Test Details: VDRL-CSF test is done to help diagnose neurosyphilis caused by Treponema pallidum. This test detects antibodies formed in response to infection with Treponema pallidum. Positive VDRL test in CSF is diagnostic of neurosyphilis. CSF VDRL may take years to become non reactive after adequate therapy. In AIDS patient serial CSF VDRL determination may be needed when neurosyphilis is suspected.