Information Section: Conditions
Condition: Tourette's Syndrome
Article: Primer on Tourette's Syndrome
Source: Leslie E. Packer, PhD
File Last Updated: February 2009

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Article Table of Contents

What is a Tic?

A tic is usually defined as a brief, repetitive, purposeless, nonrhythmic, involuntary movement or sound. Tics that produce movement are called "motor tics," while tics that produce sound are called "vocal tics" or "phonic tics."  

Tics tend to occur in bursts or "bouts." A child with an eye blinking tic, for example, will exhibit a bout of eye blinking, and not just one eye blink.  

Tics are often characterized by whether they are "simple" or "complex." A simple tic involves one muscle group or one simple sound. Many simple motor tics are associated with the face, head, and neck region, such as eye blinking, head jerking, shoulder shrugging, mouth grimacing, etc. Simple vocal tics include throat-clearing sounds, grunting, sniffing, and coughing.  

In contrast to simple tics, a complex tic involves a coordinated movement produced by a number of muscle groups (complex motor tic) or a linguistically meaningful utterance or phrase (complex vocal tic). As examples, complex motor tics can involve touching objects or other people, jumping up and down, spinning around, or even more complex motor sequences such as imitating someone else's actions (echopraxia) or exhibiting inappropriate or taboo gestures or behaviors (copropraxia). Complex vocal tics may involve having to repeat one phrase over and over, whether it is something one heard (echolalia) or one's own last words (palilalia). A chart of common tics is presented in a separate table.  

In addition to tics that we can see and hear, some people report having "internal" or nonobservable tics of internal organs, but those reports are anecdotal and there has been no research to explore these reports.  

Tics are generally understood to be "involuntary" or "unvoluntary."  The latter term may be more consistent with the experiences of adults with TS who report that on some level, they feel like they are choosing to release the tics or "let them out." The majority of adults in one sample described their tics as a "voluntary response" to an "involuntary sensation." Most young children would probably describe their tics as involuntary, however, and not being under their control. The issue of whether tics are really "Voluntary" or not has important implications for treatment as well as parenting and educational accommodations or interventions. At the present time, I think the safest approach is to view them as involuntary in children under the age of 8-10, and unvoluntary but possibly modifiable in those who are older. The fact that they may be modifiable, however, does not mean that we can assume that an older child, teen, or adult would be able to modify them on their own without training or support.

The Tic Spectrum and Tourette's Syndrome

Tic conditions represent a spectrum ranging from a simple tics that lasts only weeks or a few months to situations in which there are many tics that change in their anatomic location and frequency over time and tics are present for more than a year. Within each type of tic condition, there is also a spectrum of severity from mild and infrequent to severe and frequent. 

A significant minority of all children will experience one, or even a few, tics at some point in their development. If tic(s) are present for less than a year and do not recur, we say that the child has a "transient" tic condition. The transient tic condition observed in children is generally benign and usually does not require treatment. 

If there is a history of a number of tics that have been present -- even if not continuously -- for more than a year, we say that there is a "chronic" tic condition. A chronic motor tic condition is one in which the individual has one or several motor tics on and off for more than a year. A chronic vocal tic condition is one in which the individual has one or a number of vocal tics on and off for more than a year. 

If the individual has a history of a number of motor tics and at least one vocal tic, and tics have been present on and off for more than a year, then the individual may have Tourette's Syndrome (TS). The word "may" is important, because there are other conditions that could produce multiple tics without the individual having Tourette's Syndrome.  

As you read online or offline, you may see references to "Tourette's Disorder" or "Gilles de la Tourette Syndrome." These are just other names for TS, and there is no difference in meaning.

How is Tourette's Syndrome Diagnosed?

Currently, there is no brain test or laboratory test to determine if someone has Tourette's. The diagnosis is a clinical one, which means that it's based on the professional taking a careful history, observing the patient, and arranging for any tests that might be necessary to rule out other conditions that could look like Tourette's or that could cause tics.  

Although many people who have Tourette's Syndrome or who are in the professional field feel that there is more to Tourette's Syndrome than just the tics and would include obsessions, compulsions, and other features as being part of Tourette's, for now, we will use the term as it is defined in the Diagnostic and Statistical Manual (DSM-IV or DSM-IV-TR, the revised version) since that is the primary reference that U.S. mental health professionals use in making diagnoses.  

To simplify the diagnostic criteria for Tourette's, let us focus on the criteria that most mental health professionals really do consider: 

  • Both multiple motor tics (i.e., more than two motor tics) and one or more vocal tics have been present at some time, although not necessarily at the same time or continuously;
  • The tics occur many times a day (usually in bouts) nearly every day or intermittently throughout a period of more than 1 year;
  • Other causes of tics have been ruled out (see the next section for other conditions that can produce tics)
  • Age of onset before age 18.

 Years ago, it was common for physicians to put patients through a lot of neurological testing such as EEGs before making the diagnosis of TS. Today, many physicians do not order any tests unless there is some indication that other conditions can only be ruled out that way. Do not be surprised, therefore, if the diagnosis is made after the physician takes a detailed history and performs a neurological examination in the office. A neurological examination involves checking the cranial nerves and asking the patient to perform certain tasks or activities -- no sophisticated tests or instruments are required for that.

What Other Conditions Can Produce Tics?

There are a number of medical conditions that can produce tics or mimic Tourette's: 

  • Sydenham's Chorea
  • Wilson's Disease
  • tardive dyskinesia
  • Lesch-Neyhan Syndrome
  • cerebral palsy
  • Huntington's disease
  • postviral encephalitis
  • neuroacanthocytosis
  • stimulant medications such as methylphenidate hydrochloride (Ritalin) may also produce tics or unmask tics in some children
  • head injury
  • infections (speculative, see below) 

Depending on the patient's history, the clinician's observations, and the physical examination, the physician may order some tests to rule out some of these other conditions.  

Tics are also seen in association with other conditions such as Attention Deficit Hyperactivity Disorder, Autism Spectrum Disorders, including Asperger's Syndrome, and Obsessive-Compulsive Disorder. If the tics are mild and infrequent, they may not warrant a separate diagnosis, but if the tics are problematic for the child, then they may warrant diagnosis and treatment.  

Over the last 16 years, some intriguing but controversial studies have suggested that in some cases, streptococcal ("strep") infections may trigger an acute-onset of TS or Obsessive-Compulsive Disorder or may trigger a dramatic worsening of symptoms in individuals who already have TS and/or OCD. For those who want to read more about this topic or who first noticed their child ticcing after a recent infection, see the "PANDAS" section of this web site. If the physician suspects that PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections) is responsible, specialized blood tests may be ordered.

Information Section: Conditions
Condition: Tourette's Syndrome
Article: Primer on Tourette's Syndrome
Source: Leslie E. Packer, PhD
File Last Updated: February 2009

Article Page   1   2    3    4   

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