Tics are rapid, purposeless, repetitive but not rhythmic involuntary movements that are virtually identical to one another. They can be suppressed but only for a short time and only with conscious effort.
Tics may be simple or complex. Simple tics, such as excessive blinking, grimacing, or head jerking, may begin as nervous mannerisms. Complex tics, such as those that occur in Tourette's syndrome, often resemble fragments of normal behavior.
Tics, especially simple tics, can occur on their own. Many of these tics begin during childhood and disappear without treatment. Or tics can occur as part of another disorder, such as Huntington's disease, obsessive-compulsive disorder, some infections, or a stroke. Some drugs and toxins cause tics.
Before a tic occurs, people may feel an urge to do the tic. This urge is similar to the need to sneeze or scratch an itch. Tension builds up, usually in the affected body part. When people give in to the tic, they feel relief briefly.
The tic can sometimes be postponed for seconds to minutes, but usually it eventually becomes irresistible. Most people have trouble controlling tics, especially during times of emotional stress. However, some people can suppress some tics, usually with difficulty. Calling attention to a tic, particularly in children, may make the tic worse.
For people with a simple tic (particularly children), reassurance is often best, with as little attention paid to the tic as possible.
If tics are particularly troublesome, they can be treated with drugs. For simple tics, benzodiazepines, such as clonazepam and diazepam, may help. These drugs are mild sedatives taken by mouth. Clonidine, a drug used to treat high blood pressure, occasionally helps. It blocks the action of norepinephrine, a neurotransmitter that is thought to contribute to tics. Side effects may include excessively low blood pressure.
For severe tics, antipsychotic drugs may be effective even though psychosis is not the cause of tics (see Movement Disorders: Severe Symptoms). Or botulinum toxin can be injected into the affected muscle, paralyzing it and thus preventing the tic.
Tourette's syndrome is a hereditary disorder characterized by simple and complex muscle and vocal tics that occur frequently throughout the day for at least one year.
Tourette's syndrome is common, affecting possibly as many as 1 of 100 people. It is 3 times more common among men than among women. It often begins in early childhood. In most people, symptoms are so mild that the disorder is not recognized.
The cause is unknown but is thought to be an abnormality in dopamine or another brain neurotransmitter (a chemical messenger that nerve cells use to communicate). Genes are involved, but their precise role and the specific genes involved are unknown.
Tourette's syndrome often begins with simple muscle tics, such as grimacing, head jerking, and blinking. Simple tics may be only a nervous habit and may disappear with time. Such tics do not necessarily lead to Tourette's syndrome, which involves more than a simple tic. For example, people with Tourette's syndrome may repeatedly move their head from side to side, blink their eyes, open their mouth, and stretch their neck.
The disorder may progress to bursts of complex tics, including vocal tics, hitting, kicking, and sudden, irregular, jerky breathing. Vocal tics may start as grunting, snorting, humming, or barking noises and progress to compulsive, involuntary bouts of cursing. For no apparent reason and often in the midst of conversation, some people with Tourette's syndrome may call out obscenities or words related to feces (called coprolalia). These vocal outbursts are sometimes mistakenly thought to be intentional, especially in children. Although coprolalia is a well-known feature of Tourette's syndrome, at least 85% of people with Tourette's syndrome do not have coprolalia. People may also repeat words immediately after hearing them (called echolalia).
People with Tourette's syndrome often have difficulty functioning and experience considerable anxiety in social situations. In the past, they were shunned, isolated, or even thought to be possessed by the devil. Impulsive, aggressive, and self-destructive behaviors develop in many people, and obsessive-compulsive behavior develops in about half. Children with Tourette's syndrome often have difficulty learning. Many also have attention-deficit/hyperactivity disorder. Whether Tourette's syndrome itself or the extraordinary stresses of living with the disorder cause these problems is unclear.
The diagnosis is based on symptoms. Early diagnosis can help parents understand that the tics their children have are not voluntary and that punishment cannot stop the tics and may even make them worse.
If symptoms are mild, drugs may not be needed.
Doctors often first try clonidine or guanfacine. Clonidine, a drug used to treat high blood pressure, occasionally helps and is particularly useful in controlling anxiety and obsessive-compulsive behavior. Benzodiazepines, such as clonazepam and diazepam, may help. These drugs are mild sedatives taken by mouth.
Antipsychotic drugs may be used to help suppress the tics, even though psychosis is not the cause. The lowest dose needed to make tics tolerable is used, and doses are decreased as tics lessen. Haloperidol, the most commonly used antipsychotic drug, is effective but is more likely to have side effects than other antipsychotic drugs, such as olanzapine, pimozide, and risperidone.
Side effects of antipsychotics (see Schizophrenia and Delusional Disorder: Antipsychotic Drugs) may include symptoms similar to those of Parkinson's disease (parkinsonism), restlessness, muscle stiffness, sustained involuntary muscle contractions (dystonias), weight gain, blurred vision, sleepiness, and dulled, slowed thinking. Tardive dyskinesia, which consists of repetitive involuntary movements, may develop and persist even after the drug is stopped. Uncontrollably, the arms or legs writhe, the tongue protrudes, and the lips pucker, purse, and smack. A rare but more serious side effect called neuroleptic malignant syndrome consists of high fever, high blood pressure, muscle damage, and coma.
Injecting botulinum toxin into the muscles producing the tics may decrease the abnormal movements as well as the urge that precedes them. Botulinum, the bacterial toxin that causes botulism, is used to paralyze muscles (and to treat wrinkles).
Deep brain stimulation is considered an experimental treatment for Tourette's syndrome, but it is sometimes done in special centers when the disorder is severe and drugs have been ineffective. Electrodes are placed in the parts of the brain thought to be involved in tics.
Last full review/revision August 2007 by David Eidelberg, MD; Michael Pourfar, MD