Definition of CSF analysis:

Cerebrospinal fluid (CSF) analysis is a group of laboratory tests that measure proteins, sugar (glucose), and other chemicals in the fluid that surrounds and protects the brain and spinal cord.

How the test is performed:

A sample of CSF is needed. A lumbar puncture, also called a spinal tap, is the most common way to collect this sample. For information on this procedure, see lumbar puncture. Other methods for collecting CSF are rarely used, but may be recommended in some cases. See also:

• Cisternal puncture
• Removal of CSF from a tube that is already in the CSF, such as a shunt or ventricular drain
• Ventricular puncture

After the sample is taken, it is sent to the laboratory for evaluation.

How to prepare for the test:

See: Lumbar puncture

How the test will feel:

See: Lumbar puncture

Why the test is performed:

Analysis of CSF can help detect certain conditions and diseases. All of the following can be, but are not always, measured in a sample of CSF:

• Antibodies and DNA of common viruses
• Bacteria (including that which causes syphilis; see:VDRL test)
• Cell count
• Chloride
• Cryptococcal antigen
• Glucose
• Glutamine
• Lactate dehydrogenase
• Oligoclonal banding to look for specific proteins
• Total protein
• Whether there are cancerous cells present