Deep Gray Matter Structures Research Articles

Observational Learning in Low-Functioning Children With Autism Spectrum Disorders: A Behavioral and Neuroimaging Study.

New skills may be learned from the outcomes of their own internally generated actions (experiential learning) or from the observation of the consequences of externally generated actions (observational learning). Observational learning requires the coordination of cognitive functions and the processing of social information. Due to the “social” abilities underlying observational learning, the study of this process in individuals with limited social abilities such as those affected by Autism Spectrum Disorders (ASD) is worthy of being investigated. We asked a group of 16 low-functioning young children with ASD and group of 16 sex- and mental age-matched typically developing (TD) children to build a house with a set of bricks after a video-demonstration showing an actor who built the house (observational task – OBS task) and then to build by trial and error another house (experiential task – EXP task). For ASD group, performances in learning tasks were correlated with measures of cortical thickness of specific Regions of Interest (ROI) and volume of deep gray matter structures known to be related with such kinds of learning. According to our a priori hypothesis, for OBS task we selected the following ROI: frontal lobe (pars opercularis, pars triangularis, and premotor area), parietal lobe (inferior parietal gyrus), temporal lobe (superior temporal gyrus), cerebellar hemispheres. For EXP task, we selected the following ROI: precentral frontal gyrus and superior frontal gyrus, cerebellar hemispheres, basal ganglia, thalamus. Although performances of ASD and TD children improved in both OBS and EXP tasks, children with ASD obtained lower scores of goal achievement than TD children in both learning tasks. Only in ASD group, goal achievement scores positively correlated with hyperimitations indicating that children with ASD tended to have a “copy-all” approach that facilitated the goal achievement. Moreover, the marked hyperimitative tendencies of children with ASD were positively associated with the thickness of left pars opercularis, left premotor area, and right superior temporal gyrus, areas belonging to mirror neuron system, and with the volume of both cerebellar hemispheres. These findings suggest that in children with ASD the hyperimitation can represent a learning strategy that might be related to the mirror neuron system.

Disrupted structural connectivity of fronto-deep gray matter pathways in progressive supranuclear palsy.

BackgroundStructural connectivity is a promising methodology to detect patterns of neural network dysfunction in neurodegenerative diseases. This approach has not been tested in progressive supranuclear palsy (PSP).ObjectivesThe aim of this study is reconstructing the structural connectome to characterize and detect the pathways of degeneration in PSP patients compared with healthy controls and their correlation with clinical features. The second objective is to assess the potential of structural connectivity measures to distinguish between PSP patients and healthy controls at the single-subject level.MethodsTwenty healthy controls and 19 PSP patients underwent diffusion-weighted MRI with a 3T scanner. Structural connectivity, represented by number of streamlines, was derived from probabilistic tractography. Global and local network metrics were calculated based on graph theory.ResultsReduced numbers of streamlines were predominantly found in connections between frontal areas and deep gray matter (DGM) structures in PSP compared with controls. Significant changes in structural connectivity correlated with clinical features in PSP patients. An abnormal small-world architecture was detected in the subnetwork comprising the frontal lobe and DGM structures in PSP patients. The classification procedure achieved an overall accuracy of 82.23% with 94.74% sensitivity and 70% specificity.ConclusionOur findings suggest that modelling the brain as a structural connectome is a useful method to detect changes in the organization and topology of white matter tracts in PSP patients. Secondly, measures of structural connectivity have the potential to correctly discriminate between PSP patients and healthy controls.

Determinants of Deep Gray Matter Atrophy in Multiple Sclerosis: A Multimodal MRI Study.

