- Tourette syndrome
Name = Tourette syndrome
Georges Gilles de la Tourette
ICD10 = F95.2
ICD9 = 307.23
MedlinePlus = 000733
eMedicineSubj = med
eMedicineTopic = 3107
eMedicine_mult = eMedicine2|neuro|664
DiseasesDB = 5220
OMIM = 137580
MeshID = D005879
Tourette syndrome (also called Tourette's syndrome, Tourette's disorder, Gilles de la Tourette syndrome, GTS or, more commonly, simply Tourette's or TS) is an inherited neuropsychiatric disorder with onset in childhood, characterized by the presence of multiple physical (motor)
tics and at least one vocal (phonic) tic; these tics characteristically wax and wane. Tourette's is defined as part of a spectrum of tic disorders, which includes transient and chronic tics.
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). However, this symptom is present in only a small minority of people with Tourette's.Schapiro NA. "Dude, you don't have Tourette's:" Tourette's syndrome, beyond the tics. "Pediatr Nurs." 2002 May–Jun;28(3):243–6, 249–53. PMID 12087644 [http://www.medscape.com/viewarticle/442029 Full text (free registration required).] ] Tourette's is no longer considered a rare condition, but it may not always be correctly identified because most cases are classified as mild. Between 1 and 10 children per 1,000 have Tourette's;Lombroso PJ, Scahill L. [http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17937978 "Tourette syndrome and obsessive-compulsive disorder".] "Brain Dev". 2008 Apr;30(4):231–7. PMID 17937978] as many as 10 per 1,000 people may have tic disorders,Scahill L, Williams S, Schwab-Stone M, Applegate J, Leckman JF. "Disruptive behavior problems in a community sample of children with tic disorders". "Adv Neurol." 2006;99:184–90. PMID 16536365] with the more common tics of eye blinking, coughing, throat clearing, sniffing, and facial movements. People with Tourette's have normal life expectancyand intelligence. The severity of the tics decreases for most children as they pass through adolescence, and extreme Tourette's in adulthood is a rarity. Notable individuals with Tourette's are found in all walks of life. [ [http://www.tsa-usa.org/People/LivingWithTS/LivingTS.htm Portraits of adults with TS.] Tourette Syndrome Association. Retrieved on January 4, 2007.]
Genetic and environmental factors each play a role in the
etiologyof Tourette's, but the exact causes are unknown. In most cases, medication is unnecessary. There is no effective medication for every case of tics, but there are medications and therapies that can help when their use is warranted. Explanation and reassurance alone are often sufficient treatment;Zinner (2000).] education is an important part of any treatment plan. [Peterson BS, Cohen DJ. "The treatment of Tourette's Syndrome: multimodal, developmental intervention". "J Clin Psychiatry." 1998;59 Suppl 1:62–72; discussion 73–4. PMID 9448671. Quote: "Because of the understanding and hope that it provides, education is also the single most important treatment modality that we have in TS."]
eponymwas bestowed by Jean-Martin Charcot(1825–93) on behalf of his resident, Georges Albert Édouard Brutus Gilles de la Tourette (1859–1904), a French physician and neurologist, who published an account of nine patients with Tourette's in 1885.
Tics are sudden, repetitive, stereotyped, nonrhythmic movements (motor tics) and utterances (phonic tics) that involve discrete muscle groups.Leckman JF, Bloch MH, King RA, Scahill L. "Phenomenology of tics and natural history of tic disorders". "Adv Neurol." 2006;99:1–16. PMID 16536348] Motor tics are movement-based tics, while phonic tics are involuntary sounds produced by moving air through the nose, mouth, or throat.
Tourette's is one of several
tic disorders, which are classified by the " Diagnostic and Statistical Manual of Mental Disorders" (DSM) according to type (motor or phonic tics) and duration (transient or chronic). Transient tic disorder consists of multiple motor tics, phonic tics or both, with a duration between four weeks and twelve months. Chronic tic disorder is either single or multiple, motor or phonic tics (but not both), which are present for more than a year. Tourette's is diagnosed when multiple motor tics, and at least one phonic tic, are present for more than a year. American Psychiatric Association(2000). [http://www.mindsite.com/dsm_iv/tourette_s_disorder "Diagnostic criteria for 307.23 Tourette's Disorder".] "Diagnostic and Statistical Manual of Mental Disorders", 4th ed., text revision ( DSM-IV-TR), ISBN 0890420254. Retrieved on July 22, 2008.] Tic disorders are defined similarly by the World Health Organization(International Statistical Classification of Diseases and Related Health Problems, ICD-10codes). [ [http://www.who.int/classifications/apps/icd/icd10online/?gf90.htm+f950 ICD Version 2006.] World Health Organization. Retrieved on October 25, 2006.]
Although Tourette's is the more severe expression of the spectrum of tic disorders,Bagheri, Kerbeshian & Burd (1999).] most cases are mild. [http://web.archive.org/web/20060524115004/http://www.tsa-usa.org/what_is/whatists.html What is Tourette syndrome?]
Tourette Syndrome Association. Archived May 24, 2006.] The severity of symptoms varies widely among people with Tourette's, and mild cases may be undetected.
Tics are movements or sounds "that occur intermittently and unpredictably out of a background of normal motor activity",The Tourette Syndrome Classification Study Group. [http://web.archive.org/web/20060426232033/http://www.tsa-usa.org/research/definitions.html "Definitions and classification of tic disorders".] "Arch Neurol." 1993 Oct;50(10):1013–16. PMID 8215958 Archived April 26, 2006.] having the appearance of "normal behaviors gone wrong".Dure LS 4th, DeWolfe J. "Treatment of tics". "Adv Neurol." 2006;99:191–96. PMID 16536366] The tics associated with Tourette's constantly 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.
