Well the reason syphillis takes so long to fully take effect is that the virus multiplies within the cells of your bone marrow, which can take years to leak back into your blood stream. However, severe trauma to an area can release large quantities of the mature virus into your blood; you stubbing your toe probably delivered the necessary force to break the syphillis free, and now it is coursing through your body, preparing to go to work on your brain. Your toe received the initial blow and the highest concentration of the virus, so its feeling the effects first.