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

Protein concentration, leukocyte density, and lactate concentration were studied in 41 pairs of ventricular and lumbar CSF drawn at an interval of less 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 protein and from 0.002 to 53.5 (median=0.17) for leukocytes. The uneven distribution of leukocytes and proteins in the CSF space may produce findings that fail to indicate bacterial CNS infections. Lactate was distributed more homogeneously in the CSF space than protein and leukocytes (ventriculo-lumbar ratio 0.52 to 1.66 [median=0.811).