Coprolalia(the spontaneous utterance of socially objectionable or taboo words or phrases) is the most publicized symptom of Tourette's, but it is not required for a diagnosis of Tourette's. According to the Tourette Syndrome Association, fewer than 15% of Tourette's patients exhibit coprolalia. [http://web.archive.org/web/20060106020124/http://www.tsa-usa.org/what_is/Faqs.html Tourette Syndrome: Frequently Asked Questions.] Tourette Syndrome Association. Archived January 6, 2006.] Echolalia(repeating the words of others) and palilalia(repeating one's own words) occur in a minority of cases, while the most common initial motor and vocal tics are, respectively, eye blinking and throat clearing. [Malone DA Jr, Pandya MM. "Behavioral neurosurgery". "Adv Neurol." 2006;99:241–47. PMID 16536372]
In contrast to the abnormal movements of other
movement disorders (for example, choreas, dystonias, myoclonus, and dyskinesias), the tics of Tourette's are stereotypic, temporarily suppressible, nonrhythmic, and often preceded by a premonitory urge. [Jankovic J. "Differential diagnosis and etiology of tics". "Adv Neurol." 2001;85:15–29. PMID 11530424] Immediately preceding tic onset, most individuals with Tourette's are aware of an urge [Cohen AJ, Leckman JF. "Sensory phenomena associated with Gilles de la Tourette's syndrome". "J Clin Psychiatry". 1992 Sep;53(9):319–23. PMID 1517194] Prado HS, Rosário MC, Lee J, Hounie AG, Shavitt RG, Miguel EC. [http://cnsspectrums.com/aspx/article_pf.aspx?articleid=1540 "Sensory phenomena in obsessive-compulsive disorder and tic disorders: a review of the literature".] "CNS Spectr." 2008;13(5):425–32. PMID 18496480. Retrieved on May 31, 2008.] that is similar to the need to sneeze or scratch an itch. Individuals describe the need to tic as a buildup of tension, pressure, or energyBliss J. "Sensory experiences of Gilles de la Tourette syndrome". "Arch Gen Psychiatry". 1980 Dec;37(12):1343–47. PMID 6934713 ] which they consciously choose to release, as if they "had to do it"Kwak C, Dat Vuong K, Jankovic J. "Premonitory sensory phenomenon in Tourette's syndrome". "Mov Disord". 2003 Dec;18(12):1530–33. PMID 14673893] to relieve the sensation or until it feels "just right". 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". Published descriptions of the tics of Tourette's identify sensory phenomena as the core symptomof the syndrome, even though they are not included in the diagnostic criteria. [Scahill LD, Leckman JF, Marek KL. "Sensory phenomena in Tourette's syndrome". "Adv Neurol". 1995;65:273–80. PMID 7872145] [Miguel EC, do Rosario-Campos MC, Prado HS, "et al." "Sensory phenomena in obsessive-compulsive disorder and Tourette's disorder". "J Clin Psychiatry". 2000 Feb;61(2):150–56. PMID 10732667]
Tics are described as semi-voluntary or "unvoluntary"," because they are not strictly "involuntary"—they may be experienced as a "voluntary" response to the unwanted, premonitory urge. A unique aspect of tics, relative to other movement disorders, is that they are suppressible yet irresistible; they are experienced as an irresistible urge that must eventually be expressed. People with Tourette's are sometimes able to suppress their tics to some extent for limited periods of time, but doing so often results in an explosion of tics afterward. 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.
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. 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.Black, KJ. [http://www.emedicine.com/neuro/topic664.htm Tourette Syndrome and Other Tic Disorders.] "eMedicine" (March 22, 2006). Retrieved on June 27, 2006.] 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, 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. A 1998 study published by Leckman "et al" of the
Yale Child Study CenterLeckman JF, Zhang H, Vitale A, "et al." [http://childpsych.columbia.edu/brainimaging/PDF/PD10298.pdf "Course of tic severity in Tourette syndrome: the first two decades"] (PDF). "Pediatrics". 1998;102 (1 Pt 1):14–19. PMID 9651407. Retrieved on October 28, 2006.] 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. 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. 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).Rapin I. "Autism spectrum disorders: relevance to Tourette syndrome". "Adv Neurol." 2001;85:89–101. PMID 11530449] 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.
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. Not all persons with Tourette's have ADHD or OCD or other comorbidconditions (co-occurring diagnoses other than Tourette's), although in clinical populations, a high percentage of patients presenting for care do have ADHD.Spencer T, Biederman J, Harding M, "et al." "Disentangling the overlap between Tourette's disorder and ADHD". "J Child Psychol Psychiatry". 1998 Oct;39(7):1037–44. PMID 9804036] 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.Denckla MB. "Attention-deficit hyperactivity disorder (ADHD) comorbidity: a case for "pure" Tourette syndrome?" "J Child Neurol". 2006 Aug;21(8):701–3. PMID 16970871] 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] Another author reports that 57% of 656 patients presenting with tic disorders had uncomplicated tics, while 43% had tics plus comorbid conditions. "Full-blown Tourette's" is a term used to describe patients who have significant comorbid conditions in addition to tics.
The exact cause of Tourette's is unknown, but it is well established that both genetic and environmental factors are involved.Walkup JT, Mink JW, Hollenback PJ, (eds). "Advances in Neurology, Vol. 99, Tourette Syndrome." Lippincott, Williams & Wilkins, Philadelphia, PA, 2006, p. xv. ISBN 0-7817-9970-8] Genetic studies have shown that the overwhelming majority of cases of Tourette's are inherited, although the exact mode of inheritance is not yet known, [Robertson MM (2000), p. 425.] and no gene has been identified. In some cases, tics may not be inherited; these cases are identified as "sporadic" Tourette syndrome (also known as
tourettism) because a genetic link is missing.Mejia NI, Jankovic J. [http://www.scielo.br/pdf/rbp/v27n1/23707.pdf "Secondary tics and tourettism"] (PDF). "Rev Bras Psiquiatr". 2005;27(1):11–17. PMID 15867978]
A person with Tourette's has about a 50% chance of passing the gene(s) to one of his or her children, but Tourette's is a condition of variable expression and incomplete penetrance. [van de Wetering BJ, Heutink P. "The genetics of the Gilles de la Tourette syndrome: a review". "J Lab Clin Med." 1993 May;121(5):638–45. PMID 8478592] Thus, not everyone who inherits the genetic vulnerability will show symptoms; even close family members may show different severities of symptoms, or no symptoms at all. The gene(s) may express as Tourette's, as a milder tic disorder (transient or chronic tics), or as obsessive compulsive symptoms without tics. Only a minority of the children who inherit the gene(s) have symptoms severe enough to require medical attention. Gender appears to have a role in the expression of the genetic vulnerability: males are more likely than females to express tics.
