Overview of Tourette’s Syndrome
by Leslie E. Packer, PhD, 1998 (last Updated March 2015)
Article Table of Contents:
* What Is a Tic?
* Tic Spectrum and Tourette’s Syndrome
* How is Tourette’s Syndrome Diagnosed?
* What Other Conditions Can Produce Tics?
* Tics and Tourette’s Are Not Rare!
* How Does the Individual Experience Tics?
* Can Tics be Suppressed?
* How Does TS Usually Start?
* Tourette’s Over the Life Span
* What Other Conditions are Associated with TS?
* So What’s That Cursing Stuff?
* Psychosocial Consequences of TS and Quality of Life Issues
* Educational Consequences of Tourette’s Syndrome
* What Causes Tourette’s Syndrome?
* Stress, Emotions, and TS
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 (pdf) 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 and the individual’s awareness of their tics both have important implications for treatment as well as parenting and educational accommodations or interventions.
The Tic Spectrum and Tourette’s Syndrome
Tic conditions represent a spectrum ranging from a simple tic 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 range 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 might 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. When the DSM was revised, the DSM-5 now refers to transient tic disorder as provisional tic disorder. For a person to be diagnosed with this disorder, he or she must:
- have one or more motor tics (for example, blinking or shrugging the shoulders) or vocal tics (for example, humming, clearing the throat, or yelling out a word or phrase).
- have been present for no longer than 12 months in a row.
- have tics that start before he or she is 18 years of age.
- have symptoms that are not due to taking medicine or other drugs, or due to having a medical condition that can cause tics (for example, Huntington disease or postviral encephalitis).
- not have been diagnosed with TS or persistent motor or vocal tic disorder.
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, but no vocal tics. 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, but no motor tics. When the DSM was revised, the DSM-5 changed the “chronic” label to “persistent.” For a person to be diagnosed with a persistent tic disorder, he or she must:
- have one or more motor tics (for example, blinking or shrugging the shoulders) or vocal tics (for example, humming, clearing the throat, or yelling out a word or phrase), but not both.
- have tics that occur many times a day nearly every day or on and off throughout a period of more than a year.
- have tics that start before he or she is 18 years of age.
- have symptoms that are not due to taking medicine or other drugs, or due to having a medical condition that can cause tics (for example, seizures, Huntington disease, or postviral encephalitis).
- not have been diagnosed with TS.
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. For a person to be diagnosed with Tourette Syndrome, he or she must:
- have two or more motor tics (for example, blinking or shrugging the shoulders) and at least one vocal tic (for example, humming, clearing the throat, or yelling out a word or phrase), although they might not always happen at the same time.
- have had tics for at least a year. The tics can occur many times a day (usually in bouts) nearly every day, or off and on.
- have tics that begin before he or she is 18 years of age.
- have symptoms that are not due to taking medicine or other drugs or due to having another medical condition (for example, seizures, Huntington disease, or postviral encephalitis).
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 conclusively prove 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.
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
- stimulant medications such as methylphenidate hydrochloride (Ritalin) may also produce tics or unmask tics in some children
- head injury
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 and Tourette’s are Not Rare Conditions
For many years, TS was considered to be a rare disorder, but tics and TS are now recognized as fairly common childhood-onset conditions. There is still some controversy about its rate in the general population. The estimates you may read in the literature depend, in part, on how old the subjects were in the study (studies of adults tend to significantly underestimate rates in children), and whether the subjects were drawn from clinical settings or from the general community, to name but two factors. That said, a study by Kurlan, McDermott, et al. (2001) indicates that over 19% of children in regular education classes have tics and over 23% of children in special education classes have tics. Their study also indicated that almost 4% of children in regular education meet diagnostic criteria for Tourette’s Syndrome, while over 7% of children in special education have TS. In most cases, tics and/or TS were usually undiagnosed. These rates are somewhat higher than what was reported in UK schools, and significantly higher than what has been reported in a recent review and metanalysis that reported a population prevalence estimate of 0.3% to 0.9% (Scharf et al., 2015).
A review of data on TS from an international perspective and across the life span suggests that the prevalence of TS in the general population is slightly under 1% (Robertson, 2008).
Although there has been considerable variability in estimates of rates in children in mainstream schools, all recent studies have reported higher rates in special education settings than in mainstream settings. The disproportionate representation of children with TS in special education does not prove that it is the tics or TS that are leading to school problems, however, and parents of children with tics should not fear that the tics, by themselves, will lead to a placement in special education. At the present time, and based on limited available research, it may well be the case that children with uncomplicated TS are not generally in need of special education (as much as accommodations) although those who have TS in the presence of other conditions such as Attention Deficit Hyperactivity Disorder may be represent a population with increased need for special education.
