Tics are defined as repeated, sudden, rapid, nonrhythmic muscle movements including sounds or vocalizations. Tourette syndrome is diagnosed when people have had both motor and vocal tics for > 1 year. Diagnosis is clinical. Tics are treated only if they interfere with a child's activities or self-image; treatment may include Comprehensive Behavioral Intervention for Tics and alpha-adrenergic agonists or antipsychotics.
Tics vary widely in severity; they are common among children, many of whom are not evaluated or diagnosed. Tourette syndrome, the most severe type of tic disorder, occurs in 3 to 8/1000 children. Male to female ratio is 3:1 (1, 2).
Tics begin before 18 years of age (typically between 4 years and 6 years of age); they increase in severity to a peak at about 10 to 12 years of age and decrease during adolescence. Eventually, most tics disappear spontaneously. However, in about 1% of children, tics persist into adulthood.
Etiology is not known, but tic disorders tend to be familial. In some families, they appear in a dominant pattern with incomplete penetrance.
Comorbidities
Comorbidities are common.
Children with tics may have one or more of the following:
These disorders often interfere more with children's development and well-being than the tics do. ADHD is the most common comorbidity, and sometimes tics first appear when children with ADHD are treated with a stimulant; these children probably have an underlying tendency to tics.
Adolescents (and adults) may have
References
1. Centers for Disease Control and Prevention (CDC): Prevalence of diagnosed Tourette syndrome in persons aged 6-17 years—United States, 2007. MMWR Morb Mortal Wkly Rep 58(21):581–585, 2009.
2. Knight T, Steeves T, Day L, et al: Prevalence of tic disorders: A systematic review and meta-analysis. Pediatr Neurol 47(2):77–90, 2012. doi: 10.1016/j.pediatrneurol.2012.05.002
Classification of Tic Disorders
Tic disorders are divided into 3 categories by the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5):
Provisional tic disorder: Single or multiple motor and/or vocal tics have been present < 1 year.
Persistent tic disorder (chronic tic disorder): Single or multiple motor or vocal tics (but not both motor and vocal) have been present for > 1 year.
Tourette syndrome (Gilles de la Tourette syndrome): Both motor and vocal tics have been present for > 1 year.
Symptoms and Signs of Tic Disorders
Patients tend to manifest the same set of tics at any given time, although tics tend to vary in type, intensity, and frequency over a period of time. They may occur multiple times in an hour, then remit or barely be present for ≥ 3 months. Typically, tics do not occur during sleep.
Tics can be
Motor and/or vocal
Simple or complex
(See table Types of Tics.)
Simple tics are a very brief movement or vocalization, typically without social meaning.
Complex tics last longer and may involve a combination of simple tics. Complex tics may appear to have social meaning (ie, be recognizable gestures or words) and thus seem intentional. However, although some patients can voluntarily suppress their tics for a short time (seconds to minutes) and some notice a premonitory urge to perform the tic, tics are not voluntary and do not represent misbehavior.
Stress and fatigue can make tics worse, but tics are often most prominent when the body is relaxed, as while watching TV. Tics may lessen when patients are engaged in tasks (eg, school or work activities). Tics rarely interfere with motor coordination. Mild tics rarely cause problems, but severe tics, particularly coprolalia (which is rare), are physically and/or socially disabling.
Sometimes tics are explosive in onset, appearing and becoming constant within a day. Sometimes children with explosive-onset tics and/or related obsessive compulsiveness have a streptococcal infection—a phenomenon sometimes called pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). Many investigators do not believe that PANDAS is distinct from the spectrum of tic disorders.
Types of Tics
Type | Motor | Vocal |
|---|---|---|
Simple | Blinking Grimacing Head jerking Shoulder shrugging | Grunting or barking Sniffing or snorting Throat clearing |
Complex | Combinations of simple tics (eg, head turning plus shoulder shrugging) Copropraxia: Using sexual or obscene gestures Echopraxia: Imitating someone's movements | Coprolalia: Uttering socially inappropriate words (eg, obscenities, ethnic slurs) Echolalia: Repeating one's own or another's sounds or words |
Diagnosis of Tic Disorders
Clinical evaluation
Diagnosis is clinical.
To differentiate Tourette syndrome from transient tics, physicians may have to monitor patients over time. Tourette syndrome is diagnosed when people have had both motor and vocal tics for > 1 year.
Treatment of Tic Disorders
Comprehensive Behavioral Intervention for Tics (CBIT)
Sometimes alpha-adrenergic agonists or antipsychotics
Treatment of comorbidities
(See also the American Academy of Neurology's review summary of treatment of tics in people with Tourette syndrome and chronic tic disorders [2019].)
Treatment to suppress tics is recommended only if they are significantly interfering with children’s activities or self-image; treatment does not alter the natural history of the disorder. Often, treatment may be avoided if clinicians help children and their families understand the natural history of tics and if school personnel can help classmates understand the disorder.
A type of behavioral therapy called CBIT should be strongly considered and may help some older children control or reduce the number or severity of their tics. It includes cognitive-behavioral therapy such as habit reversal (learning a new behavior to replace the tic), education about tics, and relaxation techniques.
Sometimes the natural waxing and waning of tics makes it appear that the tics have responded to a particular treatment.
Medications
Oral alpha-adrenergic agonists are usually used for mild symptoms and also are helpful for treatment of ADHD:
guanfacine is prescribed).
An adverse effect of clonidine is fatigue, which may limit daytime dosage; hypotension is uncommon.
Oral antipsychotics may be required for symptoms that are more difficult to control—for example:
With any medication, the lowest dose required to make tics tolerable is used; doses are tapered as tics wane. Adverse effects of dysphoria, parkinsonism, akathisia, and tardive dyskinesia are rare but may limit use of antipsychotics; using lower daytime doses and higher bedtime doses may decrease adverse effects.
Treatment of comorbidities
Treating comorbidities is important.
If obsessive or compulsive traits are bothersome, a selective serotonin reuptake inhibitor may be useful.
Children who have tics and who are struggling in school should be evaluated for learning disorders and provided with support as needed.
Key Points
Tics are repeated, sudden, rapid, nonrhythmic muscle movements or vocalizations that develop in children < 18 years old.
Tics are common among children, but coprolalia, a notoriously known form of vocal tic, is rare.
Simple tics are very brief movements and/or vocalizations (eg, head jerk, grunt), typically without social meaning.
Complex tics may appear to have social meaning (ie, be recognizable gestures or words) and thus seem intentional, but they are not.
Strongly consider Comprehensive Behavioral Intervention for Tics (CBIT) as the initial treatment option for tics.
An antipsychotic may lessen severe or difficult to control tics but may cause more adverse effects.
Comorbidities (eg, attention-deficit/hyperactivity disorder, obsessive-compulsive disorder) are common and must also be diagnosed and treated.
More Information
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
American Academy of Neurology: Review summary of the treatment of tics in people with Tourette syndrome and chronic tic disorders (2019)
