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| Tourette syndrome |
Tourette syndrome (TS) is an inherited disease of the nervous system, first described more than a century ago by a pioneering French neurologist, George Gilles de la Tourette.
Before they are 18 years of age, patients with TS develop motor tics; that is, repeated, jerky, purposeless muscle movements in almost any part of the body.
Patients also develop vocal tics, which occur in the form of loud grunting or barking noises, or in some cases words or phrases. In most patients, the tics come and go, and are often replaced by different sounds or movements. The tics may become more complex as the patient grows older.
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TS is three times more common in men than in women. The motor tics, which usually occur in brief episodes several times a day, may make it very hard for the patient to perform such simple acts as tying shoelaces, not to mention work-related tasks or driving.
In addition, TS may have negative effects on the patient’s social development. Some patients have an irresistible urge to curse or use offensive racial terms (a condition called coprolalia), although these impulses are not under voluntary control.
Other people may not enjoy associating with TS patients. Even if they are accepted socially, TS patients live in fear of offending others and embarrassing themselves. In time, they may close themselves off from former friends and even relatives.
It is important to note, however, that the symptoms of Tourette syndrome are not always dramatic and are often overlooked in people with mild cases of the disorder.
A 2001 report published in Pain & Central Nervous System Week, in fact, states that TS is much more common than doctors had thought. A study of 1,596 special-education children in Rochester, NY, found that 8% met the criteria for TS, and 27% had a tic disorder.
In Rochester’s general population, 3% were found to have Tourette syndrome, and 20% had a tic disorder. The rate of 3% in the general population is 50–75 times higher than the usual estimates given.
The tics of TS are often described as involuntary, meaning that patients cannot stop them. This description is not strictly true, however. A tic is a very strong urge to make a certain motion or sound. It is more like an itch that demands to be scratched.
Some patients are able to control their tics for several hours, but once they are allowed expression, they are even stronger and last longer. Tics become worse when the patient is under stress, and usually are much less of a problem during sleep.
Some people with TS have trouble paying attention. They often seem grumpy and may have periods of depression. TS patients may think the same thoughts over and over, a mental tic known as an obsession. It is these features that place TS patients on the border between diseases of the nervous system and psychiatric illness.
In fact, before research showed that the brains of TS patients undergo abnormal chemical changes, many doctors were convinced that TS was a mental disorder. It still is not clear whether these behaviors are a direct result of TS itself or a reaction to the stress of having to live with the disease.
Causes and symptoms
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| Tauret syndrome symtomps |
Causes
Tourette syndrome has been linked to parts of the brain known as the basal ganglia, which regulate movements and are involved in concentration, paying attention, and decision-making.
Research has also demonstrated that in TS there is a malfunction in the brain’s production or use of important substances called neurotransmitters. Neurotransmitters are chemicals that control the signals that are sent along the nerve cells.
The neurotransmitters dopamine and serotonin have been implicated in TS; noradrenaline is thought to be the most important stimulant. Medications that mimic noradrenaline may cause tics in susceptible patients.
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TS has a genetic component. If one parent has TS, each child has a 50% chance of getting the abnormal gene. Seven of every 10 girls who inherit the gene, and nearly all boys who inherit it, will develop symptoms of TS.
Overall, about one in every 2,500 persons has full-blown TS. Three times as many will have some features, usually chronic motor tics or obsessive thoughts.
Patients with TS are more likely to have trouble controlling their impulses, to have dyslexia or other learning problems, and to talk in their sleep or wake frequently. Compulsive behavior, such as constantly washing the hands or repeatedly checking that a door is locked, is a common feature of TS. Compulsions are seen in 30–90% of all TS patients.
Recent research findings suggest that Tourette syndrome may also be related to an autoimmune response. A subset of TS patients have symptoms triggered by infection with Group A beta-hemolytic streptococci. In addition, blood serum antibodies against human basal ganglia have been found in patients with TS.
Symptoms
Motor tics in TS can be classified as simple or complex. Simple tics are sudden brief movements involving a single group of muscles or a few groups that may be repeated several times.
Complex tics consist of a repeated pattern of movements that can involve several muscle groups and usually occur in the same order. For instance, a boy with TS may repeatedly move his head from side to side, blink his eyes, open his mouth, and stretch his neck.
Vocal tics may be sounds or noises that lack all meaning, or repeated words and phrases that can be understood. Tics tend to get worse and better in cycles, and patients can develop new tics as they grow older. The symptoms of TS may get much better for weeks or months at a time, only to worsen later.
The following examples show why TS can be such a strange and dramatic disorder:
- Simple motor tics. These may include blinking the eyes, pouting the lips, shaking or jerking the head, shrugging the shoulders, and grimacing or making faces. Any part of the body may be tensed up or rapidly jerked, or a patient may suddenly kick. Rapid finger movements are common, as are snapping the jaws and clicking the teeth.
