The CSF-VDRL test is used to help diagnose neurosyphilis. It looks for substances called antibodies, which are sometimes produced by the body in reaction to the syphilis-causing bacteria.

Alternative Names

Venereal disease research laboratory slide test - CSF

How the Test is Performed

A sample of spinal fluid is needed.

How to Prepare for the Test

Follow the health care provider's instructions on how to prepare for this test.

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 often a sign of late-stage syphilis.

Blood screening tests (VDRL and RPR) are better at detecting middle-stage (secondary) syphilis.

Normal Results

A negative result is normal.

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 infection. 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.


LaSala PR, Smith MB. Spirochete infections. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 59.

Radolf JD, Tramont EC, Salazar JC. Syphilis (Treponema pallidum). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 239.

Review Date: 9/10/2015

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