No abstract

No abstract

When conceptualizing age-specific onsets and sex-specific characteristics of neuropsychiatric diseases in a neurobiological context, it may be crucially important to consider differential trajectories of aging. Here, we investigated effects of age, sex, and their interactions on absolute and relative volumes of subcortical structures with known involvement in psychiatric disorders, including the basal ganglia, thalamus, hippocampus, and amygdala. Structural MRI data of 76 healthy subjects (38 males, 19-70 years) from the ICBM database were analyzed. Age-related absolute atrophy was generally found in the basal ganglia and thalamus, while in the hippocampus decline was only observed in males, and was generally absent in the amygdala. Disproportionate degeneration in the basal ganglia and thalamus, exceeding cortical decline was specific for females. When allowing higher-order models, a quadratic model could better describe the negative relation of absolute volume and age in the basal ganglia in males, and generally in the hippocampus and amygdala. We could show that negative age-relations are highly specific for certain subcortical structures in either gender. Importantly these findings also emphasize the significant impact of analytical strategies when deciding for correction of subcortical volumes to the whole-brain decline. Specifically, in the basal ganglia disproportionate shrinkage in females was suggested by the relative analysis while absolute volume analysis rather stressed an accelerating decline in older males. Given strong involvement of the basal ganglia in both cognitive aging and emotional regulation, our findings may be crucial for studies investigating the onset and prevalence of dementia and depressive symptoms in male and female aging.

No abstract

Glaucoma is not only an eye disease but is also associated with degeneration of brain structures. We now investigated the pattern of visual and non-visual brain structural changes in 25 primary open angle glaucoma (POAG) patients and 25 age-gender-matched normal controls using T1-weighted imaging. MRI images were subjected to volume-based analysis (VBA) and surface-based analysis (SBA) in the whole brain as well as ROI-based analysis of the lateral geniculate nucleus (LGN), visual cortex (V1/2), amygdala and hippocampus. While VBA showed no significant differences in the gray matter volumes of patients, SBA revealed significantly reduced cortical thickness in the right frontal pole and ROI-based analysis volume shrinkage in LGN bilaterally, right V1 and left amygdala. Structural abnormalities were correlated with clinical parameters in a subset of the patients revealing that the left LGN volume was negatively correlated with bilateral cup-to-disk ratio (CDR), the right LGN volume was positively correlated with the mean deviation of the right visual hemifield, and the right V1 cortical thickness was negatively correlated with the right CDR in glaucoma. These results demonstrate that POAG affects both vision-related structures and non-visual cortical regions. Moreover, alterations of the brain visual structures reflect the clinical severity of glaucoma.

No abstract

No abstract

Tourette Syndrome (TS) is characterized with chronic motor and vocal tics beginning in childhood. Abnormality of both gray (GM) and white matter (WM) has been observed in cortico-striato-thalamo-cortical circuits and sensory-motor cortex of adult TS patient. It is not clear if these morphological changes are also present in TS children and if there are any microstructural changes of WM. To understand the developmental cause of such changes, we investigated volumetric changes of GM and WM using VBM and microstructural changes of WM using DTI, and correlated these changes with tic severity and duration. T1 images and Diffusion Tensor Images (DTI) from 21 TS children were compared with 20 age and gender matched health control children using a 1.5T Philips scanner. All of the 21 TS children met the DSM-IV-TR criteria. T1 images were analyzed using DARTEL-VBM in conjunction with statistical parametric mapping (SPM). Diffusion tensor imaging (DTI) analysis was performed using Tract-Based Spatial Statistics (TBSS). Brain volume changes were found in left superior temporal gyrus, left and right paracentral gyrus, right precuneous cortex, right pre- and post- central gyrus, left temporal occipital fusiform cortex, right frontal pole, and left lingual gyrus. Significant axial diffusivity (AD) and mean diffusivity (MD) increases were found in anterior thalamic radiation, right cingulum bundle projecting to the cingulate gurus and forceps minor. Decreases in white matter volume (WMV) in the right frontal pole were inversely related with tic severity (YGTSS), and increases in AD and MD were positively correlated with tic severity and duration, respectively. These changes in TS children can be interpreted as signs of neural plasticity in response to the experiential demand. Our findings may suggest that the morphological and microstructural measurements from structural MRI and DTI can potentially be used as a biomarker of the pathophysiologic pattern of early TS children.