Deep gray matter involvement is a consistent feature in multiple sclerosis. The aim of this study was to evaluate the relationship between different deep gray matter alterations and the development of subcortical atrophy, as well as to investigate the possible different substrates of volume loss between phenotypes. Seventy-seven patients with MS (52 with relapsing-remitting and 25 with progressive MS) and 41 healthy controls were enrolled in this cross-sectional study. MR imaging investigation included volumetric, DTI, PWI and Quantitative Susceptibility Mapping analyses. Deep gray matter structures were automatically segmented to obtain volumes and mean values for each MR imaging metric in the thalamus, caudate, putamen, and globus pallidus. Between-group differences were probed by ANCOVA analyses, while the contribution of different MR imaging metrics to deep gray matter atrophy was investigated via hierarchic multiple linear regression models. Patients with MS showed a multifaceted involvement of the thalamus and basal ganglia, with significant atrophy of all deep gray matter structures (P < .001). In the relapsing-remitting MS group, WM lesion burden proved to be the main contributor to volume loss for all deep gray matter structures (P ≤ .006), with a minor role of local microstructural damage, which, in turn, was the main determinant of deep gray matter atrophy in patients with progressive MS (P ≤ .01), coupled with thalamic susceptibility changes (P = .05). Our study confirms the diffuse involvement of deep gray matter in MS, demonstrating a different behavior between MS phenotypes, with subcortical GM atrophy mainly determined by global WM lesion burden in patients with relapsing-remitting MS, while local microstructural damage and susceptibility changes mainly accounted for the development of deep gray matter volume loss in patients with progressive MS.

Increased mean R2* in the deep gray matter of multiple sclerosis patients: Have we been measuring atrophy?

Magnetic resonance relaxometry studies in multiple sclerosis (MS) have suggested that iron accumulates within deep gray matter (DGM) structures early in the disease course. However, the commonly utilized mean R2* and magnetic susceptibility measures reflect regional iron concentration but not a structure's total iron content. Thus, tissue atrophy could impact mean R2* and magnetic susceptibility estimates. To demonstrate that both average iron concentration and total iron content need to be reported in order to distinguish between atrophy-related and definite magnetic susceptibility changes. Observational. The study was performed on 30 healthy controls (HCs) and 39 people with definite MS. 3T Philips Achieva using an 8-channel SENSE head coil. R2* data were acquired using a multiecho gradient echo sequence and diffusion tensor imaging data were acquired using an echo-planar sequence. Total iron content in DGM structures was assessed by calculating the sum of all R2* values within a region (denoted as ) and compared to the mean R2* as a measure of iron concentration. Significant group differences were investigated in a linear regression model. All DGM structures were assessed individually and the significance threshold was adjusted using the Bonferroni-Holm correction for multiple comparisons. There was an increased mean DGM R2* in MS patients compared to HCs (significant in the pallidus, P = 0.0051). In contrast, in patients was found to be lower in the thalamus and the caudate (P = 0.0011) compared to HCs, and similar between the two cohorts in the other DGM regions. An increase in mean R2* may not necessarily reflect increased iron accumulation. We propose as an additional metric to account for the effects of tissue atrophy when assessing tissue content changes, such as iron deposition or loss. 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:201-208.

Structural correlates of cognitive impairment in normal pressure hydrocephalus.

ObjectivesThe pathological bases for the cognitive and neuropsychiatric symptoms in normal pressure hydrocephalus (NPH) have not been elucidated. However, the symptoms may indicate dysfunction of subcortical regions. Previously, volume reductions of subcortical deep grey matter (SDGM) structures have been observed in NPH patients. The present study used automated segmentation methods to investigate whether SDGM structure volumes are associated with cognitive and neuropsychiatric measures.MethodsFourteen NPH patients and eight healthy controls were included in the study. Patients completed neuropsychological tests of general cognition, verbal learning and memory, verbal fluency and measures of apathy and depression pre‐ and postshunt surgery. Additionally, patients underwent 3 Tesla T1‐weighted magnetic resonance imaging at baseline and 6 months postoperatively. Controls were scanned once. SDGM structure volumes were estimated using automated segmentation (FSL FIRST). Since displacement of the caudate nuclei occurred for some patients due to ventriculomegaly, patient caudate volumes were also estimated using manual tracing. Group differences in SDGM structure volumes were investigated, as well as associations between volumes and cognitive and neuropsychiatric measures in patients.ResultsVolumes of the caudate, thalamus, putamen, pallidum, hippocampus and nucleus accumbens (NAcc) were significantly reduced in the NPH patients compared to controls. In the NPH group, smaller caudate and NAcc volumes were associated with poorer performance on neuropsychological tests and increased severity of neuropsychiatric symptoms, while reduced volume of the pallidum was associated with better performance on the MMSE and reduced apathy.ConclusionsStriatal volume loss appears to be associated with cognitive and neuropsychiatric changes in NPH.

Increased iron deposition of deep cerebral gray matter structures in hemodialysis patients: A longitudinal study using quantitative susceptibility mapping.

