Syphilitic aseptic meningitis is a complication of untreated syphilis that involves inflammation of the tissues covering the brain and spinal cord. The condition is marked by changes in mental status and problems with nerve function.

Syphilis is a sexually transmitted, infectious disease caused by the spirochete Treponema pallidum. Syphilis has three main stages: primary syphilis, secondary syphilis, and tertiary syphilis.

Syphilitic aseptic meningitis is a form of meningovascular neurosyphilis, which is a progressive, life-threatening complication of syphilis infection.

The disorder resembles meningitis caused by other conditions. There is inflammation of the meninges (the membranes that cover the brain and spinal cord). This may cause headaches, cognitive changes, or decrease in nerve functions such as vision, movement, or sensation. Vascular (blood vessel) symptoms, such as stroke secondary to syphilis, commonly accompany or follow syphilitic aseptic meningitis.

Risks of syphilitic aseptic meningitis include previous infection with syphilis or other sexually transmitted diseases such as gonorrhea (which may hide symptoms of syphilis infection). Syphilis infections are transmitted primarily through sexual contact with an infected person, but they may sometimes be transmitted by nonsexual contact.