You may think you know what Tourette syndrome is. To many Americans, it is a rare condition in which a person constantly twitches and has outbursts filled with obscenities. These thoughts are not necessarily our fault -- most of us probably got our information on Tourette's from not-so-reliable sources like TV dramas and sitcoms. So to begin, throw out what you think you know.
First, Tourette syndrome isn't as rare as you might think. An estimated one in 100 people suffers from a mild form of the syndrome, and about 200,000 Americans have the most severe form. Second, patients suffering from Tourette syndrome are not constantly twitching. The twitches, referred to as motor tics, actually often occur in intermittent bouts. Some patients experience them daily, and others have them less frequently. Tics can include actions like eye-blinking, foot-stomping and grimaces.
Probably the biggest misconception about Tourette syndrome is that those suffering from the condition are frequently belting out obscenities, a symptom known as coprolalia. This symptom actually occurs in less than 15 percent of Tourette's sufferers. Tourette syndrome can be defined as a tic disorder in which the patient suffers from several motor tics and at least one vocal tic, both of which begin in childhood or adolescence.
Now that we've cleared that up, let's find out what Tourette's is actually about.
Tourette Syndrome Origins
The history of Tourette syndrome dates back to the early 1800s. Its namesake is Gilles de la Tourette, a French physician. Another French doctor, Jean Marc Gaspard Itard, actually reported the first case of the syndrome in 1825. He described the symptoms of the Marquise de Dampierre, an 80-year-old woman of nobility who had suffered since the age of 7 from repetitive movements and vocalizations. In 1885, de la Tourette published "Study of a Nervous Affliction," his account of nine patients at a French hospital who were afflicted with involuntary movements. And so, the "tic illness" came to be known as the Gilles de la Tourette syndrome.
It wasn't until the 20th century that any real progress was made in further defining and treating Tourette syndrome. We now know that Tourette syndrome does have a genetic origin and that it usually first occurs around the age of 6 or 7 and always before the age of 18. The tics are normally most severe around the ages of 8 to 12 and decrease steadily after that. The syndrome is a dominant gene and has about a 50 percent chance of passing from parent to child. We also know that boys tend to get Tourette syndrome three to four times more often than girls. However, people who have the gene don't necessarily suffer from a noticeable form of Tourette syndrome. They might not develop any symptoms, or they could suffer from a mild form that may go undetected.Now let's find out what scientists think may cause this syndrome.
Tourette Syndrome Causes
Scientists are not sure what causes Tourette syndrome and many other brain disorders. We know that it is inherited in the majority of cases. But we don't know the exact mode of inheritance, and scientists have not yet found a specific Tourette's gene. What they can seem to agree on is that the tics of Tourette syndrome result from abnormalities in the brain. Specifically, they have pinpointed dysfunctions in the thalamus, basal ganglia and frontal cortex of the brain, as well as dysfunctions in the neurotransmitters between the brain's nerve cells.
Scientists suspect these parts of the brain because of their roles in brain function. The thalamus works to relay sensory and motor information to the cerebral cortex and the brain stem. The basal ganglia is located at the base of the brain and works in the coordination of motor movements. Therefore, disorders of the basal ganglia usually result in a patient whose movements are unintentional and occur unexpectedly. The frontal cortex is located, as the name suggests, in the front of the brain, directly behind the forehead. This part of the brain is in charge of controlling skilled motor activity, which includes speech.
Abnormalities in the neurotransmitters -- specifically, excessive amounts of the neurotransmitter dopamine -- may be involved in the syndrome as well, with some suggesting that it could be the underlying mechanism of Tourette's. Dopamine works in the brain to help regulate normal movement and emotions. Therefore, any disruption can change these factors. Decreased levels of dopamine have been a suggested cause of Parkinson's disease, an affliction that is characterized by slow movements, facial paralysis and overall weakness. In patients with excessive amounts of dopamine, sudden, spasmodic, involuntary muscular contractions, like those found in Tourette's, would be expected.
Now let's find out about the many different symptoms of Tourette syndrome.
