People with Tourette syndrome display unusual behaviors over which they have very little control. They may repeatedly blink their eyes, shrug their shoulders or stamp their feet. They may echo everything someone says, or have the urge to cough or sniff continually. They might even shout obscenities.

All these odd behaviors are called tics. With great effort and concentration, people with Tourette syndrome can sometimes suppress their tics, or at least postpone them until they can be expressed in a more convenient time and place. But most tics must be expressed eventually.

At least 100,000 Americans have Tourette syndrome. The condition is named for the French neurologist who first described the condition in 1885 and is also referred to as Tourette's syndrome. Its symptoms typically begin when children are in grade school, with males outnumbering females three to one. While there is no cure, medication can reduce symptoms. Many children outgrow Tourette syndrome after adolescence.

The first symptom of Tourette syndrome is usually a facial tic, such as eye blinking. As many as 1 in 200 children develops tics that last only a few weeks or months and then stop. Tourette syndrome, however, involves multiple motor and vocal tics that have lasted longer than a year.

When tics occur over a period of less than six months, their presence may be referred to as a transient tic disorder. A chronic tic disorder is one in which only motor tics are present and the course is longer than six months.

Tics can range from mild to severe and may include grimaces, head jerking or body twisting. The individual may touch other people excessively or repeat actions obsessively. Some tics are vocal, such as grunting, coughing or barking.

Tics can:

• Come and go
• Worsen or improve
• Change to entirely different tics
• Subside for months and then recur

In rare cases, people with Tourette syndrome may actually harm themselves by repeatedly biting their lips or cheeks, or banging their heads against hard objects.

The exact cause of Tourette syndrome is unknown, but it appears to be linked to the gene or genes that control the chemicals that carry signals from one brain cell to another. About a third of people with the disorder have relatives with Tourette syndrome, while another third have family members with milder tic disorders.

Families of people with Tourette syndrome also tend to have a higher incidence of obsessive-compulsive behaviors and attention deficit-hyperactivity disorder.

A family history of Tourette syndrome or other tic disorders is the strongest risk factor. Many people with Tourette syndrome also have problems with:

• Obsessive compulsive disorder, an intense need to perform certain acts repeatedly, such as hand washing or checking to be sure that a door is locked
• Attention deficit-hyperactivity disorder, difficulty concentrating and staying on task
• Learning disabilities, problems with reading, writing and math
• Sleep disorders, frequent awakenings or talking in sleep

There is no laboratory test to diagnose Tourette syndrome. Instead, doctors must rely on the history of the person's symptoms. The main criterion for a diagnosis of Tourette syndrome is the presence of both types of tics, movement and vocal, for at least a year.

Diagnosis often is delayed because many physicians are unfamiliar with the disorder. Tourette's symptoms can play a game of hide-and-seek with your doctor, as the tics can come and go, or even be suppressed during doctor visits. In some cases, the symptoms are incorrectly attributed to psychological or behavioral problems.

Most people with Tourette syndrome don't require medication. However, if symptoms interfere with your ability to function, the following medications may help:

• Anti-psychotic drugs, such as olanzapine (Zyprexa) and risperidone (Risperdal), can help reduce Tourette's symptoms. But they often produce unpleasant side effects, such as drooling, muscular rigidity, tremor, and lack of facial expression. Drugs used to treat Parkinson's disease often can reduce these side effects.
• A blood pressure medication called clonidine (Catapres) also helps reduce tics. However, it controls motor tics more effectively than vocal tics. Common side effects include fatigue, dry mouth, irritability, dizziness, headache and insomnia.
• Antidepressants — such as fluoxetine (Prozac), citalopram (Celexa), sertraline (Zoloft) and paroxetine (Paxil) — help control the obsessive-compulsive behavior that often accompanies Tourette syndrome.
• Stimulants are used to combat the attention deficit-hyperactivity disorder symptoms that often occur with Tourette syndrome. Two of the most commonly used are methylphenidate (Ritalin, Concerta) and dextroamphetamine (Adderall). Stimulants may increase tics in some individuals. Atomoxetine (Strattera) has been shown to improve attention without worsening tics.

It's important to understand that people with Tourette syndrome have very little — if any — control over their tics. In fact, focusing too much on the tics can make them worse.

Psychotherapy can't make Tourette syndrome disappear, but it can help people learn to cope with the social and emotional problems that often result. Because tics tend to worsen with stress, relaxation techniques can help reduce the frequency and severity of the symptoms of Tourette syndrome.

A student with Tourette syndrome may have trouble functioning in a traditional classroom. In addition to the tics, he or she also may have to contend with attention deficit-hyperactivity disorder, learning disabilities and sleep disorders, all of which can make adjustment even more challenging.

Such students may require special assistance from the school district to help address their learning issues. Learning specialists may give the student a number of educational and psychological tests. Using the results of these tests, the student's parents, teachers and counselors develop an Individualized Educational Program (IEP) that outlines his or her goals and the instructional methods to achieve them.

People with Tourette syndrome are capable of functioning perfectly well in family, social and vocational settings. Tics may be disconcerting and uncomfortable, but they shouldn't prevent anyone from living a normal, active life.