Lumbar and ventricular CSF protein, leukocytes, and lactate in suspected bacterial CNS infections

Protein concentration, leukocyte density, and lactate concentration were st udied in 41 pairs of ventricular and lumbar CSF drawn at an interval of les s than 24 hours from patients with suspected bacterial CNS infections. The ventriculo-lumbar ratios ranged from 0.003 to 10.2 (median = 0.42) for prot ein and from 0.002 to 53.5 (median = 0.17) for leukocytes. The uneven distr ibution of leukocytes and proteins in the CSF space may produce findings th at fail to indicate bacterial CNS infections. Lactate was distributed more homogeneously in the CSF space than protein and leukocytes (ventriculo-lumb ar ratio 0.52 to 1.66 [median = 0.81]).