The cerebral iron overload in hemodialysis patients has been reported in a previous study, in which the evaluation of the changes in iron content could be affected by the cross-sectional analysis. To investigate the longitudinal changes of iron deposition in hemodialysis patients using quantitative susceptibility mapping (QSM) and correlate these findings with the longitudinal changes of neurocognitive function and clinical factors. Prospective; longitudinal. In all, 34 patients and 30 healthy controls (HCs); the mean follow-up interval was 22 ± 7 months. 3.0T, susceptibility-weighted imaging (SWI). QSM reconstructed from original phase data of SWI was used to measure the susceptibility of gray matter structures including bilateral caudate nucleus (CN), globus pallidus (GP), putmen (PUT), red nucleus (RN), substantia nigra (SN), dentate nucleus (DN), thalamus (THA), pulvinar of thalamus (PT). The Mini-Mental State Examination (MMSE) test and clinical factors were recorded. Analysis of covariance adjusting for age and gender as covariates or a paired t-test for the differences in susceptibility, MMSE scores, and clinical factors among baseline, follow-up patients, and HCs. Correlation and stepwise regression analysis for the relationship between susceptibility, MMSE scores, and clinical factors. The susceptibility of bilateral CN, GP, PUT, RN, SN, DN, THA, PT in follow-up patients was significantly higher than that in baseline between patients and HCs except for left THA (all P < 0.05; Bonferroni corrected). MMSE scores significantly negatively correlated with the susceptibility of bilateral CN, PUT, and RRN in the baseline examination and bilateral CN, PUT, RN, and DN in the follow-up examination (all P < 0.05; false discovery rate [FDR] corrected). The follow-up interval, creatinine, phosphorus, and calcium were independent factors for the increased susceptibility of some nuclei (all P < 0.05). The iron deposition of gray matter nuclei in hemodialysis patients increased over roughly a 2-year period and may be a risk factor for neurocognitive impairment. Creatinine and abnormal calcium-phosphorus metabolism were independent risk factors for abnormal iron deposition. 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:786-799.

Early human brain development: insights into macroscale connectome wiring.

Early brain development is closely dictated by distinct neurobiological principles. Here, we aimed to map early trajectories of structural brain wiring in the neonatal brain. We investigated structural connectome development in 44 newborns, including 23 preterm infants and 21 full-term neonates scanned between 29 and 45 postmenstrual weeks. Diffusion-weighted imaging data were combined with cortical segmentations derived from T2 data to construct neonatal connectome maps. Projection fibers interconnecting primary cortices and deep gray matter structures were noted to mature faster than connections between higher-order association cortices (fractional anisotropy (FA) F = 58.9, p < 0.001, radial diffusivity (RD) F = 28.8, p < 0.001). Neonatal FA-values resembled adult FA-values more than RD, while RD approximated the adult brain faster (F = 358.4, p < 0.001). Maturational trajectories of RD in neonatal white matter pathways revealed substantial overlap with what is known about the sequence of subcortical white matter myelination from histopathological mappings as recorded by early neuroanatomists (mean RD 68 regions r = 0.45, p = 0.008). Employing postnatal neuroimaging we reveal that early maturational trajectories of white matter pathways display discriminative developmental features of the neonatal brain network. These findings provide valuable insight into the early stages of structural connectome development.

Widespread diffusion changes differentiate Parkinson's disease and progressive supranuclear palsy.

BackgroundParkinson's disease (PD) and progressive supranuclear palsy – Richardson's syndrome (PSP-RS) are often represented by similar clinical symptoms, which may challenge diagnostic accuracy. The objective of this study was to investigate and compare regional cerebral diffusion properties in PD and PSP-RS subjects and evaluate the use of these metrics for an automatic classification framework.Material and methodsDiffusion-tensor MRI datasets from 52 PD and 21 PSP-RS subjects were employed for this study. Using an atlas-based approach, regional median values of mean diffusivity (MD), fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD) were measured and employed for feature selection using RELIEFF and subsequent classification using a support vector machine.ResultsAccording to RELIEFF, the top 17 diffusion values consisting of deep gray matter structures, the brainstem, and frontal cortex were found to be especially informative for an automatic classification. A MANCOVA analysis performed on these diffusion values as dependent variables revealed that PSP-RS and PD subjects differ significantly (p < .001). Generally, PSP-RS subjects exhibit reduced FA, and increased MD, RD, and AD values in nearly all brain structures analyzed compared to PD subjects. The leave-one-out cross-validation of the support vector machine classifier revealed that the classifier can differentiate PD and PSP-RS subjects with an accuracy of 87.7%. More precisely, six PD subjects were wrongly classified as PSP-RS and three PSP-RS subjects were wrongly classified as PD.ConclusionThe results of this study demonstrate that PSP-RS subjects exhibit widespread and more severe diffusion alterations compared to PD patients, which appears valuable for an automatic computer-aided diagnosis approach.

