Tabes dorsalis, also known as syphilitic myelopathy, is a slow degeneration (specifically, demyelination) of the neural tracts primarily in the dorsal columns(posterior columns) of the spinal cord (the portion closest to the back of the body) and dorsal roots. These nerves normally help maintain a person's sense of position (proprioception), vibration, and discriminative touch.
Tertiary (late) syphilis. About 15 to 30 percent of people infected withsyphilis who don't get treatment will develop complications known astertiary (late) syphilis. In the latestages, the disease may damage your brain, nerves, eyes, heart, blood vessels, liver, bones and joints.