Laboratory analysis of cerebrospinal fluid.

Abstract

OBJECTIVE: To review the physiology of cerebrospinal fluid (CSF), normal laboratory reference values, and key aspects of CSF sample collection, gross and microscopic examination, microbiologic testing, and chemical analysis. DATA SOURCES: Recent professional literature. STUDY SELECTION: Selected manually by the authors. DATA EXTRACTION: Articles manually by the authors. DATA SYNTHESIS: CSF is formed by a combined process of plasma ultrafiltration and active secretion. Mechanical and osmotic barriers exist between plasma and CSF and between CSF and brain. Lumbar puncture is the preferred technique for CSF sampling. Normal CSF should be clear, colorless, and free of clotted material. CSF can be examined for presence of microbes using stains. Additionally, the chemical composition of CSF can be examined; tests of interest include glucose, protein, lactate, enzymes, glutamine, specific amino acids, biogenic amines, and various drugs. CONCLUSION: Visual, microscopic, and chemical examination of CSF is essential to the clinical management of patients with CNS disease.