INTRODUCTIONTourette syndrome (TS) is a childhood-onset movement disorder entailing vocal tics and multiple motor tics (1). Although the definite pathophysiology of TS is not yet known, there is a hypothesis that the basal ganglia and related thalamocortical circuitry are involved (2, 3).Most of the existing structural neuroimaging studies on TS were on the basal ganglia, corpus callosum, and lateral ventricle (4-10). Functional neuroimaging studies of TS using positron emission tomography (PET) suggest that the cortical system (especially, the frontal lobe area) is related with the pathophysiology of TS (11)(12)(13)(14). However, structural neuroimaging studies of TS on the cerebrum are rare, and a recent regional cerebral volumetric study reported that the broadly distributed cortical systems are involved in the pathophysiology of TS (15). Compared with controls, TS subjects were found to have larger volumes in the dorsal prefrontal regions, and larger volumes in the parieto-occipital regions, but smaller volumes in the inferior occipital regions. Nevertheless, the gray matter and white matter were not segmented in previous cerebral neuroimaging studies, needing studies on whether the pathophysiology of TS is related with the gray matter or the white matter. Previous studies posed many problems related with study methods since they did not control the effect of the disorders that frequently accompany TS including attention-deficit/hyperactivity disorder (ADHD) and obsessivecompulsive disorder (OCD), and various confounding variables including drug-effect, age, sex, and handedness that could affect neuroimaging studies (3).Traditionally, the cerebellum has been viewed as a motor coordination center (16). Studies are also needed on the cerebellum related with TS since TS is basically a movement disorder and abnormality is reported in the cerebellar vermal area in patients with ADHD, which frequently accompany TS (17, 18). However, no neuroimaging study on TS related with the cerebellum has been reported according in the literature.This structural neuroimaging study of segmented regional cerebral and cerebellar volumes tested the following three hypotheses; 1) The segmented cerebral regional volumes (especially, the frontal lobe, parietal lobe, and occipital lobe) J Korean Med Sci 2002; 17: 530-6 ISSN 1011-8934 Copyright ïżœ The Korean Academy of Medical Sciences
530The Segmented Regional Volumes of the Cerebrum and Cerebellum in Boys with Tourette SyndromeNeuropathological deficits are an etiological factor in Tourette syndrome (TS), and implicate a network linking the basal ganglia and the cerebrum, not a particular single brain region. In this study, the volumes of 20 cerebral and cerebellar regions and their symmetries were measured in normal boys and TS boys by brain magnetic resonance imaging. Brain magnetic resonance images were obtained prospectively in 19 boys with TS and 17 age-matched normal control boys. Cerebral and cerebellar regions were segmented to gray and white fractions using algorithm for ...