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tic

 
Dictionary: tic   (tĭk) pronunciation
 
n.

A habitual spasmodic muscular movement or contraction, usually of the face or extremities.

intr.v., ticced, tic·cing, tics.

To have a tic; produce tics.

[French.]


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Thesaurus: tic
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noun

    A nervous shaking of the body: quake, quiver, shake, shiver1, shudder, thrill, tremor, twitch. See repetition.

 

Definition

A tic is a nonvoluntary body movement or vocal sound that is made repeatedly, rapidly, and suddenly. It has a stereotyped but nonrhythmic character. The child or adolescent with a tic experiences it as irresistible but can suppress the movement or noise for a period of time. Tics are categorized as motor or vocal, and as simple or complex. The word "tic" itself is French.

Tics are a type of dyskinesia, which is the general medical term given to impairments or distortions of voluntary movements. Although tics vary considerably in severity, they are associated with several neuropsychiatric disorders in children and adolescents. The American Psychiatric Association (APA) defined four tic disorders in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-IV. The disorders are distinguished from one another according to three criteria: the child's age at onset; the duration of the disorder; and the number and variety of tics.

  • Transient tic disorder (also known as benign tic disorder of childhood): The criteria for transient tic disorder specify that the onset must occur before the age of 18 years; the tics must occur many times a day almost every day for at least four weeks but not longer than 12 months; and the child must not meet the criteria for Tourette syndrome or chronic tic disorder.
  • Chronic motor or vocal tic disorder: To meet the diagnosis of chronic tic disorder, the child must be younger than 18 years of age; the tics must have occurred nearly every day or intermittently for a period longer than a year, without a tic-free interval longer than three months; the tics must be either vocal or motor but not both; and the child must not meet the criteria for Tourette disorder.
  • Tourette disorder (also known as Tourette syndrome, or TS): Tourette disorder is considered the most serious of the four tic disorders. The DSM-IV criteria for Tourette disorder specify that the child must be younger 18 years of age at onset; the tics must include multiple vocal as well as motor tics, although not necessarily at the same time; the tics must occur many times a day, nearly every day or at intervals over a period longer than a year, without symptom-free intervals longer than six months; there must be variations in the number, location, severity, complexity, and frequency of the tics over time; and the tics cannot be attributed to the effects of a substance (such as stimulants) or a disease of the central nervous system.
  • Tic disorder not otherwise specified: This category includes all cases that do not meet the full criteria for any of the other tic disorders.

Description

Tics most commonly affect the child's face, neck, voice box, and upper torso but may involve almost any body part. The experience of having a tic is difficult to describe to those who have never been troubled by them. Having tics may be compared to having the sensation of having to cough because something is tickling one's throat or nose. The sensation is irresistible and immediate.

Simple Tics

Simple tics involve only a few muscles or sounds that are not yet words. Examples of simple motor tics include nose wrinkling, facial grimaces, eye blinking, jerking the neck, shrugging the shoulders, or tensing the muscles of the abdomen. Simple vocal tics include grunting, clucking, sniffing, chirping, or throat-clearing noises. Simple tics rarely last longer than a few hundred milliseconds.

Complex Tics

Complex tics involve multiple groups or muscles or complete words or sentences. Examples of complex motor tics include such gestures as jumping, squatting, making motions with the hands, twirling around when walking, touching or smelling an object repeatedly, and holding the body in an unusual position. Complex motor tics last longer than simple motor tics, usually several seconds or longer. Two specific types of complex motor tics that often cause parents concern are copropraxia, in which the tic involves a vulgar or obscene gesture, and echopraxia, in which the tic is a spontaneous imitation of someone else's movements.

Similarly, complex vocal tics involve full speech and language, which may range from the spontaneous utterance of individual words or phrases, such as "Stop," or "Oh boy," to speech blocking or meaningless changes in the pitch, volume, or rhythm of the child's voice. Specific types of complex vocal tics include palilalia, which refers to the child's repetition of his or her own words; coprolalia, which refers to the use of obscene words or abusive terms for certain racial or religious groups; and echolalia, in which the child repeats someone else's last word or phrase.

Sensory Tics

Sensory tics are less common than either motor or vocal tics. The term refers to repeated unwanted or uncomfortable sensations, usually in the child's throat, eyes, or shoulders. The child may feel a sensation of tickling, warmth, cold, or pressure in the affected area.

Phantom Tics

Phantom tics are the least common type of tic. A phantom tic is an out-of-body variation of a sensory tic in which the person feels a sensation in other people or objects. People with phantom tics experience temporary relief from the tic by touching or scratching the object involved.

