Final answer:
Late-stage syphilis, or tertiary syphilis, can cause severe neurological symptoms like paralysis, blindness, seizures, and dementia, which are indicative of the condition known as neurosyphilis.
Step-by-step explanation:
Late stage syphilis, also known as tertiary syphilis, can lead to severe neurological symptoms due to the damage it causes to the central nervous system. This condition is referred to as neurosyphilis. Some of the symptoms may include paralysis, blindness, seizures, and dementia. These symptoms appear years after the initial infection if it has not been treated effectively. In the most severe cases, tertiary syphilis can be fatal due to the systemic damage it causes, which can include granulomatous lesions known as gummas that affect multiple organs including the brain and heart.