Tourette's syndrome in children

Tic disorders affect 4-18% of children at some stage of their development.1 At one end of the spectrum are children with brief episodes of single tics, whereas at the other are children with chronic multiple tics, including Tourette's syndrome. Tics are abrupt and recurrent motor or vocal actions. Although involuntary, they may be preceded by a sensory urge, are sometimes suppressed for prolonged periods, or can even be triggered by external perceptions. They are sudden and purposeless. They can be divided into simple tics such as blinking, shrugging of the shoulders, grunting, and clearing one's throat, and complex tics such as licking, jumping, or touching objects. Tourette's syndrome is the most severe form, with multiple motor and vocal tics lasting for a year or more.2

The best known symptom of Tourette's syndrome, coprolalia (a complex vocal tic with involuntary swearing), occurs in less than 15%.3 This unusual symptom has contributed to the view that Tourette's requires extraordinary treatment. Most tic disorders including Tourette's need little medical input other than help with diagnosis and information, but an unusual or severe movement disorder requires specialist advice, and impairing emotional and behavioural problems need referral to mental health services.

The onset of Tourette's syndrome occurs around the age of 6-7 years, and, as with other neurodevelopmental disorders, it occurs more commonly in boys. Tourette's syndrome was thought to be rare, but recent school based studies have indicated a prevalence of 1-3%, if a broad definition of chronic motor and vocal tics is used.4 However, the syndrome itself might helpfully be thought of as a spectrum,1 particularly in terms of the impairment experienced by patients. Those with purely chronic tics usually have good adaptation. The presence of the more unusual Tourette's phenomena such as coprophenomena (obscene sounds or gestures) or echophenomena (repeating sounds or gestures) are rarer and may lead to distress and misunderstanding. A third group, those with psychopathology, are likely to need active and multimodal interventions.5

Parents and children need to understand that, although all these symptoms relate to the underlying brain disorder, interventions may be extremely simple—for example, allowing the child to have a short “tic break” in a long school lesson. The neurochemistry, neuroanatomy, and genetics of Tourette's syndrome have been the subject of speculation and research; dopaminergic pathways in the frontal and subcortical regions of the brain are involved, and a strong genetic basis exists.6 Recent studies have identified a group of children who suddenly develop tics and obsessive compulsive disorder associated with B-haemolytic streptococcal sore throat infection.7 However, despite streptococcal autoantibodies being a potential risk factor for developing Tourette's syndrome8 there is no evidence currently that these children should be investigated or treated differently from other children with Tourette's syndrome, other than by looking for and treating active streptococcal infection.9

Explanation and reassurance may be all that is needed for children who have mild tics.6 Educating the teachers and all professionals who come into contact with the child is important for reducing psychological distress. Children may be teased and bullied in the classroom or reprimanded by the teacher for something over which they have no control. This can lead to low self esteem and emotional difficulties. If the child has tics that are uncomfortable and cause psychological and social distress, then medication may be considered. No drug has predictable and potent efficacy in all children with tics—most studies show a reduction of only about 30% in the severity of tics.10

Surprisingly few good quality, randomised controlled trials in children are available. Double blind trials have shown tic severity and frequency are reduced using dopamine antagonists, such as haloperidol, pimozide, sulpiride, and the α₂ adrenergic receptor agonist, clonidine.6 10 11 Placebo-controlled studies of risperidone in Tourette's syndrome have shown that it is efficacious and has fewer side effects than the older dopamine antagonists.12

Other problems such as obsessive compulsive disorder and attention deficit hyperactivity disorder are often present (50-70% of children with Tourette's). The combination can be difficult to treat, and specialist advice from a child psychiatrist may be needed.

Parents often feel helpless and at a loss to know what to do when their children have tics. Helping parents adjust to the diagnosis and manage the negative reaction of peers and public can be empowering to families. A good understanding of the symptoms and their fluctuations is essential. For example, children seem able to suppress tics for periods of time such as at school, followed by a disruptive rebound on returning home.6

Most individuals with tics lead highly functional lives, and the tics themselves usually wane in teenage years. Parents should be encouraged to seek support for themselves from various organisations such as the Tourette Syndrome Association (enquiries{at}tsa.org.uk). With a good understanding of tics and related problems, including acceptance from teachers and education of peers, most children with tics do not need regular medical follow up.