Other Features of Tics

Tics typically occur in bouts or episodes alternating with periods of tic-free behavior lasting from several seconds to several hours. They generally diminish in severity when the child is involved in an absorbing activity such as reading or doing homework, and increase in frequency and severity when the child is tired, ill, or stressed. Some children have tics during the lighter stages of sleep or wake up during the night with a tic.

Severe complex motor tics carry the risk of physical injury, as the child may damage muscles or joints, fracture bones, or fall down during an episode of these tics. Some children harm themselves deliberately by self-cutting or self-hitting, while others hurt themselves unintentionally by touching or handling lighted matches, razor blades, or other dangerous objects. Severe complex vocal tics may interfere with breathing or swallowing.

Transmission

Tics as such are symptoms and are not transmitted directly from one person to another. Tic disorders, however, are known to run in families. In addition, some doctors think that tic disorders are more likely to develop in children who have had certain types of infections. These theories are discussed more fully below.

Demographics

Prevalence of Tic Disorders

The statistics given for tics and tic disorders vary from source to source, in part because tics vary considerably in severity, and many children with mild tics may never come to a doctor's attention. Estimates for the general North American population range from 3 to 20 percent for transient tics (particularly among children below the age of ten); 2–5 percent for chronic tic disorders; and 0.1–0.8 percent for Tourette syndrome. A Swedish study done in 2003 reported that 6.6 percent of a sample of Uppsala school children between the ages of 7 and 15 met DSM-IV criteria for tic disorders: 4.8 percent for transient tic disorder, 0.8 percent for chronic motor tic disorder, 0.5 percent for chronic vocal tic disorder, and 0.6 percent for Tourette syndrome. One study of American volunteers for military service reported a prevalence of 0.5 cases of TS per 1000 for males and 0.3 cases per 1000 for females. Tourette syndrome is known to be more common in males than in females, although the gender ratio is variously reported as 3: 1, 5: 1, or even 10: 1.

Little is known as of 2004 about the prevalence of tic disorders across racial or ethnic groups. One small study that was done in western North Carolina reported that Caucasian children were slightly more likely to have tic disorders than either African American or Native American children (2.1 percent to 1.5 percent and 1.5 percent respectively). The authors of the study cautioned, however, against applying their findings to larger groups of children in other parts of the United States.

Tic Disorders and Comorbid Disorders

One important characteristic of tics and tic disorders is that they rarely occur by themselves. Tic disorders—particularly TS—have a high rate of comorbidity with other childhood disorders. The term comorbid is used to refer to a disease or disorder that occurs at the same time as another disorder. The frequencies of the most common disorders that may be comorbid with tic disorders and Tourette syndrome are as follows:

  • attention-deficit/hyperactivity disorder (ADHD): 50 percent comorbidity with tic disorders, 90 percent comorbidity with TS
  • obsessive-compulsive disorder (OCD): 11 percent and 80 percent respectively
  • major depression: 40 percent and 44 percent respectively

Other psychiatric problems that often coexist with tics and tic disorders include learning disorders, impulse control disorders, school phobia, sensory hypersensitivity, and rage attacks.

Causes and Symptoms

The causes of tics and tic disorders are not fully understood as of the early 2000s, but most researchers believe that they are multifactorial, or the end result of several causes. In the early twentieth century, many doctors influenced by Freud thought that tics were caused by hysteria or other emotional problems, and treated them with psychoanalysis. Psychoanalytic treatment, however, had a very low rate of success.

Since the 1970s, researchers have been looking at genetic factors in tic disorders and Tourette syndrome. With regard to TS, genetic factors are present in about 75 percent of children diagnosed with TS, with 25 percent having inherited genetic factors from both parents. The exact pattern of genetic transmission was not known as of 2004, however; autosomal dominant, autosomal recessive, and sex-linked inheritance patterns have all been studied and rejected. Some candidate genes for TS have also been tested and excluded. What is known is that the patient's environment and heredity play a significant part in the severity and course of TS.

Tic disorders as well as OCD sometimes develop after infections (usually scarlet fever or strep throat) caused by a group of bacteria known as group A beta-hemolytic streptococci, sometimes abbreviated as GABHS. These disorders are sometimes grouped together as PANDAS disorders, which stands for Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococci. Some researchers think that the tics develop when antibodies in the child's blood produced in response to the bacteria cross-react with proteins in the brain tissue. The connection between streptococcal infections and tic disorders is questioned by some researchers, however, on the grounds that most children have a GABHS infection at some point in their early years, but the vast majority (95 percent) do not develop OCD or a tic disorder. There appears to be a closer connection between Sydenham's chorea, which is a movement disorder, and GABHS infections than between tic disorders and these infections. One prospective study done at Yale reported in 2004 that new GABHS infections do not appear to cause a worsening of tics in children diagnosed with OCD or Tourette syndrome.

