[Rapidly progressive dementia by late neurosyphilis (general paresis). Case report].

Background: The term rapidly progressive dementia (RPD) describes a disorder with rapid progression which leads to a major cognitive decline in less than 1 or 2 years. Neurosyphilis is an infectious cause of RPD and it is classified clinically into early and late forms. The latter affect the brain and spinal cord parenchyma. The objective of this report is to present a case of RPD caused by neurosyphilis. Clinical case: 55-year-old man, with no past medical history, who in July 2022 had a clinical presentation of aggressiveness, irritability, lability, difficulty in performing simple activities, amnesia, hallucinations, delusions, abulia, low responsiveness, all of which affected his independence and quality of life. Initially, it was treated as schizophrenia with no signs of improvement and clinical deterioration. When atypical data and rapid progression were evident at patient's consultation in January 2023, there was a suspicion of the presence of RPD, highlighting positive VDRL and IgM-IgG anti-Treponema pallidum antibodies in cerebrospinal fluid (CSF). Computed tomography (CT) and magnetic resonance imaging (MRI) showed global cortical atrophy, predominantly frontal. Treatment with ceftriaxone was started for 14 days, with clinical improvement observed in the MOCA test from 13/30 to 23/30. Conclusions: The etiological identification of RPD is a clinical challenge due to the wide variety of causes, which is why it is important a specific diagnostic approach and a timely treatment in order to avoid the progression of potentially reversible causes.