Can Tics be Suppressed?
Many individuals report a sensory basis for their tics — they feel the need to tic building up as a kind of tension in a particular anatomical location, and they feel that they consciously choose to release it. The sensations and internal events leading up to the expression of the tic are often referred to in the literature as “premonitory sensory phenomena,” “urges,” or by some other term. Prado and her colleagues (2008) review the literature on these experiences. These urges or internal sensations or perceptions that something is “not just right” precede tics and compulsive behaviors.
Although one early study reported that 28% of patients with TS reported such urges or phenomena (Chee & Sachdev, 1997), a study by Kwak et al. (2003) reported that over 90% of their sample reported premonitory urges prior to motor tics, with participants reporting that their most common sensation was an urge to move and an impulse to tic (“had to do it”).
Tics can sometimes be suppressed, but most people’s experience is that the tics will eventually be released. Thus, if we were to ask someone who felt that the tics were consciously released to not tic, we might observe that they could suppress a tic for a while, but eventually, they would release it.
What happens if the individual tries to suppress the tics? Some individuals have no control at all over their tics, while others have varying degrees of control. Most adults report that their ability to modify or suppress their tics improved as they matured, and recent research supports the notion that as the child matures, their awareness of their tics and their ability to suppress them increase.
With young children, it is important to remember that the child may not be aware of their tics, and even if they are aware, they may have no ability to suppress them. Asking a young child who has tics to suppress them is generally not a good idea because the effort involved in suppressing the tics will distract the child from tasks requiring their attention and may decrease their accuracy on the task (cf, Conelea & Woods, 2008) .
Parents frequently report that children or adolescents who try to suppress their tics in school all day (with varying degrees of success) will come home from school, walk in the door, and explode in tics — often accompanied by a lot of emotional behaviors. For years, many of us considered these explosions of tics to represent an actual worsening of tics due to inhibition or suppression of tics during the school day. Research, however, casts some doubt on that interpretation. Data from some studies suggest that even when tics are being consciously and actively suppressed, there is no rebound effect (Himle & Woods, 2005; Verdellen et al., 2007).
Keeping in mind that each child is unique, the parents and child are often the teacher’s best source of information about a particular child’s tics and patterns. But if you are a parent or teacher who is thinking of discussing the child’s tics with them, also keep in mind that not all young children are aware of their tics. When a child or adult denies ticcing it may not mean that they are in “denial.” They may really be unaware of their movements or sounds. And just talking about their tics may induce a temporary worsening of their tics (Woods, Watson, et al. 2001).
Banaschewski et al. (2003) conducted a survey on premonitory sensory phenomena (PSP) and suppressibility of tics in children and adolescents. Over a third of the children and adolescents in the sample reported experiencing PSP, and almost two-thirds reported being able to suppress their tics. Slightly more than one quarter of the sample (28%) reported both PSP and the ability to suppress tics, indicating that the majority of children and teens do not have awareness of sensory urges building up with the ability to suppress their tics. Changes in reports were noted at two ages developmentally. At age 10, there seemed to be an increased ability to suppress tics, and at age 14, there was more reporting of PSP. It is important to note that awareness of premonitory sensory urges did not precede ability to suppress tics, but rather, ability to suppress tics actually preceded awareness of (or experience of) premonitory sensory urges.
If tics are actively suppressed, what happens to any preceding urges? Do they diminish over time or do they intensify and then diminish, or what? Woods and colleagues found that suppressing tics when reinforcement was provided was associated with intensified urges during tic suppression for 5-minute periods (Himle & Woods, 2007). Their data provide some support for the notion that people tic to decrease or alleviate the unpleasant sensation that is building up. But what if we allow the period of tic suppression to go even longer? Would the urge continue to build or would it eventually extinguish? Verdellen et al. (2008) provide data indicating that the urge does decrease both within 2-hour sessions and between sessions using an Exposure-Response Prevention treatment. Exposure-Response Prevention for tics is the same approach used in treating Obsessive-Compulsive Disorder.
What factors predict ability to suppress tics or severity of sensory urges during training? Data provided by Woods, Himle, et al. (2008) suggest that errors of ommission on a continuous performance task correlated with ability to suppress tics, while Verdellen et al. (2008) found that tic frequency at baseline – but not tic severity – was correlated with reductions in frequency of tics and severity of sensory urges during training sessions.