Non-genetic, environmental, infectious, or
psychosocialfactors—while not causing Tourette's—can influence its severity. Autoimmuneprocesses may affect tic onset and exacerbation in some cases. In 1998, a team at the National Institute of Mental Healthproposed a hypothesis that both obsessive-compulsive disorder (OCD) and tic disorders may arise in a subset of children as a result of a poststreptococcal autoimmune process. [Swedo SE, Leonard HL, Garvey M, "et al". [http://ajp.psychiatryonline.org/cgi/reprint/155/2/264 "Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections: clinical description of the first 50 cases"] (PDF). "Am J Psychiatry." 1998 Feb;155(2):264–71. PMID 9464208 Retrieved on September 11, 2007.] Children who meet five diagnostic criteria are classified, according to the hypothesis, as having Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections ( PANDAS). [http://intramural.nimh.nih.gov/pdn/web.htm PANDAS.] NIH. Retrieved on November 25, 2006.] This contentious hypothesis is the focus of clinical and laboratory research, but remains unproven.Swerdlow, NR. "Tourette Syndrome: Current Controversies and the Battlefield Landscape". "Curr Neurol Neurosci Rep". 2005, 5:329–31. PMID 16131414] [Kurlan R, Kaplan EL. [http://pediatrics.aappublications.org/cgi/reprint/113/4/883.pdf "The pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) etiology for tics and obsessive-compulsive symptoms: hypothesis or entity? Practical considerations for the clinician"] (PDF). "Pediatrics." 2004 Apr;113(4):883–86. PMID 15060240 Retrieved on January 25, 2007.]
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 gangliaand frontal cortex. Neuroanatomic models implicate failures in circuits connecting the brain's cortex and subcortex, and imaging techniques implicate the basal ganglia and frontal cortex. [Haber SN, Wolfer D. "Basal ganglia peptidergic staining in Tourette syndrome. A follow-up study". "Adv Neurol". 1992;58:145–50. PMID 1414617 * Peterson B, Riddle MA, "et al." "Reduced basal ganglia volumes in Tourette's syndrome using three-dimensional reconstruction techniques from magnetic resonance images". "Neurology". 1993;43:941–49. PMID 8492950 * Moriarty J, Varma AR, "et al." "A volumetric MRI study of Gilles de la Tourette's syndrome". "Neurology". 1997;49:410–5. PMID 9270569]
Some forms of OCD may be genetically linked to Tourette's. [Pauls DL, Towbin KE, Leckman JF, "et al." "Gilles de la Tourette's syndrome and obsessive-compulsive disorder. Evidence supporting a genetic relationship". "Arch Gen Psychiatry". 1986 Dec;43(12):1180–82. PMID 3465280] 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. [Miguel EC, do Rosario-Campos MC, Shavitt RG, "et al." "The tic-related obsessive-compulsive disorder phenotype and treatment implications". "Adv Neurol." 2001;85:43–55. PMID 11530446] The genetic relationship of ADHD to Tourette syndrome, however, has not been fully established.
According to the revised fourth edition of the "Diagnostic and Statistical Manual of Mental Disorders" (
DSM-IV-TR), Tourette’s Disorder may be diagnosed when a person exhibits both multiple motor and one or more vocal tics (although these do not need to be concurrent) over the period of a year, with no more than three consecutive tic-free months. The previous DSM-IV included a requirement for "marked distress or significant impairment in social, occupational or other important areas of functioning", but this requirement was removed in the most recent update of the manual, in recognition that clinicians see patients who meet all the other criteria for Tourette's, but do not have distress or impairment. [ [http://dsmivtr.org/2-3changes.cfm Summary of Practice: Relevant changes to DSM-IV-TR.] "Diagnostic and Statistical Manual of Mental Disorders." Retrieved on January 25, 2007.] The onset must have occurred before the age of 18, and cannot be attributed to the "direct physiological effects of a substance or a general medical condition". Hence, other medical conditions that include tics or tic-like movements—such as autismor other causes of tourettism—must be ruled out before conferring a Tourette's diagnosis.
There are no specific medical or screening tests that can be used in diagnosing Tourette's;Swain JE, Scahill L, Lombroso PJ, King RA, Leckman JF. "Tourette syndrome and tic disorders: a decade of progress". "J Am Acad Child Adolesc Psychiatry". 2007 Aug;46(8):947–68 PMID 17667475 ] 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).The diagnosis is made based on observation of the individual's symptoms and family history, and after ruling out secondary causes of tic disorders. 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.
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
seizureactivity exists, which would call for an EEG, or if there are symptoms that indicate an MRIto rule out brain abnormalities.Scahill L, Erenberg G, Berlin CM Jr, Budman C, Coffey BJ, Jankovic J, Kiessling L, King RA, Kurlan R, Lang A, Mink J, Murphy T, Zinner S, Walkup J; Tourette Syndrome Association Medical Advisory Board: Practice Committee. "Contemporary assessment and pharmacotherapy of Tourette syndrome". "NeuroRx." 2006 Apr;3(2):192–206. PMID 16554257] TSH levels can be measured to rule out hypothyroidism, which can be a cause of tics. Brain imagingstudies are not usually warranted. In teenagers and adults presenting with a sudden onset of tics and other behavioral symptoms, a urine drug screen for cocaineand stimulantsmight be necessary. If a family history of liver diseaseis present, serum copper and ceruloplasminlevels can rule out Wilson's disease. However, most cases are diagnosed by merely observing a history of tics.
