Transient tics are common in childhood. They are seen in 20% of children and adolescents, in boys more commonly than in girls.
Tourette's syndrome is a developmental disorder where several motor tics and at least one vocal tic occur for more than one year.
Guidance and counselling are of primary importance in the treatment of tic disorders. Mild and transient tics can be assessed in primary health care.
If a chronic tic disorder is harmful for the child or adolescent, assessment in specialized care is indicated.
For severe tics which interfere with functional capacity, therapy or medication can be used. It is also important to identify and treat any other concomitant disorders.
Definition and classification
Motor tics are partly involuntary twitches of single muscles or muscle groups.
Vocal tics are sounds produced by moving air through the nose, mouth or throat.
Tics are typically sudden, arrhythmic and serial.
If tics continue for more than a month but less than one year, the condition can be called provisional tic disorder (previously known as transient tic disorder). If motor or vocal tics continue for more than one year, the child is said to have a persistent (chronic) tic disorder.
Tourette's syndrome is a developmental disorder where several motor tics and at least one vocal tic occur over a longer period (> 1 year) but not necessarily simultaneously.
By definition, tic disorders begin before the age of 18 years.
Epidemiology
Transient tics occur in as many as 20% of children.
The prevalence of provisional and persistent tic disorders is about 3% and 1.6%, respectively.
The prevalence of Tourette's syndrome in childhood and adolescence is about 1% in boys and 0.3% in girls.
Clinical picture
Tics most typically begin at the age of 4-6 years.
Motor tics may occur in any part of the body but most commonly in muscles in the head area, the face, in particular, and the upper body.
The most usual types of motor tics are eye blinking, shaking the head, grimacing, raising the eyebrows, wrinkling the nose, twitching the corners of the mouth, raising the shoulders, and flexing the limbs.
Vocal tics include sighing, yawning, coughing, sniffling, grunting, snorting and barking.
Complex motor tics are more like voluntary movements. Such tics may involve touching or retracing steps, for example.
Complex vocal tic symptoms include words, repeating other people's words (echolalia), repeating one's own words (palilalia) and sudden bursts of obscene words and phrases (coprolalia).
Tics are often preceded by premonitory urges, i.e. unpleasant somatosensory sensations that children only become conscious of at around the age of 10 years. Such premonitory sensations may be felt as, for example, pain, itching or pressure in the muscle about to be affected by a tic. The sensation subsides when the tic begins.
The frequency, intensity and severity of tics typically vary from day to day and week to week. Stress, anxiety or fatigue may increase the symptoms. Active concentration and fine motor functions, on the other hand, may subdue tics. Many patients can suppress tics momentarily but this requires active concentration.
Tourette's syndrome often involves other concomitant disorders, of which attention deficit/hyperactivity disorder and obsessive-compulsive disorder are the most common. Depression and anxiety disorders are also common.
In the long term, the natural course of Tourette's syndrome is usually favourable and tics will cease or diminish so that they will no longer cause any harm in adolescence or early adulthood.
Differential diagnostics
Epileptic absence
Myoclonus
Dystonia
Chorea and athetosis
Stereotypy
Facial spasm
Compulsive symptoms
Allergic symptoms
Background of tics
Genetic factors are significant in tic disorders and Tourette's syndrome but the genetic background would appear to be multifactorial.
There are some indications that environmental factors may be involved in the development of tic disorders but the amount of research data available is insufficient so far.
Treatment
It is most important to provide information, counselling and guidance for the child, his/her family and near environment (day care, school) on the symptom picture, and to provide adjustment training and peer support as well as support for the child's general social coping. Counselling and guidance can be provided in primary health care.
Therapy or medication is indicated if the tics disturb the child or cause functional or social harm.
If the child needs therapy or medication, these should be planned by a specialist in tic disorders.
If the child has other concomitant disorders, they may need to be treated in the first place because they may cause more harm than tics and their treatment may affect the psychosocial prognosis.
The goal of treatment is to reduce the tics. Monitoring of treatment is complicated by the naturally varying course of tics. Forms such as the Yale Global Tic Severity Scale can be used for monitoring.
Behavioural treatment is recommended primarily, but its availability may be limited.
Of various types of cognitive behavioural therapy, best results have been obtained with habit reversal training and exposure-response prevention.
Medication should be considered if tics are constant and/or severe and cause functional problems, pain or constant social problems or have a negative effect on the patient's emotional life.
Antidopaminergic drugs, such as aripiprazole or risperidone, are the first choice medication.
References
Szejko N, Robinson S, Hartmann A et al. European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part I: assessment. Eur Child Adolesc Psychiatry 2021;(Oct 18;1-20). [PubMed].
Andrén P, Jakubovski E, Murphy TL et al. European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part II: psychological interventions. Eur Child Adolesc Psychiatry 2021;(Jul 27:1-21). [PubMed]
Roessner V, Eichele H, Stern JS et al. European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part III: pharmacological treatment. Eur Child Adolesc Psychiatry 2021;(Nov 10). [PubMed].