (including virus quantity), antiviral treatment, and neurological complications were studied.

Results: Ninety-seven patients with VZV DNA in the CSF detected by PCR were identified. In 66 patients in whom VZV DNA levels were determined, significantly higher viral loads were found in those with encephalitis and acute aseptic meningitis compared to patients with cranial nerve affection (including Ramsay Hunt syndrome). Fifty patients had a follow-up; 34 (68%) had neurological symptoms 1 month after acute disease and 25 (50%) had neurological complications 3 months after discharge. A minimum yearly incidence of 1.8 per 100,000 of PCR diagnosed VZV CNS infections was estimated.

Conclusions: VZV was the most common alpha-herpesvirus detected in CSF samples from patients with CNS symptoms in the Western Gotaland region of Sweden. CSF viral loads were higher in patients with encephalitis and acute aseptic meningitis than in other CNS syndromes caused by VZV. A majority of the patients that were seen in follow-up had neurological symptoms and sequels.