Secondary causes of tics (not related to inherited Tourette syndrome) are commonly referred to as
tourettism. Dystonias, choreas, other genetic conditions, and secondary causes of tics should be ruled out in the differential diagnosisfor Tourette syndrome. Other conditions that may manifest tics or stereotyped movements include developmental disorders, autism spectrum disorders, [Ringman JM, Jankovic J. "Occurrence of tics in Asperger's syndrome and autistic disorder". "J Child Neurol." 2000 Jun;15(6):394–400. PMID 10868783] and stereotypic movement disorder; [Jankovic J, Mejia NI. "Tics associated with other disorders". "Adv Neurol." 2006;99:61–8. PMID 16536352] Freeman, RD. [http://www.tourette-confusion.blogspot.com/ Tourette's Syndrome: minimizing confusion] . Roger Freeman, MD, blog. Retrieved on February 8, 2006.] Sydenham's chorea; idiopathicdystonia; and genetic conditions such as Huntington's disease, neuroacanthocytosis, Hallervorden-Spatz syndrome, Duchenne muscular dystrophy, Wilson's disease, and tuberous sclerosis. Other possibilities include chromosomal disorders such as Down syndrome, Klinefelter's syndrome, XYY syndromeand fragile X syndrome. Acquired causes of tics include drug-induced tics, head trauma, encephalitis, stroke, and carbon monoxide poisoning. The symptoms of Lesch-Nyhan syndromemay also be confused with Tourette syndrome. 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.
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. Associated conditions include attention-deficit hyperactivity disorder (ADD or ADHD), obsessive–compulsive disorder (OCD),
learning disabilitiesand sleep disorders. [http://www.ninds.nih.gov/disorders/tourette/detail_tourette.htm Tourette Syndrome Fact Sheet] . National Institute of Neurological Disorders and Stroke/ National Institutes of Health(NINDS/NIH), February 14, 2007. Retrieved on May 14, 2007.] Disruptive behaviors, impaired functioning, or cognitiveimpairment 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. [Sukhodolsky DG, Scahill L, Zhang H, "et al." "Disruptive behavior in children with Tourette's syndrome: association with ADHD comorbidity, tic severity, and functional impairment". "J Am Acad Child Adolesc Psychiatry". 2003 Jan;42(1):98–105. PMID 12500082 * Hoekstra PJ, Steenhuis MP, Troost PW, "et al." "Relative contribution of attention-deficit hyperactivity disorder, obsessive-compulsive disorder, and tic severity to social and behavioral problems in tic disorders". "J Dev Behav Pediatr". 2004 Aug;25(4):272–79. PMID 15308928 * Carter AS, O'Donnell DA, Schultz RT, "et al." "Social and emotional adjustment in children affected with Gilles de la Tourette's syndrome: associations with ADHD and family functioning. Attention Deficit Hyperactivity Disorder". "J Child Psychol Psychiatry". 2000 Feb;41(2):215–23. PMID 10750547] Disruption from tics is commonly overshadowed by comorbid conditions that present greater interference to the child. Tic disorders in the absence of ADHD do not appear to be associated with disruptive behavior or functional impairment, while impairment in school, family, or peer relations is greater in patients who have more comorbid conditions and often determines whether therapy is needed.
Because comorbid conditions such as OCD and ADHD can be more impairing than tics, these conditions are included in an evaluation of patients presenting with tics. "It is critical to note that the comorbid conditions may determine functional status more strongly than the tic disorder," according to Samuel Zinner, MD. The initial assessment of a patient referred for a tic disorder should include a thorough evaluation, including a family history of tics, ADHD, obsessive–compulsive symptoms, and other chronic medical, psychiatric and neurological conditions. Children and adolescents with TS who have learning difficulties are candidates for psychoeducational testing, particularly if the child also has ADHD. Undiagnosed comorbid conditions may result in functional impairment, and it is necessary to identify and treat these conditions to improve functioning. Complications may include depression, sleep problems, social discomfort and self-injury.
The treatment of Tourette's focuses on identifying and helping the individual manage the most troubling or impairing symptoms. Most cases of Tourette's are mild, and do not require pharmacological treatment; instead, psychobehavioral therapy, education, and reassurance may be sufficient. [Robertson MM, (2000), p. 435.] 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. Not all people with tics have comorbid conditions, but when those conditions are present, they often take treatment priority.
There is no cure for Tourette's and no medication that works universally for all individuals without significant adverse effects. Knowledge, education and understanding are uppermost in management plans for tic disorders. The management of the symptoms of Tourette's may include pharmacological,
behavioral and psychological therapies. While pharmacological intervention is reserved for more severe symptoms, other treatments (such as supportive psychotherapy or cognitive behavioral therapy) may help to avoid or ameliorate depression and social isolation, and to improve family support. Educating a patient, family, and surrounding community (such as friends, school, and church) is a key treatment strategy, and may be all that is required in mild cases.Stern JS, Burza S, Robertson MM. "Gilles de la Tourette's syndrome and its impact in the UK". "Postgraduate Medicine Journal." 2005 Jan;81(951):12–9. PMID 15640424 ]
(Luvox)—may be prescribed when a Tourette's patient also has symptoms of obsessive–compulsive disorder.
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. Frequently, the tics subside with explanation, reassurance, understanding of the condition and a supportive environment. 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.
