Tourette syndrome

Most published research on Tourette syndrome originates in the United States; in international TS research and clinical practice, the Diagnostic and Statistical Manual of Mental Disorders (DSM) is preferred over the World Health Organization (WHO) classification, while vocal (phonic) tics involve laryngeal, pharyngeal, oral, nasal or respiratory muscles to produce sounds. The tics must not be explained by other medical conditions or substance use. Some experts believe that TS and persistent (chronic) motor or vocal tic disorder should be considered the same condition, because vocal tics are also motor tics in the sense that they are muscular contractions of nasal or respiratory muscles. in its ICD-11, the International Statistical Classification of Diseases and Related Health Problems, Tourette syndrome is classified as a disease of the nervous system and a neurodevelopmental disorder, and only one motor tic and one or more vocal tics are required for diagnosis. Older versions of the ICD called it "combined vocal and multiple motor tic disorder [de la Tourette]". Genetic studies indicate that tic disorders cover a spectrum that is not recognized by the clear-cut distinctions in the current diagnostic framework. Since 2008, studies have suggested that Tourette's is not a unitary condition with a distinct mechanism, as described in the existing classification systems. Instead, the studies suggest that subtypes should be recognized to distinguish "pure TS" from TS that is accompanied by attention deficit hyperactivity disorder (ADHD), obsessive–compulsive disorder (OCD) or other disorders, similar to the way that subtypes have been established for other conditions, such as type 1 and type 2 diabetes. Elucidation of these subtypes awaits fuller understanding of the genetic and other causes of tic disorders. == Characteristics ==

Tics Tics are movements or sounds that take place "intermittently and unpredictably out of a background of normal motor activity", having the appearance of "normal behaviors gone wrong". The tics associated with Tourette's wax and wane; they change in number, frequency, severity, anatomical location, and complexity; each person experiences a unique pattern of fluctuation in their severity and frequency. Tics may also occur in "bouts of bouts" (i.e., tics in general wax and wane over longer periods; within waxing periods, there may be short bursts of both motor and phonic tics), which also vary among people. The variation in tic severity may occur over hours, days, or weeks. Over time, about 90% of individuals with Tourette's feel an urge preceding the tic, similar to the urge to sneeze or scratch an itch. The urges and sensations that precede the expression of a tic are referred to as premonitory sensory phenomena or premonitory urges. People describe the urge to express the tic as a buildup of tension, pressure, or energy which they ultimately choose consciously to release, as if they "had to do it" to relieve the sensation Complex tics related to speech include coprolalia, echolalia and palilalia. Coprolalia is the spontaneous utterance of socially objectionable or taboo words or phrases. Although it is the most publicized symptom of Tourette's, only about 10% of people with Tourette's exhibit it, and it is not required for a diagnosis. Echolalia (repeating the words of others) and palilalia (repeating one's own words) occur in a minority of cases. Complex motor tics include copropraxia (obscene or forbidden gestures, or inappropriate touching), echopraxia (repetition or imitation of another person's actions) and palipraxia (repeating one's own movements). Onset and progression There is no typical case of Tourette syndrome, but the age of onset and the severity of symptoms follow a fairly reliable course. Although onset may occur anytime before eighteen years, the typical age of onset of tics is from five to seven, and is usually before adolescence. Severity declines steadily for most children as they pass through adolescence, when half to two-thirds of children see a dramatic decrease in tics. In people with TS, the first tics to appear usually affect the head, face, and shoulders, and include blinking, facial movements, sniffing and throat clearing. many people with TS may not realize they have tics. Because tics are more commonly expressed in private, Tourette syndrome may go unrecognized, and casual observers might not notice tics. Most studies of TS involve males, who have a higher prevalence of TS than females, and gender-based differences are not well studied; a 2021 review suggested that the characteristics and progression for females, particularly in adulthood, may differ and better studies are needed. Co-occurring conditions (center) was a French Minister of Culture, author and adventurer who may have had Tourette syndrome. Because people with milder symptoms are unlikely to be referred to specialty clinics, studies of Tourette's have an inherent bias towards more severe cases. When symptoms are severe enough to warrant referral to clinics, ADHD and OCD are often also found. In the absence of ADHD, tic disorders do not appear to be associated with disruptive behavior or functional impairment, while impairment in school, family, or peer relations is greater in those who have more comorbid conditions. Compared to the more typical compulsions of OCD without tics that relate to contamination, tic-related OCD presents with more "counting, aggressive thoughts, symmetry and touching" compulsions. There are increased rates of anxiety and depression in those adults with TS who also have OCD. but one study indicates that a high association of autism and TS may be partly due to difficulties distinguishing between tics and tic-like behaviors or OCD symptoms seen in autistic people. Not all people with Tourette's have ADHD or OCD or other comorbid conditions, and estimates of the rate of pure TS or TS-only vary from 15% to 57%; in clinical populations, a high percentage of those under care do have ADHD. Only slight impairments are found in intellectual ability, attentional ability, and nonverbal memory—but ADHD, other comorbid disorders, or tic severity could account for these differences. In contrast with earlier findings, visual motor integration and visuoconstructive skills are not found to be impaired, while comorbid conditions may have a small effect on motor skills. Comorbid conditions and severity of tics may account for variable results in verbal fluency, which can be slightly impaired. There might be slight impairment in social cognition, but not in the ability to plan or make decisions. Children with TS-only do not show cognitive deficits. They are faster than average for their age on timed tests of motor coordination, and constant tic suppression may lead to an advantage in switching between tasks because of increased inhibitory control. Learning disabilities may be present, but whether they are due to tics or comorbid conditions is controversial; older studies that reported higher rates of learning disability did not control well for the presence of comorbid conditions. There are often difficulties with handwriting, and disabilities in written expression and math are reported in those with TS plus other conditions. == Causes ==

