GILLES DE LA TOURETTE SYNDROME (TOURETTE'S DISORDER)
This is probably the most widely known tic disorder due to the unusual nature of the symptoms. It is named after Gilles de la Tourette who described it in 1885, but was first identified by Itard in 1825.
It is characterised by multiple motor tics and at least one vocal tic. Tics may first appear at the same time or at different times during the course of the disorder. Following onset, tics are experienced many times each day and must last for at least one year. Symptoms begin before the age of 18 years.
Motor tics may arise in any part of the body and the location of them may change over time, as too may the number of different types of tics, and their frequency, complexity and severity. Simple motor tics may include eye blinking or muscle contractions, complex motor tics can include repeatedly squatting, bending the knees, or twirling around when walking. Sometimes stereotyped movements are present e.g. dancing or jumping. or dancing.
Simple vocal tics include utterances such as grunting, coughing, or barking. Coprolalia (uttering obscenities) is present only in a minority of cases with estimates varying between 10 and 30%, and it is rarer in children. Between 10 and 40% have echolalia or echopraxia (copying someone else's speech or movements).
Associated features include obsessions and compulsions which also occur more frequently in biological relatives than the general population. ADHD is also more frequent amongst children with Tourette's disorder than in the general population. Emotional disturbances are also often present such as feeling demoralised, shameful or self-conscious. Learning difficulties and social problems may also be present. Younger children may not show any distress or other impairments related to their symptoms. Many children and adolescents do not seek medical help but those with severe symptoms which cause them social stigma do.
- Prevalence & Course - this disorder affects three to four times more boys than girls. It affects more children than adults with estimates of around 5 in 10,000 children being affected compared to 1-2 in 10,000 adults (by definition, in adults it must have begun before age 18 years and persisted into adulthood). Onset may be as early as age 2 years with the average age of onset being around 6-7 years. Sometimes symptoms may remit for months or years at a time before recurring. Symptoms often diminish in severity and frequency during adulthood and may disappear completely in early adulthood. Occasionally, symptoms become worse in adulthood. Often tics and obsessive-compulsive symptoms endure over the individual’s lifetime.
- Causes - there is evidence to suggest a genetic basis with some children inheriting a genetic vulnerability to the disorder. However, the type of tic disorder inherited may vary from one generation to the next and it would seem that OCD is amongst the possible vulnerabilities. If there is an inherited genetic vulnerability its expression is likely to be influenced by the environment. Not all cases are of genetic origin though. Some other studies indicating a possible connection with a neuro-chemical disorder involving dopamine production.
- Treatment - many different types of treatment have been used to control the symptoms of Tourette's disorder. Where symptoms are mild to moderate no treatment may be necessary, rather it is sometimes better to allow symptoms to run their course and gradually remit. Where symptoms persist and are severely problematic medication has been used. In particular, Haloperidol proved reasonably effective but it can produce side-effects which might also generate concern. Selective serotonin reuptake inhibitors may control obsessive-compulsive symptoms. If there is co-morbid ADHD or OCD then these are often treated in preference.
