Tourette’s Syndrome
Tourette’s syndrome (TS) is a neuropsychiatric disorder of childhood onset characterized by the presence of motor and vocal tics for a duration of at least 1 year. Tics are typically brief and stereotypical movements (eg, eye blinking, head jerks) or vocalizations (eg, throat clearing, grunting), but they can also be more complex movements involving multiple muscle groups and combinations of movements and sounds. There is a great range of tic severity. Tics can be so subtle or occur so infrequently as to be unnoticeable, even to the person with the tics. However, tics can also be so intense and frequent that they are readily noticeable by others, and they can be disruptive of daily activities. Indeed, in some cases (eg, severe head jerks), tics can cause pain or physical injury (eg, cervical disc and spine damage). Tics usually begin in childhood; the average age at diagnosis is 7 years. They reach peak severity in the early teen years and then lessen in intensity and frequency during young adulthood (Leckman et al., 2001). Tics wax and wane in severity, worsening with excitement and stress and improving during calm, focused activities. Coprolalia and its motor counterpart copropraxia (uttering obscene words or making obscene gestures, respectively) are uncommon symptoms, occurring in less than 10% of patients with TS and are not required for a diagnosis of TS (Robertson and Stern, 1998). Many patients describe a sensation or urge prior to tic occurrence, commonly referred to as a premonitory sensation or urge (Miguel et a1., 2000). Even though tics are considered involuntary, they can be voluntarily suppressed for short periods of time. Prevalence estimates of TS have varied and depend a great deal on the threshold for diagnosis and setting in which cases are identified. A review of the many epidemiologic studies suggests that 0.1% to 1% of people are affected with TS (Scahill et al., 2005). Despite this variability in specific rates, epidemiologic studies have consistently identified that males are more commonly affected than females, children are more frequently affected than adults, and that milder forms of TS are more common than severe forms.