Tourette’s Syndrome (TS) involves the chronic presence of both motor and vocal tics (though not always at the same time). A tic is often characterized as being a sudden, rapid, recurrent, nonrhythmic motor movement or vocalization,1 often preceded by a premonitory sensation.2 While not everyone who experiences tics will have Tourette Syndrome, those diagnosed tend to have a persistent presence of tics starting early in childhood.
What Is Tourette Syndrome?
Tourette Syndrome is a specific disorder in the Diagnostic and Statistical Manual of Mental Disorders (DSM 5)1 involving the presence of one or more vocal tic at some time during the course of the individual’s life. Importantly, these unusual vocal or motor movements do not need to occur at the same time. It is not uncommon for tics to wax and wane in frequency, intensity, and duration throughout the lifetime; this variability can, at times, make TS a challenging disorder to assess and treat.
There are also several different medical and psychiatric conditions that can also co-occur with tic disorders, including:
- Attention Deficit Hyperactivity Disorder (ADHD)
- Obsessive-Compulsive Disorders (OCD)
- Disruptive Behavior Disorders
- Depression/Anxiety
- Bipolar Disorder
- Learning Disabilities
- Autism Spectrum Disorders
- Substance Use Disorders
What Are Motor and/or Vocal Tics?
As previously mentioned, tics are sudden, rapid, recurrent, nonrhythmic motor movements or vocalizations.1 Tics can include almost any muscle group or type of vocalization; however, the most common involve eye blinking or throat clearing. Some individuals with tics can be symptom-free for periods of days or even months, and are sometimes context-specific (i.e. they tend to occur with higher frequency/intensity in specific situations).
Tics are categorized as being either simple (use of fewer muscle groups and of short duration, such as milliseconds) or complex (use of multiple muscle groups and of longer duration, such as seconds).
Simple motor tics can include:
- Eye blinking
- Finger/arm extensions
- Lip pursing
Simple vocal tics can include:
- Throat clearing
- Sniffing
- Grunting
Complex motor tics can include:
- Head turning
- Shoulder shrugging
- Arm flailing
Complex vocal tics can include:
- Repeating one’s own sounds and/or words (palilalia)
- Repeating previously heard words/phrases (echolalia)
- Uttering socially unacceptable words (coprolalia)
Onset and Course of Tics
Onset of tics typically occurs between ages 4-6.1 Tics tend to be most severe and functionally impairing between ages 10-12, with a gradual decline in intensity during adolescence.2 While the expression of tics can extend into adulthood, many adults report diminished symptoms with decreased severity. A small proportion of adults experience worsening tic symptoms into adulthood. There is some report in the medical literature of adult-onset tic disorders, though most can either be attributed to recurrences of childhood onset tics, or are the result of insults to the brain or other acquired conditions.3
Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infection (PANDAS)
The hypothesis that chronic, recurrent tics and OCD-like behaviors can occur following infection with group A-Beta streptococcus has still not been unequivocally confirmed by the medical community. The diagnosis of PANDAS is a clinical one, which means that there are no lab tests that can be used to confirm its existence.4 Ultimately, there is still insufficient evidence to definitively conclude that strep infection plays a causal role in the development of tics or OCD.2
Diagnosing Tic Disorders and Tourette Syndrome
There are several tic disorders listed in the DSM 5,1 all of which share characteristics including an onset occurring prior to the age of 18. In addition, the presence of tics cannot be attributed to the physical effects from a substance (e.g., cocaine) or another medical condition (e.g., Huntington’s disease).
The following are disorders listed in order of their complexity:1
- Provisional Tic Disorder is a diagnosis given following the occurrence of a single or multiple motor and/or vocal tics. These tics need to have been present for less than 1 year.
- Persistent (Chronic) Motor of Vocal Tic Disorder is diagnosed if single or multiple motor or vocal tics have been present in an individual, but not both motor and vocal. These tics may have waxed and waned in frequency, but they must have persisted for more than 1 year since their onset.
- Tourette’s Disorder is the most commonly known tic disorder, and is diagnosed when both multiple motor and one or more vocal tics have been present at some time in an individual. Tics may also have waxed and waned in frequency, but they must have persisted for more than one year since the first onset.
When seeking a diagnosis for a tic disorder, providers will typically take a thorough clinical history, including taking a family history for tics, ADHD, OCD, and impulse control disorders. Additional information about psychosocial stressors is often collected, and providers will inquire about the functional impact of tics. Use of neuroimaging or electroencephalography is typically not needed, though one or both might be used if there are unexpected findings from the clinical interview.2
Differential Diagnosis
While motor tics, motor stereotypy, and behavior compulsions can sometimes look similar, there are important differences. Motor stereotypy tends to be categorized as being rhythmic and repetitive, often appearing purposeful but not serving a clear adaptive function. Examples of motor stereotypy include hand flapping, body rocking, and finger-wiggling. Age of onset of stereotypies tend to be earlier than tics (typically prior to age 3), and the duration of the behavior tends to be significantly longer than tics (i.e. seconds to minutes, if uninterrupted).1,2
Compulsions are behaviors that are purposeful and ritualistic, and can be somewhat harder to differentiate from tics, as tics are thought to be more “quasi-voluntary.” If there is an easily recognized thought-process associated with an idiosyncratic behavior, such as the need to avoid contamination or performing a task until it is “just right,” the behavior may be considered more in line with a compulsion than a tic.2 In addition, goal-directed unusual behavior (e.g. hair pulling or skin picking) tend to be thought of as compulsive even if they occur at times unconsciously.
