Late-stage neurosyphilis presenting with severe neuropsychiatric deficits: diagnosis, therapy, and course of three patients

Neurosyphilis is an infectious disease that has reappeared over the past two decades. It is caused by Treponema pallidum subspecies pallidum that can affect the central nervous system (CNS) during any stage of the disease. Besides early CNS involvement predominantly presenting with symptoms of meningitis, a parenchymal affection of the brain leading to severe neuropsychiatric symptoms particularly emerges at later stages, but is rarely seen nowadays due to early antibiotic treatment. Together with the clinical findings, a characteristic combination of serological and cerebrospinal fluid (CSF) abnormalities leads to the diagnosis of neurosyphilis and is required to assess its activity. However, particularly at later stages of disease and after antibiotic treatment, serological and CSF abnormalities may become ambiguous and, therefore, difficult to interpret. This can be accompanied by persisting or fluctuating neuropsychological deficits. To this day, no well-controlled clinical data exists concerning the treatment of late-stage neurosyphilis, neither on type, optimal dosage, duration, and long-term efficacy of antibiotic therapy. Therefore, treatment and follow-up of late-stage neurosyphilis are challenging tasks. Here, we present three cases of neurosyphilis with severe neuropsychiatric symptoms in non-immunocompromised patients and a review of the recent literature.