Neurosyphilis presents as atypical encephalitis or cerebral vasculitis: Report of two cases

Neurosyphilis first presented as acute encephalitis or encephalopathy with seizures had only been rarely reported in the literature. We reported two human immunodeficiency virus-negative patients with neurosyphilis, both first attracting medical attention due to seizures and acute confusional state. The first patient was clinically indistinguishable from acute herpes simplex encephalitis, including the electroen-cephalographic patterns and head magnetic resonance imaging findings. The second patient had left hemiparesis and seizures, with angiographic evidence of diffuse cerebral vasculitis. In patients with late onset seizures, the differential diagnosis of underlying focal brain lesions should include neurosyphilis.