Tourette Syndrome Foundation of Canada

http://www.tourette.ca/

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.