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What is Tourette Syndrome?
Tourette Syndrome (TS) is an inherited, neurological disorder
characterized by multiple involuntary movements, called motor tics, and
uncontrollable vocalizations called vocal or phonic tics. A tic is a
sudden rapid, recurrent, non-rhythmic, stereotyped motor movement or
vocalization. 1
Diagnostic criteria for Tourette Syndrome (DSM-IV TR)
2
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Both motor and vocal tics are present during the illness, although not
always at the same time.
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The tics occur many times a day (usually in bouts) nearly every day or
off and on for more than 1 year, with never a tic-free period of more
than 3 months in a row.
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The onset of TS occurs before 18 years of age.
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The disturbance is not caused by the direct physiological effects of
medications or other substances, and is not the result of a general
medical condition (e.g., seizures, Huntington's disease or postviral
encephalitis).
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In rare cases, people with TS may involuntarily shout obscenities (coprolalia)
or constantly repeat the words of other people (echolalia).
TS can affect people of all racial and ethnic groups; males are affected
3 to 4 times more often than females. An estimated 200,000 Americans
have TS, and perhaps as many as 1 in 100 people show a milder form of
the disorder, such as chronic or transient tics in childhood.
1
Worldwide estimates of TS from population-based studies range from
1/1000-30/1000. Recent community-based studies, which include both
diagnosed and previously unidentified cases, provide a range of TS
prevalence from 3.0 to 8.0 per 1000.
The first-ever national estimate among a nationally representative
sample of U.S. children revealed that 3 out of every1000 children
between the age of 6 and 17 in the United States have been diagnosed
with Tourette Syndrome (TS).
The study, "Prevalence of Diagnosed Tourette Syndrome in Children in the
United States, 2007," found that a TS diagnosis is three times more
common in boys than in girls, and approximately twice as common in
children between 12-17 years as those aged 6-12 years. Among children
with TS, 27% were reported as having moderate or severe TS and 79% of
children had also been diagnosed with at least one additional mental
health or neurodevelopmental condition.
The onset of TS and tics typically occurs when a child is 6 to 8 years
old, with diagnosis usually occurring around this time as well. Although
TS and tics might appear, disappear, and reappear, these disorders are
considered chronic.
TS and related disorders can place individuals at higher risk for
learning, behavioral, and social difficulties. Many studies have linked
TS and tic disorders to higher rates of Attention Deficit/Hyperactivity
Disorder, obsessive-compulsive disorder, and impairments associated with
these co-morbid conditions.
References:
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National Institute of Neurological Disorders and Stroke Tourette
Syndrome Fact Sheet
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American Psychiatric Association. Diagnostic and Statistical Manual
of Mental Disorders, Fourth Edition, Text Revision. Washington, DC,
American Psychiatric Association: 2000.
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Date Last Reviewed:
July 30, 2009
Page last updated:
July 30, 2009
Content source: National Center on Birth Defects and Developmental
Disabilities
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