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.
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.