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The neural architecture of executive functions is established by middle childhood.

Sat, 10/13/2018 - 22:09
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The neural architecture of executive functions is established by middle childhood.

Neuroimage. 2018 Oct 09;:

Authors: Engelhardt LE, Harden KP, Tucker-Drob EM, Church JA

Abstract
Executive functions (EFs) are regulatory cognitive processes that support goal-directed thoughts and behaviors and that involve two primary networks of functional brain activity in adulthood: the fronto-parietal and cingulo-opercular networks. The current study assessed whether the same networks identified in adulthood underlie child EFs. Using task-based fMRI data from a diverse sample of N = 117 children and early adolescents (M age = 10.17 years), we assessed the extent to which neural activity was shared across switching, updating, and inhibition domains, and whether these patterns were qualitatively consistent with adult EF-related activity. Brain regions that were consistently engaged across switching, updating, and inhibition tasks closely corresponded to the cingulo-opercular and fronto-parietal networks identified in studies of adults. Isolating brain activity during more demanding task periods highlighted contributions of the dorsal anterior cingulate and anterior insular regions of the cingulo-opercular network. Results were independent of age and time-on-task effects. These results indicate that the two core brain networks that support EFs are in place by middle childhood, in agreement with resting-state findings of adultlike brain network organization. Improvement in EFs from middle childhood to adulthood, therefore, are likely due to quantitative changes in activity within these networks, rather than qualitative changes in the organization of the networks themselves. Improved knowledge of how the brain's functional organization supports EF in childhood has critical implications for understanding the maturation of cognitive abilities.

PMID: 30312810 [PubMed - as supplied by publisher]

Central Nervous System involvement in Late Onset Pompe Disease (LOPD): clues from neuroimaging and neuropsychological analysis.

Sat, 10/13/2018 - 22:09
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Central Nervous System involvement in Late Onset Pompe Disease (LOPD): clues from neuroimaging and neuropsychological analysis.

Eur J Neurol. 2018 Oct 12;:

Authors: Musumeci O, Marino S, Granata F, Morabito R, Bonanno L, Brizzi T, Lo Buono V, Corallo F, Longo M, Toscano A

Abstract
BACKGROUND: Late Onset Pompe Disease (LOPD) is a rare, multisystem disorder, that is well established to mainly impair skeletal muscle function. Systematic studies exploring brain functions in LOPD are lacking. Aim of this study is to detect morphological and functional brain alterations as well as neuropsychological impairment in LOPD.
MATERIALS AND METHODS: We studied 21 patients (10M, 11F, mean-age 49±18,4years), with defined diagnosis of LOPD, divided in two groups: one with presymptomatic hyperCKemia with no muscle weakness and the second with Limb-Girdle Muscle Weakness (LGMW group). All patients performed 3TMRI to obtain morphological/angiographic evaluation as well as normalized cortical brain volume and Resting-state functional MRI (Rs-fMRI). To quantify white matter lesions Fazekas score wasapplied whereas Smoker's criteria were used to examine dolichoectasia. A complete neuropsychological assessment was performed.
RESULTS: MRI data showed that 12/21 patients (57%) demonstrated signs of cerebral vasculopathy, with a Fazekas score >2 in the 67%. According to Smoker's criteria, 11/21pts (52%) had a dolichoectasia of the vertebrobasilar system; in 3/21pts (14%) an intracranial aneurysm was detected. Rs-fMRI evidenced significantly decreased brain connectivity in Salience Network (SN) with a more relevant reduction in the bilateral middle and superior frontal gyrus. A grey matter atrophy correlated with age and disease duration. A mild impairment in executive functions was also identified.
CONCLUSION: In this LOPD cohort the results showed morphological and functional brain alterations with mild neuropsychological dysfunction, mainly in the LGMW group. Cerebrovascular alterations seem not related to common risk factors, suggesting a major role of enzymatic deficiency in the pathogenesis of brain abnormalities. This article is protected by copyright. All rights reserved.

PMID: 30312517 [PubMed - as supplied by publisher]

Functional network connectivity is altered in patients with upper limb somatosensory impairments in the acute phase post stroke: A cross-sectional study.

