Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neuro-developmental disorders occurring in childhood, characterized by symptoms of age-inappropriate inattention, hyperactivity/impulsivity, and the prevalence is higher in boys. Although gray matter volume deficits have been frequently reported for ADHD children via structural magnetic resonance imaging, few of them had specifically focused on male patients. The present study aimed to explore the alterations of gray matter volumes in medicated-naive boys with ADHD via a relatively new voxel-based morphometry technique. According to the criteria of DSM-IV-TR, 43 medicated-naive ADHD boys and 44 age-matched healthy boys were recruited. The magnetic resonance image (MRI) scan was performed via a 3T MRI system with three-dimensional (3D) spoiled gradient recalled echo (SPGR) sequence. Voxel-based morphometry with diffeomorphic anatomical registration through exponentiated lie algebra in SPM8 was used to preprocess the 3D T1-weighted images. To identify gray matter volume differences between the ADHD and the controls, voxel-based analysis of whole brain gray matter volumes between two groups were done via two sample t-test in SPM8 with age as covariate, threshold at P＜0.001. Finally, compared to the controls, significantly reduced gray matter volumes were identified in the right orbitofrontal cortex (peak coordinates [-2,52,-25], t=4.01), and bilateral hippocampus (Left: peak coordinates [14,0,-18], t=3.61; Right: peak coordinates [-14,15,-28], t=3.64) of ADHD boys. Our results demonstrated obvious reduction of whole brain gray matter volumes in right orbitofrontal cortex and bilateral hippocampus in boys with ADHD. This suggests that the abnormalities of prefrontal-hippocam-pus circuit may be the underlying cause of the cognitive dysfunction and abnormal behavioral inhibition in medicated-naive boys with ADHD.
In the current study, we aim to investigate whether post-traumatic stress disorder (PTSD) is associated with structural alterations in specific subfields of hippocampus comparing with trauma-exposed control (TC) in a relatively large sample. We included 67 PTSD patients who were diagnosed under Diagnostic and Statistical Manual of Mental Disorders (4th Edition) (DSM-Ⅳ) criteria and 78 age- and sex-matched non-PTSD adult survivors who experienced similar stressors. High resolution T1 weighted images were obtained via a GE 3.0 T scanner. The structural data was automatically segmented using FreeSurfer software, and volume of whole hippocampus and subfield including CA1, CA2-3, CA4-DG, fimbria, presubiculum, subiculum and fissure were extracted. Volume differences between the two groups were statistically compared with age, years of education, duration from the events and intracranial volume (ICV) as covariates. Hemisphere, sex and diagnosis were entered as fixed factors. Relationship between morphometric measurements with Clinician-Administered PTSD Scale (CAPS) score and illness duration were performed using Pearson’s correlation with SPSS. Comparing to TC, PTSD patients showed no statistically significant alteration in volumes of the whole hippocampus and all the subfields (P > 0.05). In male patients, there were significant correlations between CAPS score and volume of right CA2-3 ( R2 = 0.197, P = 0.034), right subiculum (R2 = 0.245, P = 0.016), and duration statistically correlated with right fissure (R2 = 0.247, P = 0.016). In female patients, CAPS scores significant correlated with volume of left presubiculum (R2 = 0.095, P = 0.042), left subiculum (R2 = 0.090, P = 0.048), and left CA4-DG (R2 = 0.099, P = 0.037). The main findings of the current study suggest that stress event causes non-selective damage to hippocampus in both PTSD patients and TC, and gender-specific lateralization may underlie PTSD pathology.
ObjectiveSeizure-related respiratory or cardiac dysfunction was once thought to be the direct cause of sudden unexpected death in epilepsy (SUDEP), but both may be secondary to postictal cerebral inhibition. An important issue that has not been explored to date is the neural network basis of cerebral inhibition. Our aim was to investigate the features of neural networks in patients at high risk for SUDEP using a blood oxygen level-dependent (BOLD) resting-state functional MRI (Rs-fMRI) technique. MethodsRs-fMRI data were recorded from 13 patients at high risk for SUDEP and 12 patients at low risk for SUDEP. The amplitude of low-frequency fluctuations (ALFF) values were compared between the two groups to decipt the regional brain activities. ResultsCompared with patients at low risk for SUDEP, patients at high risk exhibited significant ALFF reductions in the right superior frontal gyrus, the left superior orbital frontal gyrus, the left insula and the left thalamus; and ALFF increase in the right middle cigulum gyrus, the right supplementary motor area and the left thalamus. ConclusionsThese findings highlight the need to understand the fundamental neural network dysfunction in SUDEP, which may fill the missing link between seizure-related cardiorespiratory dysfunction and SUDEP, and provide a promising neuroimaging biomarker for risk prediction of SUDEP.
A great number of studies have demonstrated functional abnormalities in children with attention-deficit/hyperactivity disorder (ADHD), although conflicting results have also been reported. And few studies analyzed homotopic functional connectivity between hemispheres. In this study, resting-state functional magnetic resonance imaging (MRI) data were recorded from 45 medication-naïve ADHD children and 26 healthy controls. The regional homogeneity (ReHo), degree centrality (DC) and voxel-mirrored homotopic connectivity (VMHC) values were compared between the two groups to depict the intrinsic brain activities. We found that ADHD children exhibited significantly lower ReHo and DC values in the right middle frontal gyrus and the two values correlated with each other; moreover, lower VMHC values were found in the bilateral occipital lobes of ADHD children, which was negatively related with anxiety scores of Conners' Parent Rating Scale (CPRS-R) and positively related with completed categories of Wisconsin Card Sorting Test (WCST). Our results might suggest that less spontaneous neuronal activities of the right middle frontal gyrus and the bilateral occipital lobes in ADHD children.