scholarly journals Waves of Maturation and Senescence in Micro-Structural MRI Markers of Human Cortical Myelination over the Lifespan

2018 ◽  
Author(s):  
Håkon Grydeland ◽  
Petra E. Vértes ◽  
František Váša ◽  
Rafael Romero-Garcia ◽  
Kirstie Whitaker ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Age At Onset ◽  
Growth Curves ◽  
Structural Mri ◽  
Bimodal Distribution ◽  
Fine Grained ◽  
Age Related ◽  
Growth Stability ◽  
Magnetic Resonance Imaging Mri ◽  
Second Wave

AbstractSeminal human brain histology work has demonstrated developmental waves of myelination. Here, using a micro-structural magnetic resonance imaging (MRI) marker linked to myelin, we studied fine-grained age differences to deduce waves of growth, stability, and decline of cortical myelination over the life-cycle. In 484 participants, aged 8-85 years, we fitted smooth growth curves to T1- to T2-weighted ratio in each of 360 regions from one of 7 cytoarchitectonic classes. From the first derivatives of these generally inverted-U trajectories, we defined three milestones: the age at peak growth; the age at onset of a stable plateau; and the age at the onset of decline. Age at peak growth had a bimodal distribution comprising an early (pre-pubertal) wave of primary sensory and motor cortices and a later (post-pubertal) wave of association, insular and limbic cortices. Most regions reached stability in the 30s but there was a second wave reaching stability in the 50s. Age at onset of decline was also bimodal: in some right hemisphere regions, the curve declined from the 60s, but in other left hemisphere regions, there was no significant decline from the stable plateau. These results are consistent with regionally heterogeneous waves of intracortical myelinogenesis and age-related demyelination.

scholarly journals Interleukin-6 is linked to longitudinal rates of cortical thinning in aging

2014 ◽  
Vol 5 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Anna McCarrey ◽  
Jennifer Pacheco ◽  
Olga Carlson ◽  
Josephine Egan ◽  
Madhav Thambisetty ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Right Hemisphere ◽  
Cell Types ◽  
Inflammatory Biomarker ◽  
Cortical Thinning ◽  
Age Related ◽  
Dementia Risk ◽  
Mri Scans ◽  
Magnetic Resonance Imaging Mri ◽  
The Right

AbstractInterleukin-6 (IL-6) is a pro-inflammatory cytokine produced by immune cells and other cell types such as microglia throughout the brain. Higher levels of IL-6 in older adults have been cross-sectionally and longitudinally associated with physical and cognitive impairment, as well as increased dementia risk. The association between IL-6 levels and structural and functional brain changes is less clear. In the present study, we investigated the relationship between IL-6 concentrations and cortical thinning with aging. Magnetic Resonance Imaging (MRI) scans from the Baltimore Longitudinal Study of Aging were analyzed for 121 older subjects (M = 69.3; SD = 7.3; range = 56.1–85.9 yrs) who were repeatedly tested over an average period of 7.5 yrs, and who remained non-demented for the entire follow-up period. The Freesurfer longitudinal processing stream was utilized for image processing, and IL-6 measures were based on serum ELISA assays averaged across time points. Results showed that higher mean IL-6 concentrations were associated with accelerated annual rates of cortical thinning in the inferior temporal poles bilaterally. Additional pronounced regions of IL-6 -accelerated thinning included the transverse frontopolar gyri within the left hemisphere, and subcentral gyrus and sulcus within the right hemisphere. Our results indicate that sustained high levels of the inflammatory biomarker IL-6 are associated with regionally increased rates of age-related cortical thinning. These data build on previous findings that link IL-6 to chronic disease and demonstrate one mechanism through which high levels of inflammation may have adverse effects on physical and cognitive function.

Reduced cortical thickness and increased gyrification in generalized anxiety disorder: a 3 T MRI study

2017 ◽  
Vol 48 (12) ◽  
pp. 2001-2010 ◽  
Author(s):  
Cinzia Molent ◽  
Eleonora Maggioni ◽  
Filippo Cecchetto ◽  
Marco Garzitto ◽  
Sara Piccin ◽  
...  
Keyword(s):  
Anxiety Disorder ◽  
Generalized Anxiety Disorder ◽  
Cortical Thickness ◽  
Right Hemisphere ◽  
Gray Matter Volume ◽  
Structural Mri ◽  
Generalized Anxiety ◽  
Magnetic Resonance Imaging Mri ◽  
The Right ◽  
Mri Study

AbstractBackgroundAlthough the study of the neuroanatomical correlates of generalized anxiety disorder (GAD) is gaining increasing interest, up to now the cortical anatomy of GAD patients has been poorly investigated and still no data on cortical gyrification are available. The aim of the present study is to quantitatively examine the cortical morphology in patients with GAD compared with healthy controls (HC) using magnetic resonance imaging (MRI). To the best of our knowledge, this is the first study analyzing the gyrification patterns in GAD.MethodsA total of 31 GAD patients and 31 HC underwent 3 T structural MRI. For each subject, cortical surface area (CSA), cortical thickness (CT), gray matter volume (GMV), and local gyrification index (LGI) were estimated in 19 regions of interest using the Freesurfer software. These parameters were then compared between the two groups using General Linear Model designs.ResultsCompared with HC, GAD patients showed: (1) reduced CT in right caudal middle frontal gyrus (p < 0.05, Bonferroni corrected), (2) hyper-gyrification in right fusiform, inferior temporal, superior parietal and supramarginal gyri and in left supramarginal and superior frontal gyri (p < 0.05, Bonferroni corrected). No significant alterations in CSA and GMV were observed.ConclusionsOur findings support the hypothesis of a neuroanatomical basis for GAD, highlighting a possible key role of the right hemisphere. The alterations of CT and gyrification in GAD suggest a neurodevelopmental origin of the disorder. Further studies on GAD are needed to understand the evolution of the cerebral morphology with age and during the clinical course of the illness.

