Tourette Syndrome: Involuntary Motor and Vocal or Phonic Tics

Tourette Syndrome is an inherited, neurological disorder characterized by 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

How is Tourette Syndrome Diagnosed?

Diagnosis is made by observing symptoms and evaluating the history of their onset. No blood analysis, X-ray or other type of medical test can identify this condition. 2

According to the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders 3:

• Both motor and vocal tics are present during the illness, although not always at the same time.

• 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.

• The onset of Tourette Syndrome occurs before 18 years of age.

• 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).

• In rare cases, people with Tourette Syndrome may involuntarily shout obscenities (coprolalia) or constantly repeat the words of other people (echolalia).

Who is Affected by Tourette Syndrome?

Tourette Syndrome 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 Tourette Syndrome, 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

How Many People Have Tourette Syndrome?

Although further research into the prevalence of Tourette Syndrome will provide better data on rates in the United States, it is believed that it affects 3 to 5 in every 10,000 individuals, and about 10 in every 10,000 school-age children.

The onset of Tourette Syndrome and tics typically occurs when a child is 6 to 8 years old, with diagnosis usually occurring around this time as well. Although Tourette Syndrome and tics might appear, disappear, and reappear, these disorders are considered chronic.

Tourette Syndrome and related disorders can place individuals at higher risk for learning, behavioral and social difficulties. Many studies have linked Tourette Syndrome and tic disorders to higher rates of attention deficit/hyperactivity disorder, obsessive-compulsive disorder, and impairments associated with these co-morbid conditions.

References:

1. National Institute of Neurological Disorders and Stroke Tourette Syndrome Fact Sheet.

2. Tourette Syndrome Association Tourette Syndrome Fact Sheet.

3. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision.
 Washington, DC, American Psychiatric Association: 2000.

For More Information

• Tourette Syndrome
• CDC Research and Projects, Tourette Syndrome
• Tourette Syndrome Fact Sheet, The National Institute of Neurological Disorders and Stroke
• Tourette Syndrome Association*