Abstract
Metabolic Brain Disease, Vol . 10, No . 2, 1995 Review Article P.R. Chokkal, G .B. Bakerh3 , R.A. Bornstein2 and C.M. de Groot2 INTRODUCTION Tourette's Syndrome (TS) is a childhood-onset, familial, chronic neuropsychiatric disorder described in 1885 by Georges Gilles de la Tourette (Shapiro et al., 1988). Once thought to be a rare condition, the prevalence figure in a survey in North Dakota was estimated to be 0 .5 per thousand (Burd et al., 1986) . Even this figure may be an underestimate, with an incidence as high as 1 out of every 169 school-age children being al., reported in a study from California (Comings et 1991) . TS is characterized by motor tics primarily involving the face, head, neck and shoulders and phonic tics resulting from contraction of respiratory, laryngeal, oral and nasopharyngeal musculature (Jankovic, 1992 ; ., . The syndrome can present anywhere from Scahill et al 1993 ; Suchowersky, 1994) infancy to adulthood, and the mean age of onset is around 7 years, although the diagnosis is often not established until the mid-teens (Bruun, 1988) . TS is 3-4 times more common al., in males than in females (Moldofsky et 1974) . The most accepted