Venereal disease research laboratory slide test - CSF
How the test is performed
A sample of spinal fluid is needed. For information on how this is taken, see: Lumbar puncture (spinal tap)
Why the test is performed
The CSF-VDRL test is done to diagnose syphilis in the brain or spinal cord. Brain and spinal cord involvement is usually a sign of late stage syphilis.
Blood screening tests (VDRL and RPR) are better at detecting middle stage (secondary) syphilis.
A negative result is normal.
However, false-negatives can occur. This means you can have syphilis even if this test is normal. Therefore, a negative test does not always rule out the disease. Other signs and tests may be used to diagnose neurosyphilis.
What abnormal results mean
A positive result is abnormal and is a sign of neurosyphilis.
Tramont EC. Treponema pallidum (Syphilis). In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 238.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.