ABSTRACT

Tourette syndrome (TS) has been described as a developmentally regulated neurological disorder characterized by involuntary, repetitive, stereotyped movements (Albin & Mink, 2006; Chang, Tu, & Wang, 2004; Jankovic, 2001; Mink, 2003; Spencer et al., 1998). The Tourette Syndrome Classification Study Group (1993) has formulated a set of criteria for the diagnosis of TS. These include motor and vocal tics that cannot be explained by other medical conditions, lasting in excess of 1 year and with an onset during childhood (specifically before the age of 21). The cause of such tics is poorly understood but from the perspective of the sufferer they can have an apparent cause in the form of a prodrome. In other words, they are perceived as having been initiated by an urge or a sensation, and may increase during periods of stress. In particular, motor and phonetic tics are often preceded by premonitory sensations (such as burning sensation of the eye before an eyeblink tic, or a sore throat sensation before grunting), which are alleviated by the performance of the tic (Jankovic, 2001).