Gilles De La Tourette Syndrome

Synonyms: Tourette's syndrome (actually a misnomer as the full surname was Gilles De La Tourette), Brissaud's syndrome, Guinon's disease, compulsive swearing syndrome, coprolalia-compulsive syndrome, chronic motor tics.

This is a neuropsychiatric syndrome characterised by motor and vocal tics which runs a fluctuating course. It may be associated with behavioural abnormalities and other psychological conditions e.g. obsessive-compulsive disorder¹.

Dr Georges Gilles De La Tourette in 1885 described 9 patients with the syndrome which was subsequently named after him. However, the original description was by Dr Itard in 1825 who described the case of the cursing Marquise de Dampierre.
The disorder was originally thought to be psychiatric - however, it most likely represents a combination of pathologies.

• Not as rare as originally thought to be. In UK schoolchildren (aged 5 - 17 years) the prevalence is 1%. It is possible that there are many mild cases and the actual prevalence is much higher.¹
• It is also thought to be more common in Ashkenazi jews (not confirmed in some studies) and patients of Mediterranean origin. 10% of patients have an affected first degree relative and twin studies report 90% concordance in monozygotes.
• Onset usually in childhood - 2 - 14 years of age (mean age of 7 years). 3-4 times commoner in males.

The aetiology of Gilles De La Tourette syndrome is controversial and several theories have been proposed:

• A genetic cause is thought to underlie the syndrome - probably by an autosomal dominant transmission. However, it is possible that the expression and penetration of the gene is variable. Also OCD and tics may actually be part of the same spectrum and related to the Tourette syndrome gene¹.
  Several mutations have been proposed e.g. mutation in SLITRK1 gene on chromosome 13q.
• Other theories include:
  1. Reduced serotonin to platelet ratio.
  2. Reduced blood tryptophan levels.
  3. Abnormalities of dopamine regulation with excess dopamine have been proposed. Abnormalities of dopamine in mesencephalic-mesolimbic system are thought to result in disinhibition of the limbic system. This is supported by differences in symmetry of the putamen and lenticular nuclei. Furthermore, dopamine D2 receptor antagonists relieve some of the symptoms², ³.
  4. Abnormal discharges in the frontal lobes⁴.

It is most likely that Gilles De La Tourette Syndrome is a combination of genetic and environmental factors.

Tics can be defined as sudden, purposeless, repetitive, non-rhythmic, stereotyped movements or vocalisations e.g. eye twitching or blinking. Examples of vocal tics are throat clearing, grunting and barking.

Other features that may be seen in Gilles De La Tourette Syndrome:

1. Echolalia - involuntary copying of others words.
2. Pallilalia - repeating others sentences.
3. Coprolalia - compulsory saying of dirty words which is pathognomic of the syndrome and is seen in about 10% of patients.
4. Copropraxia - making obscene gestures.
5. Echopraxia - involuntary copying of others movements.
6. Difficulty concentrating or easily distracted.

Gilles De La Tourette Syndrome is associated with a number of other problems:

The causes of these associations is not clearly understood and may be related to medication use and stigma⁵.

20% of children have a transient tic disorder - usually lasts < 1 year.

1. Full history (include age of onset, whether tics wax and wane and family history of Huntington's or Wilson's disease) and examination. Include a mental state examination. There are scales available e.g. MOVES scale for tic severity.
2. Recognise co-existent disorders e.g. ADHD, depression, sleep problems or learning disabilities. Each of these will need treatment¹, ⁶.
3. Differentiate tics from other movement disorders e.g. dystonias and chorea.
4. Check TFT and consider a throat swab for streptococcus if rapid onset.
5. An EEG may help if there is concern regarding presence of epilepsy.
6. A urine drug screen may help.
7. Rule out secondary causes of tics e.g.

• Timely and accurate diagnosis is important. Remember that many patients are children and may have difficulty at school.
• Individualize treatment.
• Education - should involve the nature and cause of tics. Also that anxiety, stress and fatigue and stimulants worsen tics. Offer reassurance and support.
• Treat any secondary causes of tics.
• If there is no underlying cause then the tics may be transient (in which case they will settle) or chronic (may be Gilles De La Tourette syndrome).
• If tics are mild - try observation or non-pharmacological measures e.g. education, supportive therapy, counselling or psychotherapy or behavioural therapy (such as positive reinforcement techniques)⁶.
• Moderate to severe tics should be treated pharmacologically and the patient referred to specialists (e.g. neurologist, mental health specialists)⁶.

• Use the lowest dose necessary to reduce the tics so that the patient can function at an acceptable level. Some patients may require 2 or more drugs - although monotherapy is preferred⁷.
• Treatment usually needs to continue for 1 - 2 years - but some need long-term therapy¹.
• Neuroleptics, such as haloperidol are used as first line but they have a number of problematic side effects⁸.
• Other agents - sulpiride (may be a better first line in older patients), pimozide or clonidine ( α 2 adrenergic presynaptic agonist - may be preferred first line in younger children)⁹.
• Other drugs - haloperidol, risperidone, clonazepam, benzodiazepines⁷.
• Clonidine may also help in ADHD. It's side effects include sedation, weight gain and impaired mental performance.
• Pimozide, a dopamine D2 antagonist, has cardiac side effects and thus requires regular ECGs¹.
• Associated disorders will also need treating e.g. SSRIs in OCD.

• Stereotactic surgery has been used in Gilles De La Tourette syndrome¹⁰.
• The target areas are diverse e.g. frontal lobe, limbic system or thalamus.
• The procedure is not without risk e.g. hemiplegia.
• This procedure is still in experimental stages, although there have been some case reports of success.

These include immune modulation and use of calcium channel blockers and botulinum toxin. However, these are experimental therapies.
ECT, bilateral thalamic stimulation and tryptophan have also been used but the benefit is inconclusive¹¹.

Severity of each case varies from person to person and peaks in the early teenage years. in some cases the symptoms may gradually diminish.
Approximately 10% of cases are severe, and the condition usually lasts for life.