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Tourette syndrome

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Tourette syndrome
Classification and external resources
Specialty Pediatrics, neurology
ICD-10 F95.2
ICD-9-CM 307.23
eMedicine med/3107 neuro/664


Tourette's was once considered a rare and bizarre syndrome, most often associated with the exclamation of obscene words or socially inappropriate and derogatory remarks (coprolalia), but this symptom is present in only a small minority of people with Tourette's.[1] Tourette's is no longer considered a rare condition, but it is not always correctly identified because most cases are mild and the severity of tics decreases for most children as they pass through adolescence. Between 0.4% and 3.8% of children ages 5 to 18 may have Tourette's;[2] the prevalence of other tic disorders in school-age children is higher, with the more common tics of eye blinking, coughing, throat clearing, sniffing, and facial movements. Extreme Tourette's in adulthood is a rarity, and Tourette's does not adversely affect intelligence or life expectancy.

Genetic and environmental factors play a role in the etiology of Tourette's, but the exact causes are unknown. In most cases, medication is unnecessary. There is no effective treatment for every case of tics, but certain medications and therapies can help when their use is warranted. Education is an important part of any treatment plan, and explanation and reassurance alone are often sufficient treatment.[1][3] Comorbid conditions (co-occurring diagnoses other than Tourette's) such as attention-deficit hyperactivity disorder (ADHD) and obsessive–compulsive disorder (OCD) are present in many patients seen in tertiary specialty clinics. These other conditions often cause more functional impairment to the individual than the tics that are the hallmark of Tourette's; hence, it is important to correctly identify comorbid conditions and treat them.[4]






Although Tourette's is the more severe expression of the spectrum of tic disorders,[11] most cases are mild.[2] The severity of symptoms varies widely among people with Tourette's, and mild cases may be undetected.[5]


Examples of motor tics

Tics are movements or sounds "that occur intermittently and unpredictably out of a background of normal motor activity",[12] having the appearance of "normal behaviors gone wrong".[13] The tics associated with Tourette's change in number, frequency, severity and anatomical location. Waxing and waning—the ongoing increase and decrease in severity and frequency of tics—occurs differently in each individual. Tics also occur in "bouts of bouts", which vary for each person.[5]


In contrast to the abnormal movements of other movement disorders (for example, choreas, dystonias, myoclonus, and dyskinesias), the tics of Tourette's are temporarily suppressible, nonrhythmic, and often preceded by an unwanted premonitory urge.[15] Immediately preceding tic onset, most individuals with Tourette's are aware of an urge,[16][17] similar to the need to sneeze or scratch an itch. Individuals describe the need to tic as a buildup of tension, pressure, or energy[17][18] which they consciously choose to release, as if they "had to do it"[19] to relieve the sensation[17] or until it feels "just right".[19][20] Examples of the premonitory urge are the feeling of having something in one's throat, or a localized discomfort in the shoulders, leading to the need to clear one's throat or shrug the shoulders. The actual tic may be felt as relieving this tension or sensation, similar to scratching an itch. Another example is blinking to relieve an uncomfortable sensation in the eye. These urges and sensations, preceding the expression of the movement or vocalization as a tic, are referred to as "premonitory sensory phenomena" or premonitory urges. Because of the urges that precede them, tics are described as semi-voluntary or "unvoluntary",[12] rather than specifically involuntary; they may be experienced as a voluntary, suppressible response to the unwanted premonitory urge.[1] Published descriptions of the tics of Tourette's identify sensory phenomena as the core symptom of the syndrome, even though they are not included in the diagnostic criteria.[18][21][22]

While individuals with tics are sometimes able to suppress their tics for limited periods of time, doing so often results in tension or mental exhaustion.[1][4] People with Tourette's may seek a secluded spot to release their symptoms, or there may be a marked increase in tics after a period of suppression at school or at work.[13] Some people with Tourette's may not be aware of the premonitory urge. Children may be less aware of the premonitory urge associated with tics than are adults, but their awareness tends to increase with maturity.[12] They may have tics for several years before becoming aware of premonitory urges. Children may suppress tics while in the doctor's office, so they may need to be observed while they are not aware they are being watched.[23] The ability to suppress tics varies among individuals, and may be more developed in adults than children.

