CP, formerly known as "Cerebral Paralysis," was first identified by English surgeon William Little in 1860. Little raised the possibility of asphyxia during birth as a chief cause of the disorder. It was not until 1897 that Sigmund Freud, then a neurologist, suggested that a difficult birth was not the cause but rather only a symptom of other effects on fetal development.[80] Research conducted during the 1980s by the National Institute of Neurological Disorders and Stroke (NINDS) suggested that only a small number of cases of CP are caused by lack of oxygen during birth.[81]