The exact cause of Tourette's is unknown, but it is well established that both genetic and environmental factors are involved. Genome-wide association studies were published in 2013 Twin studies show that 50 to 77% of identical twins share a TS diagnosis, while only 10 to 23% of fraternal twins do. A few rare highly penetrant genetic mutations have been found that explain only a small number of cases in single families (the SLITRK1, HDC, and CNTNAP2 genes). Psychosocial or other non-genetic factors—while not causing Tourette's—can affect the severity of TS in vulnerable individuals and influence the expression of the inherited genes. PANDAS and the newer pediatric acute-onset neuropsychiatric syndrome (PANS) hypotheses are the focus of clinical and laboratory research, but remain unproven. Some forms of OCD may be genetically linked to Tourette's, A genetic link between autism and Tourette's has not been established as of 2017. == Mechanism ==

and thalamus are implicated in Tourette syndrome. The exact mechanism affecting the inherited vulnerability to Tourette's is not well established. The caudate nuclei may be smaller in subjects with tics compared to those without tics, supporting the hypothesis of pathology in CSTC circuits in Tourette's. A reduced level of histamine in the H3 receptor may result in an increase in other neurotransmitters, causing tics. Postmortem studies have also implicated "dysregulation of neuroinflammatory processes". == Diagnosis ==

{{quote box According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), Tourette's may be diagnosed when a person exhibits both multiple motor tics and one or more vocal tics over a period of one year. The motor and vocal tics need not be concurrent. The onset must have occurred before the age of 18 and cannot be attributed to the effects of another condition or substance (such as cocaine). Hence, other medical conditions that include tics or tic-like movements—for example, autism or other causes of tics—must be ruled out. There are no specific medical or screening tests that can be used to diagnose Tourette's; the diagnosis is usually made based on observation of the individual's symptoms and family history, Delayed diagnosis often occurs because professionals mistakenly believe that TS is rare, always involves coprolalia, or must be severely impairing. The DSM has recognized since 2000 that many individuals with Tourette's do not have significant impairment; diagnosis does not require the presence of coprolalia or a comorbid condition, such as ADHD or OCD. and are ruled out in the differential diagnosis for Tourette syndrome. and stereotypic movement disorder. The stereotyped movements associated with autism typically have an earlier age of onset; are more symmetrical, rhythmical and bilateral; and involve the extremities (for example, flapping the hands). If another condition might better explain the tics, tests may be done; for example, if there is diagnostic confusion between tics and seizure activity, an EEG may be ordered. An MRI can rule out brain abnormalities, but such brain imaging studies are not usually warranted. Measuring thyroid-stimulating hormone blood levels can rule out hypothyroidism, which can be a cause of tics. If there is a family history of liver disease, serum copper and ceruloplasmin levels can rule out Wilson's disease. Described in 2006 as psychogenic, or functional tic-like movements. These tics are inconsistent with the classic tics of TS in several ways: the premonitory urge (present in 90% of those with tics disorders A thorough evaluation for comorbidity is called for when symptoms and impairment warrant, Children and adolescents with TS who have learning difficulties are candidates for psychoeducational testing, particularly if the child also has ADHD. == Management ==

