How do you get help for someone with neurosyphilis?

The same as usual: A person with an infection can see his primary care doctor as usual, unless the patient is having a medical emergency (then he should be taken to the ER). Medical emergency infections are, for example, something like bacterial meningitis with fever, neck stiffness, the worst headache, etc... For neurosyphilis, the doctor might refer to specialists such as in Neurology and Infectious Diseases.