Alternative Names syphilis test, venereal disease laboratory test of the cerebrospinal fluid , spinal fluid venereal disease test, VDRL
Definition This is a test for syphilis, a type of sexually transmitted disease. The test is done on a sample of cerebrospinal fluid (CSF), which fills the space between the brain and spinal cord and the membranes that surround them. The test can detect antibodies to the organism that causes syphilis. An antibody is a protein that the body produces in response to a foreign substance.
Who is a candidate for the test? A doctor may want to perform this test if they suspect a person has syphilis that involves the central nervous system, or the brain and spinal cord.
How is the test performed? To perform the CSF VDRL test, a sample of cerebrospinal fluid is required. A sample is usually collected by a spinal tap, which is also called a lumbar puncture. This procedure is done in the hospital. 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, sterilised and injected with a local anaesthetic (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 cerebrospinal 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.
What is involved in preparation for the test? A person should request specific instructions from his or her doctor prior to a spinal tap.
What do the test results mean? Normally, 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 found and the person has neurosyphilis. Neurosyphilis is a serious, late stage of syphilis that affects the central nervous system.
Author: David T. Moran, MD Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 6/05/2005 Contributors Potential conflict of interest information for reviewers available on request