Cognitive behavioral therapy(CBT) is a useful treatment when OCD is present, [Coffey BJ, Shechter RL. "Treatment of co-morbid obsessive compulsive disorder, mood, and anxiety disorders". "Adv Neurol." 2006;99:208–21. PMID 16536368] and there is increasing evidence supporting the use of habit reversal in the treatment of tics. [Himle MB, Woods DW, Piacentini JC, Walkup JT. "Brief review of habit reversal training for tourette syndrome". "J Child Neurol." 2006 Aug;21(8):719–25. PMID 16970874] 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. [Woods DW, Himle MB, Conelea CA. "Behavior therapy: other interventions for tic disorders". "Adv Neurol." 2006;99:234–40. PMID 16536371]
Tourette syndrome is a spectrum disorder—its severity ranges over a spectrum from mild to severe. The majority of cases are mild and require no treatment. In these cases, the impact of symptoms on the individual may be mild, to the extent that casual observers might not know of their condition. The overall prognosis is positive, but a minority of children with Tourette syndrome have severe symptoms that persist into adulthood.Walkup JT, Mink JW, Hollenback PJ, (eds). "Advances in Neurology, Vol. 99, Tourette Syndrome." Lippincott, Williams & Wilkins, Philadelphia, PA, 2006, p. xv.] A study of 46 subjects at 19 years of age found that the symptoms of 80% had minimum to mild impact on their overall functioning, and that the other 20% experienced at least a moderate impact on their overall functioning. The rare minority of severe cases can inhibit or prevent individuals from holding a job or having a fulfilling social life. In a follow-up study of thirty-one adults with Tourette's, all patients completed high school, 52% finished at least two years of college, and 71% were full-time employed or were pursuing higher education.Pappert EJ, Goetz CG, Louis ED, "et al." "Objective assessments of longitudinal outcome in Gilles de la Tourette's syndrome." "Neurology." 2003 Oct 14;61(7):936–40. PMID 14557563]
Regardless of symptom severity, individuals with Tourette's can expect to live 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. 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".
Several studies have demonstrated that the condition in most children improves with maturity. Tics may be at their highest severity at the time that they are diagnosed, and often improve with understanding of the condition by individuals and their families and friends. The statistical age of highest tic severity is typically between eight and twelve, with most individuals experiencing steadily declining tic severity as they pass through adolescence. One study showed no correlation with tic severity and the onset of puberty, in contrast with the popular belief that tics increase at puberty. In many cases, a complete remission of tic symptoms occurs after adolescence. [Burd L, Kerbeshian PJ, Barth A, "et al." "Long-term follow-up of an epidemiologically defined cohort of patients with Tourette syndrome". "J Child Neurol". 2001;16(6):431–37. PMID 11417610] However, a study using videotape to record tics in adults found that, although tics diminished in comparison with childhood, and all measures of tic severity improved by adulthood, 90% of adults still had tics. Half of the adults who considered themselves tic-free still displayed evidence of tics.
It is not uncommon for the parents of affected children to be unaware that they, too, may have had tics as children. Because Tourette's tends to subside with maturity, and because milder cases of Tourette's are now more likely to be recognized, the first realization that a parent had tics as a child may not come until their offspring is diagnosed. It is not uncommon for several members of a family to be diagnosed together, as parents bringing children to a physician for an evaluation of tics become aware that they, too, had tics as a child.
Children with Tourette's may suffer socially if their tics are viewed as "bizarre". If a child has disabling tics, or tics that interfere with social or academic functioning, supportive
psychotherapyor school accommodations can be helpful. Because comorbidconditions (such as ADHD or OCD) can cause greater impact on overall functioning than tics, a thorough evaluation for comorbidity is called for when symptoms and impairment warrant.
A supportive environment and family generally gives those with Tourette's the skills to manage the disorder. [Leckman & Cohen (1999), p. 37. "For example, individuals who were misunderstood and punished at home and at school for their tics or who were teased mercilessly by peers and stigmatized by their communities will fare worse than a child whose interpersonal environment was more understanding and supportive."] [Cohen DJ, Leckman JF, Pauls D. "Neuropsychiatric disorders of childhood: Tourette’s syndrome as a model". "Acta Paediatr Suppl" 422; 106–11, Scandinavian University Press, 1997. "The individuals with TS who do the best, we believe, are: those who have been able to feel relatively good about themselves and remain close to their families; those who have the capacity for humor and for friendship; those who are less burdened by troubles with attention and behavior, particularly aggression; and those who have not had development derailed by medication."] People with Tourette's may learn to camouflage socially inappropriate tics or to channel the energy of their tics into a functional endeavor. Accomplished musicians, athletes, public speakers, and professionals from all walks of life are found among people with Tourette's. Outcomes in adulthood are associated more with the perceived significance of having severe tics as a child than with the actual severity of the tics. A person who was misunderstood, punished, or teased at home or at school will fare worse than children who enjoyed an understanding and supportive environment.
A study of eight children, age 8–17, found that children with Tourette syndrome were quicker at processing certain mental grammar skills than are children without the condition. The abnormalities that lead to tics may also lead to "other rapid behaviors, including the cognitive processing of rule-governed forms in language and other types of procedural knowledge". [Walenski M, Mostofsky SH, Ullman MT. "Speeded processing of grammar and tool knowledge in Tourette's syndrome". "Neuropsychologia" 2007;45(11):2447–2460. DOI|10.1016/j.neuropsychologia.2007.04.001]
Tourette syndrome is found among all social, racial and ethnic groups, [Robertson MM, (2000), p. 427.] has been reported in all parts of the world,Robertson MM (August 1, 2005). "Tourette syndrome". "Psychiatry" 4 (8): 92–97. DOI|10.1383/psyt.2005.4.8.92] and is three to four times more frequent among males than among females. [Bagheri, Kerbeshian and Burd (1999) report that TS is "three to nine times more frequent in males than in females". Zinner (2000) says, "Data from most studies suggest ... [a] male:female ratio typically ranging from 2:1 to 4:1." Leckman & Cohen (1999), p. 180, Table 10.1 report a range based on six studies of 1.6:1 to 9.3:1 male:female ratio. Robertson, MM (2000), p. 427 says, "TS is ... three to four times more common in males (Robertson, 1989, 1994; Staley "et al"., 1997; Tanner and Goldman, 1997; Robertson and Baron-Cohen, 1998)", reflecting the most commonly reported ratio (3:1 to 4:1) from the Tourette Syndrome Association. What is Tourette syndrome? and the
National Institute of Neurological Disorders and Stroke/ National Institutes of Health(NINDS/NIH) Tourette Syndrome Fact Sheet.] The tics of Tourette syndrome begin in childhood and tend to remit or subside with maturity; thus, a diagnosis may no longer be warranted for many adults, and prevalenceis much higher among children than adults. Children are five to twelve times more likely than adults to be identified as having tic disorders; [Leckman JF, Peterson BS, Pauls DL, Cohen DJ. "Tic disorders". "Psychiatr Clin North Am." 1997 Dec;20(4):839–61. PMID 9443353] as many as 1 in 100 people experience tic disorders, including chronic tics and transient tics in childhood.
