Syphilis is a very unusual disease, with very unusual patterns. The basic primary stage begins after an approximate 3 week incubation period. After a period of about 9 months, all the symptoms disappear, even without any treatment, and the latent stage starts. In the latent stage a person is not infectious and syphilis can only be detected through the blood test. The latent stage lasts from 1 to 50 years.
Tertiary syphilis is most serious when it attacks heart, the brain or the nervous system.
Today syphilis is a curable affliction and it is almost extinct, but in the thirties it was quite frequent. Those who do know it rarely suspect the possibility of its affecting the nervous system. Brain syphilis follows original infection by many years. It is difficult for the public to realize that syphilis far more frequently betrays itself by queer conduct than by starting skin eruptions. Brain syphilis may exist for years without being suspected by anyone, least by the victim.