Neuroimaging studies have shown that tic disorders are related to abnormal levels of neurotransmitters known as dopamine, serotonin, and cyclic AMP in certain parts of the brain. A neurotransmitter is a chemical produced by the body that conveys nerve impulses across the gaps (synapses) between nerve cells. In addition to abnormalities in the production or absorption of these chemical messengers, imaging studies indicate that the blood flow and metabolism in a part of the brain called the basal ganglia are abnormally low. The basal ganglia are groups of nerve cells deep in the brain that control movement as well as emotion and certain aspects of thinking. In contrast to the low level of blood flow in the basal ganglia, the motor areas in the frontotemporal cortex of the brain show increased levels of activity.

The various types of tics themselves have already been described. Other symptoms that may be associated with tics and tic disorders include obsessive thoughts; difficulty concentrating or paying attention in school; forgetfulness; slowness in completing tasks; losing the thread of a conversation. These symptoms are usually regarded as side effects of interrupted thinking or behavior caused by the tics.

When to Call the Doctor

Most cases of mild tics do not require medical treatment and will clear up on their own over time. Doctors usually recommend that family members try to ignore simple tics, since teasing or other unwanted attention may make the tics worse. A visit to the doctor is recommended, however, under any of the following circumstances:

  • The child is falling behind in school because of the tics.
  • The child's relationships with peers and adults outside the family are affected by the tics.
  • The child cannot carry out activities of daily living (self-feeding, bathing, getting dressed, etc.).
  • The child has fallen, injured himself, or developed other physical problems because of the tics.
  • Other family members have or have had tic disorders.
  • The child has recently had an episode of strep throat or other streptococcal infection.
  • The child has been diagnosed with OCD, ADHD, or depression.
  • The tics have come on suddenly.

Diagnosis

Tic disorders are diagnosed by a process of excluding other possibilities; there are no definitive tests for these disorders as of the early 2000s. For this reason, the diagnosis of tic disorders is often delayed or sometimes missed altogether in milder cases. One study reported an average delay of five to 12 years between the initial symptoms and the correct diagnosis. In addition, diagnosis is complicated by the fact that children often learn to mask their tics by converting them to more socially acceptable or apparently voluntary movements or sounds.

History and Physical Examination

The first part of a medical workup for tics is the taking of a medical history and a general physical examination. The doctor will want to know whether there is a family history of tics or tic disorders, whether the child has been diagnosed with other childhood developmental or psychiatric disorders, and whether he or she has recently had strep throat or a similar infection.

The physical examination helps the doctor rule out such other possible diagnoses as Sydenham's chorea, a self-limited movement disorder that most commonly affects children between five and 15 years of age; other movement disorders; seizure disorders; encephalitis; neurosyphilis; Wilson's disease (a rare inherited disease that causes the body to retain copper); schizophrenia; carbon monoxide poisoning; cocaine intoxication; brain injuries caused by trauma; cerebral palsy;or the side effects of certain medications, particularly stimulants and antiepileptic drugs.

The doctor may not be able to observe the tic(s) during the child's first office visit, often because the child has learned to suppress or mask them. In some cases, a follow-up visit may be scheduled, or the doctor may refer the child to a child psychiatrist or neurologist for further observation. Another approach that can be used to confirm the diagnosis is to audiotape or videotape the child at home or in another less stressful setting.

Psychiatric Inventories

Most child psychiatrists will administer the Yale Global Tic Severity Scale (YGTSS) during the intake interview and at follow-up visits in order to identify the particular tic disorder affecting the child, identify comorbid disorders if present, evaluate the severity of the tics, and monitor the child's response to treatment.

The YGTSS, which was first published in 1989, is a semi-structured interview that is widely used by researchers who study tic disorders. "Semi-structured" means that it is an open-ended set of questions that allow the child's parents to describe the tics and other symptoms in detail rather than just answer brief yes-or-no questions.

Laboratory Tests

As mentioned earlier, there are no laboratory tests to diagnose tics as such. In some cases, however, the doctor may order a blood test to rule out Wilson's disease or other metabolic disorders, or order a throat culture if the child has recently had strep throat. If the doctor suspects that the child has a PANDAS disorder, he or she may order a blood test to measure the level of antibodies against group A streptococci.