Discrepancies across current and prior prevalence estimates come from several factors:
ascertainment biasin earlier samples drawn from clinically referred cases, assessment methods that may fail to detect milder cases, and differences in diagnostic criteria and thresholds.Scahill, L. "Epidemiology of Tic Disorders". "Medical Letter: 2004 Retrospective Summary of TS Literature." Tourette Syndrome Association. The [http://www.tsa-usa.org/Medical/images/MedLetr2004_M114g_pg1.pdf first page] (PDF), is available without subscription. Retrieved on June 11, 2007.] 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 careor specialty clinics. [Zohar AH, Apter A, King RA "et al." "Epidemiological studies". In J.F. Leckman & D.J. Cohen (Eds.), "Tourette's syndrome – tics, obsessions, compulsions: Developmental psychopathology and clinical care" (pp. 177–92). Wiley & Sons, 1999. ISBN 0-471-16037-7 ] Children with milder symptoms are unlikely to be referred to specialty clinics, so these studies have an inherent bias towards more severe cases. [Coffey BJ, Park KS. "Behavioral and emotional aspects of Tourette syndrome". "Neurol Clin." 1997 May;15(2):277–89. PMID 9115461] 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;Soliman, E. [http://www.emedicine.com/med/topic3107.htm Tourette Syndrome.] "eMedicine" (August 5, 2005). Retrieved on June 28, 2006.] approximately 20% of persons with Tourette syndrome do not recognize that they have tics. Recent 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.Leckman JF. "Tourette's syndrome". "Lancet". 2002 Nov 16;360(9345):1577–86. PMID 12443611] As the diagnostic threshold and assessment methodology have moved towards recognition of milder cases, the result is an increase in estimated prevalence.
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, [Cohen DJ, Jankovic J, Goetz CG, (eds). "Advances in neurology, Vol. 85, Tourette syndrome." Lippincott, Williams & Wilkins, Philadelphia, PA, 2001, p. xviii. ISBN 0-7817-2405-8] and a 1973 registry reported only 485 cases worldwide. [Abuzzahab FE, Anderson FO. "Gilles de la Tourette's syndrome; international registry". "Minnesota Medicine". 1973 Jun;56(6):492–6. PMID 4514275] However, multiple studies published since 2000 have consistently demonstrated that the prevalence is much higher than previously thought. [Scahill, L. "Epidemiology of Tic Disorders". "Medical Letter: 2004 Retrospective Summary of TS Literature." Tourette Syndrome Association. The [http://www.tsa-usa.org/Medical/images/MedLetr2004_M114g_pg1.pdf first page] (PDF), is available without subscription. Retrieved on June 11, 2007.
* Kadesjö B, Gillberg C. "Tourette's disorder: epidemiology and comorbidity in primary school children". "J Am Acad Child Adolesc Psychiatry". 2000 May;39(5):548–55. PMID 10802971
* Kurlan R, McDermott MP, Deeley C, "et al." "Prevalence of tics in schoolchildren and association with placement in special education". "Neurology". 2001 Oct 23;57(8):1383–8. PMID 11673576
* Khalifa N, von Knorring AL. "Prevalence of tic disorders and Tourette syndrome in a Swedish school population". "Dev Med Child Neurol". 2003 May;45(5):315–19. PMID 12729145
* Hornsey H, Banerjee S, Zeitlin H, Robertson M. "The prevalence of Tourette syndrome in 13–14-year-olds in mainstream schools". "J Child Psychol Psychiatry". 2001 Nov;42(8):1035–39. PMID 11806685] The emerging consensus is that 1–10 children per 1,000 have Tourette's, with several studies supporting a tighter range of 6–8 children per 1,000. Using year 2000 census data, a prevalence range of 1–10 per 1,000 yields an estimate of 53,000–530,000 school-age children with Tourette's in the US and a prevalence range of 6–10 per 1,000 means that 64,000–106,000 children aged 5–18 years may have Tourette's in the UK. Most of these children are undiagnosed and have mild symptoms without distress or impairment.
History and research directions
A French doctor,
Jean Marc Gaspard Itard, reported the first case of Tourette syndrome in 1825, [Itard JMG. "Mémoire sur quelques functions involontaires des appareils de la locomotion, de la préhension et de la voix". "Arch Gen Med." 1825;8:385–407. From Newman, Sara. "Study of several involuntary functions of the apparatus of movement, gripping, and voice" by Jean-Marc Gaspard Itard (1825) "History of Psychiatry". 2006 17: 333–39. DOI|10.1177/0957154X06067668] describing Marquise de Dampierre, an important woman of nobility in her time. 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 hysteriaand from chorea.
