Usually, contrast enhancement is administered during the scan for better visualization. Computed tomography (CT) scan of the head to view leak location and produce detailed images of skull anatomy and tissue.Table 1 lists CSF colors associated with various conditions.A combination of diagnostic tests is typically used to provide a diagnosis and also detect the location of the cerebrospinal fluid (CSF) condition. 2 Newborn CSF is often xanthochromic because of the frequent elevation of bilirubin and protein levels in this age group. CSF protein levels of at least 150 mg per dL (1.5 g per L)-as seen in many infectious and inflammatory conditions, or as a result of a traumatic tap that contains more than 100,000 RBCs per mm 3-also will result in xanthochromia. 5 Xanthochromia is present in more than 90 percent of patients within 12 hours of subarachnoid hemorrhage onset 2 and in patients with serum bilirubin levels between 10 to 15 mg per dL (171 to 256.5 μmol per L). Discoloration begins after RBCs have been in spinal fluid for about two hours, and remains for two to four weeks. Xanthochromia is a yellow, orange, or pink discoloration of the CSF, most often caused by the lysis of RBCs resulting in hemoglobin breakdown to oxyhemoglobin, methemoglobin, and bilirubin. However, as few as 200 white blood cells (WBCs) per mm 3 or 400 red blood cells (RBCs) per mm 3 will cause CSF to appear turbid. To prove herpetic, cryptococcal, or tubercular infection, special staining techniques or collection methods may be required. Latex agglutination, with high sensitivity but low specificity, may have a role in managing partially treated meningitis. However, polymerase chain reaction is much faster and more sensitive in some circumstances. Culture is the gold standard for determining the causative organism in meningitis. White blood cell differential may be misleading early in the course of meningitis, because more than 10 percent of cases with bacterial infection will have an initial lymphocytic predominance and viral meningitis may initially be dominated by neutrophils. Diagnostic uncertainty can be decreased by using accepted corrective formulas. Red blood cells in CSF caused by a traumatic tap or a subarachnoid hemorrhage artificially increase the white blood cell count and protein level, thereby confounding the diagnosis. The three-tube method, commonly used to rule out a central nervous system hemorrhage after a “traumatic tap,” is not completely reliable. The presence of blood can be a reliable predictor of subarachnoid hemorrhage but takes several hours to develop. Xanthochromia is most often caused by the presence of blood, but several other conditions should be considered. Protein level, opening pressure, and CSF-to-serum glucose ratio vary with age. Proper evaluation of CSF depends on knowing which tests to order, normal ranges for the patient's age, and the test's limitations. Properly interpreted tests can make cerebrospinal fluid (CSF) a key tool in the diagnosis of a variety of diseases. Lumbar puncture is frequently performed in primary care.

Brain fluid