RESUMEN
OBJECTIVE: To investigate the microstructural integrity of basal ganglia and thalamus in children with first episode drug-naive Tourette's syndrome (TS) by diffusion tensor imaging (DTI). METHODS: Ten right handed patients with TS (mean age = 8.1 +/- 2.7 years old, 7 males and 3 females) and 10 age and gender-matched healthy control subjects (mean age = 9.5 +/- 1.6 years old, 9 males and 1 female) were recruited. All of the participants had normal findings on conventional MRI. DTI was performed using a 3.0T MR scanner by employing a spin echo single-shot EPI sequence with 15 diffusion encoding directions. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps were generated from each participant's DTI images using DTIStudio software. Bilateral regions of interest (ROI) for the caudate nucleus, putamen,globus pallidus and thalamus were manually traced through ROIEditor software on averaged DWI maps. The differences on DT-MRI variables (ADC, FA) between the two groups were compared using the SPSS13.0 software. Significance level was set at 0.05. RESULTS: Significant decrease in FA values in left globus pallidus and bilateral thalamus, and increase in ADC values in the bilateral caudate nucleus, bilateral putamen and bilateral thalamus were found in the children with TS compared with the normal controls. CONCLUSION: The results support the hypothesis of abnormalities in basal ganglia and thalamus in the pathophysiology of TS.