What is Tourette Syndrome?
Occurring in 1% of school-aged children, Tourette syndrome is a neurodevelopmental disorder characterised by uncontrollable movements and vocalisations known as tics.
Tics can be simple (e.g., blinking, grimacing, throat clearing, sniffing) or complex (e.g., movements involving multiple body parts, repeated words, coprolalia).
First symptoms usually appear between 4-6 years of age, with tics often coming and going over time, varying in type, frequency, location and severity. Tics often reach a peak during adolescence, becoming less frequent or less severe as a person enters adulthood. For some people though (~25%), Tourette’s is a lifelong condition that can worsen over time.
Tics can significantly impact on many aspects of life. They can physically, socially and emotionally impact on daily living, academic and occupational achievement, and participation in leisure and play.
Tourette syndrome is a heterogeneous condition. Intensity of symptoms varies from person to person. For some children, tics are mild or there are lengthy periods where tics are absent, meaning they can enjoy the same things that other children do. For others, the disability is more substantial, having a greater impact on quality of life.
What Causes Tourette Syndrome?
The causes of Tourette syndrome are not well understood. It is a complex condition likely caused by a combination of genetic, environmental and immunological factors. Several genes have been implicated (e.g., CNTN6, NRXN1, SLITRK1) and there are high rates of heritability. Exposures have been implicated, including stress, pre-term birth and infection, in particular during the perinatal period.
Like most neurodevelopmental disorders, alterations in neurophysiology and brain networks during critical periods of brain development, likely lead to the symptoms associated with Tourette syndrome.
Although tics are the hallmark feature of Tourette syndrome, psychiatric, mental health and behavioural comorbidities are highly prevalent. Attention deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD) are amongst the highest co-occurring conditions, although rates of anxiety, mood and conduct disorders are much higher than the general population.
Diagnosis
To be diagnosed with Tourette syndrome, a child needs to present with: 1. a combination of movements (motor tics) and vocalisations (vocal/phonic tics) for at least 12 months, 2. tics that occur nearly every day or on and off (i.e., waxing and waning pattern), 3. onset prior to 18 years of age, and 4. tics that are not associated directly associated with another medical condition or the result of medication.
Children presenting with only one category of tics (i.e., motor or vocal) for at least 12 months are typically diagnosed with a persistent/chronic tic disorder.
Diagnosis is normally made by a paediatrician or neurologist who will likely take a detailed medical history, conduct neurological assessment, and rule out other potential causes for the tics prior to making a diagnosis.
Tics can resolve spontaneously within short periods of time (i.e., <12 months). This is why diagnosis is not made until ongoing tic presentation is confirmed. Children presenting with tics for less than 12 months are commonly referred to as having a provisional tic disorder.
Management
There is no cure for Tourette syndrome or tic disorders.
Medication is sometimes effective in the management of tics. Some psychologists can provide evidence-based behavioural treatments (e.g., Cognitive Behavioural Intervention for Tics, CBIT) and therapy to support social, emotional and behavioural difficulties.