Functional tics are "not fully sterotypical", do not respond to medications, do not demonstrate the classic waxing and waning pattern of Tourettic tics, and do not progress in the typical fashion, in which tics often first appear in the face and gradually move to limbs.Other conditions that may manifest tics include Sydenhams chorea; idiopathic dystonia; and genetic conditions such as Huntingtons disease, neuroacanthocytosis, pantothenate kinase-associated neurodegeneration, Duchenne muscular dystrophy, Wilsons disease, and tuberous sclerosis. Other possibilities include chromosomal disorders such as Down syndrome, Klinefelter syndrome, XYY syndrome and fragile X syndrome. Acquired causes of tics include drug-induced tics, head trauma, encephalitis, stroke, and carbon monoxide poisoning. The extreme self-injurious behaviors of Lesch-Nyhan syndrome may be confused with Tourette syndrome or stereotypies, but self-injury is rare in TS even in cases of violent tics. Most of these conditions are rarer than tic disorders and a thorough history and examination may be enough to rule them out without medical or screening tests. Screening for other conditions
Although not all those with Tourettes have comorbid conditions, most presenting for clinical care exhibit symptoms of other conditions along with their tics. ADHD and OCD are the most common, but autism spectrum disorders or anxiety, mood, personality, oppositional defiant, and conduct disorders may also be present. Learning disabilities and sleep disorders may be present; higher rates of sleep disturbance and migraine than in the general population are reported.
The eponym was bestowed by Charcot after and on behalf of Gilles de la Tourette, who later became Charcots senior resident.Following the 19th-century descriptions, a psychogenic view prevailed and little progress was made in explaining or treating tics until well into the 20th century. The possibility that movement disorders, including Tourette syndrome, might have an organic origin was raised when an encephalitis lethargica epidemic from 1918 to 1926 was linked to an increase in tic disorders.During the 1960s and 1970s, as the beneficial effects of haloperidol on tics became known, the psychoanalytic approach to Tourette syndrome was questioned. The turning point came in 1965, when Arthur K. Shapiro—described as "the father of modern tic disorder research"—used haloperidol to treat a person with Tourettes, and published a paper criticizing the psychoanalytic approach. In 1975, The New York Times headlined an article with "Bizarre outbursts of Tourettes disease victims linked to chemical disorder in brain", and Shapiro said: "The bizarre symptoms of this illness are rivaled only by the bizarre treatments used to treat it. "During the 1990s, a more neutral view of Tourettes emerged, in which a genetic predisposition is seen to interact with non-genetic and environmental factors.