Tourette Syndrome (TS) is a neurological or "neurochemical" disorder characterized by tics -- involuntary, rapid, sudden movements or vocalizations that occur repeatedly in the same way.

The cause has not been established, although current research presents considerable evidence that the disorder stems from the abnormal metabolism of at least one brain chemical (neurotransmitter) called dopamine. Very likely other neurotransmitters, such as serotonin, are also involved.

The most common first symptom is a facial tic, such as rapidly blinking eyes or twitches of the mouth. However, involuntary sounds, such as throat clearing and sniffing, or tics of the limbs may be the initial signs. For some, the disorder begins abruptly with multiple symptoms of movements and sounds.

The symptoms include:

1. Both multiple motor and one or more vocal tics present at some time during the illness although not necessarily in the same way;
2. The occurrence of tics many times a day (usually in bouts) nearly every day or intermittently throughout a span of more than one year;
3. The periodic change in the number, frequency, type and location of the tics, disappear for weeks or months at a time; and
4. Onset before the age of 18.

The term "involuntary" used to describe TS tics is a source of confusion since it is known that most people with TS do have some control over the symptoms. What is recognized is that the control which can be exerted from seconds to hours at a time, may merely postpone more severe outbursts of symptoms. Tics are experienced as irresistible as the urge to sneeze and must eventually be expressed. People with TS often seek a secluded spot to release their symptoms after delaying them in school or at work. Typically, tics increase as a result of tension or stress (but are not caused by stress) and decrease with relaxation or concentration on an absorbing task.

Individuals not only struggle with the condition itself, they must bear the double burden of the stigma attached.