ABSTRACT
ObjectivesTo identify the related abnormalities of gray matter in pediatric patients with Tourette syndrome (TS) by using the optimized voxel-based morphometry (VBM).Methods Three dimensional T1WI was acquired in 31 TS children (28 boys,3 girts,mean age 8 years,range 4-15 years) and 50 age- and sex-matched controls on a 1.5 Tesla Philips scanner. Images were pre-processed and analyzed using a version of VBM 2 in SPM 2.The whole brain gray matter volume was compared between the study and control group by using t-test.Multivariate linear regression analysis was used for analyzing the correlation between the change of grey matter volume within each brain region (mm3 ) and YGTSS score and course of disease of TS patients.Statistical analyses were performed by using SPSS 13.0.ResultsUsing VBM,significant increases in gray matter volumes in left superior parietal lobule, right cerebellar hemisphere and left parahippocampal gyrus were detected in TS patients,and the volume changes were 4059,2126 and 84 mm3 ( t =3.93,3.71,3.58,P ＜ 0.05 ) respectively.Compared to the control group,decreased grey matter volumes were found in medulla and left pons,and the volume changes were 213 and 117 mm3( t =3.53,3.48,P ＜ 0.05 )respectively.Tic severity was not correlated with any volume changes of gray matter in brain (P ＞ 0.05,a small volume correction,KE ≥ 10 voxel).Tic course was negatively correlated with the gray matter volume of left parahippocampal gyrus ( Beta =- 0.391,P =0.039 ).ConclusionsUsing VBM technique,the gray matter abnormalities can be revealed in TS patients without obvious lesions on conventional MR imaging.The increasing volume of temporal and parietal lobes and cerebellar may be an adaptive anatomical change in response to experiential demand. The gray matter volume of the parahippocampal gyrus may be used as one potential objective index for evaluating the prognosis of TS.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of pyrethroids on the concentrations of thyroid hormone in rat brain.</p><p><b>METHOD</b>Permethrin (PM) and deltamethrin (DM) were administered to the rats with daily doses of 100, 200 and 400 mg.kg-1.d-1 and 6.25, 12.5 and 25 mg.kg-1.d-1, respectivelly for 15 days. Serum and brain tissue determinations of thyroxin (T4) and triiodothyronine (T3) were performed by radioimmunoassay (RIA).</p><p><b>RESULTS</b>PM induced a dose dependent decrease in the serum levels of T4, T3, fT4 and fT3 and an increase in the serum TSH levels, whereas DM was only able to induce a dose dependent decrease in the serum levels of T4. PM treatment reduced both the levels of T4 and T3 in homogenates of the cerebral cortex and hippocampus respectively, whereas the highest dose of DM decreased only the cerebral cortex levels of T4. The effects of subchronic treatment with PM and DM on the concentrations of T3 were further investigated in the subcellular fractions, namely nuclei, mitochondria, myelin and synaptosomes of the cerebral cortex and hippocampus. PM treatment induced a decrease in the nuclear and synaptosomal concentrations of T3 of either the cerebral cortex or hippocampus, whereas DM reduced the levels of T3 especially in the mitochondria of the cortex and hippocampus.</p><p><b>CONCLUSIONS</b>Treatment with pyrethroids subchronically to the rats would affect the serum and brain tissue levels of T4 and T3. These results indicate that the pyrethroids-induced neurotoxicity may involve at least in part an impairment of the physiological action of T3 at its subcellular targets.</p>