In 1885, Gilles de la Tourette published an account of nine patients, "Study of a Nervous Affliction", concluding that a new clinical category should be defined. [Gilles de la Tourette G, Goetz CG, Llawans HL, trans. "Étude sur une affection nerveuse caractérisée par de l'incoordination motrice accompagnée d'echolalie et de coprolalie". In: Friedhoff AJ, Chase TN, eds. "Advances in Neurology: Volume 35. Gilles de la Tourette syndrome." New York: Raven Press; 1982;1–16. Discussed at Black, KJ. [http://www.emedicine.com/neuro/topic664.htm Tourette Syndrome and Other Tic Disorders.] "eMedicine" (March 22, 2006). Retrieved on June 27, 2006. [http://www.bium.univ-paris5.fr/histmed/medica/cote?epo0383 Original text (in French).] Retrieved on January 25, 2007.] The eponym was later bestowed by Charcot after and on behalf of Gilles de la Tourette. [Enersen, Ole Daniel. [http://www.whonamedit.com/doctor.cfm/357.html Georges Albert Édouard Brutus Gilles de la Tourette.] WhoNamedIt.com Retrieved on May 14, 2007.]
Little progress was made over the next century in explaining or treating tics, and a psychogenic view prevailed well into the 20th century. The possibility that movement disorders, including Tourette syndrome, might have an organic origin was raised when an
encephalitis epidemicfrom 1918–1926 led to a subsequent epidemic of tic disorders.Blue, Tina. [http://ri.essortment.com/tourettesyndrom_rnkl.htm Tourette syndrome.] "Essortment " 2002. Pagewise Inc. Retrieved on May 14, 2007.]
During the 1960s and 1970s, as the beneficial effects of
haloperidol(Haldol) on tics became known, the psychoanalytic approach to Tourette syndrome was questioned. [Rickards H, Hartley N, Robertson MM. "Seignot's paper on the treatment of Tourette's syndrome with haloperidol. Classic Text No. 31". "Hist Psychiatry." 1997 Sep;8 (31 Pt 3):433–36. PMID 11619589] The turning point came in 1965, when Arthur K. Shapiro—described as "the father of modern tic disorder research" [Gadow KD, Sverd J. "Attention deficit hyperactivity disorder, chronic tic disorder, and methylphenidate". "Adv Neurol." 2006;99:197–207. PMID 16536367] —treated a Tourette’s patient with haloperidol, and published a paper criticizing the psychoanalytic approach.
Since the 1990s, a more neutral view of Tourette's has emerged, in which biological vulnerability and adverse environmental events are seen to interact. In 2000, the
American Psychiatric Associationpublished the DSM-IV-TR, revising the text of DSM-IV to no longer require that symptoms of tic disorders cause distress or impair functioning. [ [http://www.psychnet-uk.com/dsm_iv/_misc/what_is_dsm_iv_tr.htm What is DSM-IV-TR?] Psychnet-UK. Retrieved on May 14, 2007.]
Findings since 1999 have advanced TS science in the areas of genetics,
neuroimaging, neurophysiology, and neuropathology. Questions remain regarding how best to classify Tourette syndrome, and how closely Tourette's is related to other movement disorders or psychiatric disorders. Good epidemiologicdata is still lacking, and available treatments are not risk free and not always well tolerated.Walkup JT, Mink JW, Hollenback PJ, (eds). (2006) pp. xvi–xviii] High-profile media coverage focuses on treatments that do not have established safety or efficacy, such as deep brain stimulation, and alternative therapies involving unstudied efficacy and side effects are pursued by many parents.
ociety and culture
Not everyone with Tourette's wants treatment or a "cure", especially if that means they may "lose" something else in the process. [Sacks, O (1985). "". Harper and Row, New York, pp. 92–100. ISBN 0-684-85394-9] Leckman & Cohen (1999), p. 408. ISBN 0-471-16037-7 ] Some people believe that there may be latent advantages associated with genetic vulnerability to the syndrome. There is evidence to support the clinical lore that children with "TS-only" (Tourette's in the absence of
comorbidconditions) are unusually gifted: neuropsychological studies have identified advantages in children with TS-only. [Schuerholz LJ, Baumgardner TL, Singer HS, "et al." "Neuropsychological status of children with Tourette's syndrome with and without attention deficit hyperactivity disorder". "Neurology." 1996 Apr;46(4):958–65. PMID 8780072] One study found that children with TS-only are faster than the average for their age group on timed motor coordination. [Schuerholz LJ, Cutting L, Mazzocco MM, "et al." "Neuromotor functioning in children with Tourette syndrome with and without attention deficit hyperactivity disorder". "J Child Neurol." 1997 Oct;12(7):438–42. PMID 9373800]
Notable individuals with Tourette syndrome are found in all walks of life, including musicians, athletes and authors. The best-known example of a person who may have used obsessive–compulsive traits to advantage is
Dr Samuel Johnson, the 18th-century English man of letters, who had Tourette syndrome as clearly evidenced by the writings of James Boswell. [ [http://web.archive.org/web/20050407083830/http://www.tsa-usa.org/what_is/johnson.html Samuel Johnson.] Tourette Syndrome Association. Archived April 7, 2005.] [Pearce JM. [http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1294650&blobtype=pdf "Doctor Samuel Johnson: 'the great convulsionary' a victim of Gilles de la Tourette's syndrome"] (PDF). "Journal of the Royal Society of Medicine". 1994 Jul;87(7):396–9. PMID 8046726] Johnson wrote " A Dictionary of the English Language" in 1747, and was a prolific writer, poet, and critic.
Although it has been speculated that Mozart had Tourette's,Simkin, Benjamin. "Medical and Musical Byways of Mozartiana." Fithian Press, 2001. ISBN 1-56474-349-7 [http://www.danielpublishing.com/books/suppl/simkin.html Review,] Retrieved on May 14, 2007. * Simkin B. [http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=1286388 "Mozart's scatological disorder".] "BMJ". 1992 Dec 19–26;305(6868):1563–7. PMID 1286388] [http://web.archive.org/web/20050407060420/http://www.tsa-usa.org/what_is/Mozart.html Did Mozart really have TS?]
