University of California San Francisco | About UCSF | UCSF Benioff Children's Hospital San Francisco
Search Site | Find a Doctor

CSF Cell Count

Definition

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.

How the test is performed

A sample of CSF is needed. A lumbar puncture (spinal tap) is the most common way to collect this sample. For information on this procedure, see the article on lumbar puncture.

Other methods for collecting CSF are rarely used, by may be recommended in some cases. They include:

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

After the sample is taken, it is sent to a 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

The CSF cell count may help diagnose meningitis and infection of the brain or spinal cord, a tumor, abscess, or area of tissue death (infarct), and it helps identify inflammation. The cell count may also help identify a hemorrhage.

Normal Values

The normal white blood cell count is between 0 and 5. The normal red blood cell count is 0.

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 increase of white blood cells indicates infection, inflammation, or bleeding into the cerebrospinal fluid. Some causes include:

  • Abscess
  • Acute infection
  • Encephalitis
  • Hemorrhage
  • Meningitis
  • Multiple sclerosis
  • Stroke
  • Tumor

Finding red blood cells in the CSF may be a sign of bleeding. However, red blood cells in the CSF may also be due to the spinal tap needle hitting a blood vessel while entering the skin or dura.

It is important to see if the red blood cell count returns to normal in samples taken later in the procedure as opposed to earlier. A ratio of the red blood cells to the white blood cells is also calculated to help with diagnosis.

Additional conditions which this test may help diagnose include:

  • Arteriovenous malformation (cerebral)
  • Cerebral aneurysm
  • Delirium
  • Dementia
  • Epilepsy
  • Guillain-Barre syndrome
  • Hemorrhagic stroke
  • Neurosyphilis
  • Primary lymphoma of the brain
  • Spinal tumor
  • Stroke secondary to syphilis
  • Syphilitic aseptic meningitis
  • Syphilitic myelopathy

What the risks are

Risks of lumbar puncture include:

  • Allergic reaction to the anesthetic
  • Discomfort during the test
  • Headache after the test
  • Bleeding into the spinal canal
  • Infection

Brain herniation may occur if performed on a person with a mass in the brain such as a tumor or abscess. This can result in brain damage or death. For this reason, a lumbar puncture is not done if other tests show signs of a tumor or abscess.

There may be temporary leg discomfort if a nerve root is irritated by the needle. This passes when the needle is withdrawn.

References

Griggs RC, Jozefowicz 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.

Review Date: 6/24/2009

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright ©2010 A.D.A.M., Inc., as modified by University of California San Francisco. Any duplication or distribution of the information contained herein is strictly prohibited.

Information developed by A.D.A.M., Inc. regarding tests and test results may not directly correspond with information provided by UCSF Medical Center. Please discuss with your doctor any questions or concerns you may have.