Overview
Tics are involuntary, repetitive, non-rhythmic motor movements of vocal sounds. Tourette’s syndrome (TS) is a neurodevelopmental disorder characterised by tics that are preceded by an unwanted urge to perform the tic that increases in intensity as the tic is suppressed, known as a premonitory urge. Once the tic has been performed, the person experiences relief.
Epidemiology
- Tourette syndrome (TS) typically presents in 5-6-year-olds
- TS is more common in boys
Risk Factors
Overview
Although the exact cause of TS is unknown, it has the following risk factors and associations:
- Obsessive-compulsive disorder (OCD)
- Attention deficit hyperactivity disorder (ADHD)
- Learning difficulties
- Behavioural problems
- Deliberate self-harm
Presentation
Overview
Simple tics are sudden, meaningless, short movements that usually involve one group of muscles. This can include:
- Eye twitching
- Blinking
- Throat clearing
- Grunting
- Facial grimacing
- Shoulder shrugging
Complex tics appear more purposeful and are longer in duration. Some complex tics include:
- Echolalia – involuntarily copying other people’s words
- Palilalia – repeating one’s own words
- Echopraxia – involuntarily copying other people’s movements
- Coprolalia – involuntarily saying obscene words – in around 10% of patients
- Other movements such as pulling on clothes, touching objects etc.
Diagnosis
Overview
Patients are generally referred to a neurologist or Child and Adolescent Mental Health Services (CAMHS) for diagnosis. Some investigations may be considered to screen for other causes of tics such as an MRI to screen for neurological lesions or brain structure abnormalities.
Diagnostic criteria
For a diagnosis of TS, the following must be met:
- Multiple motor tics and one or more vocal tics starting before 18 years of age
- Presence for more than 1 year, may occur many times a day or be intermittent
- Tics lead to significant impairment in function (e.g. in activities of daily living, school, or work)
- The tics are not secondary to drug abuse or secondary causes (e.g. Huntington’s syndrome, other psychiatric disorders etc.)
Management
Overview
If there is no underlying cause, then tics may settle over time or become chronic (Tourette syndrome). In more severe cases, habit reversal training and exposure and response prevention may be considered and as a last resort in severe cases, medication such as antipsychotics may be considered.
Prognosis
- Around 1/3 of children are asymptomatic as adults, 1/3 have mild tics, and 1/3 require continued clinical care
