Cerebral morphometric abnormalities in Tourette's syndrome

Abstract

Although the pathologic substrate of Tourette's syndrome (TS) is unknown, studies have implicated subtle changes in the basal ganglia. To further investigate structural basal ganglia pathology in TS, we performed morphometric analyses of MRIs of 10 monozygotic twin pairs discordant for severity of TS but concordant for the presence of tic disorders (mean age, 16.3 years; range, 9 to 31 years). Right caudate volume was slightly but significantly reduced in the relatively more severely affected twins as a group compared with the less affected twins (mean difference = 6%, p < 0.01). Most of this difference was attributable to volume reduction in the anterior right caudate (p < 0.02), which was smaller in the more severely affected twin in nine of 10 twin sets. The mean volume of the left lateral ventricle was 16% smaller in the more severely affected twins than in the less severely affected twins (p < 0.01). The normal asymmetry of the lateral ventricles (left greater than right) was not present in the more severely affected twins, who had a trend toward a larger right lateral ventricle. Moreover, the difference within a pair in the degree of loss of the normal ventricular asymmetry correlated with the difference within a pair in the severity of the tic disorder (r = 0.75, p < 0.02). There were no other basal ganglia, ventricular volumetric, or asymmetry abnormalities. These findings partially replicate other MRI studies and suggest that subtle structural abnormalities in the CNS, particularly in the caudate, may play a role in the pathophysiology of TS.(ABSTRACT TRUNCATED AT 250 WORDS)

Postural control anomalies in children with Tourette syndrome

“…Alternatively, the postural control deWcit observed in TS could be related to basal ganglia dysfunction. The basal ganglia are strongly connected to the pedunculopontine tegmental nucleus (PTN) which projects to reticulospinal systems involved in posture (Hyde et al 1995;Shink et al 1997). There is evidence of mesencephalic anomalies in TS (Garraux et al 2006).…”

“…Increased white matter and asymmetry in the frontal lobe was shown in TS (Hong et al 2002). Also, reduced volume, abnormal asymmetries (Hyde et al 1995;Peterson et al 1993;Singer et al 1993) as well as increased dopamine binding within the caudate nucleus (Malison et al 1995;Wolf et al 1996) have been observed in TS. In addition, abnormal blood Xow was found in both basal ganglia and the frontal lobe in patients with TS (Buckingham et al 1993;Diler et al 2002).…”

Minor physical anomalies in Tourette syndrome

“…Our study on the minor physical anomaly profile in Tourette patients emphasize the scientific importance of previous studies on the structural morphology among patients with this disorder 4,6,8 . Hyde et al 7 performed a morphometric analyses of magnetic resonance imagings of 10 monozygotic twin pairs discordant for severity of Tourette syndrome but concordant for the presence of tic disorders. In the relatively more severely affected twins they could demonstrate significantly reduced volumes of the right caudate, while the mean volume of the left lateral ventricle was 16% smaller in the more severely affected twins than the less severely affected twins.…”

“…Both structural and functional neuroimaging studies have contributed to the understanding the aetiology of the syndrome. Studies using structural magnetic resonance imaging found decreased volume of the left basal ganglia [4][5][6] , while other studies reported abnormal size of the corpus callosum and enlarged right lateral ventricle 7,8 . As in other disorders (autism, attention-deficit hyperactivity disorder, dyslexia, schizophrenia, bipolar affective disorder, obsessive-compulsive disorder) from the neurodevelopmental spectrum 9,10 , results from structural neuroimaging studies can get a parallel support by investigations on the phenotypical marker profile.…”

Neurocognitive Aspects of Tourette Syndrome and Related Disorders

“…Other MRI and positron emission tomography (PET) studies consistently reported volumetric and metabolic reductions in lentiform (Braun et al, 1995;Eidelberg et al, 1997) and caudate nuclei (Bloch, Leckman, Zhu, & Peterson, 2005;Hyde et al, 1995;Stoetter et al, 1992). The basal ganglia are not the sole cerebral structures involved in the pathogenesis of GTS.…”