Abnormal cortical amyloid deposition in 18F-Florbetapir PET/CT: General paresis of the insane mimicking early-onset Alzheimer's disease.

F-FDG) PET/CT. The patient's cerebrospinal fluid (CSF) test and genotyping results further excluded coexistent genetic AD. This case highlights the significance of considering neurosyphilis as a possible differential diagnosis in dementia patients with atypical positive amyloid PET findings. The mechanisms underlying aberrant amyloid deposition in neurosyphilis require further investigation.