Sat, 10/13/2018 - 22:09
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Functional network connectivity is altered in patients with upper limb somatosensory impairments in the acute phase post stroke: A cross-sectional study.

PLoS One. 2018;13(10):e0205693

Authors: De Bruyn N, Meyer S, Kessner SS, Essers B, Cheng B, Thomalla G, Peeters A, Sunaert S, Duprez T, Thijs V, Feys H, Alaerts K, Verheyden G

Abstract
BACKGROUND: Aberrant functional connectivity in brain networks associated with motor impairment after stroke is well described, but little is known about the association with somatosensory impairments.
AIM: The objective of this cross-sectional observational study was to investigate the relationship between brain functional connectivity and severity of somatosensory impairments in the upper limb in the acute phase post stroke.
METHODS: Nineteen first-ever stroke patients underwent resting-state functional magnetic resonance imaging (rs-fMRI) and a standardized clinical somatosensory profile assessment (exteroception and higher cortical somatosensation) in the first week post stroke. Integrity of inter- and intrahemispheric (ipsilesional and contralesional) functional connectivity of the somatosensory network was assessed between patients with severe (Em-NSA< 13/32) and mild to moderate (Em-NSA> 13/32) somatosensory impairments.
RESULTS: Patients with severe somatosensory impairments displayed significantly lower functional connectivity indices in terms of interhemispheric (p = 0.001) and ipsilesional intrahemispheric (p = 0.035) connectivity compared to mildly to moderately impaired patients. Significant associations were found between the perceptual threshold of touch assessment and interhemispheric (r = -0.63) and ipsilesional (r = -0.51) network indices. Additional significant associations were found between the index of interhemispheric connectivity and light touch (r = 0.55) and stereognosis (r = 0.64) evaluation.
CONCLUSION: Patients with more severe somatosensory impairments have lower inter- and ipsilesional intrahemispheric connectivity of the somatosensory network. Lower connectivity indices are related to more impaired exteroception and higher cortical somatosensation. This study highlights the importance of network integrity in terms of inter- and ipsilesional intrahemispheric connectivity for somatosensory function. Further research is needed investigating the effect of therapy on the re-establishment of these networks.

PMID: 30312350 [PubMed - in process]

The corticotopic organization of the human basal forebrain as revealed by regionally selective functional connectivity profiles.

Sat, 10/13/2018 - 22:09
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The corticotopic organization of the human basal forebrain as revealed by regionally selective functional connectivity profiles.

Hum Brain Mapp. 2018 Oct 11;:

Authors: Fritz HJ, Ray N, Dyrba M, Sorg C, Teipel S, Grothe MJ

Abstract
The cholinergic basal forebrain (CBF), comprising different groups of cortically projecting cholinergic neurons, plays a crucial role in higher cognitive processes and has been implicated in diverse neuropsychiatric disorders. A distinct corticotopic organization of CBF projections has been revealed in animal studies, but little is known about their organization in the human brain. We explored regional differences in functional connectivity (FC) profiles within the human CBF by applying a clustering approach to resting-state functional magnetic resonance imaging (rs-fMRI) data of healthy adult individuals (N = 85; 19-85 years). We further examined effects of age on FC of the identified CBF clusters and assessed the reproducibility of cluster-specific FC profiles in independent data from healthy older individuals (N = 25; 65-89 years). Results showed that the human CBF is functionally organized into distinct anterior-medial and posterior-lateral subdivisions that largely follow anatomically defined boundaries of the medial septum/diagonal band and nucleus basalis Meynert. The anterior-medial CBF subdivision was characterized by connectivity with the hippocampus and interconnected nodes of an extended medial cortical memory network, whereas the posterior-lateral subdivision was specifically connected to anterior insula and dorsal anterior cingulate components of a salience/attention network. FC of both CBF subdivisions declined with increasing age, but the overall topography of subregion-specific FC profiles was reproduced in independent rs-fMRI data of healthy older individuals acquired in a typical clinical setting. Rs-fMRI-based assessments of subregion-specific CBF function may complement established volumetric approaches for the in vivo study of CBF involvement in neuropsychiatric disorders.

