Tourette's syndrome

Question 1

Tourette’s syndrome

Answer 1

Tourette’s syndrome is a form of tic disorder in which there are multiple motor tics and one or more vocal tics.

Question 2

Tic

Answer 2

A tic is an involuntary, rapid, recurrent, non-rhythmic motor movement (usually involving circumscribed muscle groups), or vocal production that is of sudden onset and serves no apparent purpose. Tics tend to be experienced as irresistible but they can be suppressed for varying periods of time. Tics disappear during sleep.

Question 3

Factors which differentiate tics from other motor disorders

Answer 3

Lack of rhythmicity differentiates tics from the stereotyped repetitive movements seen in autism and mental retardation. Stereotypies can be classified into simple movements (such as rocking, tapping, hugging, and lip biting) and complex movements (which include ritualistic behaviors such as spitting into a hand and smearing it in a particular fashion, or running forward a set number of paces then running backwards, repeated raising and lowering of the arms, waving and flapping of the arms and hands, and finger wiggling). The most typical stereotypies include rocking, hugging, self-touching, patting, grunting, foot tapping, leg swinging, and hair pulling.

Manneristic motor activities tend to form more complex and variable movements than those seen with tics. A mannerism is an odd, voluntary, idiosyncratic method of performing a task that is unique to an individual and serves no apparent function (i.e. a person who cocks an arm in a peculiar way in order to drink from a cup). Patient’s are often unaware of their mannerisms.

Obsessive compulsive acts sometimes resemble complex tics but differ in that their form tends to be defined by their purpose (such as touching the same object or turning a number of times.

Onset is usually in childhood (the mean age of onset is six to seven years). There is often a history of motor tics preceding vocal tics. As many as 80% of affected individuals with tics will have outgrown them by adult life (in most cases, tics peak in severity between nine and 11 years of age). The estimated prevalence is 1% of children (Maudsley guidelines).

Tics tend to wax and wane and are exacerbated by external factors such as stress, inactivity, and fatigue. Tics are 3-4 times more common in boys than girls and a family history of tics is common.