Although there is no such thing as a "typical" case of Tourette syndrome,[24] the condition follows a fairly reliable course in terms of the age of onset and the history of the severity of symptoms. Tics may appear up to the age of eighteen, but the most typical age of onset is from five to seven.[5] A 1998 study published by Leckman and colleagues from the Yale Child Study Center[25] showed that the ages of highest tic severity are eight to twelve (average ten), with tics steadily declining for most patients as they pass through adolescence.[20] The most common, first-presenting tics are eye blinking, facial movements, sniffing and throat clearing. Initial tics present most frequently in midline body regions where there are many muscles, usually the head, neck and facial region.[24] This can be contrasted with the stereotyped movements of other disorders (such as stims and stereotypies of the autism spectrum disorders), which typically have an earlier age of onset, are more symmetrical, rhythmical and bilateral, and involve the extremities (e.g., flapping the hands).[26] Tics that appear early in the course of the condition are frequently confused with other conditions, such as allergies, asthma, and vision problems: pediatricians, allergists and ophthalmologists are typically the first to see a child with tics.[5]

Among patients whose symptoms are severe enough to warrant referral to clinics, obsessive–compulsive disorder (OCD) and attention-deficit hyperactivity disorder (ADHD) are often associated with Tourette's.[20] Compulsions resembling tics are present in some individuals with OCD; "tic-related OCD" is hypothesized to be a subgroup of OCD, distinguished from non-tic related OCD by the type and nature of obsessions and compulsions.[27] Not all persons with Tourette's have ADHD or OCD or other comorbid conditions, although in clinical populations, a high percentage of patients presenting for care do have ADHD.[20][28] One author reports that a ten-year overview of patient records revealed about 40% of patients with Tourette's have "TS-only" or "pure TS", referring to Tourette syndrome in the absence of ADHD, OCD and other disorders.[29][30] Another author reports that 57% of 656 patients presenting with tic disorders had uncomplicated tics, while 43% had tics plus comorbid conditions.[13] People with "full-blown Tourette's" have significant comorbid conditions in addition to tics.[13]


The exact cause of Tourette's is unknown, but it is well established that both genetic and environmental factors are involved.[31] Genetic epidemiology studies have shown that the overwhelming majority of cases of Tourette's are inherited, although the exact mode of inheritance is not yet known and no gene has been identified.[4][32][33] In other cases, tics are associated with disorders other than Tourette's, a phenomenon known as tourettism.[34]


Non-genetic, environmental, post-infectious, or psychosocial factors—while not causing Tourette's—can influence its severity.[24] Autoimmune processes may affect tic onset and exacerbation in some cases. In 1998, a team at the US National Institute of Mental Health proposed a hypothesis based on observation of 50 children that both obsessive–compulsive disorder (OCD) and tic disorders may arise in a subset of children as a result of a poststreptococcal autoimmune process.[2] Children who meet five diagnostic criteria are classified, according to the hypothesis, as having Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS).[37] This contentious hypothesis is the focus of clinical and laboratory research, but remains unproven.[1][2][38]

Some forms of OCD may be genetically linked to Tourette's.[20][39] A subset of OCD is thought to be etiologically related to Tourette's and may be a different expression of the same factors that are important for the expression of tics.[40] The genetic relationship of ADHD to Tourette syndrome, however, has not been fully established.[30]


Brain structures implicated in Tourette syndrome

The exact mechanism affecting the inherited vulnerability to Tourette's has not been established, and the precise etiology is unknown. Tics are believed to result from dysfunction in cortical and subcortical regions, the thalamus, basal ganglia and frontal cortex.[31] Neuroanatomic models implicate failures in circuits connecting the brain's cortex and subcortex,[24] and imaging techniques implicate the basal ganglia and frontal cortex.[32]



There are no specific medical or screening tests that can be used in diagnosing Tourette's;[20] it is frequently misdiagnosed or underdiagnosed, partly because of the wide expression of severity, ranging from mild (the majority of cases) or moderate, to severe (the rare, but more widely recognized and publicized cases).[25] Coughing, eye blinking, and tics that mimic unrelated conditions such as asthma are commonly misdiagnosed.[1]

The diagnosis is made based on observation of the individual's symptoms and family history,[1] and after ruling out secondary causes of tic disorders.[36] In patients with a typical onset and a family history of tics or obsessive–compulsive disorder, a basic physical and neurological examination may be sufficient.[11]

There is no requirement that other comorbid conditions (such as ADHD or OCD) be present,[1] but if a physician believes that there may be another condition present that could explain tics, tests may be ordered as necessary to rule out that condition. An example of this is when diagnostic confusion between tics and seizure activity exists, which would call for an EEG, or if there are symptoms that indicate an MRI to rule out brain abnormalities.[44] TSH levels can be measured to rule out hypothyroidism, which can be a cause of tics. Brain imaging studies are not usually warranted.[44] In teenagers and adults presenting with a sudden onset of tics and other behavioral symptoms, a urine drug screen for cocaine and stimulants might be necessary. If a family history of liver disease is present, serum copper and ceruloplasmin levels can rule out Wilson's disease.[11] Most cases are diagnosed by merely observing a history of tics.[24]