Imaging Studies

As of 2004, imaging studies were not routinely performed on children or adolescents with tics unless the doctor suspects a brain injury, infection, or structural abnormality. Magnetic resonance imaging (MRIs), PET scans, and single-photon emission computed tomography (SPECT) scans have been used by researchers, however, to study the brains of patients diagnosed with Tourette syndrome.

In the summer of 2004, two engineers in Taiwan reported on the development of a computerized diagnostic system that will allow radiologists to use SPECT imaging to distinguish between chronic tic disorder and Tourette syndrome with a much higher degree of accuracy. The system appears to be potentially useful in speeding up the process of diagnosis and allowing earlier treatment of TS.

Treatment

After psychoanalysis was discredited in the 1970s as a treatment for tic disorders, some doctors urged using such antipsychotic drugs as haloperidol (Haldol) to treat TS by suppressing the tics. These drugs, which are sometimes called neuroleptics, have severe side effects and are likely to interact with other medications that the child may be taking. In addition, tics are increasingly recognized as complex phenomena that have an emotional as well as a physical dimension. As a result, the treatment of tic disorders has changed in the early 2000s in the direction of minimizing the use of medications in favor of a multidisciplinary approach.

The approach to assess a child with a tic disorder is as follows:

  • Administer the YGTSS in order to evaluate the areas of the child's functioning that are most severely affected by the tics.
  • Identify any comorbid disorders if present. In many cases, the tics do not interfere with the child's life as much as ADHD, OCD, or depression. ADHD should be the primary target of management in children diagnosed with a tic disorder and comorbid ADHD.
  • Rank the symptoms in order of importance in order to focus treatment on the ones that are most significant to the child and the family.
  • Emphasize controlling the tics and learning to live with them rather than trying to eliminate them with drugs.
  • Use behavioral and psychotherapeutic approaches as well as medications.
  • Involve the patient's teachers and other significant adults as well as parents in order to help monitor the child's symptoms and response to treatment.

Medications

There is no medication that can cure a tic disorder; all drugs that are used to treat these disorders as of the early 2000s are used only to manage tics. In general, doctors prefer to avoid medications in treating mild tics; start the treatment of moderate or severe tics with medications that have relatively few side effects, and prescribe stronger drugs only when necessary.

Children whose throat cultures or blood tests are positive for a GABHS infection are treated aggressively with antibiotics, most commonly penicillin V.

Psychotherapy

Psychotherapy for tics and tic disorders typically involves education about tic disorders and therapy for the family as well as individual treatment for the child. The American Academy of Child and Adolescent Psychiatry (AACAP) urges parents to avoid blaming or punishing the child for the tics, as shaming or harsh treatment increases the child's level of emotional stress and usually makes the tics worse.

Cognitive-behavioral approaches are the most common type of individual psychotherapy used to treat tics and tic disorders. Specific behavioral approaches include the following:

  • Massed negative practice: In this form of behavioral treatment, the child is asked to perform the tic intentionally for specified periods of time interspersed with rest periods.
  • Competing response training: This is a form of treatment of motor tics in which the child is taught to make the opposite movement to the tic.
  • Self-monitoring: In awareness training, the child keeps a diary, small notebook, or wrist counter for recording tics. It is supposed to reduce the frequency of tic bouts by increasing the child's awareness of them.
  • Contingency management: This approach works best in the home and is usually carried out by the parents. The child is praised or rewarded for not performing the tics and for replacing them with acceptable alternative behaviors.

As of the early 2000s, however, no controlled studies have been done comparing the effectiveness of these various behavioral approaches. At best, they appear to produce mixed results.

Surgery

Surgery is used very rarely to treat tic disorders; it is usually tried only if the tic has not responded to any medication and interferes significantly with the patient's life. Some patients with TS, however, have been successfully treated with stereotactic surgery involving high-frequency stimulation of the thalamus. Stereotactic surgery involves an approach that calculates angles and distances from the outside of the patient's skull to locate very small lesions or structures deep inside the brain. It allows the surgeon to remove tissue or treat injured areas through much smaller incisions.

Alternative Treatments

The place of alternative or complementary therapies in treating tics is debated. One group of Chinese physicians reported successfully treating patients diagnosed with TS with acupuncture. However, a group of researchers studying traditional medicine in Bali found it ineffective in treating tic disorders, and a second group at Johns Hopkins reported that relaxation therapy did not have a statistically significant effect in treating children diagnosed with TS. There is also some evidence that gingko, ginseng, and some other herbs taken for their stimulant effects may increase the severity of tics in children and adolescents.