So…. can tics be actively suppressed without any rebound effects or worsened sensory urges? The answer appears to be “Possibly, but not, perhaps in very young children, and not without risking distracting the person from attention-demanding tasks.” Hopefully, longer-term studies will shed light on whether suppression can become more automatic and less of a risk of distracting the individual. In any event, these studies offer hope and promise of nonmedication treatments that may be of value, and suggest that what we all described as “involuntary” may be more modifiable than we had recognized.
How Does Tourette’s Syndrome Usually Start?
In the majority of cases, the first tics are usually simple motor tics of the head, face, neck, and shoulder region or simple phonic tics. Eye blinking is the most common ‘first tic,’ but it is important to remember that having this tic does not necessarily indicate that the child will develop Tourette’s, as approximately 1 in every 5 children will have a tic at some point in their development.
The tic increases in frequency and severity for a few weeks to a month or so, then starts to subside and eventually disappears. Unless the parents or teachers are already aware of a history of tic disorders in the family or are familiar with tics or Tourette’s Syndrome from other sources, the first tics are not likely to be recognized as tics.
Following the disappearance of the first tic (or tics), a few months may go by and then the tic may re-emerge or a new tic may appear. The tic (or tics) will increase in frequency and severity over weeks and then subside and disappear.
The pattern of new tics emerging and worsening (“waxing”) followed by a symptom decrease (“waning”), a relative “lull,” and then new tics emerging and starting to increase in severity and frequency (repeat cycle) is characteristic of TS. Indeed, this variability is the hallmark of TS, and is frequently a source of confusion for parents and educators.
While the average age of onset of TS is 6 – 7 years old, there are many cases where parents later realized that their child’s tics had actually started much younger. In almost all cases, TS emerges before age 18, but there are exceptions.
In some children, TS may emerge more forcefully or explosively. A child with no recognized history of tics may suddenly erupt in a number of tics within a very short period, or the child may present with complex tics instead of simple tics. Another situation in which severe tics or symptoms may emerge is those cases that appear to be related to infections.
Because of the changing anatomical location of the tics, the long tic-free periods between bouts of tic worsening, and because tics are often misunderstood as being due to other things, it used to take years before someone was properly diagnosed. In the last decade, however, we have seen evidence that children are being diagnosed sooner, but the delay depends on a number of factors, including awareness by doctors, presence of other disorders, and age of the child at time of onset of symptoms. For example, in Israel, the median delay to diagnosis was only 6 months, but it was longer in cases where vocal tics were the first presentation or where the child was older. The co-occurrence of other disorders resulted in a shorter delay to diagnosis (Shilon et al., 2008). In Denmark, the median delay to diagnosis was 2.8 years (Debes et al., 2008), while in Poland, the delay in diagnosis was on the order of 3.9 years (Janik et al., 2007).
The Course of Tourette’s Over the Life Span
Most cases of TS are thought to be “mild,” meaning that the individual does not seek treatment and/or does not experience significant interference in their life from their tics. If tics become problematic, you may wish to consider treatment options (treatment options are discussed in the article, “Treatment of Tics and Tourette’s Syndrome,” also on this web site.
In the first years after tics first emerge, many people report that the waxing periods tend to worsen from one waxing cycle to the next. The child may experience more tics and/or more severe tics over time, and there seems to be a tendency for things to get worse before they get better. The good news is that for many individuals, the tics will ease up significantly or go into remission in the teen years. A report by Leckman et al. (1998) suggests that tics seem to reach their peak severity between the ages of 10 – 12 in the majority of cases, and that by age 18, half of the children may be virtually tic-free, with other children showing significant improvement.
In another study on changes over time, Burd, Kerbeshian, et al. (2001) followed 39 out of 73 patients who had been diagnosed with TS as children in 1984-1985. They reported that symptom severity decreased by 59%, global functioning improved by 50%, and the average number of comorbidities (other conditions also present) decreased by 42%. Similar to findings by Leckman, they reported that 44% of the patients were essentially symptom free at follow-up; only 22% were on medication as adults. In their sample, improvement in males was more variable than improvement in females, but overall, males demonstrated more improvement than females.
