Tourette syndrome (TS) is an inherited, neurological disorder
characterized by repeated involuntary movements and uncontrollable vocal
(phonic) sounds called tics. In a few cases, such tics can include
inappropriate words and phrases.
The disorder is named for Dr. Georges Gilles de la Tourette, the
pioneering French neurologist who first described an 86-year-old French
noblewoman with the condition in 1885.
The symptoms of TS generally appear before the individual is 18 years
old. TS can affect people of all ethnic groups; males are affected 3 to 4
times more often than females. It is estimated that 100,000 Americans have
full-blown TS, and that perhaps as many as 1 in 200 show a partial
expression of the disorder, such as chronic multiple tics or transient
childhood tics.
The natural course of TS varies from patient to patient. Although TS
symptoms range from very mild to quite severe, the majority of cases fall
in the mild category.
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The first symptoms of TS are usually facial tics--commonly eye
blinking. However, facial tics can also include nose twitching or
grimaces. With time, other motor tics may appear such as head jerking,
neck stretching, foot stamping, or body twisting and bending.
TS patients may utter strange and unacceptable sounds, words, or
phrases. It is not uncommon for a person with TS to continuously clear his
or her throat, cough, sniff, grunt, yelp, bark, or shout.
People with TS may involuntarily shout obscenities (coprolalia) or
constantly repeat the words of other people (echolalia). They may touch
other people excessively or repeat actions obsessively and unnecessarily.
A few patients with severe TS demonstrate self-harming behaviors such as
lip and cheek biting and head banging against hard objects. However, these
behaviors are extremely rare.
Tics alternately increase and decrease in severity, and periodically
change in number, frequency, type, and location. Symptoms may subside for
weeks or months at a time and later recur.
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There are two categories of tics: simple and complex. Simple tics are
sudden, brief movements that involve a limited number of muscle groups.
They occur in a single or isolated fashion and are often repetitive. Some
of the more common examples of simple tics include eye blinking, shoulder
shrugging, facial grimacing, head jerking, yelping, and sniffing. Complex
tics are distinct, coordinated patterns of successive movements involving
several muscle groups. Complex tics might include jumping, smelling
objects, touching the nose, touching other people, coprolalia, echolalia,
or self-harming behaviors.
People with TS can sometimes suppress their tics for a short time, but
the effort is similar to that of holding back a sneeze. Eventually tension
mounts to the point where the tic escapes. Tics worsen in stressful
situations; however they improve when the person is relaxed or absorbed in
an activity. In most cases tics decrease markedly during sleep.
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Although the basic cause of TS is unknown, current research suggests
that there is an abnormality in the gene(s) affecting the brain's
metabolism of neurotransmitters such as dopamine, serotonin, and
norepinephrine. Neurotransmitters are chemicals in the brain that carry
signals from one nerve cell to another.
Not all people with TS have disorders other than tics. However, many
people experience additional problems such as obsessive compulsive
behavior, where the person feels that something must be done repeatedly,
such as hand washing or checking that a door is locked; attention deficit
disorder, where the person has difficulty concentrating and is easily
distracted; learning disabilities, which include reading, writing,
arithmetic, and perceptual difficulties; problems with impulse control,
which can result in overly aggressive behaviors or socially inappropriate
acts; or sleep disorders, which include frequent awakenings or talking in
one's sleep.
The wide range of behavioral symptoms that can accompany tics may, in
fact, be more disabling than the tics themselves. Patients, families, and
physicians need to determine which set of symptoms is most disabling so
that appropriate medications and therapies can be selected.
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Generally, TS is diagnosed by observing the symptoms and evaluating
family history. For a diagnosis of TS to be made, both motor and phonic
tics must be present for at least 1 year. Neuroimaging studies, such as
magnetic resonance imaging (MRI), computerized tomography (CT), and
electroencephalogram (EEG) scans, or certain blood tests may be used to
rule out other conditions that might be confused with TS. However, TS is a
clinical diagnosis. There are no blood tests or other laboratory tests
that definitively diagnose the disorder.
