Paediatric medicine - Tourette's syndrome

This condition has a wide variation in severity. By Professor Amanda Kirby

The average age of onset of Tourette’s syndrome is between five and seven years and it is more common in boys (Photograph: Istock)
The average age of onset of Tourette’s syndrome is between five and seven years and it is more common in boys (Photograph: Istock)

Tourette's syndrome (TS) was named after Dr Georges Gilles de la Tourette in 1885 who described the condition. It is the most common cause of tics and is sometimes known as multiple tic disorder or tic spectrum disorder. TS is also commonly associated with other disorders including ADHD and obsessive compulsive disorder (OCD).

It affects one school child in every hundred and more than 300,000 children and adults in the UK. It is three to four times more common in boys than girls.

Symptoms
Tics are relatively brief, rapid, intermittent, purposeless and involuntary movements (motor tics) or sounds. The latter are called vocal or phonic tics.

Most tics are abrupt in onset and duration (clonic tics), but may be slow and sustained, either dystonic (associated with a twisting type of movement), or tonic (if the muscle contractions are isometric and not associated with any movement, such as arm or abdominal tensing).

Tics may be 'simple' and include sniffing and throat clearing, or 'complex', which are coordinated, sequential movements resembling normal motor acts or gestures but are inappropriately intense and may be repetitive.

Complex vocal/phonic tics may include barking and animal noises. Tics may fluctuate in severity and are also suppressible, and persist during sleep. Most patients describe a sensation before the tic begins.

Other symptoms include echolalia (copying what others say), echopraxia (copying what others do) and palilalia (repeating the last word or part of sentence). Coprolalia (inappropriate and involuntary swearing) is uncommon, occurring only in 10-15 per cent of patients. However, it has been misconceived by some to be the main presenting feature of TS.

There is a wide variation in severity in TS. Symptoms range from relatively mild, not very obvious signs, such as shrugging or tossing hair that may not interfere with every day functioning, to severe, pervasive and impairing signs and symptoms alongside other comorbidities (such as ADHD and OCD) that affect educational and social outcomes.

There is also evidence of increased self-injurious behaviour, anxiety and depression in this latter group.

Onset
The average age of onset is between five and seven years but can vary anywhere between two and 21 years. Vocal tics tend to start a little later, around 11 years of age. Around 50 per cent of children's tics will resolve in adolescence.

Aetiology
TS is now recognised as a biological disorder and the majority of cases have a positive family history suggesting a genetic background. Some specific genes have recently been found to be associated with TS.

Some periand post-natal difficulties have been implicated in TS including low birth weight, low Apgar scores and severe nausea and vomiting in the first trimester. The pattern of overlap with TS and ADHD has led to a greater understanding that TS may not be a single syndrome and individuals with TS and ADHD, for example, are different from those with TS alone and may have a different aetiological basis.1

Diagnosis
For TS to be diagnosed, multiple motor tics and at least one vocal tic must be present for at least 12 months, without a break of more than three months.2,3

A complete assessment, including EEG, MRI, and CT scan where appropriate, should be undertaken to rule out other conditions that might be confused with TS, such as epilepsy, autism, dystonia and Sydenham's chorea.

ManagementThe first stage in management is reassurance and explanation. A multidisciplinary approach assessing the other potential comorbidities, such as ADHD, OCD, developmental coordination disorder and dyslexia, is important.

It is vital to consider the full impact the difficulties may have on everyday functioning at home and school and in peer relationships.

Habit reversal training has been demonstrated to be significantly better than other methods, such as supportive psychotherapy.

Medication is often required for the treatment of the tics and any other associated disorders. Antipsychotic drugs have been shown to be the most effective, such as haloperidol, pimozide, risperidone and sulpiride.

However, there are a range of side-effects that need to be considered when using these drugs, such as sedation and cognitive difficulties, as well as raised prolactin levels. The newer antipsychotic medication has a particular side-effect profile of significant weight gain which can become a major problem.

  • Professor Kirby is a former primary care physician who founded and runs the Dyscovery Centre supporting children and adolescents with developmental disorders in Newport, Gwent

Resources
UK support organisations

References
1. Haddad DH, Umoh G, Bhatia V et al. Adults with Tourette's syndrome with and without Attention Deficit Hyperactivity Disorder. Acta Psychiatrica Scandinavica 2009; 120(4): 299-307.

2. American Psychiatric Association, Diagnostic and statistical manual of mental disorders. DSM-IV-TR, 2002. 4th Edition Revised. Washington DC, American Psychiatric Association.

3. World Health Organisation (1992a) International statistical classification of diseases and related health problems (10th Edition), Vol. 1; ICD-10. Geneva: World Health Organisation.

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