NeuroImage. Clinical
-
NeuroImage. Clinical · Jan 2015
Patterns of brain structural connectivity differentiate normal weight from overweight subjects.
Alterations in the hedonic component of ingestive behaviors have been implicated as a possible risk factor in the pathophysiology of overweight and obese individuals. Neuroimaging evidence from individuals with increasing body mass index suggests structural, functional, and neurochemical alterations in the extended reward network and associated networks. ⋯ 1. An increased BMI (i.e., overweight subjects) is associated with distinct changes in gray-matter and fiber density of the brain. 2. Classification algorithms based on white-matter connectivity involving regions of the reward and associated networks can identify specific targets for mechanistic studies and future drug development aimed at abnormal ingestive behavior and in overweight/obesity.
-
NeuroImage. Clinical · Jan 2015
Meta AnalysisAnatomical likelihood estimation meta-analysis of grey and white matter anomalies in autism spectrum disorders.
Autism spectrum disorders (ASD) are characterized by impairments in social communication and restrictive, repetitive behaviors. While behavioral symptoms are well-documented, investigations into the neurobiological underpinnings of ASD have not resulted in firm biomarkers. Variability in findings across structural neuroimaging studies has contributed to difficulty in reliably characterizing the brain morphology of individuals with ASD. ⋯ White matter alterations included fiber tracts thought to play key roles in information processing and sensory integration. Many current theories of pathobiology ASD suggest that the brains of individuals with ASD may have less-functional long-range (anterior-to-posterior) connections. Our findings of decreased cortical matter in parietal-temporal and occipital regions, and thickening in frontal cortices in older adults with ASD may entail altered cortical anatomy, and neurodevelopmental adaptations.
-
NeuroImage. Clinical · Jan 2015
Randomized Controlled TrialRelationship of white matter network topology and cognitive outcome in adolescents with d-transposition of the great arteries.
Patients with congenital heart disease (CHD) are at risk for neurocognitive impairments. Little is known about the impact of CHD on the organization of large-scale brain networks. We applied graph analysis techniques to diffusion tensor imaging (DTI) data obtained from 49 adolescents with dextro-transposition of the great arteries (d-TGA) repaired with the arterial switch operation in early infancy and 29 healthy referent adolescents. ⋯ Finally, structural network topology mediated the neuroprotective effect of longer duration of core cooling during reparative neonatal cardiac surgery, as well as the detrimental effects of prolonged hospitalization. Taken together, worse neurocognitive function in adolescents with d-TGA is mediated by global differences in white matter network topology, suggesting that disruption of this configuration of large-scale networks drives neurocognitive dysfunction. These data provide new insights into the interplay between perioperative factors, brain organization, and cognition in patients with complex CHD.
-
NeuroImage. Clinical · Jan 2015
PTSD symptom severity is associated with increased recruitment of top-down attentional control in a trauma-exposed sample.
Recent neuroimaging work suggests that increased amygdala responses to emotional stimuli and dysfunction within regions mediating top down attentional control (dorsomedial frontal, lateral frontal and parietal cortices) may be associated with the emergence of anxiety disorders, including posttraumatic stress disorder (PTSD). This report examines amygdala responsiveness to emotional stimuli and the recruitment of top down attention systems as a function of task demands in a population of U.S. military service members who had recently returned from combat deployment in Afghanistan/Iraq. Given current interest in dimensional aspects of pathophysiology, it is worthwhile examining patients who, while not meeting full PTSD criteria, show clinically significant functional impairment. ⋯ We suggest that these data may reflect two phenomena associated with increased PTSD symptomatology in combat-exposed, but PTSD negative, armed services members. First, these data indicate increased emotional responsiveness by: (i) the positive relationship between PTSD symptom severity and amygdala responsiveness to emotional relative to neutral stimuli; (ii) greater BOLD response as a function of PTSD symptom severity in regions implicated in emotion (striatum) and representation (occipital and temporal cortices) during emotional relative to neutral conditions; and (iii) increased connectivity between the amygdala and regions implicated in emotion (insula/caudate) and representation (middle temporal cortex) as a function of PTSD symptom severity during emotional relative to neutral trials. Second, these data indicate a greater need for the recruitment of regions implicated in top down attention as indicated by (i) greater BOLD response in superior/middle frontal gyrus as a function of PTSD symptom severity in task relative to view conditions; (ii) greater BOLD response in dmFC/dACC, lateral frontal and inferior parietal cortices as a function of PTSD symptom severity in emotional relative to neutral conditions and (iii) greater functional connectivity between the amygdala and inferior parietal cortex as a function of PTSD symptom severity during emotional relative to neutral conditions.
-
NeuroImage. Clinical · Jan 2015
Regional vulnerability of longitudinal cortical association connectivity: Associated with structural network topology alterations in preterm children with cerebral palsy.
Preterm born children with spastic diplegia type of cerebral palsy and white matter injury or periventricular leukomalacia (PVL), are known to have motor, visual and cognitive impairments. Most diffusion tensor imaging (DTI) studies performed in this group have demonstrated widespread abnormalities using averaged deterministic tractography and voxel-based DTI measurements. Little is known about structural network correlates of white matter topography and reorganization in preterm cerebral palsy, despite the availability of new therapies and the need for brain imaging biomarkers. ⋯ Both along tract and structural topology network measurements correlated strongly with motor and visual clinical outcome scores. This study shows the value of combining along-tract analysis and structural network topology in depicting not only selective parietal occipital regional vulnerability but also reorganization of frontal-striatal and frontal-limbic pathways in preterm children with cerebral palsy. These finding also support the concept that widespread, but selective posterior-anterior neural network connectivity alterations in preterm children with cerebral palsy likely contribute to the pathogenesis of neurosensory and cognitive impairment in this group.