Studies show that correct diagnosis of TS is frequently delayed after
the start of symptoms because many physicians may not be familiar with the
disorder. The behavioral symptoms and tics are easily misinterpreted,
often causing children with TS to be misunderstood at school, at home, and
even in the doctor's office. Parents, relatives, and peers who are
unfamiliar with the disorder may incorrectly attribute the tics and other
symptoms to psychological problems, thereby increasing the social
isolation of those with the disorder. And because tics can wax and wane in
severity and can also be suppressed, they are often absent during doctor
visits, which further complicates making a diagnosis.
In many cases, parents, relatives, friends, or even the patients
themselves become aware of the disorder based on information they have
heard or read in the popular media.
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Because symptoms do not impair most patients and development usually
proceeds normally, the majority of people with TS require no medication.
However, medications are available to help when symptoms interfere with
functioning. Unfortunately, there is no one medication that is helpful to
all persons with TS, nor does any medication completely eliminate
symptoms; in addition, all medications have side effects. Instead, the
available TS medications are only able to help reduce specific symptoms.
Some patients who require medication to reduce the frequency and
intensity of the tic symptoms may be treated with neuroleptic drugs such
as haloperidol and pimozide. These medications are usually given in very
small doses that are increased slowly until the best possible balance
between symptoms and side effects is achieved.
Recently scientists have discovered that long-term use of neuroleptic
drugs may cause an involuntary movement disorder called tardive dyskinesia.
However, this condition usually disappears when medication is
discontinued. Short-term side effects of haloperidol and pimozide include
muscular rigidity, drooling, tremor, lack of facial expression, slow
movement, and restlessness. These side effects can be reduced by drugs
commonly used to treat Parkinson's disease. Other side effects such as
fatigue, depression, anxiety, weight gain, and difficulties in thinking
clearly may be more troublesome.
Clonidine, an antihypertensive drug, is also used in the treatment of
tics. Studies show that it is more effective in reducing motor tics than
reducing vocal tics. Fatigue, dry mouth, irritability, dizziness,
headache, and insomnia are common side effects associated with clonidine
use. Fluphenazine and clonazepam may also be prescribed to help control
tic symptoms.
Medications are also available to treat some of the associated
behavioral disorders. Stimulants such as methyphenidate, pemoline, and
dextroamphetamine, usually prescribed for attention deficit disorders,
although somewhat effective, have also been reported to increase tics;
therefore their use is controversial. For obsessive compulsive behaviors
that significantly disrupt daily functioning, fluoxetine, clomipramine,
sertraline, and paroxetine may be prescribed.
Other types of therapy may also be helpful. Although psychological
problems do not cause TS, psychotherapy may help the person better cope
with the disorder and deal with the secondary social and emotional
problems that sometimes occur. Psychotherapy does not help suppress the
patient's tics.
Relaxation techniques and biofeedback may be useful in alleviating
stress which can lead to an increase in tic symptoms.
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Evidence from genetic studies suggests that TS is inherited in a
dominant mode and the gene(s) involved can cause a variable range of
symptoms in different family members. A person with TS has about a 50-50
chance of passing on the gene(s) to one of his or her offspring. However,
that genetic predisposition may not necessarily result in full-blown TS;
instead, it may express itself as a milder tic disorder or as obsessive
compulsive behaviors or possibly attention deficit disorder with few or no
tics at all. It is also possible that the gene-carrying offspring will not
develop any TS symptoms. A higher than normal incidence of milder tic
disorders and obsessive compulsive behaviors has been found in families of
individuals with TS.
Gender also plays an important role in TS gene expression. If the
gene-carrying offspring of a TS patient is male, then the risk of
developing symptoms is 3 to 4 times higher. However, most people who
inherit the gene(s) will not develop symptoms severe enough to warrant
medical attention. In some cases of TS, inheritance cannot be determined.
These cases are called sporadic and their cause is unknown.
There is no cure for TS; however, the condition in many individuals
improves as they mature. Individuals with TS can expect to live a normal
life span. Although the disorder is generally lifelong and chronic, it is
not a degenerative condition. TS does not impair intelligence. Tics tend
to decrease with age, enabling some patients to discontinue using
medication. In a few cases, complete remission occurs after adolescence.