Nutritional Concerns

Although some nutritionists have suggested a possible connection between sugar or food coloring and tic severity, no studies published as of 2004 had demonstrated such a connection. One study done at the University of Kansas did find a connection between caffeine (which is found in cola beverages and some other soft drinks as well as tea and coffee) consumption and tic severity in children. The study sample, however, was quite small.

Prognosis

The prognosis for most tics and tic disorders is quite good. In the majority of cases, the tics diminish in severity and eventually disappear as the child grows older. Even in Tourette syndrome, about 85 percent of children find that their tics diminish or go away entirely during or after adolescence. Tics that persist beyond the teenage years, however, usually become permanent.

Factors associated with a poorer prognosis for all tic disorders include the following:

  • history of complications during the child's birth
  • chronic physical illness in childhood
  • physical or emotional abuse in the family or a history of family instability
  • exposure to anabolic steroids or cocaine
  • comorbid psychiatric or developmental disorders

Prevention

There are no known ways to prevent either tics or tic disorders.

Nutritional Concerns

In some cases, parents may find it helpful to monitor the child's intake of cola, iced tea, other drinks containing caffeine, and certain herbal teas.

Parental Concerns

Parental concerns related to tics and tic disorders are difficult to address in general terms, because tics can range in type and severity from simple noises or movements of short duration that do not attract much attention from others to complex tics of a physically harmful or socially embarrassing nature that attract a lot of attention. In addition, tics must often be managed in the context of another disorder affecting the child. Since the treatment of tics is individualized, it is best for parents to consult with the child's doctor(s) regarding special educational programs or settings, explaining the tics or tic disorder to others, dealing with the side effects of medications, and managing rage attacks or other symptoms that may be associated with the tics.

See also Movement disorders; Tourette syndrome.

Resources

Books

Diagnostic and Statistical Manual of Mental Disorders,4th ed., Text Revision. Washington, DC: American Psychiatric Association, 2000.

"Dyskinesias." Section 14, Chapter 179 in The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers and Robert Berkow. Whitehouse Station, NJ: Merck Research Laboratories, 2002.

Periodicals

Dale, R. C., et al. "Dyskinesias and Associated Psychiatric Disorders Following Streptococcal Infections." Archives of Disease in Childhood 89 (July 2004): 604–10.

Evidente, Virgilio G. H. "Is It a Tic or Tourette?" Postgraduate Medicine 108 (October 2000): 175–82.

Khalifa, N., and A. L. von Knorring. "Prevalence of Tic Disorders and Tourette Syndrome in a Swedish School Population." Developmental Medicine and Child Neurology 45 (May 2003): 315–19.

Lavenstein, Bennett L. "Treatment Approaches for Children with Tourette's Syndrome." Current Neurology and Neuroscience Reports 3 (2003): 143–48.

Lemelson, R. B. "Traditional Healing and Its Discontents: Efficacy and Traditional Therapies of Neuropsychiatric Disorders in Bali." Medical Anthropology Quarterly 18 (March 2004): 48–76.

Luo, F., et al. "Prospective Longitudinal Study of Children with Tic Disorders and/or Obsessive-Compulsive Disorder: Relationship of Symptom Exacerbations to Newly Acquired Streptococcal Infections." Pediatrics 113 (June 2004): 578–85.

McEvoy, J. P., and T. B. Allen. "The Importance of Nicotinic Acetylcholine Receptors in Schizophrenia, Bipolar Disorder, and Tourette's Syndrome." Current Drug Targets: CNS and Neurological Disorders 1 (August 2002): 433–42.

Yin, T. K., and N. T. Chiu. "A Computer-Aided Diagnosis for Distinguishing Tourette's Syndrome from Chronic Tic Disorder in Children by a Fuzzy System with a Two-Step Minimization Approach." IEEE Transactions on Biomedical Engineering 51 (July 2004): 1286–95.

Organizations

American Academy of Child and Adolescent Psychiatry. 3615 Wisconsin Avenue, NW, Washington, DC 20016–3007. Web site: www.aacap.org..

National Institute of Neurological Disorders and Stroke (NINDS). National Institutes of Health. 9000 Rockville Pike, Bethesda, MD 20892. Web site: www.ninds.nih.gov.

Tourette Syndrome Association Inc. 42–40 Bell Blvd., Bayside, New York 11361–2820. Web site; .

Web Sites

Black, Kevin J., and Heather Webb. "Tourette Syndrome and Other Tic Disorders." eMedicine, November 9, 2004. Available online at www.emedicine.com/neuro/topic664.htm (accessed December 1, 2004).