- Complex motor tics. These may include jumping, touching parts of the body or certain objects, smelling things over and over, stamping the feet, and twirling about. Some TS patients throw objects, others arrange things in a certain way. Biting, head-banging, writhing movements, rolling the eyes up or from side to side, and sticking out the tongue may all be seen. A child may write the same letter or word over and over, or may tear apart papers and books. Though they do not intend to be offensive, TS patients may make obscene gestures like “giving the finger,” or they may imitate any movements or gestures made by others.
- Simple vocal tics. These include clearing the throat, coughing, snorting, barking, grunting, yelping, and clicking the tongue. Patients may screech or make whistling, hissing, or sucking sounds. They may repeat sounds such as “uh, uh,” or “eee.”
- Complex vocal tics and patterns. Older children with TS may repeat a phrase such as “Oh boy,” “All right,” or “What’s that?” Or they may repeat everything they or others say a certain number of times.
Some patients speak very rapidly or loudly, or in a strange tone or accent. Coprolalia (saying “dirty words” or suggestive or hostile phrases) is probably the best known feature of TS, but fewer than one-third of all patients display this symptom.
Behavioral abnormalities that may be associated with TS include attention deficit hyperactivity disorder (ADHD) and disruptive behaviors, including conduct disorder and oppositional defiant disorder, with aggressive, destructive, antisocial, or negativistic behavior. Academic disorders, learning disorders, and sleep abnormalities (such as sleepwalking and nightmares) are also seen in TS patients.
Diagnosis
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| Tauret syndrome infographic |
There are no specific tests for TS. TS is diagnosed by observing the symptoms and asking whether relatives have had a similar condition. To qualify as TS, both motor and vocal tics should be present for at least a year and should begin before age 18 (or, some believe, age 21).
Often, the diagnosis is delayed because the patient is misunderstood not only at home and at school, but in the doctor’s office as well. It may take some time for the patient to trust the doctor enough not to suppress the strangest or most alarming tics. Blood tests may be done in some cases to rule out other movement disorders.
A test of the brain’s electrical activity (electroencephalograph or EEG) is often abnormal in TS, but not specific. A thorough medication history is very important in making the diagnosis as well, because stimulant drugs may provoke tics or aggravate the symptoms of TS.
Treatment
Although there is no cure for TS, many alternative treatments may lessen the severity and frequency of the tics. These include:
- Acupuncture. In one study, acupuncture treatment of 156 children with TS had a 92.3% effective rate.
- Behavioral treatments. Some of these can help TS patients control tics. A large variety of these methods exist, some with proven success.
- Cognitive behavioral therapy. This form of therapy helps the patient to change his or her ingrained response to a particular stimulus. It is somewhat effective in treating the obsessive-compulsive behaviors associated with TS.
- Neurofeedback (electroencephalographic biofeedback). In neurofeedback, the patient learns to control brain wave patterns; it may be effective in reducing the symptoms of TS. There are, however, no data on this modality as a treatment for TS.
- Psychotherapy. This form of treatment can help the TS patient, and his or her family, cope with depression, poor relationships, and other issues commonly associated with TS.
- Relaxation techniques. Yoga and progressive muscular relaxation are believed to help TS, especially when used in combination with other treatments, because they lower the patient’s stress level. One small study found that relaxation therapy (awareness training, deep breathing, behavioral relaxation training, applied relaxation techniques, and biofeedback) reduced the severity of tics, although the difference between the treatment group and control group was not statistically significant.
- Stress reduction training. This training may help relieve the symptoms of TS because stress worsens the tics.
- Other alternative therapies. Homeopathy, hypnosis, guided imagery, and eliminating allergy-provoking foods from the diet have all been reported as helping some TS patients.
Allopathic treatment
Most TS patients do not need to take drugs, as their tics do not seriously interfere with their lives. Drugs that are used to reduce the symptoms of TS include haloperidol (Haldol), pimozide (Orap), clonidine (Catapres), guanfacine (Tenex), and risperidone (Risperdal).
One interesting recent finding is that the transdermal nicotine patch, developed to help people quit smoking, improves the control of TS symptoms in children who take haloperidol. Use of the patch allows the haloperidol dosage to be cut in half without loss of effectiveness in symptom control.
Stereotactic treatment, which is high-frequency stimulation of specific regions of the brain, was reported to be successful in significantly reducing tics in a TS patient who had failed to respond to other treatments.
Expected results
Although there is no cure for TS, many patients improve as they grow older, often to the point where they can manage their lives without drugs. A few patients recover completely after their teenage years.
Others learn to live with their condition. There is always a risk, however, that a patient who continues having severe tics will become more antisocial or depressed, or develop severe mood swings and panic attacks.
Prevention
The only known way to prevent TS as of 2004 is for a couple not to have children when one of them has the condition. Any child of a TS parent has a 50% chance of inheriting the syndrome.
