The CSF VDRL test is for a sexually transmitted infection called syphilis. The test is done on a sample of cerebrospinal fluid (CSF). CSF fills the space between the brain and spinal cord and the membranes that surround them. The test can detect antibodies to the bacteria that cause syphilis. An antibody is a protein that the body produces in response to a foreign substance.
A healthcare professional may want to perform this test if he or she suspects a person has syphilis that involves the central nervous system, the brain, or the spinal cord.
To perform the CSF VDRL test, a sample of cerebrospinal fluid is usually collected by a spinal tap, also known as a lumbar puncture. This procedure can be done in the hospital or in a healthcare professional's office. The person lies on his or her side with the knees bent. An area on the lower back above lumbar vertebrae 3 and 4 is cleaned and sterilized.
Next, the area is injected with a local anesthetic, a drug designed to numb the area to pain. When the area is numb, a needle is gently inserted between the vertebrae into the fluid-filled space around the spinal cord. A small sample of the fluid is removed. It is then sent to the laboratory for testing.
The person is asked to lie flat for several hours after the test. This can help prevent some of the side effects of the test, such as headache.
A person should request instructions from his or her healthcare professional prior to a spinal tap.
In a healthy person, the test is negative. This means that no antibodies to the organism that causes syphilis are found. If the test is positive, then antibodies were detected, meaning that the person has neurosyphilis, a serious, late stage of syphilis that affects the central nervous system.