There is no cure for Tourette's. There is no single most effective medication, Treatment is focused on identifying the most troubling or impairing symptoms and helping the individual manage them. Practice guidelines for the treatment of tics were published by the American Academy of Neurology in 2019. In particular, psychoeducation targeting the patient and their family and surrounding community is a key management strategy. Watchful waiting "is an acceptable approach" for those who are not functionally impaired. and have been shown to be effective. Comprehensive behavioral intervention for tics (CBIT) is based on HRT, the best researched behavioral therapy for tics. Medication is one of the medications typically tried first when medication is needed for Tourette's. Children with tics typically present when their tics are most severe, but because the condition waxes and wanes, medication is not started immediately or changed often. The most effective medication for tics is haloperidol, but it has a higher risk of side effects. Despite this lack of evidence, up to two-thirds of parents, caregivers and individuals with TS use dietary approaches and alternative treatments and do not always inform their physicians. There is low confidence that tics are reduced with tetrahydrocannabinol, There is no good evidence supporting the use of acupuncture or transcranial magnetic stimulation; neither is there evidence supporting intravenous immunoglobulin, plasma exchange, or antibiotics for the treatment of PANDAS. although it is an experimental treatment. Selecting candidates who may benefit from DBS is challenging, and the appropriate lower age range for surgery is unclear; Pregnancy A quarter of women report that their tics increase before menstruation; however, studies have not shown consistent evidence of a change in frequency or severity of tics related to pregnancy or hormonal levels. Overall, symptoms in women respond better to haloperidol than they do for men. When needed, medications are used at the lowest doses possible. During pregnancy, neuroleptic medications are avoided when possible because of the risk of pregnancy complications. When needed, olanzapine, risperidone and quetiapine are most often used as they have not been shown to cause fetal abnormalities. One report found that haloperidol could be used during pregnancy, although it may cross the placenta. If severe tics might interfere with administration of local anesthesia, other anesthesia options are considered. Neuroleptics in low doses may not affect the breastfed infant, but most medications are avoided. Clonidine and amphetamines may be present in breast milk. == Prognosis ==

, described in 2019 by a staff writer for the Los Angeles Times as the "greatest goalkeeper in U.S. soccer history", attributes his success in the sport to his Tourette's. Intelligence among those with pure TS follows a normal curve, although there may be small differences in intelligence in those with comorbid conditions. By the age of fourteen to sixteen, when the highest tic severity has typically passed, a more reliable prognosis might be made. Tics may be at their highest severity when they are diagnosed, and often improve as an individual's family and friends come to better understand the condition. Quality of life People with Tourette's are affected by the consequences of tics and by the efforts to suppress them. Outcomes in adulthood are associated more with the perceived significance of having 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 is likely to fare worse than a child who enjoyed an understanding environment. Comorbid ADHD can severely affect the child's well-being in all realms, and extend into adulthood. Factors impacting quality of life change over time, given the natural fluctuating course of tic disorders, the development of coping strategies, and a person's age. As ADHD symptoms improve with maturity, adults report less negative impact in their occupational lives than do children in their educational lives. Tics have a greater impact on adults' psychosocial function, including financial burdens, than they do on children. Adults are more likely to report a reduced quality of life due to depression or anxiety; depression contributes a greater burden than tics to adults' quality of life compared to children. As coping strategies become more effective with age, the impact of OCD symptoms seems to diminish. == Epidemiology ==