Although not all people with Tourette's have comorbid conditions, most Tourette's patients presenting for clinical care at specialty referral centers may exhibit symptoms of other conditions along with their motor and phonic tics.[30] Associated conditions include attention-deficit hyperactivity disorder (ADD or ADHD), obsessive–compulsive disorder (OCD), learning disabilities and sleep disorders.[1] Disruptive behaviors, impaired functioning, or cognitive impairment in patients with comorbid Tourette's and ADHD may be accounted for by the comorbid ADHD, highlighting the importance of identifying and treating comorbid conditions.[1][4][20][28] Disruption from tics is commonly overshadowed by comorbid conditions that present greater interference to the child.[24] Tic disorders in the absence of ADHD do not appear to be associated with disruptive behavior or functional impairment,[48] while impairment in school, family, or peer relations is greater in patients who have more comorbid conditions and often determines whether therapy is needed.[13]




The treatment of Tourette's focuses on identifying and helping the individual manage the most troubling or impairing symptoms.[1] Most cases of Tourette's are mild, and do not require pharmacological treatment;[36] instead, psychobehavioral therapy, education, and reassurance may be sufficient.[49] Treatments, where warranted, can be divided into those that target tics and comorbid conditions, which, when present, are often a larger source of impairment than the tics themselves.[44] Not all people with tics have comorbid conditions,[30] but when those conditions are present, they often take treatment priority.




Because children with tics often present to physicians when their tics are most severe, and because of the waxing and waning nature of tics, it is recommended that medication not be started immediately or changed often.[24] Frequently, the tics subside with explanation, reassurance, understanding of the condition and a supportive environment.[24] When medication is used, the goal is not to eliminate symptoms: it should be used at the lowest possible dose that manages symptoms without adverse effects, given that these may be more disturbing than the symptoms for which they were prescribed.[24]

Cognitive behavioral therapy (CBT) is a useful treatment when OCD is present,[53] and there is increasing evidence supporting the use of habit reversal (HRT) in the treatment of tics.[54] There is evidence that HRT reduces tic severity, but there are methodological limitations in the studies, and a need for more trained specialists and better large-scale studies.[55]

Relaxation techniques, such as exercise, yoga or meditation, may be useful in relieving the stress that may aggravate tics, but the majority of behavioral interventions (such as relaxation training and biofeedback, with the exception of habit reversal) have not been systematically evaluated and are not empirically supported therapies for Tourette's.[56] Deep brain stimulation has been used to treat adults with severe Tourette's that does not respond to conventional treatment, but it is regarded as an invasive, experimental procedure that is unlikely to become widespread.[1][2][4][57][58]


André Malraux (1901–1976) was a French author, adventurer and Minister of Culture who had Tourette syndrome.[59][60][61][62] President Kennedy, Marie-Madeleine Lioux, Malraux, Jackie Kennedy and Vice President Johnson were photographed at the unveiling of the Mona Lisa at the National Gallery of Art, Washington, DC, in 1963.[63]


Regardless of symptom severity, individuals with Tourette's have a normal life span. Although the symptoms may be lifelong and chronic for some, the condition is not degenerative or life-threatening. Intelligence is normal in those with Tourette's, although there may be learning disabilities.[1] Severity of tics early in life does not predict tic severity in later life,[1] and prognosis is generally favorable,[65] although there is no reliable means of predicting the outcome for a particular individual. The gene or genes associated with Tourette's have not been identified, and there is no potential "cure".[65] A higher rate of migraines than the general population and sleep disturbances are reported.[65]


Top half of a male athlete who appears to be running
Tim Howard, goalkeeper for Everton F.C., attributes his success in association football (soccer) to this Tourette's.[67]






Tourette syndrome is found among all social, racial and ethnic groups and has been reported in all parts of the world;[1][20] it is three to four times more frequent among males than among females.[2] The reported prevalence of TS varies "according to the source, age, and sex of the sample; the ascertainment procedures; and diagnostic system"[20] from a low of .05% in a 1993 study to a high of 2.9% in a 1998 study.[1]