Ellis, Cynthia R., and Holly Jean Zumpfe. "Childhood Habit Behaviors and Stereotypic Movement Disorder." eMedicine, October 26, 2004. Available online at www.emedicine.com/ped/topic909.htm (accessed December 1, 2004).

Other

American Academy of Child and Adolescent Psychiatry (AACAP). Tic Disorders. AACAP Facts for Families #35. Washington, DC: AACAP, 2000.

National Institute of Neurological Disorders and Stroke (NINDS). Tourette Syndrome Fact Sheet. Bethesda, MD: NINDS, 2001.

[Article by: Rebecca Frey, PhD]



 

Sudden rapid, recurring muscle contraction — usually a blink, sniff, twitch, or shrug — always brief, irresistible, and localized. Frequency decreases from head to foot. Unlike a spasm, a cramp, or the movements of chorea or epilepsy, it does not interfere with other movement and can be held off for a time. It can become ingrained as a habit of which the person (most often a nervous child 5 – 12 years old) is unaware. Most tics are probably psychological, but similar movements occur in some physical disorders (e.g., late-stage encephalitis). People with tics have some control over the movement but feel impelled to go through with it to feel better. Tension increases the movement's likelihood, and distraction reduces it. Psychotherapy, relaxation training, and biofeedback training have had some success in treating tics.

For more information on tic, visit Britannica.com.

 
Abbreviations: TIC
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is short for:

Meaning Category
ALLFIX FTN special file with associated file descriptionComputing->File Extensions
Taken Into ConsiderationGovernmental->Police
Talented Impressive And CreativeCommunity->Educational
Talking In CharacterInternet->Chat
Talking In ConfidenceComputing->Telecom
Targeting Interlock CircuitGovernmental->Military
Teams In CompetitionCommunity->Sports
Technical Integrity CheckComputing->General
Technical Interface CertificationGovernmental->Military
Technical Interface ConceptGovernmental->Military
Technical Issues CommitteeBusiness->Accounting
Technique Insight And CommunicationBusiness->General
Technology Integration CenterGovernmental->Military
Tenancy In CommonCommunity->Law
Tenant In CommonBusiness->Stock Exchange
Tenants In CommonBusiness->Stock Exchange
Thailand Information CenterBusiness->Firms
The Immaculate CollectionCommunity->Music
The Independent CaverCommunity->Media
The Infernal CatfishMiscellaneous->Funnies
The Information CenterCommunity->Non-Profit Organizations
The Inner CircleBusiness->General
The Internet ClassAcademic & Science->Universities
The Internet ClassroomCommunity->Educational
The Internet ClubInternet->Chat
Theater Intelligence CenterGovernmental->Military
This Is ChinaMiscellaneous->Funnies
Threatening Intellectual CliqueAcademic & Science->Universities
Tickler Copy of Documents madeGovernmental->FBI Files
Tinak Island, Marshall IslandsRegional->Airport Codes
Together In ChristCommunity->Religion
Tolkowsky Ideal CutsBusiness->Firms
Tongue In CheekCommunity->Media
Tongue in cheekInternet->Chat
Total Input CostsBusiness->Accounting
Total Investment CapitalBusiness->Firms
Total Ion CurrentAcademic & Science->Chemistry
Tourist Information CenterCommunity
Tourist Information CentreGovernmental->US Government
Community
Trade Information CenterBusiness->International Business
Traffic Information CollectingGovernmental->Transportation
Transvaal Indian CongressRegional->African
Travel Insurance And CreditGovernmental->Transportation
Traveler Information CenterGovernmental->Transportation
Troops In ContactGovernmental->Military
True Interest CostBusiness->Accounting

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Word Tutor: tic
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pronunciation

IN BRIEF: A local and habitual twitching especially in the face.

pronunciation Did the medication cause the patient's facial tic?

 
Wikipedia: Tic
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Tic
Classification and external resources
MeSH D020323

A tic is a sudden, repetitive, nonrhythmic, stereotyped motor movement or vocalization involving discrete muscle groups.[1][2] Tics can be invisible to the observer, such as abdominal tensing or toe crunching. Common motor and vocal tics are, respectively, eye blinking and throat clearing.[3] Movements of other movement disorders (for example, chorea, dystonia, myoclonus) must be distinguished from tics. Other conditions like autism and stereotypic movement disorder also include movements which may be confused with tics. Tics must also be distinguished from compulsions of OCD and seizure activity.