Tourette syndrome is a common but underdiagnosed condition It is three to four times more frequent in males than in females. Observed prevalence rates are higher among children than adults because tics tend to remit or subside with maturity and a diagnosis may no longer be warranted for many adults. Many individuals with tics do not know they have tics, and Stern state that the prevalence in children is 1%. However, numerous studies published since 2000 have consistently demonstrated that the prevalence is much higher. Recognizing that tics may often be undiagnosed and hard to detect, newer studies use direct classroom observation and multiple informants (parents, teachers and trained observers), and therefore record more cases than older studies. As the diagnostic threshold and assessment methodology have moved towards recognition of milder cases, the estimated prevalence has increased. A 2021 review stated that females may see a later peak than males in symptoms, with less remission over time, along with a higher prevalence of anxiety and mood disorders. == History ==

was a French neurologist and professor who named Tourette syndrome for his intern, Georges Gilles de la Tourette. In A Clinical Lesson at the Salpêtrière (1887), André Brouillet portrays a medical lecture by Charcot (the central standing figure) and shows de la Tourette in the audience (seated in the first row, wearing an apron). A French doctor, Jean Marc Gaspard Itard, reported the first case of Tourette syndrome in 1825, describing the Marquise de Dampierre, an important woman of nobility in her time. In 1884, Jean-Martin Charcot, an influential French physician, assigned his student and intern Georges Gilles de la Tourette, to study patients with movement disorders at the Salpêtrière Hospital, with the goal of defining a condition distinct from hysteria and chorea. In 1885, Gilles de la Tourette published an account in Study of a Nervous Affliction of nine people with "convulsive tic disorder", concluding that a new clinical category should be defined. The eponym was bestowed by Charcot after and on behalf of Gilles de la Tourette, who later became Charcot's senior resident. 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 Tourette's, and published a paper criticizing the psychoanalytic approach. During the 1990s, a more neutral view of Tourette's emerged, in which a genetic predisposition is seen to interact with non-genetic and environmental factors. The fourth revision of the DSM (DSM-IV) in 1994 added a diagnostic requirement for "marked distress or significant impairment in social, occupational, or other important areas of functioning", which led to an outcry from TS experts and researchers, who noted that many people were not even aware they had TS, nor were they distressed by their tics; clinicians and researchers resorted to using the older criteria in research and practice. recognizing that clinicians often see people who have Tourette's without distress or impairment. == Society and culture ==

1772. Johnson is likely to have had Tourette syndrome. Not everyone with Tourette's wants treatment or a cure, especially if that means they may lose something else in the process. The researchers Leckman and Cohen believe that there may be latent advantages associated with an individual's genetic vulnerability to developing Tourette syndrome that may have adaptive value, such as heightened awareness and increased attention to detail and surroundings. Accomplished musicians, athletes, public speakers and professionals from all walks of life are found among people with Tourette's. The athlete Tim Howard, described by the Chicago Tribune as the "rarest of creatures—an American soccer hero", and by the Tourette Syndrome Association as the "most notable individual with Tourette Syndrome around the world", says that his neurological makeup gave him an enhanced perception and an acute focus that contributed to his success on the field. Samuel Johnson is a historical figure who likely had Tourette syndrome, as evidenced by the writings of his friend James Boswell. Johnson wrote A Dictionary of the English Language in 1747, and was a prolific writer, poet, and critic. There is little support for speculation that Mozart had Tourette's: the potentially coprolalic aspect of vocal tics is not transferred to writing, so Mozart's scatological writings are not relevant; the composer's available medical history is not thorough; the side effects of other conditions may be misinterpreted; and "the evidence of motor tics in Mozart's life is doubtful". Likely portrayals of TS or tic disorders in fiction predating Gilles de la Tourette's work are "Mr. Pancks" in Charles Dickens's Little Dorrit and "Nikolai Levin" in Leo Tolstoy's Anna Karenina. The entertainment industry has been criticized for depicting those with Tourette syndrome as social misfits whose only tic is coprolalia, which has furthered the public's misunderstanding and stigmatization of those with Tourette's. The coprolalic symptoms of Tourette's are also fodder for radio and television talk shows in the US and for the British media. 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. == Research directions ==

Research since 1999 has advanced knowledge of Tourette's in the areas of genetics, neuroimaging, neurophysiology, and neuropathology, but questions remain about how best to classify it and how closely it is related to other movement or psychiatric disorders. ==See also==