Causes of Tourette Syndrome
Current information about the causes of Tourette Syndrome suggest that it is the result of genetic and/or neurochemical imbalances and not due to an emotional illness. Research into the origins of TS suggests that it may result from a failure in development to acquire inhibitory function within the frontal-subcortical brain circuits that control voluntary movement.5 A dysfunction in dopamine neurotransmitters is also implicated in the presence of tics, particularly related to the over-release of dopamine in the basal ganglia.6 Tourette Syndrome tends to run in families, though the pattern of inheritance is complex and not yet fully understood.
Other possible contributors to the development of tics include lesions resulting from trauma, carbon monoxide poisoning,7 or stroke,8 genetic and/or neurodegenerative conditions (Wilson disease, Huntington disease), or infections of the central nervous system (viral encephalitis). Obstetric complications, older paternal age, low birth weight, and maternal smoking are also associated with increased tic severity.1
Psychosocial factors also play a role in the development, frequency, and maintenance of tics. Specifically, tics are often worsened by anxiety, excitement, stress, and exhaustion.1 Observing a gesture or sound in the environment may induce a similar response among individuals with a tic disorder, which may the behavior falsely appear as deliberate.
Treatment for Tics
There are several treatment options available to those experiencing tics including various forms of therapy and medication.
Behavior Therapy
Behavioral approaches generally target tics by teaching tic awareness (i.e. awareness training) and rewarding tic suppression via focus on alternative, often incompatible behaviors (i.e. competing response training). Habit Reversal Therapy (HRT) is a behavioral approach that focuses on mitigation of individual tics through these cognitive and behavioral methods of recognition and reinforcement of alternate behaviors.10
Although there are behavioral treatments that include additional components like relaxation and self-monitoring training (i.e., Comprehensive Behavioral Intervention for tics, CBIT), awareness training and competing response training are thought to be the most effective components of any behavioral intervention.11 Overall, the available research suggests that HRT is an effective non-pharmacological method of suppressing tics without the concern from side effects associated with the use of medication.12
Medication
Medications are typically prescribed for tics to treat tics that are significantly interfering or disabling (e.g. resulting in discomfort, stigmatization, or self-injury). However, the evidence for the use of medication in tic-suppression also suggests an influence of placebo-response.13 Alpha-2-agonists (drugs used to treat hypertension and in sedation) have been demonstrated to be moderately effective in tic reduction, and tend to be the first prescribed.2 Examples of alpha agonist drugs include clonidine and guanfacine. Additional classes of drugs used to treat the expression of tics include dopamine-blocking agents, including haloperidol, risperidone, and aripiprazole.14
These antipsychotic medications have the most strong evidence for treating tics, but the side effect profile (including weight gain, sedation and movement disorders) causes many clinicians to try the alpha-agonists first. Using medications for tics often comes down to weighing the impairments and discomfort caused by the tics versus the potential side effects of the medication.
Statistics on Tic Disorders1
Motor and vocal tics are fairly common in early childhood (occurring in as many as 1 in 5 school-aged children), though they tend to last for only a short time. During their school-aged years, approximately 3 to 8 per 1,000 will meet criteria for Tourette Syndrome. Males tend to be disproportionately affected at a ratio ranging from 2:1 to 4:1. While frequencies of identified cases have been reported to be lower in African American and Hispanic Americans, these statistics likely reflect cultural factors and access to care.
How to Get Help for Tourette Syndrome
Tourette Syndrome can be diagnosed by physicians, including pediatricians and neurologists. Psychologists and licensed therapists can also provide a diagnosis, though they will often do so in consultation with medical providers. Many TS advocacy groups highlight the importance of educating others as an initial intervention.2
Specifically, parents and children are encouraged to tell other family, friends, and teachers about Tourette Syndrome as a way of addressing misconceptions of tics as being purposeful and/or deliberately disruptive. Special accommodations may be needed in school settings due to the potential for disruption or distraction that may result from tic disorders. As diagnosed TS and tic disorders are considered a disability, students can seek special accommodations under IDEA laws protecting individuals with disabilities.
For Further Reading
There are several local, state, and national organizations that provide help and support for children and families suffering from tic disorders. Specifically, the Tourette Association of America © provides information on specialized providers, tools, support groups, and events available to patients, families, and community members.