Contents

Description and classification

Video clips of tics
HBO documentary video clip
CBS News video clip
From the TSA, an adult with tics

Tics are classified as motor vs. phonic and simple vs. complex.

Motor tics are movement-based tics affecting discrete muscle groups.

Phonic tics are involuntary sounds produced by moving air through the nose, mouth, or throat. They may be alternately referred to as verbal tics or vocal tics, but most diagnosticians prefer the term phonic tics to reflect the notion that the vocal cords are not involved in all tics that produce sound.[4]

Tics may increase as a result of stress, tiredness, or high energy emotions, which can include negative emotions, such as anxiety, but positive emotions as well, such as excitement or anticipation. Relaxation may result in a tic increase (for instance, watching television or using a computer), while concentration in an absorbing activity often leads to a decrease in tics.[5][6] Neurologist and writer Oliver Sacks described a physician with severe Tourette syndrome (Canadian Mort Doran, M.D., a pilot and surgeon in real life, although a pseudonym was used in the book), whose tics remitted almost completely while he is performing surgery.[7][8]

Immediately preceding tic onset, most individuals are aware of an urge[9] that is similar to the need to yawn, sneeze, blink, or scratch an itch. Individuals describe the need to tic as a buildup of tension[10] which they consciously choose to release, as if they "had to do it".[11] Examples of this premonitory urge are the feeling of having something in one's throat, or a localized discomfort in the shoulders, leading to the need to clear one's throat or shrug the shoulders. The actual tic may be felt as relieving this tension or sensation, similar to scratching an itch. Another example is blinking to relieve an uncomfortable sensation in the eye.

Tics are described as semi-voluntary or "unvoluntary",[12] because they are not strictly involuntary—they may be experienced as a voluntary response to the unwanted, premonitory urge. A unique aspect of tics, relative to other movement disorders, is that they are suppressible yet irresistible;[13] they are experienced as an irresistible urge that must eventually be expressed.[12] Some people with tics may not be aware of the premonitory urge. Children may be less aware of the premonitory urge associated with tics than are adults, but their awareness tends to increase with maturity.[12]

Simple tics

Simple motor tics are typically sudden, brief, meaningless movements that usually involve only one group of muscles, such as eye blinking, head jerking or shoulder shrugging.[14] Motor tics can be of an endless variety and may include such movements as hand-clapping, neck stretching, mouth movements, head, arm or leg jerks, and facial grimacing.

A simple phonic tic can be almost any sound or noise, with common vocal tics being throat clearing, sniffing, or grunting.[14]

Complex tics

Complex motor tics are typically more purposeful-appearing and of a longer nature. They may involved a cluster of movements and appear coordinated.[14] Examples of complex motor tics are pulling at clothes, touching people, touching objects, echopraxia and copropraxia.

Complex phonic tics may fall into various series (categories), including echolalia (repeating words just spoken by someone else), palilalia (repeating one's own previously spoken words), lexilalia (repeating words after reading them) and coprolalia (the spontaneous utterance of socially-objectionable or taboo words or phrases). Coprolalia is a highly-publicized symptom of Tourette syndrome; however, only about 10% of TS patients exhibit coprolalia.[14]

Complex tics are rarely seen in the absence of simple tics. Tics "may be challenging to differentiate from compulsions",[15] as in the case of klazomania (compulsive shouting).

Tic disorders

Tic disorders occur along a spectrum, ranging from mild to more severe, and are classified according to duration and severity (transient tics, chronic tics, or Tourette syndrome). Tourette syndrome is the more severe expression of a spectrum of tic disorders, which are thought to be due to the same genetic vulnerability. Nevertheless, most cases of Tourette syndrome are not severe.[16] The treatment for the spectrum of tic disorders is similar to the treatment of Tourette syndrome.

Differential diagnosis

Tourettism refers to the presence of Tourette-like symptoms in the absence of Tourette syndrome as the result of other diseases or conditions—also known as "secondary causes". Although tic disorders are commonly considered to be childhood syndromes, tics occasionally develop during adulthood; adult-onset tics often have a secondary cause.[17] Tics that begin after the age of 18 are generally not considered symptoms of Tourette's syndrome.

Tics must be distinguished from fasciculations. Small twitches of the upper or lower eyelid, for example, are not tics because they don't involve a whole muscle. They are twitches of a few muscle fibre bundles, which you can feel but barely see.[18]

Society and culture

There is some confusion in media portrayals of tics.

