Infectious causes and outcomes in patients presenting with cerebral spinal fluid pleocytosis

To evaluate the infectious etiologies, clinical features, and outcomes of patients with CNS infections at a tertiary care center. Patients that present with a pleocytosis in the cerebral spinal fluid (CSF), defined as a CSF WBC count > 5 cells/mm³, from July 2015 to June 2016 at a tertiary care hospital were analyzed for this report. Data from patients with confirmed (n = 43) and presumed (n = 51) CNS infections were analyzed. CNS infection was the leading known cause of CSF pleocytosis (n = 43, 18% of all patients with a pleocytosis in the CSF), and HSV-2 was identified as the leading causative pathogen (n = 10) followed by varicella zoster virus (n = 5). Fifty-three percent of patients with a pleocytosis in the CSF did not receive a diagnosis. In the patients that did not receive a diagnosis, CNS infection was presumed to be the cause in 51 patients (21% of patients with CSF pleocytosis). The mean time to diagnosis for patients with confirmed CNS infection was 16 days, but time to diagnosis was highly variable depending on the causative pathogen. There was a significant overlap in CSF parameters and peripheral white blood cell counts in patients diagnosed with a viral, bacterial, or fungal infection. Neuroimaging changes were present in only 44% of CNS infections. The overall mortality was 7% for CNS infections, and 17% of patients with a CNS infection had a severe neurologic deficit at presentation while only 3% had a severe deficit at the last neurologic assessment. This study provides new insights into the infectious causes of disease in a cohort of patients with pleocytosis in the CSF. The study provides new insights into the time to diagnosis and outcomes in patients that present with pleocytosis in the CSF.