How do you approach the diagnosis and treatment of recurrent neurosyphilis in a previously treated patient?

This question is answered by CDC guidelines:

https://www.cdc.gov/std/treatment-guidelines/neurosyphilis.htm

A patient with neurosyphilis needs to get serial non-treponemal (VDRL/RPR) tests from serum after completion of the 14-day IV penicillin course (3,6,9,12 and 24 months). A 4-fold reduction of ...