844The Clinical Significance of Cerebrospinal Fluid Neutrophilic Pleocytosis in Viral Central Nervous System Infections

Background. Viral meningitis and encephalitis is typically characterized by a cerebrospinal fluid (CSF) lymphocytic pleocytosis. A CSF neutrophilic pleocytosis presentation has been described but its prognostic and clinical significance is unknown. The objectives of our study were to compare the clinical and laboratory characteristics of viral central nervous system (CNS) infections with CSF neutrophilic to lymphocytic predominance and to evaluate factors associated with adverse clinical outcomes (ACO). Methods. We conducted a retrospective study of 182 patients with confirmed viral CNS infections from Houston, TX and New Orleans, LA from 1999 to 2013. The patients were divided into CSF neutrophilic pleocytosis (neutrophils >50%) (n = 45) and CSF lymphocytic pleocytosis (lymphocytes + monocytes >50%) (n = 137). We compared the clinical characteristics, laboratory findings, imaging results and clinical outcomes between two groups. An adverse clinical outcome was defined as a Glasgow outcome scale 1-4. Results. Of the 182 patients, 45 (25%) patients had CSF neutrophilic pleocytosis. CSF neutrophilic predominance was more frequently seen in patients with enteroviral infection (64% vrs 33%; p < 0.001) and less commonly in herpetic infections (20% vrs 46%; p = 0.003). The CSF neutrophilic pleocytosis group also presented more commonly in younger patients (p = 0.001) with more respiratory symptoms (P = 0.04) and had higher CSF WBC (p = 0.004). An adverse clinical outcome was presented in 29 patients (16%). Factors associated with ACO included arboviral infection, Caucasian race, Charlson comorbidity index ≥ 1, Age ≥ 60, fever, focal neurological deficit, altered mental status, encephalitis, and abnormal MRI (p < 0.05). Conclusion. CSF neutrophilic pleocytosis occurs in 25% of patients with confirmed viral CNS infections and is most likely seen in younger patients with enteroviral infections and is associated with higher CSF pleocytosis but is not associated with higher adverse clinical outcome. Disclosures. All authors: No reported disclosures.