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.
Glucose test - CSF; Cerebrospinal fluid glucose test
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:
The sample is sent to a laboratory for testing.
Why the Test is Performed
This test may be done to diagnose:
- Inflammation of the central nervous system
- Other neurological and medical conditions
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:
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.
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.