Brain imaging and behavior
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Brain Imaging Behav · Feb 2018
Considering total intracranial volume and other nuisance variables in brain voxel based morphometry in idiopathic PD.
Voxel-based morphometry (VBM) studies of Parkinson's disease (PD), have yielded mixed results, possibly due to several studies not accounting for common nuisance variables (age, sex, and total intracranial volume [TICV]). TICV is particularly important because there is evidence for larger TICV in PD. We explored the influence of these covariates on VBM by 1) comparing PD patients and controls before adding covariates, after adding age and sex, and after adding age, sex and TICV, and 2) by comparing controls split into large and small TICV before and after controlling for TICV, with age and sex accounted for in both analyses. ⋯ None of these differences survived controlling for TICV. This demonstrates that TICV influences VBM results independently from other factors. Controlling for TICV in VBM studies is recommended.
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Brain Imaging Behav · Feb 2018
Comparative StudyModifications in resting state functional anticorrelation between default mode network and dorsal attention network: comparison among young adults, healthy elders and mild cognitive impairment patients.
Resting state brain activity incorporates different components, including the Default Mode Network and the Dorsal Attention Network, also known as task-negative network and task-positive network respectively. These two networks typically show an anticorrelated activity during both spontaneous oscillations and task execution. However modifications of this anticorrelated activity pattern with age and pathology are still unclear. ⋯ Moreover, the anticorrelation between the posterior cingulate cortex node of the Default Mode Network and the right inferior parietal sulcus node of the Dorsal Attention Network was significantly decreased when comparing Mild Cognitive Impairment with normal elders (p < 0.001, False Discovery Rate corrected). The functional connectivity changes in patients were not related to significant differences in grey matter content. Our results suggest that a reduced anticorrelated activity between Default Mode Network and Dorsal Attention Network is part of the normal aging process and that Mild Cognitive Impairment status is associated with more evident inter-networks functional connectivity changes.
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Brain Imaging Behav · Feb 2018
Attention and processing speed performance in multiple sclerosis is mostly related to thalamic volume.
Cognitive impairment (CI), mainly involving attention and processing speed (A-PS), is a common and disabling symptom in multiple sclerosis (MS). Symbol Digit Modalities Test (SDMT) is one of the more sensitive and reliable tests to assess A-PS deficits in MS. Structural MRI correlates of A-PS in MS still need to be clarified. ⋯ Thalamus, cerebellum and putamen also showed significant GM atrophy in MS patients compared to HC. Thalamic atrophy is also an independent and additional contributor to A-PS deficits in MS patients. These findings support the role of thalamus as the most relevant GM structure subtending A-PS performance in MS, as measured by SDMT.
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Brain Imaging Behav · Feb 2018
Relevance of neuroimaging for neurocognitive and behavioral outcome after pediatric traumatic brain injury.
This study aims to (1) investigate the neuropathology of mild to severe pediatric TBI and (2) elucidate the predictive value of conventional and innovative neuroimaging for functional outcome. Children aged 8-14 years with trauma control (TC) injury (n = 27) were compared to children with mild TBI and risk factors for complicated TBI (mildRF+, n = 20) or moderate/severe TBI (n = 17) at 2.8 years post-injury. Neuroimaging measures included: acute computed tomography (CT), volumetric analysis on post-acute conventional T1-weighted magnetic resonance imaging (MRI) and post-acute diffusion tensor imaging (DTI, analyzed using tract-based spatial statistics and voxel-wise regression). ⋯ FA had superior predictive value for functional outcome (i.e. intelligence, attention and working memory, encoding in verbal memory and internalizing problems) relative to acute CT-scanning (i.e. internalizing problems) and conventional MRI (no predictive value). We conclude that children with mildRF+ TBI and moderate/severe TBI are at risk of persistent white matter abnormality. Furthermore, DTI has superior predictive value for neurocognitive out-come relative to conventional neuroimaging.
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Brain Imaging Behav · Dec 2017
Compensatory increase of functional connectivity density in adolescents with internet gaming disorder.
Behavioral studies have demonstrated visual attention bias and working memory deficits in individuals with internet gaming disorder (IGD). Neuroimaging studies demonstrated that individuals with IGD presented abnormalities in brain structures and functions including resting-state functional connectivity (rsFC) disturbance. However, most previous studies investigated IGD-related rsFC alterations by using hypothesis-driven methods with priori selection of a region of interest, which cannot provide a full picture of the rsFC changes in IGD individuals. ⋯ The IGD adolescents exhibited higher global/long-range rsFCD in the bilateral dorsal lateral prefrontal cortex (DLPFC) and the right inferior temporal cortex (ITC)/fusiform compared with the HCs. Although no significant correlation survived after Bonferroni correction, higher global/long-range rsFCD of the bilateral DLPFC was correlated with the Young's internet addiction test (IAT) score and/or behavioral performance in IGD adolescents using an uncorrected threshold of P < 0.05. In conclusion, IGD adolescents demonstrated increased rsFCD in the brain regions involved in working memory, spatial orientation and attention processing, which indicated that increased rsFCD may reflect a compensatory mechanism for maintaining the normal behavioral performance in IGD adolescents compared with the HCs.