Tourette syndrome (TS) is an inherited disease of the nervous system, first described more than a century ago by the pioneering French neurologist, Dr. George Gilles de la Tourette. Before age 18, patients with TS develop motor tics, that is, repeated, jerky, stereotyped, purposeless muscle movementsin almost any part of the body. Vocal tics occur in the form of loudgrunting or "barking" noises or, in some cases, words or phrases. In most cases, the tics come and go, and they often are replaced by different types of sounds or movements, which may become more complex as the patient grows older.
TS is three times more common in men than in women. The motor tics, which usually occur in bouts several times a day, may make it very hard for the patient to perform simple acts like tying shoelaces, not to mention work-related tasks or driving. In addition, TS may be very detrimental socially. Some patients have an irresistible urge to curse or use offensive racial terms (a condition called coprolalia), though this is not under voluntary control. Other people may not wish to be with TS patients and, even if they are accepted, TS patients live in fear of shocking others and embarrassing themselves. In time,they may close themselves off from former friends and even relatives.
Research shows that, in TS, something is wrong with the way in which the brain produces or uses important substances called neurotransmitters, which control how signals are sent along the nerve cells. The neurotransmitters dopamineand serotonin have been implicated in TS; noradrenaline is thought to be themost important stimulant. Medications that mimic noradrenaline may cause tics in susceptible patients. Whatever the exact defect, it is handed down through the genes from parents to children. If one parent has TS, each child has a50% chance of getting the abnormal gene. Seven of every ten girls who inherit the gene, and nearly all boys who inherit it, will develop symptoms of TS.
Patients with TS are more likely to have trouble controlling their impulses,to have dyslexia (or other learning problems), and to talk during 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, seen in30-90% of all patients.
- A number of examples will show why TS can be such a strange and dramaticdisorder:
- Simple motor tics (blinking the eyes, pouting the lips, shakingor jerking the head, shrugging the shoulders, and grimacing or "making faces"). Rapid finger movements are common, as are snapping the jaws and clicking the teeth.
- Complex motor tics (jumping, touching part of the body orcertain objects, smelling things over and over, stamping the feet, and twirling about). Some TS patients throw objects, others arrange things in a certainway. Biting, head-banging, writhing (snake-like) movements, rolling the eyesup or from side to side, and sticking out the tongue all may 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 mean to, TS patients may make obscene gestures.
- Simple vocal tics (clearing the throat, coughing, snorting, barking,grunting, yelping, clicking the tongue). They may repeat sounds such as "uh,uh," or "eee."
- Complex vocal tics and patterns. Older children withTS 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. Somepatients speak very rapidly or loudly, or in a strange tone or accent. Coprolalia (saying "dirty words" or phrases that are sexual or aggressive) is probably the best known feature of TS, but fewer than one-third of all patients actually do this.
Behavioral abnormalities that may be associated with TS include attention-deficit/hyperactivity disorder (ADHD) and disruptive behaviors, includingconduct 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 alsoseen.
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 bepresent for at least a year and should begin before age 18 (or, some believe, age 21). There are no specific tests for TS. Often, the diagnosis is delayed because the patient is misunderstood not only at home and at school, but often in the doctor's office as well. It may take some time for the patient totrust the doctor enough not to suppress the strangest or most alarming tics.A test of the brain's electrical activity (electroencephalograph or EEG) is often abnormal, but not specific. Medication history is very important in making the diagnosis as well, because stimulant drugs may provoke tics or aggravate the symptoms of TS.
A majority of patients with TS do not need to take drugs, as their tics do not interfere much with their lives, and they develop normally. In serious cases, a drug used to treat severe mental illness, such as haloperidol (Haldol) or pimozide (Orap), is given, starting with a very low dose and increasing until the tics respond without side effects occurring. Researchers are developing new antipsychotic drugs that may be targeted to particular symptoms of TS.