Patient reports of symptom improvement are often subjective, and a study by Pappert, Goetz, et al. (2003) suggests that many adults report being tic-free when they actually still have tics. In this study, the investigators compared videotapes of 31 adults with TS to the same individuals’ videotapes during childhood.They found that motor tic severity significantly decreased by adulthood, as did objective measures of overall tic disability. In contrast to previous studies that had relied on subjective reports, these investigators found that 90% of the adults still had tics. As a group, the adults were somewhat inaccurate in their self-assessment in the sense that those who reported having tics did, in fact, display tics, but 50% of those who reported being tic-free also displayed objective evidence of tics. The investigators suggest that tics may persist into adulthood more than studies using subjective reporting might suggest, but that when adults report improvement or being tic-free, it’s probably because of a significant improvement in motor tic severity.
While the majority of individuals seen in clinics appear to have a significant remission or improvement in tics, there are people who do not show improvement with age or whose tics worsen in adulthood. As an example, Pappert et al. (2003) computed a “global tic impairment” score based on five tic factors (number of body areas with tics, motor tic frequency, motor tic severity, phonic tic frequency, phonic tic severity) and compared the childhood global tic impairment scores to the scores of the same individuals as adults. For their sample, they found that that 10 of the 31 adults in their study had worse objective global tic disability scores as adults. There was a reliable and moderately strong correlation between the severity of objective global tic impairment at childhood and the severity of objective global tic impairment in adulthood.
A number of adults have reported that either their TS re-emerged after decades of being tic-free or that they are beginning to suffer adverse physical effects after years of severe ticcing. Unfortunately, while most clinicians seem to be aware of this, no one seems to be doing any long-term research to address these compelling adult needs and only a handful of published articles even refer to the re-emergence of TS after decades of quiet.
Other Conditions Associated With Tourette’s Syndrome
A significant percentage of individuals with TS also have symptoms of other disorders or conditions. As you read more about Tourette’s, you will probably encounter terms like “co-morbid” or “associated,” so I will begin by defining those terms as they are used on this web site. Two conditions are “comorbid” when they are present in the same individual. Two conditions are “associated disorders” when there appears to be a significant probability that the two conditions will occur together at a higher rate than we would expect by chance.
When I first began talking to people about TS, I realized that when some people would say “That’s a symptom of my son’s TS,” they weren’t talking about tics but about features or symptoms of disorders such as Attention Deficit Hyperactivity Disorder or obsessive-compulsive symptoms. So to decrease confusion in our communication, in 1991, I introduced the term “TS+” to refer to individuals who have TS plus features of one or more other disorders such as Attention Deficit Hyperactivity Disorder (ADHD), Obsessive-Compulsive Disorder (OCD), or non-OCD anxiety, to name but some of the conditions that may be associated with or frequently comorbid with TS. The goal was to help people remember that not everything may be a tic of TS, and that the child may have other conditions that may be responsible for any impairment they are experiencing.
“TS+” is not a technical or diagnostic term, but rather a convenient way to remind ourselves that there is often other things affecting a child who has been diagnosed with TS. This is particularly evident when we examine school functioning. In the vast majority of cases I’ve dealt with over the years, it is seldom the tics that are the child’s or teen’s biggest problem.
Unfortunately, and despite my best efforts to remind people not to attribute everything to TS when it may be due to something else, all too many people continue to describe people with TS as having a variety of problems that may not be due to TS at all, but rather to some other condition.
So, what other disorders tend to be associated with or frequently comorbid with TS? In a community-based study of school children that employed direct interviews and standardized rating scales for 1596 children, Kurlan and his colleagues found that OCD, ADHD, separation anxiety, overanxious disorder, simple phobia, social phobia, agoraphobia, mania, major depression, and oppositional defiant behavior occurred significantly more frequently in the children who had tics compared to their non-tic peers [Kurlan, Como, Miller, et al., 2002]. But are all of these conditions really associated with tics, or is it the case that some of them are just associated with each other?
A new study by the Tourette Syndrome Association International Consortium for Genetics (Hischtritt, 2015) sheds some light on lifetime prevalence and comorbidity rates. Some of the key findings include:
- The lifetime prevalence of any psychiatric comorbidity among individuals with TS was 85.7%;
- 57.7% of individuals with TS had 2 or more psychiatric disorders.
- 72.1% of individuals with TS met DSM-IV-TR diagnostic criteria for OCD or ADHD.
- Other disorders, including mood, anxiety, and disruptive behavior, each occurred in approximately 30% of the participants.
- The age of greatest risk for the onset of most comorbid psychiatric disorders was between 4 and 10 years, with the exception of eating and substance use disorders, which began in adolescence.