Staging of cortical and deep grey matter functional connectivity changes in multiple sclerosis

ObjectiveFunctional connectivity is known to increase as well as decrease throughout the brain in multiple sclerosis (MS), which could represent different stages of the disease. In addition, functional connectivity changes...

P 3 Cerebellar gray matter volume decrease is associated with epileptic seizures in multiple sclerosis

Background Prevalence rates of epileptic seizures are three times higher in patients with multiple sclerosis (MS) compared to healthy controls ( van Munster et al., 2015 ). There is some evidence of gray matter (GM) as well as white matter (WM) lesions associated with epilepsy in MS ( van Munster et al., 2015 ). Here, we compared regional GM volume decrease using voxel based morphometry (VBM) to compare MS patients with and without epilepsy. Methods MRI images of 30 MS patients (15 with, 15 without epilepsy, matched due to disease duration, disease course, EDSS and age) were analyzed using voxel based morphometry. Second level analysis was done comparing regional GM volume in MS patients without compared to with epileptic seizures. Results MS-patients with epilepsy had regional GM volume decrease in the cerebellum compared to MS patients without epilepsy, mainly in the posterior lobe. Neither cerebral or deep GM structures revealed significant regional GM volume decrease. Discussion There is some evidence of hippocampal GM pathology associated with epilepsy ( Nicholas et al., 2016 ). In contrast, our VBM analyses did not reveal any association to cortical or subcortical GM volume decrease. Against our expectations, we found significant cerebellar GM volume decrease in the patients with, compared to without epileptic seizures. Interestingly, there is some evidence of cerebellar lesions generating seizures ( Foit et al., 2016 ), cerebellar abnormalities in idiopathic generalized epilepsy ( Li et al., 2010 ) as well as a cerebellar mediated, inhibitory effect on hippocampal seizures ( Krook-Magnuson et al., 2014 ). Our data has to be confirmed in larger samples, but at least are indicating a possible role of the cerebellum in MS patients with epilepsy.

Neonatal basal ganglia and thalamic volumes: very preterm birth and 7-year neurodevelopmental outcomes.

BackgroundThis study aims to (1) compare volumes of individual basal ganglia nuclei (caudate nucleus, pallidum, putamen) and the thalamus between very preterm (VP) and term-born infants at term-equivalent age; (2) explore neonatal basal ganglia and thalamic volume relationships with 7-year neurodevelopmental outcomes, and whether these relationships differed between VP and term-born children.Methods210 VP (<30 weeks’ gestational age) and 39 term-born (≥37 weeks’ gestational age) infants underwent brain magnetic resonance imaging at term-equivalent age, and deep grey matter volumes of interest were automatically generated. 186 VP and 37 term-born children were assessed for a range of neurodevelopmental measures at age 7 years.ResultsAll deep grey matter structures examined were smaller in VP infants compared with controls at term-equivalent age; ranging from (percentage mean difference (95% confidence intervals) −6.2%(−10.2%,−2.2%) for the putamen, to −9.5%(−13.9%,−5.1%) for the caudate nucleus. Neonatal basal ganglia and thalamic volumes were positively related to motor, IQ and academic outcomes at age 7 years, with mostly similar relationships in the VP and control groups.ConclusionVP birth results in smaller basal ganglia and thalamic volumes at term-equivalent age, and these smaller volumes are related to a range of 7-year neurodevelopmental deficits in VP children.

Deep gray matter iron measurement in patients with liver cirrhosis using quantitative susceptibility mapping: Relationship with pallidal T1 hyperintensity.