Tourette Syndrome Symptoms
A myriad of symptoms can be attributed to Tourette syndrome. However, some of the most well known, like bursts of obscenities, are the rarest symptoms. The most common symptoms are usually normal activities, like eye-blinking, performed in repetition. Some common symptoms may be so slight that many observers would not notice them at al
A tic is a sudden, spasmodic, involuntary muscular contraction that usually occurs in midline body regions like the face, neck, pharynx, shoulders and torso. These tics can be classified by type (motor or vocal) and severity (simple or complex). A motor tic involves involuntary movements, and a vocal tic involves involuntary utterances. A simple tic is a sudden, spasmodic, involuntary contraction of only a small number of muscle groups. A common example of a simple motor tic is eye-blinking, and a simple vocal tic could be throat-clearing. A complex tic involves distinct and coordinated patterns of many different muscle groups. A common example is eye-blinking coupled with shoulder shrugs and facial grimaces. A complex vocal tic involves spontaneous expression of words or phrases.
The location of a patient's tics can change, but they usually begin in the face and neck. The most common initial tics are eye-blinking and facial movements. Over time, tics tend to spread in a downward progression. From the face and neck, tics could progress to the arms and hands, with patients shrugging their shoulders or clenching their fists. They can then move on through the body and lower extremities, possibly causing patients to stomp their feet or walk peculiarly. Finally, the tics can progress to the respiratory and alimentary(digestive) system, where they can include hiccuping, whistling, belching and throat-clearing.
The tics can change in frequency, location and severity and are usually preceded by an urge. Patients describe this urge as a rising tension that is released by the tic. Patients can suppress their tics for a short time period, which usually results in a more severe tic later. Tourette's tics can increase in times of emotional stress or if the patient sees someone perform their involuntary action. For example, a patient who suffers from a motor tic like repetitive sniffing may be triggered by hearing someone else sniff. Tics can decrease in times of intense focus or during sleep.
Other Movement Disorders
While Tourette's is classified under the large umbrella of movement disorders, and more specifically as a tic disorder, there are other disorders that cause tic-like movements. So how can you tell Tourette's from another movement disorder?
There are many movement disorders, neurological conditions that can affect a person's movement by changing the speed, fluency, quality and ease of a given movement. A few are commonly confused with Tourette syndrome.
- Chorea: rapid, involuntary movements that are commonly seen in Huntington's disease. These tics occur throughout the body and are more unpredictable than Tourette's tics.
- Dystonia: repetitive muscle contractions that may result in jerking movements. These movements are more prolonged than Tourette's tics.
- Stereotypic movement disorder: involves repetitive motions like hand-waving. Patients usually have symptoms before the age of 2, and their movements tend to happen on both sides of the body and in the extremities. The tics are also longer in duration than Tourette's tics.
- Myoclonus: brief, involuntary twitches of a muscle or muscles that are shorter than Tourette's twitches
Now we'll find out how Tourette's is diagnosed.
Diagnosing Tourette Syndrome
Tourette's diagnosis is an exclusionary process. This means that doctors have to rule out all other causes of the patient's symptoms before they diagnose Tourette's. They use EEGs, MRIs and blood tests to test for other possible causes, which can include seizures, brain abnormalities, hyperthyroidism and movements induced by drugs.
Once they rule out all other possibilities, doctors diagnose Tourette's through determining the age of onset and observing movements. The tics must begin before the patient is 18 years old. Patients must display multiple motor tics and at least one vocal tic. The motor and vocal tics do not have to occur at the same time, but they both must be experienced in the same year. Within that year, the patient can't have more than three consecutive "tic-free" months.
If the patient does not meet these rather strict criteria, he may be suffering from another type of tic disorder. If he has motor tics (but not vocal tics) daily or week;y for more than a year, he may be diagnosed with a chronic motor tic disorder. If he has vocal tics but not motor tics, chronic vocal motor tic disorder could be the diagnosis. A person who displays both motor and vocal tics, but for less than a year, could have a transient tic disorder.
Several conditions, including obsessive-compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD), have been linked with Tourette syndrome. In fact, because of the lack of definitive testing and the possibility of mild symptoms, doctors often diagnose Tourette's after a child has been diagnosed with OCD or ADHD. Learning and sleeping disorders are also common in with patients with Tourette's. Doctors often diagnose these conditions first because they cause a disturbance, or impairment, in the patient's life.
