Tourette’s Disorder (TD), also known as Tourette Syndrome (TS), is a neurodevelopmental disorder characterized by motor and vocal tics that begin in childhood and persist over time. Tics are sudden, non-rhythmic repetitive movements or vocalizations. Tics are not purposeful and are generally experienced as involuntary (although they can be voluntarily suppressed to varying degrees).
Symptoms of TD often emerge early in childhood. Severity of tic symptoms typically peaks in the early to mid-teenage years. Movement tics typically precede vocal tics and simple tics usually precede complex tics. Initial symptoms often involve facial tics (e.g., eye blink, nose twitch, or grimace). For the vast majority of children and teens with TD, tics lessen in late adolescence and into adulthood.
Even when tics are at the height of their severity, most cases of TD are mild to moderate and the tics themselves do not cause substantial problems in functioning. Approximately 10% of children with TD experience severe tic symptoms that substantially interfere with important areas of functioning (such as school, with friends, or at home).
Transient tics are quite common in childhood – affecting 12 to 18% of school-age children. Chronic tics appear in approximately 1% of children and teens. TD affects more males than females.
Causes and Risk Factors
Studies indicate that TD is an inherited condition. Several neurochemical systems have been seem to cause TD. Most evidence points to the important role of the chemical messenger called dopamine, although the role of noradrenaline, serotonin, and GABA systems has also been considered. Most theories point to the basal ganglia (structures deep in brain) as having a central role in TD.
Who is affected by Tourette's Disorder?
Transient tics are quite common in childhood – affecting 12 to 18% of school-age children. The prevalence of chronic tics is approximately 1% of children and teens. TD affects more males than females.
Symptoms and Types
TD is characterized by both multiple movement (motor) tics and one or more vocal tics. Tic symptoms seen in TD change over time, and vary in their frequency and complexity. For a diagnosis of TD to be given, tics need to have persisted for more than 1 year. Onset of TD occurs before the age of 18.
Simple motor tics involve abrupt, brief, repetitive motor movements. Examples of simple motor tics include:
- Blinking or squinting
- Head/neck jerking
- Arm or hand movements
- Abdominal tensing
- Rapid jerking of any part of body
Some of the more complex motor tics associated with TD may be slower than simple motor tics and might appear purposeful. Additionally, some of the complex motor tics seen in TD can be difficult to distinguish from compulsions seen in obsessive compulsive disorder (OCD). Examples of complex motor tics include:
- Eye movements (e.g., rolling upwards or side to side)
- Touching, rubbing, tapping objects or people
- Sticking out the tongue or lip-biting
- Clapping, throwing or pinching
- Kissing or silly expressions
- Bending or gyrating
- Imitating movements
- Making obscene gestures (rare)
Examples of simple and complex vocal tics (also called phonic tics) include:
- Throat clearing
- Sniffing or snorting
- Whistling or hissing
- Grunting or gurgling
- Squeaking or screeching
- Animal or bird noises
- Phrases (e.g., “shut up,” “stop that,” “wow, that’s it”)
- Sudden changes in volume or pitch
- Repeating sounds or phrases
- Obscenities (rare)
The symptoms of TD may resemble other conditions or medical problems. Always consult your child's health care provider for a diagnosis.
Individuals with TD or chronic tics often experience other difficulties. The most frequently reported co-occurring conditions include attention-deficit/hyperactivity disorder (AD/HD), OCD, other anxiety disorders, learning difficulties, sensory sensitivities, disordered sleep, mood disorders, and explosive/aggressive behavior. For example, roughly 50% of youth diagnosed with TD also have AD/HD and 30 - 40% of those with TD develop OCD. The conditions that occur with TD typically interfere more with psychosocial adjustment than the tics themselves.
Diagnosis and Tests
A pediatrician, neurologist, child psychiatrist, child psychologist or other qualified behavioral health professional usually diagnoses TD in children and adolescents.
When diagnosing TD, tics need to be distinguished from other abnormal movements or motor conditions (e.g., stereotypies, chorea) or compulsive behaviors. A complete evaluation includes more than confirming a tic disorder. Understanding the nature, severity, and functional consequences of tics and how tics are influenced by the child’s environment is integral to the development of an effective treatment plan. Equally important is assessing for the presence of co-occurring disorders (e.g., AD/HD, OCD) and their associated impairment.
The most frequent treatment for TD involves education about tics (including information regarding the typical course and prognosis) and the passage of time.
When TD is interfering with a child’s functioning, primary treatment options include both psychosocial interventions and medication. Historically, medication treatments have been the primary active treatment option recommended when tic severity is distressing and is causing impairment in functioning.
In recent years, strong research evidence has emerged for the benefits of comprehensive behavioral intervention for tics (CBIT).
CBIT psychosocial intervention includes:
- learning how to modify the environments that impact tics
- developing the child’s skills for tic awareness
- applying effective competing responses
CBIT has been found to be as effective as medications for the amelioration of tics and does not have the complications or potential adverse effects that are sometimes found with medications.
In light of the co-occurrence of other disorders with TD, it is important for the treatment provider to prioritize the most impairing condition. More often than not, it is the co-occurring disorder or disorders, rather than tics themselves, that are causing the most impairment and, thus, need to be addressed by treatment.