Neurological Manifestations of West Nile Virus at Olive View-UCLA Medical Center, 2012-2013

Abstract

80% of individuals infected with West Nile virus (WNV) are asymptomatic and 1% will suffer from neuroinvasion that can result in permanent neurological deficits or mortality. A two-year retrospective study was performed to identify patients with confirmed WNV infection with neuroinvasion. Patient demographics, physical exam findings, and laboratory diagnostics were reviewed. 22 patients (59% male, age 50.2+/-10.6 years) were identified between August 2012 and September 2013. The most common positive findings on review of symptoms included fever (77.3%), nausea/ vomiting (72.7%), and headache (68.2%). Motor strength was reduced in 22.7% of patients and 27.2% of patients were hyporeflexive. Lumbar puncture was performed in 90.9% of patients (cerebrospinal fluid [CSF] protein 78.3+/-29.4 mg/dL and glucose 70.3+/-24.2 mg/dL). Elevated CSF anti-WNV IgM and IgG was present in 82.4% and 58.8% of the 17 tested cases, respectively. Elevated serum anti-WNV IgM and IgG was present in 100% and 83.3% of the 18 tested cases, respectively. Encephalitic presentations, with or without focal neurological deficits (e.g. motor weakness, hypotonia), dominated this series. In endemic areas, seasonal presentation of such symptoms should raise suspicion for WNV with neuroinvasion.