Tics vary widely in severity; they occur in about 20% of children, many of whom are not evaluated or diagnosed. Tourette syndrome, the most severe type, occurs in 3 to 8/1000 children. Male to female ratio is 3:1.
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 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
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.
These categories typically form a continuum in which patients begin with provisional tic disorder and sometimes go on to persistent tic disorder or Tourette syndrome. In all cases, age at onset must be < 18 years, and the disturbance cannot be due to physiologic effects of a substance (eg, cocaine) or another disorder (eg, Huntington disease, postviral encephalitis).
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
(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
(See also the American Academy of Neurology's review summary of treatment of tics in people with Tourette syndrome and chronic tic disorders.)
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 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.
Oral clonidine 0.05 to 0.1 mg once a day to 4 times a day is effective in some patients. Adverse effects of fatigue may limit daytime dosage; hypotension is uncommon.
Oral antipsychotics may be required—for example:
Fluphenazine is also effective in suppressing tics.
With any drug, 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.
Treating comorbidities is important.
ADHD can sometimes be successfully treated with low doses of stimulants without exacerbating tics, but an alternative treatment (eg, atomoxetine) may be preferable.
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.
Tics are repeated, sudden, rapid, nonrhythmic muscle movements or vocalizations that develop in children < 18 years old.
Tics are common, but the most severe manifestation of tics, coprolalia, is rare.
Simple tics are a very brief movement or vocalization (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.
Comprehensive Behavioral Intervention for Tics (CBIT) and sometimes clonidine or an antipsychotic may lessen severe or troublesome tics, which also tend to lessen with time although a few persist into adulthood.
Comorbidities (eg, attention-deficit/hyperactivity disorder, obsessive-compulsive disorder) are common and must also be diagnosed and treated.