This document discusses various components and measurements of cerebrospinal fluid (CSF). It provides normal ranges for CSF lactate, glutamine, and enzymes. Elevated lactate levels can indicate bacterial meningitis or unexplained neurological disease. Increased glutamine suggests liver failure or hepatic encephalopathy. Certain enzyme levels are elevated in conditions like brain tumors or bacterial meningitis. The document also discusses differences between CSF and blood measurements, indications of hemorrhage or blockage, replacement rate of CSF, and guidelines for CSF sample collection and handling.