PMID: 30311315 [PubMed - as supplied by publisher]

Long-chain polyunsaturated fatty acid supplementation in the first year of life affects brain function, structure, and metabolism at age nine years.

Sat, 10/13/2018 - 22:09
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Long-chain polyunsaturated fatty acid supplementation in the first year of life affects brain function, structure, and metabolism at age nine years.

Dev Psychobiol. 2018 Oct 11;:

Authors: Lepping RJ, Honea RA, Martin LE, Liao K, Choi IY, Lee P, Papa VB, Brooks WM, Shaddy DJ, Carlson SE, Colombo J, Gustafson KM

Abstract
The present study sought to determine whether supplementation of long-chain polyunsaturated fatty acids (LCPUFA) during the first year of life influenced brain function, structure, and metabolism at 9 years of age. Newborns were randomly assigned to consume formula containing either no LCPUFA (control) or formula with 0.64% of total fatty acids as arachidonic acid (ARA; 20:4n6) and variable amounts of docosahexaenoic acid (DHA; 22:6n3) (0.32%, 0.64%, or 0.96% of total fatty acids) from birth to 12 months. At age 9 years (±0.6), 42 children enrolled in a follow-up multimodal magnetic resonance imaging (MRI) study including functional (fMRI, Flanker task), resting state (rsMRI), anatomic, and proton magnetic resonance spectroscopy (1 H MRS). fMRI analysis using the Flanker task found that trials requiring greater inhibition elicited greater brain activation in LCPUFA-supplemented children in anterior cingulate cortex (ACC) and parietal regions. rsMRI analysis showed that children in the 0.64% group exhibited greater connectivity between prefrontal and parietal regions compared to all other groups. In addition, voxel-based analysis (VBM) revealed that the 0.32% and 0.64% groups had greater white matter volume in ACC and parietal regions compared to controls and the 0.96% group. Finally, 1 H MRS data analysis identified that N-acetylaspartate (NAA) and myo-inositol (mI) were higher in LCPUFA groups compared to the control group. LCPUFA supplementation during infancy has lasting effects on brain structure, function, and neurochemical concentrations in regions associated with attention (parietal) and inhibition (ACC), as well as neurochemicals associated with neuronal integrity (NAA) and brain cell signaling (mI).

PMID: 30311214 [PubMed - as supplied by publisher]

The relationship between amplitude of low frequency fluctuations and gray matter volume of the mirror neuron system: Differences between low disability multiple sclerosis patients and healthy controls.

Sat, 10/13/2018 - 22:09
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The relationship between amplitude of low frequency fluctuations and gray matter volume of the mirror neuron system: Differences between low disability multiple sclerosis patients and healthy controls.

IBRO Rep. 2018 Dec;5:60-66

Authors: Plata-Bello J, Pérez-Martín Y, Castañón-Pérez A, Modroño C, Hernández-Martín E, González-Platas M, Marcano F, González-Mora JL

Abstract
The study of the relationship between function and structure of the brain could be particularly interesting in neurodegenerative diseases like multiple sclerosis (MS). The aim of the present work is to identify differences of the amplitude of low frequency fluctuations (ALFF) in the mirror neuron system (MNS) between MS patients and healthy controls and to study the relationship between ALFF and the gray matter volume (GMV) of the regions that belong to the MNS. Relapsing-remitting MS patients with minor disability were compared to healthy controls (HC) using resting-state functional magnetic resonance imaging (fMRI), anatomic T1 weighted images and diffusion tensor imaging (DTI). Region of interest (ROI) analyses was performed in the MNS regions. A decrease of ALFF in MS patients was observed in the left inferior frontal gyrus (IFG). Furthermore, a correlation between ALFF in the IFG and the GMV of the left inferior parietal lobule (IPL) was identified. This relationship was different for MS patients than for HC, which may be associated with changes in diffusivity measures which were impaired in MS patients. MS patients with low disability may show ALFF differences in the MNS without clinical correspondence. This functional difference may be associated with cortical and subcortical changes related to the disease.

PMID: 30310873 [PubMed]