Up to 1% of the overall population experiences tic disorders, including chronic tics and transient tics of childhood.[48] Chronic tics affect 5% of children, and transient tics affect up to 20%.[71] Robertson (2011) suggests that the prevalence of Tourette syndrome alone in the general population is also 1%, with a range reported between .4% and 3.8% for children ages 5 to 18.[2] Singer (2011) states the prevalence of TS in the overall population at any time is .1% for impairing cases and .6% for all cases,[1] while Bloch and colleagues (2011) state the overall prevalence as between .3 and 1%.[32] According to Lombroso and Scahill (2008), the emerging consensus is that .1 to 1% of children have Tourette's,[72] with several studies supporting a tighter range of .6 to .8%.[48] Bloch and Leckman (2009) and Swain (2007) report a range of prevalence in children of .4 to .6%,[20][71] Knight et al (2012) estimate .77% in children,[68] and Du et al (2010) report that 1 to 3% of Western school-age children have Tourette's.[4] Prevalence rates in special education populations are higher.[2] Using year 2000 census data, a prevalence range of .1 to 1% yields an estimate of 53,000–530,000 school-age children with Tourette's in the US,[48] and a prevalence estimate of .1% means that in 2001 about 553,000 people in the UK age 5 or older would have Tourette's. Most cases would be mild and almost unrecognizable in older individuals.[73]

Tourette syndrome was once thought to be rare: in 1972, the US National Institutes of Health (NIH) believed there were fewer than 100 cases in the United States,[74] and a 1973 registry reported only 485 cases worldwide.[75] However, multiple studies published since 2000 have consistently demonstrated that the prevalence is much higher than previously thought.[76] Discrepancies across current and prior prevalence estimates come from several factors: ascertainment bias in earlier samples drawn from clinically referred cases, assessment methods that may fail to detect milder cases, and differences in diagnostic criteria and thresholds.[76] There were few broad-based community studies published before 2000 and until the 1980s, most epidemiological studies of Tourette syndrome were based on individuals referred to tertiary care or specialty clinics.[77] Individuals with mild symptoms may not seek treatment and physicians may not confer an official diagnosis of TS on children out of concern for stigmatization;[68] children with milder symptoms are unlikely to be referred to specialty clinics, so prevalence studies have an inherent bias towards more severe cases.[78] Studies of Tourette syndrome are vulnerable to error because tics vary in intensity and expression, are often intermittent, and are not always recognized by clinicians, patients, family members, friends or teachers;[24][79] approximately 20% of persons with Tourette syndrome do not recognize that they have tics.[24] Newer studies—recognizing that tics may often be undiagnosed and hard to detect—use direct classroom observation and multiple informants (parent, teacher, and trained observers), and therefore record more cases than older studies relying on referrals.[50][80] As the diagnostic threshold and assessment methodology have moved towards recognition of milder cases, the result is an increase in estimated prevalence.[76]

Tourette's is associated with several comorbid conditions, or co-occurring diagnoses, which are often the major source of impairment for an affected child.[20][32] Most individuals with tics do not seek medical attention, so epidemiological studies of TS "reflect a strong ascertainment bias",[32] but among those who do warrant medical attention, the majority have other conditions, and up to 50% have ADHD or OCD.[32] One author reports that a ten-year overview of patient records revealed about 40% of patients with Tourette's have "TS-only" or "pure TS", referring to Tourette syndrome in the absence of ADHD, OCD and other disorders.[29][30] In children with tics, the additional presence of ADHD is associated with functional impairment, disruptive behavior, and tic severity. Other comorbid conditions include self-injurious behaviors (SIB), anxiety, depression, personality disorders, oppositional defiant disorder, and conduct disorders.[81]

History and research directions


The first presentation of Tourette syndrome is thought to be in the book, Malleus Maleficarum ("Witch's hammer") by Jakob Sprenger and Heinrich Kraemer, published in the late 15th century and describing a priest whose tics were "believed to be related to possession by the devil".[82][83] A French doctor, Jean Marc Gaspard Itard, reported the first case of Tourette syndrome in 1825,[84] describing Marquise de Dampierre, an important woman of nobility in her time.[85] Jean-Martin Charcot, an influential French physician, assigned his resident Georges Albert Édouard Brutus Gilles de la Tourette, a French physician and neurologist, to study patients at the Salpêtrière Hospital, with the goal of defining an illness distinct from hysteria and from chorea.[23]

In 1885, Gilles de la Tourette published an account in Study of a Nervous Affliction describing nine persons with "convulsive tic disorder", concluding that a new clinical category should be defined.[86][87] The eponym was later bestowed by Charcot after and on behalf of Gilles de la Tourette.[23][88]

Little progress was made over the next century in explaining or treating tics, and a psychogenic view prevailed well into the 20th century.[23] The possibility that movement disorders, including Tourette syndrome, might have an organic origin was raised when an encephalitis epidemic from 1918–1926 led to a subsequent epidemic of tic disorders.[89]

