Tourette syndrome, a disorder of the nervous system, is characterized by tics that are manifested by involuntary repetitive movements or sounds. The syndrome was first discovered in 1885 by the French neurologist Gilles de la Tourette (1857 to 1904), who provided the first formal description as "an inherited neurological condition characterized by motor and vocal tics."
Although motor and vocal tics are the hallmarks of Tourette syndrome, other symptoms such as the expression of socially inappropriate comments, behaviors, attention deficit disorders, obsessive-compulsive disorder, self-injuring behavior, anxiety and depression can also be associated with the condition. Research suggests that Tourette syndrome is an autosomal dominant disorder, which means it can be passed down through families.
Tourette syndrome is found in all populations and ethnic groups, although it is three to four times more likely to be diagnosed in males rather than females. It is also more common in children than adults. The cause is unknown but research suggests that the tics associated with Tourette syndrome are usually caused by an increased amount of a neurotransmitter in the brain called dopamine. The defect in the syndrome involves another neurotransmitter called serotonin, which is present in all people. It is required for normal functioning of the brain.
The primary symptoms of Tourette syndrome include a combination of simple and complex motor and vocal tics. Simple motor tics can be characterized by brief muscle contractions such as an eye twitch. Meanwhile, complex motor tics are generally more complicated than simple tics. They involve coordinated contractions of several muscle groups at the same time. For example, this could involve hitting one self or jumping.
Vocal tics are manifestations of motor tics that involve the muscles required for vocalization. Examples of vocal tics include stammering, stuttering, abnormal emphasis of words and inarticulate noises such as throat clearing and high-pitched sounds. Complex vocal tics typically involve the involuntary expression of words. The most obvious example of this is coprolalia, which is the involuntary expression of obscene words or phrases. Coprolalia typically occurs in less than one-third of people with Tourette syndrome.
Tourette syndrome usually occurs between infancy and the age of 18, with symptoms often occurring before early adolescence. Individuals with symptoms initially experience simple muscle tics involving the eyes and the head. These symptoms can eventually progress to tics involving the arms, neck, hands, upper torso, and in some cases, the legs and feet. Research suggests that increased stress levels can cause a greater severity and frequency of tics, while concentration on another part of the body that is not involved in a tic can result in the temporary alleviation of symptoms.
People with Tourette syndrome are generally more susceptible to symptoms of anxiety and depression. They may also be at a greater risk of having learning disabilities and personality disorders. In some cases, those with the condition are more likely to experience and demonstrate aggressive, anti-social or inappropriate sexual behaviors.
Tourette syndrome cannot be diagnosed via a blood test. Its diagnosis is also further complicated due to the fact that some tics appear to be within the range of normal behavior. Guidelines suggested for the diagnosis of Tourette syndrome include:
- Presence of both motor and vocal tics at some time during the course of the illness;
- The occurrence of multiple tics nearly every day through a period of more than one year - without a remission of tics for a period of greater than three consecutive months;
- The symptoms cause distress or impairment in functioning;
- Age of onset of prior to 18 years of age;
- The symptoms are not due to medications or drugs and are not related to another medical condition.
There is currently no cure for Tourette syndrome, although the disorder can be managed via a variety of treatments. These involve the control of symptoms through educational and psychological interventions or medications. Medication used for the effective treatment of tics includes haloperidol, pimozide, sulpiride and tiapride, all of which decrease the amount of dopamine in the body.
Psychological treatments such as counseling are not generally applied for the treatment of tics, although this method has been successful in the treatment of associated symptoms including obsessive-compulsive behavior and attention deficit hyperactivity disorder (ADHD). Such methods may also help suffers to cope with the causes of stress that trigger their tics. The education of family members, teachers and peers about the disorder has helped to foster acceptance and the prevention of social isolation.