CSF analysis

CSF chemistry — Cerebrospinal fluid (CSF) is a clear fluid that circulates in the space surrounding the spinal cord and brain. CSF protects the brain and spinal cord from injury by acting like a liquid cushion. CSF is usually obtained through a lumbar puncture (spinal tap). During the procedure, a needle is inserted usually between the 3rd and 4th lumbar vertebrae and the CSF fluid is collected for testing.

Also known as: Cerebrospinal fluid analysis

Definition

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

Normal Values

Antibodies and DNA of common viruses: None
Bacteria: No bacteria grows in a lab culture
Cancerous cells: No cancerous cells present
Cell count: less than 5 white blood cells (all mononuclear) and 0 red blood cells
Chloride: 110 to 125 mEq/L
Fungus: None
Glucose: 50 to 80 mg/100 mL (or greater than two-thirds of blood sugar level)
Glutamine: 6 to 15 mg/dL
Lactate dehydrogenase: less than 2.0 to 7.2 U/mL
Oligoclonal bands: 0 or 1 bands that are not present in a matched serum sample
Protein: 15 to 60 mg/100 dL

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean

An abnormal CSF analysis result may be due to many different causes, including:

Cancer
Encephalitis (such as West Nile and Eastern Equine)
Hepatic encephalopathy
Infection
Inflammation
Reye syndrome
Meningitis due to bacteria, fungus, tuberculosis, or a virus

What the risks are

For information regarding risks of a spinal tap, see: Lumbar puncture

References

Griggs RC, Józefowicz RF, Aminoff MJ. Approach to the patient with neurologic disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 418.

Test

CSF cell count

A CSF cell count is a test to measure the number of red and white blood cells that are in cerebrospinal fluid (CSF). CSF is a clear fluid that circulates in the space surrounding the spinal cord and brain.
Test

CSF glucose test

A CSF glucose test measures the amount of sugar (glucose) in the cerebrospinal fluid (CSF). CSF is a clear fluid that flows in the space surrounding the spinal cord and brain. See also:
Test

CSF-VDRL test

The CSF-VDRL test is used to diagnose . This test looks for antibodies called reagins, which are sometimes produced by the body in reaction to the syphilis-causing bacteria. See also:
Test

CSF total protein

CSF total protein is a test to determine the amount of in cerebrospinal fluid (CSF). CSF is a clear fluid that circulates in the space surrounding the spinal cord. An abnormal protein level in the CSF suggests that there is an abnormal process occurring in the central nervous system.
Disease

Reye syndrome

Reye syndrome is sudden (acute) brain damage (encephalopathy) and liver function problems of unknown cause. The syndrome has occurred with the use of aspirin to treat chickenpox or the flu in children. However, it has become very uncommon since aspirin is no longer recommended for routine use in ...
Test

CSF oligoclonal banding

CSF oligoclonal banding is a test to look for inflammation-related proteins in the cerebrospinal fluid (CSF), the clear fluid that flows in the space surrounding the spinal cord and brain. Oligoclonal bands are proteins called immunoglobulins, which suggest inflammation of the central nervous ...
Disease

Hepatic encephalopathy

Hepatic encephalopathy is a worsening of brain function that occurs when the liver is no longer able to remove toxic substances in the blood.
Disease

Meningitis

Meningitis is a bacterial infection of the membranes covering the brain and spinal cord (meninges). See also:
Test

Cerebrospinal fluid culture

A cerebrospinal fluid (CSF) culture is a laboratory test to look for bacteria, fungi, and viruses in the normally clear fluid that moves in the space surrounding the spinal cord.
Test

CSF coccidioides complement fixation

CSF coccidioides complement fixation looks for antibodies to the fungus Coccidioides immitis in the cerebrospinal (CSF) fluid, the fluid surrounding the brain and spine.
Special Topic

Cytologic evaluation

Cytologic evaluation is the analysis under a microscope of cells collected from a part of the body. This is done to determine what the cells look like, and how they form and function. The test is usually used to look for cancers and precancerous changes. It may also be used to look for viral ...
Test

Lactate dehydrogenase test

The lactate dehydrogenase (LDH) test measures the amount of LDH in the blood. See also:

Review date:: June 24, 2009
Reviewed by:: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine Department of Medicine, University of Washington School of Medicine; and Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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