Neurosyphilis With Psychosis as the Primary Presentation

Patients with neurosyphilis, which is now a rare disease because of the availability of antibiotics, can initially present with psychiatric symptoms instead of the more well-known physical findings, such as general paresis, tabes dorsalis, and Argyll Robertson pupils. A subset of patients with primarily psychiatric symptoms beginning later in life tend to be incorrectly diagnosed as having late-onset schizophrenia. This case report describes a 67-year-old female with psychiatric symptoms starting 8 years prior to presentation who was misdiagnosed with late-onset schizophrenia. Because her symptoms first appeared at the later age of 59, additional testing was performed to rule out a medical etiology. The patient was found to be positive for syphilis infection in the serum and cerebrospinal fluid. She displayed no other notable symptoms of syphilis aside from bizarre behaviors and paranoid delusions. This case demonstrates the importance of considering organic infectious diseases, such as syphilis, when psychosis initially presents at an older age.