Tourette Syndrome Association. Archived April 7, 2005.] no Tourette's expert or organization has presented credible evidence to show that this was the case, and there are problems with the available data. [Kammer T. [http://www.uni-ulm.de/~tkammer/pdf/Kammer_2007_Mozart_preprint.pdf "Mozart in the neurological department—who has the tic?"] (PDF). "Front Neurol Neurosci." 2007;22:184–92. PMID 17495512 DOI|10.1159/0000102880 Retrieved on September 10, 2007 * Ashoori A, Jankovic J. "Mozart's movements and behaviour: a case of Tourette's syndrome?" "J Neurol Neurosurg Psychiatry". 2007 Nov;78(11):1171–5 DOI|10.1136/jnnp.2007.114520 PMID 17940168. * Sacks O. "Tourette's syndrome and creativity". "BMJ." 1992 Dec 19–26;305(6868):1515–6. PMID 1286364]
The entertainment industry often depicts 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.Holtgren, Bruce. "Truth about Tourette's not what you think". "
Cincinnati Enquirer" (January 11, 2006). "As medical problems go, Tourette's is, except in the most severe cases, about the most minor imaginable thing to have. ... the freak-show image, unfortunately, still prevails overwhelmingly. The blame for the warped perceptions lies overwhelmingly with the video media – the Internet, movies and TV. If you search for 'Tourette' on Google or YouTube, you'll get a gazillion hits that almost invariably show the most outrageously extreme examples of motor and vocal tics. Television, with notable exceptions such as Oprah, has sensationalized Tourette's so badly, for so long, that it seems beyond hope that most people will ever know the more prosaic truth."] The coprolalic symptoms of Tourette's are also fodder for radio and television talk shows in the US [ [http://web.archive.org/web/20011006192716/http://tsa-usa.org/drlaura.html Oprah and Dr. Laura – Conflicting Messages on Tourette Syndrome. Oprah Educates; Dr. Laura Fosters Myth of TS as "Cursing Disorder".] Tourette Syndrome Association(May 31, 2001). Archived October 6, 2001. * [http://www.tsa-usa.org/news/DrPhil.htm Letter of response to Dr. Phil.] Tourette Syndrome Association. Retrieved on May 8, 2006. * [http://tsa-usa.org/news/Garrison-Keillor.htm Letter of response to Garrison Keillor radio show.] Tourette Syndrome Association. Retrieved on May 8, 2006. * [http://www.dailymail.co.uk/tvshowbiz/article-386969/Big-Brother-Tourettes-housemate-exploited.html Big Brother: Tourette's housemate 'exploited'] . Mail online, (May 19, 2006). Retrieved on September 19, 2008.] and in the British media.Guldberg, Helene. [http://www.spiked-online.com/index.php?/site/article/321/ Stop celebrating Tourette's.] "Spiked" (May 26, 2006). Retrieved on December 26, 2006.]
Notes:note label|TradeName|A|A Medication trade names may differ between countries. In general, this article uses North American trade names.
* Bagheri MM, Kerbeshian J, Burd L. [http://www.aafp.org/afp/990415ap/2263.html "Recognition and management of Tourette's syndrome and tic disorders".] "American Family Physician". 1999; 59:2263–74. PMID 10221310 Retrieved on October 28, 2006.
* Leckman JF, Cohen DJ. "Tourette's Syndrome—Tics, Obsessions, Compulsions: Developmental Psychopathology and Clinical Care." John Wiley & Sons, Inc., New York, 1999. ISBN 0-471-16037-7 [http://info.med.yale.edu/chldstdy/tsocd/tsbook.htm Outline.] Retrieved on October 28, 2006.
* Robertson MM. [http://brain.oxfordjournals.org/cgi/reprint/123/3/425.pdf "Tourette syndrome, associated conditions and the complexities of treatment"] (PDF). "Brain". 2000;123 Pt 3:425–62. PMID 10686169 Retrieved on January 25, 2007.
* [http://web.archive.org/web/20060106020124/http://www.tsa-usa.org/what_is/Faqs.html Tourette Syndrome: Frequently Asked Questions.]
Tourette Syndrome Association. Retrieved on January 6, 2006.
* [http://web.archive.org/web/20060524115004/http://www.tsa-usa.org/what_is/whatists.html What is Tourette syndrome?] Tourette Syndrome Association. Archived May 24, 2006.
* The Tourette Syndrome Classification Study Group. [http://web.archive.org/web/20060426232033/http://www.tsa-usa.org/research/definitions.html "Definitions and classification of tic disorders".] "Arch Neurol." 1993 Oct;50(10):1013–16. PMID 8215958 Archived April 26, 2006.
* Walkup, JT, Mink, JW, Hollenback, PJ, (eds). "Advances in Neurology, Vol. 99, Tourette syndrome." Lippincott, Williams & Wilkins, Philadelphia, PA, 2006. ISBN 0-7817-9970-8
* Zinner SH. "Tourette disorder". "Pediatr Rev". 2000;21(11):372–83. PMID 11077021
*Kushner, HI. "A cursing brain?: The histories of Tourette syndrome". Harvard University Press, 2000. ISBN 0-674-00386-1.
*Olson, S. [http://www.tsa-usa.org/Medical/images/Science_Mag_0904.pdf "Making Sense of Tourette's"] (PDF). "Science." 2004 Sep 3;305(5689):1390–92. PMID 15353772
* [http://www.tourette-confusion.blogspot.com/ Tourette's Syndrome: minimizing confusion] —a blog by Roger Freeman, MD, clinical head of the Neuropsychiatry Clinic,
British Columbia's Children's Hospital, professional advisory board member of the Tourette Syndrome Foundation of Canada, and former member of the Tourette Syndrome AssociationMedical Advisory Board. Dr. Freeman has over 180 journal-published articles on [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi PubMed.]
* [http://tsa-usa.org/ZNewDiag01/content.html Tourette syndrome: Newly diagnosed] —a 3-hour video/slide presentation by John Walkup, MD, deputy director of the Division of Child and Adolescent Psychiatry,
Johns Hopkins Hospitaland 2007 Chair of the Tourette Syndrome AssociationMedical Advisory Board
Wikimedia Foundation. 2010.