ABSTRACT
Tourette syndrome, a chronic tic disorder with autosomal dominant inheritance, exhibits considerable phenotypic variability even within monozygotic twin pairs. The origins of this variability remain unclear. Recent findings have implicated the caudate nucleus as a locus of pathology, and pharmacological evidence supports dopaminergic involvement. Georges Gilles de la Tourette originally described Tourette syndrome (TS) in 1885 as a neuropsychiatric disorder characterized by chronic motor and vocal tics that begin in childhood. TS is found in all cultures and racial groups; although an accurate prevalence rate for TS has not been established, it is increasingly recognized as being a relatively-common disorder. The caudate nucleus is a key node in certain behavior-linked neural circuits, which are distinct from putamcnal motor circuits.