During the 1960s and 1970s, as the beneficial effects of haloperidol (Haldol) on tics became known, the psychoanalytic approach to Tourette syndrome was questioned.[90] The turning point came in 1965, when Arthur K. Shapiro—described as "the father of modern tic disorder research"[91]—treated a Tourette’s patient with haloperidol, and published a paper criticizing the psychoanalytic approach.[89]

Since the 1990s, a more neutral view of Tourette's has emerged, in which biological vulnerability and adverse environmental events are seen to interact.[23][24] In 2000, the American Psychiatric Association published the DSM-IV-TR, revising the text of DSM-IV to no longer require that symptoms of tic disorders cause distress or impair functioning,[41] recognizing that clinicians often see patients who meet all the other criteria for Tourette's, but do not have distress or impairment.[42][43]


Society and culture


Not everyone with Tourette's wants treatment or a "cure", especially if that means they may "lose" something else in the process.[93][94] Researchers Leckman and Cohen, and former US Tourette Syndrome Association (TSA) national board member Kathryn Taubert, believe that there may be latent advantages associated with an individual's genetic vulnerability to developing Tourette syndrome, such as a heightened awareness and increased attention to detail and surroundings that may have adaptive value.[95] There is evidence to support the clinical lore that children with "TS-only" (Tourette's in the absence of comorbid conditions) are unusually gifted: neuropsychological studies have identified advantages in children with TS-only.[30][96] Children with TS-only are faster than the average for their age group on timed tests of motor coordination.[30][97]

Notable individuals with Tourette syndrome are found in all walks of life, including musicians, athletes, media figures, teachers, physicians and authors.[98] The best-known example of a person who may have used obsessive–compulsive traits to advantage is Samuel Johnson, the 18th-century English man of letters, who likely had Tourette syndrome as evidenced by the writings of James Boswell.[99][100] Johnson wrote A Dictionary of the English Language in 1747, and was a prolific writer, poet, and critic. Tim Howard, described by the Chicago Tribune as the "rarest of creatures – an American soccer hero"[101] and by the TSA as the "most notable individual with Tourette Syndrome around the world"[102] says that his neurological makeup gave him an enhanced perception and an ability to hyper-focus that contributed to his success on the field.[67]

Although it has been speculated that Mozart had Tourette's,[103][104] no Tourette's expert or organization has presented credible evidence to support such a conclusion,[104] and there are problems with the arguments supporting the diagnosis: tics are not transferred to the written form, as is supposed with Mozart's scatological writings; the medical history in retrospect is not thorough; side effects due to other conditions may be misinterpreted; "it is not proven whether written documents can account for the existence of a vocal tic" and "the evidence of motor tics in Mozart's life is doubtful".[105]

Pre-dating Gilles de la Tourette's 1885 publication, likely portrayals of TS or tic disorders in fictional literature are Mr. Pancks in Little Dorritt by Charles Dickens and Nikolai Levin in Anna Karenina by Leo Tolstoy.[106] The entertainment industry has been criticized for depicting those with Tourette syndrome as social misfits whose only tic is coprolalia, which has furthered stigmatization and the public's misunderstanding of those with Tourette's.[107] The coprolalic symptoms of Tourette's are also fodder for radio and television talk shows in the US[108] and in the British media.[109]


  2. ^ a b c d e f g h Robertson MM. "Gilles de la Tourette syndrome: the complexities of phenotype and treatment". Br J Hosp Med (Lond). 2011 Feb;72(2):100–7. PMID 21378617
  7. ^ Neurodevelopmental disorders. American Psychiatric Association. Retrieved on December 29, 2011.
  30. ^ a b c d e f g Denckla MB. "Attention deficit hyperactivity disorder: the childhood co-morbidity that most influences the disability burden in Tourette syndrome". Adv Neurol. 2006;99:17–21. PMID 16536349
  36. ^ a b c d e f Tourette Syndrome: Frequently Asked Questions. Tourette Syndrome Association. Retrieved on December 29, 2011.
  37. ^ PANDAS. NIH. Retrieved on November 25, 2006.
  60. ^ What is Tourette Syndrome? Tourette Syndrome Foundation of Canada. Retrieved on January 15, 2010.
  61. ^ Todd, Olivier. Malraux: A Life. Knopf, 2005.
  85. ^ What is Tourette syndrome? Tourette Syndrome Association. Retrieved on December 29, 2011.
  105. ^ Mozart:
  108. ^ US media:
  109. ^ UK media:

Further reading

External links