Skip navigation

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.

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 the article on lumbar puncture.

Other methods for collecting CSF are rarely used, but 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

The sample is sent to a laboratory for testing.

Why the Test is Performed

This test may be done to diagnose:

  • Tumors
  • Infections
  • Inflammation of the central nervous system
  • Delirium
  • Other neurological and medical conditions

Normal Results

The glucose level in the CSF should be 50 - 80 mg/100 mL (or greater than 2/3 of the blood sugar level).

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

The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.

What Abnormal Results Mean

Abnormal results include higher and lower glucose levels. Abnormal results may be due to:

  • Infection (bacterial or fungus)
  • Inflammation of the central nervous system
  • Tumor

Alternative Names

Glucose test - CSF; Cerebrospinal fluid glucose test

References

Griggs RC, Jozefowicz RF, Aminoff MJ. Approach to the patient with neurologic disease. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 403.

Rosenberg GA. Brain edema and disorders of cerebrospinal fluid circulation. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley's Neurology in Clinical Practice. 6th ed. Philadelphia, PA: Saunders Elsevier; 2012:chap 59.

Update Date: 5/28/2013

Updated by: Luc Jasmin, MD, PhD, FRCS (C), FACS, Department of Neurosurgery at Cedars-Sinai Medical Center, Los Angeles CA; Department of Surgery at Los Robles Hospital, Thousand Oaks CA; Department of Surgery at Ashland Community Hospital, Ashland OR; Department of Surgery at Cheyenne Regional Medical Center, Cheyenne WY; Department of Anatomy at UCSF, San Francisco CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.

A.D.A.M Quality Logo

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

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 1997-2014, A.D.A.M., Inc. Duplication for commercial use must be authorized in writing by ADAM Health Solutions.

A.D.A.M Logo