The liver is a central organ for the metabolism of iron and manganese and the places where those metals are commonly deposited overlap in the brain. To elucidate the relationship between pallidal T1 hyperintensity and iron deposition in the deep gray matter of liver cirrhosis patients using quantitative susceptibility mapping (QSM). Retrospective case-control study SUBJECTS: In all, 38 consecutive liver cirrhosis patients who received brain magnetic resonance imaging (MRI) as pretransplant evaluation. QSM was reconstructed from 3D multi- or single-echo phase images at 3T. T1 -weighted images were used for the assessment of pallidal hyperintensity and pallidal index (PI). Patients were divided into two groups according to the presence of pallidal hyperintensity by consensus of two radiologists. Susceptibility values were acquired for five deep gray matter structures. QSM measures were compared between two groups using the t-test. We also calculated Pearson correlations between QSM measures and PI. In all, 26 patients showed pallidal hyperintensity (T1 h group) and 12 did not (T1 n group). The susceptibility of the globus pallidus (GP) in the T1 h group (120.6 ± 38.1 ppb) was significantly lower than that in the T1 n group (150.0 ± 35.2, P = 0.030). The susceptibility of the dentate nucleus (DN) in the T1 h group (88.1 ± 31.0) was significantly lower than that in the T1 n group (125.6 ± 30.6, P = 0.001). Negative correlation between the susceptibility of GP (r = -0.37, P = 0.022) and the PI, and between DN (r = -0.43, P < 0.001) and the PI was found. Liver cirrhosis patients with pallidal T1 hyperintensity had lower susceptibility values in the GP and DN than those without it. This suggests a possible interaction between iron and manganese in the brains of liver cirrhosis patients. 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:1342-1349.

Subregional Structural Alterations in Hippocampus and Nucleus Accumbens Correlate with the Clinical Impairment in Patients with Alzheimer's Disease Clinical Spectrum: Parallel Combining Volume and Vertex-Based Approach.

Deep gray matter structures are associated with memory and other important functions that are impaired in Alzheimer’s disease (AD) and mild cognitive impairment (MCI). However, systematic characterization of the subregional atrophy and deformations in these structures in AD and MCI still need more investigations. In this article, we combined complex volumetry- and vertex-based analysis to investigate the pattern of subregional structural alterations in deep gray matter structures and its association with global clinical scores in AD (n = 30) and MCI patients (n = 30), compared to normal controls (NCs, n = 30). Among all seven pairs of structures, the bilateral hippocampi and nucleus accumbens showed significant atrophy in AD compared with NCs (p < 0.05). But only the subregional atrophy in the dorsal–medial part of the left hippocampus, the ventral part of right hippocampus, and the left nucleus accumbens, the posterior part of the right nucleus accumbens correlated with the worse clinical scores of MMSE and MOCA (p < 0.05). Furthermore, the medial–ventral part of right thalamus significantly shrank and correlated with clinical scores without decreasing in its whole volume (p > 0.05). In conclusion, the atrophy of these four subregions in bilateral hippocampi and nucleus accumbens was associated with cognitive impairment of patients, which might be potential target regions of treatment in AD. The surface analysis could provide additional information to volume comparison in finding the early pathological progress in deep gray matter structures.

MRI evaluation of thalamic volume differentiates MS from common mimics.

Objective:To determine whether MRI evaluation of thalamic volume differentiates MS from other disorders that cause MRI white matter abnormalities.Methods:There were 40 study participants: 10 participants with MS without additional comorbidities for white matter abnormalities (MS − c); 10 participants with MS with additional comorbidities for white matter abnormalities (MS + c); 10 participants with migraine, MRI white matter abnormalities, and no additional comorbidities for white matter abnormalities (Mig − c); and 10 participants previously incorrectly diagnosed with MS (Misdx). T1-magnetization-prepared rapid gradient-echo and T2-weighted three-dimensional fluid attenuation inversion recovery sequences were acquired on a Phillips Achieva d-Stream 3T MRI, and scans were randomly ordered and de-identified for a blinded reviewer who performed MRI segmentation using LesionTOADS.Results:Mean normalized thalamic volume differed among the 4 cohorts (analysis of variance, p = 0.005) and was smaller in the 20 MS participants compared with the 20 non-MS participants (p < 0.001), smaller in MS − c compared with Mig − c (p = 0.03), and smaller in MS + c compared with Misdx (p = 0.006). The sensitivity and specificity were both 0.75 for diagnosis of MS with a thalamic volume <0.0077.Conclusions:MRI volumetric evaluation of the thalamus, but not other deep gray-matter structures, differentiated MS from other diseases that cause white matter abnormalities and are often mistaken for MS. Evaluation for thalamic atrophy may improve accuracy for diagnosis of MS as an adjunct to additional radiologic criteria. Thalamic volumetric assessment by MRI in larger cohorts of patients undergoing evaluation for MS is needed, along with the development of automated and easily applied volumetric assessment tools for future clinical application.Classification of evidence:This study provides Class III evidence that MRI evaluation of thalamic volume differentiates MS from other diseases that cause white matter abnormalities.

