Infantile is a term usually used in conjunction with medical terms to refer to conditions that usually effect newborns and infants such as infantile dystonia (lack of muscle tone) or infantile spasms. However, the term it is also used as part of the formal name of some conditions such as Infantile Paralysis, a disease that is also known as Poliomyelitis, or for adult conditions that that are a relic of childhood such as Infantile Amnesia.