Tourette syndrome (TS or simply Tourette’s) is a common neuropsychiatric disorder with onset in childhood, characterized by multiple motor tics and at least one vocal (phonic) tic. These tics characteristically wax and wane, can be suppressed temporarily, and are typically preceded by an unwanted urge or sensation in the affected muscles. Some common tics are eye blinking, coughing, throat clearing, sniffing, and facial movements. Tourette’s does not adversely affect intelligence or life expectancy.
Tourette’s is defined as part of a spectrum of tic disorders, which includes provisional, transient and persistent (chronic) tics. While the exact cause is unknown, it is believed to involve a combination of genetic and environmental factors. There are no specific tests for diagnosing Tourette’s; 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. Extreme Tourette’s in adulthood, though sensationalized in the media, is a rarity; tics are often unnoticed by casual observers.
In most cases, medication for tics is not necessary. Education is an important part of any treatment plan, and explanation and reassurance alone are often sufficient treatment. Many individuals with Tourette’s go undiagnosed or never seek medical care. Among those who are seen in specialty clinics, attention-deficit hyperactivity disorder (ADHD) and obsessive–compulsive disorder (OCD) are present at higher rates. These co-occurring diagnoses often cause more impairment to the individual than the tics; hence, it is important to correctly identify associated conditions and treat them.
About 1% of school-age children and adolescents have Tourette’s. It was once considered a rare and bizarre syndrome, most often associated with coprolalia (the utterance of obscene words or socially inappropriate and derogatory remarks), but this symptom is present in only a small minority of people with Tourette’s. The condition was named by Jean-Martin Charcot (1825–1893) on behalf of his resident, Georges Albert Édouard Brutus Gilles de la Tourette (1857–1904), a French physician and neurologist, who published an account of nine patients with Tourette’s in 1885.
According to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), Tourette’s may be diagnosed when a person exhibits both multiple motor and one or more vocal tics over the period of a 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—such as autism or other causes of tourettism—must be ruled out before conferring a Tourette’s diagnosis. Since 2000, the DSM has recognized that clinicians see patients who meet all the other criteria for Tourette’s, but do not have distress or impairment.
There are no specific medical or screening tests that can be used in diagnosing Tourette’s; 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). Coughing, eye blinking, and tics that mimic unrelated conditions such as asthma are commonly misdiagnosed.
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.
There is no requirement that other comorbid conditions (such as ADHD or OCD) be present, 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. TSH levels can be measured to rule out hypothyroidism, which can be a cause of tics. Brain imaging studies are not usually warranted. 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. 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 diagnosis for Tourette syndrome. Other conditions that may manifest tics or stereotyped movements include developmental disorders, autism spectrum disorders, and stereotypic movement disorder; Sydenham’s chorea; idiopathic dystonia; 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 syndrome, XYY syndrome and fragile X syndrome. Acquired causes of tics include drug-induced tics, head trauma, encephalitis, stroke, and carbon monoxide poisoning. The symptoms of Lesch-Nyhan syndrome may 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.
Content retrieved from: https://en.wikipedia.org/wiki/Tourette_syndrome.