Scientists continue to study the link between ADHD and Tourette's and between OCD and Tourette's. Some studies suggest that patients with Tourette's are 20 times more likely to display the symptoms of OCD. In addition, relatives of Tourette's patients have high rates of OCD, and OCD patients have a higher chance of having a child with Tourette's syndrome. All of these factors lead scientists to suspect a similar genetic component for each of the disorders. While OCD and Tourette's have a rather clear genetic relationship, ADHD and Tourette's don't seem to have such obvious ties. However, it has been shown that more than 25 percent of patient's with Tourette's also suffer from ADHD.
After diagnosis comes treatment. See what works in treating Tourette's.
Tourette Syndrome Treatments
There is no cure for Tourette's, but there are several ways to control it. Treatments include behavioral therapy, daily medications and deep brain stimulation, and the choice is dependent on how much the syndrome affects the person's life.
Behavioral changes are indicated for patients with mild symptoms, but this treatment should be attempted before or in conjunction with other therapies. Common behavioral changes include relaxation techniques that relieve stressors and may help reduce the frequency of tics. Cognitive behavioral therapy can be helpful in patients suffering from both Tourette's and obsessive-compulsive disorder. This is a psychotherapy that works by modifying assumptions, beliefs and behaviors in an effort to influence disruptive behaviors.
Habit reversal therapy is a type of behavioral therapy that has been shown to be successful in patients suffering from tics. The therapy has five components: awareness training, competing response training, contingency management, relaxation training and generalization training. Experts believe that the competing response part is the key to the therapy's success. A patient suffering from tics is trained to better identify when a tic is going to occur. When he has an urge to tic, he performs a competing response -- usually an action that uses the same muscles as the tic would use. For example, if he suffers from a shoulder-shrugging tic, a competing response would be to stretch the neck muscles and push the shoulders down.
Most Tourette's patients need medication only if and when their symptoms are severely interfering with their daily lives. Doctors usually avoid medication for several reasons: side effects, the large variation in the severity of a patient's tics, and because the majority of tics can be controlled with support and awareness. While there are no medications specifically for the suppression of tics, doctors can prescribe several types of medication, with different degrees of success, for the control of Tourette's symptoms. The most commonly used are antipsychotics like pimozide or haloperidol.
Antipsychotics work by blocking receptors, including dopamine receptors, inside and outside the central nervous system. Many scientists believe that excessive levels of dopamine in the brain could contribute to Tourette's. So, dopamine-receptor blockage should help to reduce the amount of dopamine in the brain and, therefore, reduce some symptoms. However, doctors often avoid these drugs because of their possible side effects, many of which can be worse than Tourette's itself. They include severe muscle spasms throughout the body, drooling, tremors, extreme restlessness, sexual dysfunction, seizures and even the development of breasts in male patients.
If a patient requires medication, doctors should consider any concurrent condition (such as OCD or ADHD). A patient suffering from both Tourette's and ADHD may benefit from stimulants like Ritalin. A Tourette's sufferer who also has OCD may benefit from antidepressants known as SSRIs, like Prozac and Zoloft.
Finally, if a patient has pronounced, debilitating symptoms and has not gotten relief from the treatments mentioned above, deep brain stimulation (DBS) may be an option. In DBS, surgeons implant tiny electrodes into the brain to act like a pacemaker. The electrodes are connected to wires from a small battery pack installed in the patient's chest. This pacemaker works much like a pacemaker that stimulates the heart, but it sends electrical impulses to specific areas in the brain. It usually targets the thalamic region, which controls movement, and blocks abnormal firing of neurons. This type of treatment has successfully treated other movement conditions, like Parkinson's disease. However, DBS is still considered experimental in patients with Tourette's syndrome due to the small number of patients who have received the surgery and the even smaller number who have found relief from it.
For more information about Tourette syndrome, check out the links on the next page.
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More Great Links
- Emedicine: Tourette Syndrome and Other Tic Disorders. http://www.emedicine.com/neuro/topic664.htm
- Tourette Syndrome Association. http://www.tsa-usa.org/
- National Institute of Neurological Disorders. http://www.ninds.nih.gov/disorders/tourette/detail_tourette.htm