- TS was associated with increased risk of anxiety and decreased risk of substance use disorders independent from comorbid OCD and ADHD; however, high rates of mood disorders among participants with TS (29.8%) may be accounted for by comorbid OCD.
- Parental history of ADHD was associated with a higher burden of non-OCD, non-ADHD comorbid psychiatric disorders.
- Genetic correlations between TS and mood, anxiety, and disruptive behavior disorders may be accounted for by ADHD and, for mood disorders, by OCD.
The fact that over 85% of individuals with TS have at least one comorbid disorder should serve as a reminder of the need to think in terms of TS+ and not just “TS.”
So What’s That “Cursing” Stuff?
Although Tourette’s has been stigmatized by the media as the “Cursing Disease,” only a minority of individuals who have Tourette’s experience unvoluntary outbursts of socially inappropriate or taboo expressions known as coprolalia. A number of studies suggest that less than half of individuals seen in clinics that specialize in Tourette’s may have this type of symptom (cf, Kobierska et al., 2014), and that it occurs in less than 10% of children with TS (cf, Goldenberg et al., 1994).
Coprolalia is not required for diagnosis of TS.
Some coprolalia is immediately obvious as a tic: the individual may have one obscene or socially unacceptable word or phrase that they blurt out repetitively and inappropriately in the middle of speech. Other coprolalia may be more difficult to recognize as a symptom since it is often triggered by cues in the immediate environment. As an example, an individual who has coprolalia may just blurt out whatever is inappropriate or unacceptable in a particular situation. Walking down the street, the sight of a buxom woman may lead to “Big boobs!”
Psychosocial Consequences of Tourette’s
TS is not a fatal disorder, but it can be a stigmatizing one for those who live in environments that do not or cannot support or tolerate anyone who might appear a bit different.
In the author’s experience, parents are often most concerned about the psychosocial impact of TS, and worry about “How will other children view my child? Will teachers think he’s crazy? Will he be teased, rejected, or bullied because of his tics?” Teenagers who are already struggling with the agonies of adolescence may feel particular concerns as to how their symptoms may affect their attractiveness to others or their ability to form friendships and romantic relationships.
Even children or adults with extremely mild tics may experience psychosocial consequences. Two surveys of parents of children with TS indicate that many children are teased because of their tics, and a subset are actually rejected because of their tics (see Packer, 2005). Even young children may reject peers for their tics. While peer education may help, and there is some evidence supporting its use, gaps in the research leave us without clear evidence that peer education will actually change the behavior of peers, even if they report improved attitude or intention-to-behave.
In light of data confirming peer rejection due to tics, it is not surprising that some studies of quality of life (QOL) measures would indicate a difference between youth with TS and those without (cf, Eddy et al., 2011). Decreased QOL is also reported in studies of adults with TS.
Although most studies looking at QOL look at what factors correlate with QOL or whether reducing tic severity improves QOL, a recent study evaluated a cognitive behavioral intervention (“Living with Tics”) in reducing tic-related impairment and improving quality of life (McGuire et al., 2015). The intervention consisted of up to 10 weekly sessions targeted at reducing tic-related impairment and developing skills to manage psychosocial consequences of tics. Youth in the treatment condition experienced significantly reduced clinician-rated tic-impairment relative to the wait-list control group, and reported improved quality of life.
Educational Consequences of Tourette’s Syndrome
Does the presence of tics or Tourette’s Syndrome impact educational functioning? All available research and clinical experience suggest that it does, but the assessment of its impact has been somewhat muddied by the presence of comorbid conditions.
Pappert, Goetz, et al. (2003) found that 52% of children seen in their clinic experienced social or educational dysfunction. Of these, 39% required special education placement, 10% had been retained at least 1 year in school, and 29% experienced disciplinary problems. Their findings are consistent with other published reports from tertiary clinics, but it is their follow-up data on these children as adults that is of special interest and concern here. Whereas half the sample experienced significant social and education dysfunction as children, (only) 32% of the same sample experienced social or education dysfunction as adults. On a positive note, all of the sample participants had completed high school and at least two years of college (adult sampling was conducted while the individuals were in their 20’s). The investigators found that 71% of the adults were currently employed or pursuing their education. Of the adults who had social or educational dysfunction as children, 50% had social or education dysfunction as adults, and 13% of children who had not experienced education or social dysfunction went on to develop social or education dysfunction. Out of their sample of 31, then, while the majority were doing well and were well-integrated in their communities, over one quarter of the adults were disabled with problems that included alcohol abuse, unemployment or criminal activity. That these measures did not correlate with tic severity measures but did correlate with early childhood dysfunction suggests that early and effective interventions for comorbid conditions (perhaps even more so than for tics) may impact on the prevention of dysfunction in adulthood.