Notes

  1. ^ Leckman JF, Bloch MH, King RA, Scahill L. "Phenomenology of tics and natural history of tic disorders". Adv Neurol. 2006;99:1–16. PMID 16536348
  2. ^ American Psychiatric Association (2000). "Diagnostic criteria for 307.23 Tourette's Disorder". Diagnostic and Statistical Manual of Mental Disorders, 4th ed., text revision (DSM-IV-TR), ISBN 0890420254. Retrieved on July 22, 2008.
  3. ^ Malone DA Jr, Pandya MM. "Behavioral neurosurgery". Adv Neurol. 2006;99:241–47. PMID 16536372
  4. ^ Robertson MM. Tourette syndrome, associated conditions and the complexities of treatment. Brain. 2000 Mar;123 Pt 3:425-62. PMID 10686169
  5. ^ National Institutes of Health (NIH). Tourette Syndrome Fact Sheet. Retrieved on March 23, 2005.
  6. ^ Packer, L. Tourette Syndrome "Plus". Retrieved on February 12, 2006.
  7. ^ Doran, Morton L. The Tourette Syndrome Association, Inc., Connecticut Chapter 1998 Educators' Conference; 1998 Nov 6; Danbury, CT.
  8. ^ Sacks O. An Anthropologist on Mars. Knopf, New York, 1995.
  9. ^ Cohen AJ, Leckman JF. Sensory phenomena associated with Gilles de la Tourette's syndrome. J Clin Psychiatry. 1992 Sep;53(9):319–23. PMID 1517194
  10. ^ Bliss J. Sensory experiences of Gilles de la Tourette syndrome. Arch Gen Psychiatry. 1980 Dec;37(12):1343–47. PMID 6934713
  11. ^ Kwak C, Dat Vuong K, Jankovic J. "Premonitory sensory phenomenon in Tourette's syndrome". Mov Disord. 2003 Dec;18(12):1530–33. PMID 14673893
  12. ^ a b c "The Tourette Syndrome Classification Study Group. Definitions and classification of tic disorders". Arch Neurol. 1993 Oct;50(10):1013–16. PMID 8215958 Full text, archived April 26, 2006.
  13. ^ Dure LS 4th, DeWolfe J. Treatment of tics. Adv Neurol. 2006;99:191-96. PMID 16536366
  14. ^ a b c d Singer HS. "Tourette's syndrome: from behaviour to biology". Lancet Neurol. 2005 Mar; 4(3):149–59. PMID 15721825
  15. ^ Scamvougeras, Anton. "Challenging Phenomenology in Tourette Syndrome and Obsessive–Compulsive Disorder: The Benefits of Reductionism". Canadian Psychiatric Association (February 2002). Retrieved on June 5, 2007.
  16. ^ Zinner SH. Tourette disorder. Pediatr Rev. 2000 Nov;21(11):372-83. PMID 11077021
  17. ^ Adult-onset tic disorder, motor stereotypies, and behavioural disturbance associated with antibasal ganglia antibodies
  18. ^ Freeman, R. Tourette syndrome: minimizing confusion. Retrieved on February 18, 2006.

Further reading


 
Translations: Tic
Top

Dansk (Danish)
n. - nervøs trækning
v. intr. - have nervøs trækning

Nederlands (Dutch)
zenuwtrekje

Français (French)
n. - tic
v. intr. - avoir un tic, faire des tics

Deutsch (German)
n. - nervöse Muskelzuckung
v. - unter einer nervösen Muskelzuckung leiden

Ελληνική (Greek)
n. - (φυσιολ.) νευρική σύσπαση, τικ

Italiano (Italian)
tic

Português (Portuguese)
n. - contração espasmódica (f), tique (m)

Русский (Russian)
тик

Español (Spanish)
n. - tic
v. intr. - tener un tic

Svenska (Swedish)
n. - tic (med.)

中文(简体)(Chinese (Simplified))
痉挛, 局部的抽筋, 抽筋

中文(繁體)(Chinese (Traditional))
n. - 痙攣, 局部的抽筋
v. intr. - 痙攣, 抽筋

한국어 (Korean)
n. - 안면 경련, 병적인 집착
v. intr. - 안면 경련이 일다

日本語 (Japanese)
n. - チック, 三叉神経痛性チック

العربيه (Arabic)
‏(الاسم) تقلص لا أرادي في عضلات ألوجه, ألعرة‏

עברית (Hebrew)
n. - ‮עווית חוזרת ונשנית (בייחוד של שרירי-הפנים), התכווצות-שרירים, טיק‬
v. intr. - ‮היה בעל עווית לא-רצונית (בייחוד בפנים), עשה עוויתות בלתי-רצוניות בפניו‬


 
 

 

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