What Are the Different Causes of Tourette Syndrome?

Tourette syndrome (TS), also known as Tourette's Syndrome or Gilles de la Tourette syndrome (GTS), is a neurological disorder first described by George Gilles de la Tourette in the late 1800s. It is culturally infamous for one of its least frequently occurring symptoms, coprolalia or verbalizations of profanity or socially inappropriate words. The predominant symptoms of Tourette syndrome and the criteria for a diagnosis, however, are physical or verbal tics. Tourette syndrome patients are predominantly male and the condition usually appears in childhood prior to puberty. Unfortunately, the specific causes of Tourette syndrome are unknown, but it is generally agreed by researchers to involve specific regions of the brain and major neurotransmitters, including dopamine and serotonin.

The tics of Tourette syndrome include both physical and verbal tics. Both tics types are further classified as simple or complex. Simple physical tics — sometimes overlooked as idiosyncrasies or attributed to other conditions prior to a formal diagnosis of TS — often include blinking, grunting, grimacing and jerking of the head, shoulders or arms. Complex motor tics are multi-step processes that may resemble the exacting routines of an individual with obsessive-compulsive disorder. Tics and their exhibition provide clues as to the causes of Tourette syndrome and the areas of the brain that may be involved.

Verbal tics are another symptom of Tourette syndrome. These tics may consist of specific but meaningless word repetitions or copying the phrases or words of another person, a symptom known as echolalia. The expression of tics both physically and verbally lends researchers additional valuable clues about the causes of Tourette syndrome. For instance, the brain's frontal lobe, known to be involved in language, has also been identified as an area of abnormal activity in TS.

Other clues as to the causes of Tourette syndrome include its primary appearance in males — who make up 75 percent of the TS population — as well as the usual age of onset, the medications that might be used to control symptoms and other conditions that frequently accompany this condition. For example, Tourette syndrome patients are predisposed to attention deficit hyperactivity disorder (ADHD), anxiety and depression. While the latter two conditions might sometimes be psychological responses to social ostracism secondary to TS symptoms, the association with ADHD helps researchers seeking different causes of Tourette syndrome. The effectiveness of drugs usually used to reduce or prevent seizures makes up another piece of the puzzle. Another important clue as to possible causes of Tourette syndrome is the inheritability of the disease, indicating a specific genetic component to the condition.