When reading reports on the educational impact of TS, be careful to consider whether the sample consists of youth with TS-only or TS+. If your child only has tics without any other comorbid symptoms or conditions, they may do quite well in a regular classroom as long as appropriate accommodations are made for interference they may experience from their tics. Also consider whether your child suffers from fine motor control impairment or impaired visual-motor integration, as those two functions have a significant impact on academic functioning. The school’s occupational therapist and psychologist can screen for impairment in those domains.
What Causes Tourette’s Syndrome and Is There a Cure?
Tourette’s Syndrome appears to be familial (i.e., it “runs” in families) in the vast majority of cases, suggesting a genetic component or an inherited vulnerability to it, but our understanding of the mode of genetic transmission is incomplete. At the present time, it appears that there is likely to be a significant genetic factor, although prenatal, perinatal, autoimmune, and environmental factors may contribute to or modulate the severity of symptoms.
Gender is also linked to expression of TS: boys are significantly more likely to develop TS than are girls. One question adults often ask when they are thinking of starting a family is whether there are any tests such as amniocentesis that can screen or test a fetus for Tourette’s Syndrome. The answer is “not at this time.”
While we cannot yet predict the severity of tics based on family, family history appears to be correlated with severity of obsessive-compulsive behaviors that are often seen in conjunction with Tourette’s Syndrome. Lichter et al. (1999) reported that more severe obsessive-compulsive symptoms were associated with bilineal transmission (i.e., the presence of probable or definite tics or obsessive-compulsive behaviors in both parents or relatives on both sides of the family) than in unilineal transmission (family history on only one side of the family). Children who had a family history of tics or obsessive-compulsive behaviors on both sides of the family were not only more likely to have more severe obsessive-compulsive behaviors, but they were also more likely to exhibit self-injurious behaviors.
There is no cure for Tourette’s Syndrome at the present time.
In addition to what appears to be a genetic vulnerability or component, some research also suggests that prenatal events or factors (such as maternal smoking, drug use, exposure to toxins) and perinatal events (such as jaundice, infections) may be associated with severity of TS. While some factors do not necessarily cause TS, they may be correlated with symptom severity in children who do develop TS. Some of the environmental factors that may affect symptom severity are mentioned later in this primer in the section on stress.
Stress and Tourette’s Syndrome
While stress does not cause TS, it would seem almost intuitively obvious that stressors might make the symptoms worse for at least some individuals with tics. Stressors might take the form of environmental or ambient weather factors such as temperature, illness factors such as infection, foods or substances like caffeine, or they might include potential psychosocial stressors such as hassles on the job or in school, demanding environments, time pressure, breakup of romances or marriages, death in the family, or even small life events.
Environmental factors have also been noted to be significantly correlated with tic severity, and children or adults with TS may find that their symptoms are worse during allergy seasons, or when they are too hot. Because correlations between physiological responses and ambient environmental factors may not be present for all individuals and because such correlations may also vary by region and direction of correlation in individuals exposed to the same environmental conditions, more research is needed before we can truly understand the contribution of ambient environmental factors to variability in tic severity.
One other stressor that has recently been investigated is the presence of allergic diseases. A study by Chang et al. (2011) using a large Taiwanese database found a significant correlation between allergic diseases and TS whereby children with allergic rhinitis were twice as likely to have TS as non-allergic controls. The greater the number of allergic comorbidities and the older the child, the greater the risk of TS. Their study did not correlate tic severity or frequency with the presence or absence of specific allergic symptoms, however. If we find that allergy symptoms correlate with tic symptom worsening, then does treating the allergic condition reduce tic symptom severity? Instead of just suffering mild seasonal allergy symptoms, should we be treating them more aggressively?
If stress does make the symptoms worse for a particular child or adult, does relaxation make the symptoms better? While relaxation may lead to less tics, some people tic more as they start to relax and let all the tics out. Similarly, a child or adult may come home from school or work and seemingly “explode” in tics for the first hour or so. Under such circumstances, the most likely explanation is that they are “letting it all out.” Tics generally decrease significantly or disappear completely during sleep.
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