What is Tourette syndrome?
Tourette syndrome is a neurological disorder characterized by multiple repeated tics. Tics are abrupt, purposeless, and involuntary vocal sounds or muscular jerks. They can involve any body part and may vary in severity — from very mild and hardly noticeable to very disrupting, frequent, and severe.
Symptoms of Tourette usually begin between the ages of 5 and 10 with mild, simple tics involving the face, head, or arms. Over time, tics become more frequent and increase in variety, involving more body parts such as the trunk or legs, and often become disruptive to activities of daily living.
Nearly 10 percent of school-aged children experience transient tic disorder — the most common type of tic disorder, with symptoms lasting at least four months, but no longer than one year. Symptoms of transient tic disorder may be more prevalent in periods of stress, fatigue, or as a result of certain types of medications, and may be confused with other symptoms of nervousness, anxiety, or restlessness that many children experience.
Tics that are seen lasting more than one year are classified as chronic tics. Chronic tics affect less than 1 percent of school-aged children and must be differentiated between Tourette disorder in which multiple motor tics and at least one or more vocal tics must be present.
Tics are generally differentiated based on the type of tics presented, the age of onset of symptoms, and the duration of symptoms.
Tourette Syndrome | Symptoms & Causes
What are the symptoms of Tourette syndrome?
Tic behaviors seen in Tourette syndrome change over time, and vary in frequency and complexity. The following are the most common tic behaviors associates with Tourette syndrome. However, each child experiences symptoms differently. Symptoms may include:
- involuntary, purposeless, motor movements (may involve different parts of the body, such as the face, neck, shoulders, trunk, or hands)
- head jerking
- any excessively repeated movements (i.e., foot tapping, leg jerking, scratching)
Some of the more complex tic behaviors associated with Tourette syndrome may appear purposeful, and may include the following:
- sticking out the tongue or lip-smacking
- touching behaviors
- making obscene gestures
In addition to some, or all, of the above symptoms, Tourette is also characterized by one or more vocal tics (meaningless sound), in order for a diagnosis to be made, including the following:
- grunting or moaning sounds
- tongue clicking
- throat clearing, snorts, or coughs
- squeaking noises
- echoing sounds or phrases repeatedly
Forty percent of children and adolescents who have Tourette syndrome also have attention problems, and 30 percent have academic difficulties. However, most have a normal intelligence and do not usually have primary learning disabilities. Twenty-five to 30 percent also experience symptoms of obsessive-compulsive disorder (OCD), which is an anxiety disorder in which a person has an unreasonable thought, fear, or activity (obsession) that he/she tries to manage through a ritualized activity (compulsion) to reduce the anxiety.
The symptoms of Tourette syndrome may resemble other conditions or medical problems. Always consult your child's physician for a diagnosis.
What causes Tourette syndrome?
Tourette syndrome is an autosomal dominant disorder. Autosomal means that both males and females are affected, and dominant means that one copy of the gene is necessary to have the condition. This means that a parent with Tourette syndrome or a parent who has the gene for Tourette syndrome has a 50/50 chance, with each pregnancy, to pass the gene on. Tourette syndrome is associated with a non-genetic cause in 10 to 15 percent of children. Complications of pregnancy, low birthweight, head trauma, carbon monoxide poisoning, and encephalitis are thought to be associated with the onset of non-genetic Tourette.
Dominant disorders exhibit something known as incomplete penetrance, which means that not everyone with the gene will have symptoms of Tourette syndrome. In other words, if a parent passes the gene on to a child, the child may not have any symptoms of the syndrome. If a daughter inherits the gene, there is a 70 percent chance that she will have at least one of the signs of Tourette. On the other hand, if a son inherits the gene, there is a 90 percent chance that he will have at least one of the signs of Tourette.
Finally, dominant syndromes can also exhibit something known as variable expressivity. This means that there are differences in the expression of the Tourette syndrome gene in different people. For example, one person with Tourette syndrome may have obsessive-compulsive disorder, while another has a chronic tic syndrome, while another has full-blown Tourette syndrome. In addition, there are differences in expressivity between males and females: males are more likely to have full-blown Tourette syndrome or chronic tics, while females are more likely to have obsessive-compulsive disorder.
Tourette Syndrome | Diagnosis & Treatments
How is Tourette syndrome diagnosed?
A pediatrician, child psychiatrist, or a qualified mental health professional usually identifies Tourette syndrome in children and adolescents. A comprehensive evaluation of the child or adolescent's psychological, social, and educational status is recommended, as well as a thorough medical, developmental, and family assessment. A detailed history of the child's behavior from parents and teachers, in addition to observations of the child's behavior, contribute to making the diagnosis.
What is the treatment for Tourette syndrome?
Specific treatment for Tourette syndrome will be determined by your child's physician based on:
- your child's age, overall health, and medical history
- the extent of disruption caused by tic behavior
- your child's tolerance for specific medications, procedures, or therapies
- expectations for the course of the syndrome
- your opinion or preference
The effect of symptoms on the child's or adolescent's self-concept, family and peer relationships, and classroom participation determines what needs may need to be addressed in treatment. In many cases, TD is not disabling. Development may proceed normally and there is no need for treatment. However, when tics interfere with functioning or school performance, and/or if there are other disorders also present (obsessive-compulsive disorder, attention-deficit/hyperactivity disorder), some effective medications are available. Children with TD can generally function well at home and in a regular classroom. If they have accompanying emotional or learning problems, they may require special classes, psychotherapy, and/or medication.
The genetics behind Tourette syndrome is complicated. For this reason, it is important for individuals and families to have genetic counseling by a geneticist (a physician with specialized training and certification in clinical genetics) or a genetic counselor, once a diagnosis has been made in the family.