Iron Concentration in Deep Gray Matter Structures is Associated with Worse VisualMemory Performance in Healthy Young Adults.

Abnormally high deposition of iron can contribute to neurodegenerative disorders with cognitive impairment. Since previous studies investigating cognition-brain iron accumulation relationships focused on elderly people, our aim was to explore the association between iron concentration in subcortical nuclei and two types of memory performances in a healthy young population. Gender difference was found only in the globus pallidus. Our results showed that iron load characterized by R2* value on the MRI in the caudate and putamen was related to visual memory, while verbal memory was unrelated to iron concentration.

Amygdala and hippocampus volumes are differently affected by childhood trauma in patients with bipolar disorders and healthy controls

Volumetric studies on deep gray matter structures in bipolar disorder (BP) have reported contrasting results. Childhood trauma, a relevant environmental stressor for BP, could account for the variability of the results, modulating differences in the amygdala and hippocampus in patients with BP compared with healthy controls (HC). Our study aimed to test this hypothesis. We assessed 105 outpatients, diagnosed with bipolar disorder type I (BP-I) or bipolar disorder type II (BP-II) according to DSM-IV-TR criteria, and 113 HC subjects. History of childhood trauma was obtained using the Childhood Trauma Questionnaire (CTQ). High-resolution magnetic resonance imaging was performed on all subjects and volumes of the amygdala, hippocampus, nucleus accumbens, caudate, pallidum, putamen, and thalamus were measured using FreeSurfer. Patients with BP showed a global reduction of deep gray matter volumes compared to HCs. However, childhood trauma modulated the impact of the diagnosis specifically on the amygdala and hippocampus. Childhood trauma was associated with bilateral decreased volumes in HCs and increased volumes in patients with BP. The results suggest that childhood trauma may have a different effect in health and disease on volumes of gray matter in the amygdala and hippocampus, which are brain areas specifically involved in response to stress and emotion processing.

Evolution of deep gray matter volume across the human lifespan.

Magnetic resonance imaging of subcortical gray matter structures, which mediate behavior, cognition and the pathophysiology of several diseases, is crucial for establishing typical maturation patterns across the human lifespan. This single site study examines T1-weighted MPRAGE images of 3 healthy cohorts: (i) a cross-sectional cohort of 406 subjects aged 5-83 years; (ii) a longitudinal neurodevelopment cohort of 84 subjects scanned twice approximately 4 years apart, aged 5-27 years at first scan; and (iii) a longitudinal aging cohort of 55 subjects scanned twice approximately 3 years apart, aged 46-83 years at first scan. First scans from longitudinal subjects were included in the cross-sectional analysis. Age-dependent changes in thalamus, caudate, putamen, globus pallidus, nucleus accumbens, hippocampus, and amygdala volumes were tested with Poisson, quadratic, and linear models in the cross-sectional cohort, and quadratic and linear models in the longitudinal cohorts. Most deep gray matter structures best fit to Poisson regressions in the cross-sectional cohort and quadratic curves in the young longitudinal cohort, whereas the volume of all structures except the caudate and globus pallidus decreased linearly in the longitudinal aging cohort. Males had larger volumes than females for all subcortical structures, but sex differences in trajectories of change with age were not significant. Within subject analysis showed that 65%-80% of 13-17 year olds underwent a longitudinal decrease in volume between scans (∼4 years apart) for the putamen, globus pallidus, and hippocampus, suggesting unique developmental processes during adolescence. This lifespan study of healthy participants will form a basis for comparison to neurological and psychiatric disorders. Hum Brain Mapp 38:3771-3790, 2017. © 2017 Wiley Periodicals, Inc.

Changes of deep gray matter magnetic susceptibility over 2years in multiple sclerosis and healthy control brain.

