A Narrative Review of the Many Psychiatric Manifestations of Neurosyphilis: The Great Imitator

Neurosyphilis is an infection of the central nervous system caused by the spirochete, Treponema pallidum. New syphilis infections have been increasing around the world each year. This disease was much of a concern in the pre-penicillin era, where when left untreated many cases progressed to tertiary syphilis which can commonly manifest as neurosyphilis. Of particular interest, neurosyphilis has been linked to masquerading itself as various psychiatric conditions. This narrative review focuses on exploring psychiatric manifestations of neurosyphilis as well as the importance of screening in psychiatric settings and clinicians maintaining high clinical suspicion of the disease. A systematic search was conducted for published articles from 2003 to 2023 using PubMed, EMBASE, and Google Scholar. A total of 66 articles met the criteria and were used for detailed analysis, where psychiatric manifestations and clinical progression of patients were discussed in detail. Psychiatric manifestations that were explored include dementia, delirium, depression, mania, personality changes, and psychosis. One of the most common manifestations of neurosyphilis appears to be severe neurocognitive impairment. There are also rare psychiatric conditions neurosyphilis mimics that have been described in literature such as Capgras syndrome and Geschwind syndrome. A narrative review of the literature revealed a low level of clinical awareness of neurosyphilis as a possible etiology of various psychiatric disorders. This resulted in delayed or inaccurate diagnosis and consequently delayed initiation of adequate treatment. Considering that many psychiatric manifestations of neurosyphilis are reversible with proper treatment, it is imperative to implement routine screening for syphilis among psychiatric patients.