APA Dictionary of Psychology

n. a late manifestation of untreated or inadequately treated syphilis, usually occurring years after the initial infection, in which the causative bacterium, Treponema pallidum, damages and destroys the brain and spinal cord. This results in blindness and severe neurological deficits, including memory impairment, inability to concentrate, and behavioral deterioration. See asymptomatic neurosyphilis; general paresis; locomotor ataxia.