In multiple sclerosis, pathological changes of both tissue iron and myelin occur, yet these factors have not been characterized in a longitudinal fashion using the novel iron- and myelin-sensitive quantitative susceptibility mapping (QSM) MRI technique. We investigated disease-relevant tissue changes associated with myelin loss and iron accumulation in multiple sclerosis deep gray matter (DGM) over two years. One-hundred twenty (120) multiple sclerosis patients and 40 age- and sex-matched healthy controls were included in this prospective study. Written informed consent and local IRB approval were obtained from all participants. Clinical testing and QSM were performed both at baseline and at follow-up. Brain magnetic susceptibility was measured in major DGM structures. Temporal (baseline vs. follow-up) and cross-sectional (multiple sclerosis vs. controls) differences were studied using mixed factorial ANOVA analysis and appropriate t-tests. At either time-point, multiple sclerosis patients had significantly higher susceptibility in the caudate and globus pallidus and lower susceptibility in the thalamus. Over two years, susceptibility increased significantly in the caudate of both controls and multiple sclerosis patients. Inverse thalamic findings among MS patients suggest a multi-phase pathology explained by simultaneous myelin loss and/or iron accumulation followed by iron depletion and/or calcium deposition at later stages.

Abnormal subcortical nuclei shapes in patients with type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) increases the risk of brain atrophy and dementia. We aimed to elucidate deep grey matter (GM) structural abnormalities and their relationships with T2DM cognitive deficits by combining region of interest (ROI)-based volumetry, voxel-based morphometry (VBM) and shape analysis. We recruited 23 T2DM patients and 24 age-matched healthy controls to undergo T1-weighted structural MRI scanning. Images were analysed using the three aforementioned methods to obtain deep GM structural shapes and volumes. Biochemical and cognitive assessments were made and were correlated with the resulting metrics. Shape analysis revealed that T2DM is associated with focal atrophy in the bilateral caudate head and dorso-medial part of the thalamus. ROI-based volumetry only detected thalamic volume reduction in T2DM when compared to the controls. No significant between-group differences were found by VBM. Furthermore, a worse performance of cognitive processing speed correlated with more severe GM atrophy in the bilateral dorso-medial part of the thalamus. Also, the GM volume in the bilateral dorso-medial part of the thalamus changed negatively with HbA1c. Shape analysis is sensitive in identifying T2DM deep GM structural abnormalities and their relationships with cognitive impairments, which may greatly assist in clarifying the neural substrate of T2DM cognitive dysfunction. • Type 2 diabetes mellitus is accompanied with brain atrophy and cognitive dysfunction • Deep grey matter structures are essential for multiple cognitive processes • Shape analysis revealed local atrophy in the dorso-medial thalamus and caudatum in patients • Dorso-medial thalamic atrophy correlated to cognitive processing speed slowing and high HbA1c. • Shape analysis has advantages in unraveling neural substrates of diabetic cognitive deficits.

The different effect of childhood trauma on amygdala and hippocampus in patients with bipolar disorder and healthy controls

IntroductionChildhood trauma (CT) is a relevant environmental stressor for bipolar disorder (BP). Amygdala and hippocampus are key areas involved both in the pathophysiology of BP and in mediating the biological response to stress.ObjectivesStructural neuroimaging studies help clarifying neural correlates of the relationship between BP diagnosis and CT.AimsTo verify the impact of CT on amygdala and hippocampus and hippocampal subfields volumes in BP patients and healthy control (HC).MethodsWe assessed 105 outpatients, diagnosed with BPI or BPII according to DSM-IV-TR criteria, and 113 HC subjects. History of CT was obtained using the childhood trauma questionnaire (CTQ). High-resolution magnetic resonance imaging was performed on all subjects and volumes of amygdala, hippocampus, nucleus accumbens, caudate, pallidum, putamen, thalamus and hippocampal subfields were measured through FreeSurfer.ResultsAll deep gray matter structures were smaller in BP than HC. CT modulated the impact of the diagnosis on bilateral amygdala and hippocampus, in particular on subiculum, presubiculum and cornu ammonis CA1. It was associated with bilateral decreased volumes in HC and increased volumes in patients with BP.ConclusionsChildhood trauma impacts on the amygdala and hippocampus, brain areas involved in response to stress and emotion processing, and specifically on the hippocampal subfields most implicated in learning trough positive/negative reinforcement.Disclosure of interestThe authors have not supplied their declaration of competing interest.