Although tic symptoms tend to decrease with age, it is possible that
neuropsychiatric disorders such as depression, panic attacks, mood swings,
and antisocial behaviors may increase.
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Although students with TS often function well in the regular classroom,
it is estimated that many may have some kind of learning disability. When
attention deficit disorder, obsessive compulsive disorder, and frequent
tics greatly interfere with academic performance or social adjustment,
students should be placed in an educational setting that meets their
individual needs. These students may require tutoring, smaller or special
classes, and in some cases special schools.
All students with TS need a tolerant and compassionate setting that
both encourages them to work to their full potential and is flexible
enough to accommodate their special needs. This setting may include a
private study area, exams outside the regular classroom, or even oral
exams when the child's symptoms interfere with his or her ability to
write. Untimed testing reduces stress for students with TS.
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Within the Federal Government, the leading supporter of research on TS
and other neurological disorders is the National Institute of Neurological
Disorders and Stroke (NINDS). The NINDS, a part of the National Institutes
of Health (NIH), is responsible for supporting and conducting research on
the brain and central nervous system.
NINDS sponsors research on TS both in its laboratories at the NIH and
through grants to major medical institutions across the country. The
National Institute of Mental Health,the National Center for Research
Resources, the National Institute of Child Health and Human Development,
the National Institute on Drug Abuse, and the National Institute on
Deafness and Other Communication Disorders also support research of
relevance to TS.
Recent research has led to several notable advances in the
understanding of TS. Already scientists have learned that TS is inherited
from a dominant gene(s) that causes different symptoms from patient to
patient, and that the disorder is more common than was previously thought.
Genetic studies. Currently, investigators are conducting genetic
linkage studies in large multigenerational families affected with TS in an
effort to find the chromosomal location of the TS gene(s). Finding a
genetic marker (a biochemical abnormality that all TS patients might
share) for TS would be a major step toward understanding the genetic risk
factors for TS. Once the marker is found, research efforts would then
focus on locating the TS gene(s).
Understanding the genetics of TS will directly benefit patients who are
concerned about recurrence in their families and will ultimately help to
clarify the development of the disorder. Localization of the TS gene will
strengthen clinical diagnosis, improve genetic counseling, lead to the
clarification of pathophysiology, and provide clues for more effective
therapies.
Neurotransmitter studies. Investigators continue to study certain
neurotransmitters to increase our understanding of the syndrome, explore
the role they play in the disease process, and provide more effective
therapies.
Environmental studies. Other research projects currently under way
include analyzing young unaffected children at high risk for TS in order
to identify environmental factors such as life stresses or exposure to
certain medications that may influence the expression of the disorder.
Scientists are also conducting neuropsychological tests and
neuroimaging studies of brain activity and structure to determine the
extent to which specific environmental exposures may affect the emergence
of tics and/or obsessive compulsive symptoms.
Tourette's,
Other Tic Disorders Far More Common Than Once Thought
One out of
four students in special-education classes has a tic-related disorder like
Tourette syndrome, and the rate of Tourette’s among students in the
general population is 50 to 75 times higher than has been traditionally
thought by doctors, according to a study published in the Oct. 23 issue of
the journal Neurology.
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For more information about TS or other neurological disorders, or about
the NINDS and its research programs, contact the NINDS Office
of Scientific and Health Reports.
The Tourette Syndrome Association, Inc., is a voluntary, nonprofit
organization whose members include people with TS, their families and
friends, and health care professionals. The Association funds research,
provides services to patients and their families, and offers a variety of
publications, including a newsletter, brochures, and fact sheets. For
further information, contact:
Tourette Syndrome Association, Inc.
42-40 Bell Boulevard
Bayside, New York 11361-2861
(718) 224-2999
(800) 237-0717
Books available from Amazon.com:
A
Mind of Its Own : Tourette's Syndrome : A Story and a Guide
Ryan
: A Mother's Story of Her Hyperactive/Tourette Syndrome Child
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Prepared by
Office of Scientific and Health Reports
National Institute of Neurological Disorders and Stroke
National Institutes of Health
Bethesda, MD 20892
NIH Publication No. 95-2163
Original Publication Date: February 1995
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