Examining the episodic-semantic interplay during future thinking – A reanalysis of external details

2020 ◽  
Author(s):  
Cherie Strikwerda-Brown ◽  
John Hodges ◽  
Olivier Piguet ◽  
Muireann Irish
Keyword(s):  
Life Story ◽  
Semantic Content ◽  
Structural Mri ◽  
Future Thinking ◽  
Fine Grained ◽  
Differential Vulnerability ◽  
Clinical Disorders ◽  
External Component ◽  
Future Narratives ◽  
General Semantic

Traditional analyses of autobiographical construction have tended to focus on the ‘internal’ or episodic details of the narrative. Contemporary studies employing fine-grained scoring measures, however, reveal the ‘external’ component of autobiographical narratives to contain important information relevant to the individual’s life story. Here, we used the recently developed NExt scoring protocol to explore profiles of external details generated by patients with Alzheimer’s disease (AD) (n = 11) and semantic dementia (SD) (n = 13) on a future thinking task. Voxel-based morphometry analyses of structural MRI were used to determine the neural correlates of external detail profiles in each patient group. Overall, distinct NExt profiles were observed across past and future temporal contexts in AD and SD groups, which involved elevations in external details, in the context of reduced internal details, relative to healthy Controls. Specifically, AD patients provided significantly more General Semantic details compared with Controls during past retrieval, whereas Specific Episode external details were elevated during future simulation. These increased external details within future narratives related to grey matter integrity in medial and lateral frontal regions in AD. By contrast, SD patients displayed an elevation of Specific Episode, Extended Episode, and General Semantic details exclusively during future simulation relative to Controls, which related to integrity of medial and lateral parietal regions. Our findings suggest that the compensatory external details generated during future simulation comprise an array of episodic and semantic details that vary in terms of specificity and self-relevance. Moreover, these profiles appear to be differentially affected depending on the locus of underlying neuropathology in dementia. Adopting a fine-grained approach to external details provides important information regarding the interplay between episodic and semantic content during future stimulation and highlights the differential vulnerability and preservation of distinct components of the constructed narrative in clinical disorders.

Asymmetry in Event-Related Potentials to Simulated Auditory Motion in Children, Young Adults, and Seniors

2002 ◽  
Vol 13 (01) ◽  
pp. 001-013 ◽  
Author(s):  
James Jerger ◽  
Rebecca Estes
Keyword(s):  
Young Adults ◽  
Right Hemisphere ◽  
Apparent Movement ◽  
Event Related Potentials ◽  
Auditory Evoked Responses ◽  
Age Related ◽  
Related Potentials ◽  
Velocity Information ◽  
The Right ◽  
Age Range

We studied auditory evoked responses to the apparent movement of a burst of noise in the horizontal plane. Event-related potentials (ERPs) were measured in three groups of participants: children in the age range from 9 to 12 years, young adults in the age range from 18 to 34 years, and seniors in the age range from 65 to 80 years. The topographic distribution of grand-averaged ERP activity was substantially greater over the right hemisphere in children and seniors but slightly greater over the left hemisphere in young adults. This finding may be related to age-related differences in the extent to which judgments of sound movement are based on displacement versus velocity information.

AGE-RELATED CHANGES IN THICKNESS OF CORTEX AND ITS LAYERS IN THE PARAMEDIAN LOBULE OF THE CEREBELLUM IN CHILDREN

2020 ◽  
pp. 14-18
Author(s):  
Татьяна Александровна Цехмистренко ◽  
Аслан Батразович Мазлоев ◽  
Дмитрий Константинович Обухов
Keyword(s):  
Right Hemisphere ◽  
Molecular Layer ◽  
First Year ◽  
Age Related ◽  
Average Group ◽  
Computer Morphometry ◽  
The Right ◽  
First Year Of Life ◽  
Granular Layers ◽  
Age Related Changes

Цель - изучение возрастных изменений толщины коры и ее слоев в парамедианной дольке мозжечка у детей. Материал и методы. Работа выполнена на постмортальном материале (62 мозжечка), полученном от детей в возрасте от рождения до 12 лет, умерших в результате травм без повреждений головного мозга. С помощью компьютерной морфометрии на окрашенных методом Ниссля фронтальных гистологических срезах коры, взятой билатерально в области парамедианной (тонкой) дольки (HVIIB) на вершине листков мозжечка, измеряли толщину коры, а также толщину ее молекулярного и зернистого слоев. Анализ количественных данных проводили в годовых интервалах. Результаты. В парамедианной дольке мозжечка увеличение толщины коры происходит в четыре этапа: в правом полушарии - от рождения к 1, 3, 5 и 9 годам, в левом полушарии - к 1, 5, 7 и 9 годам. Левосторонняя асимметрия толщины коры мозжечка отмечается у детей 1 и 2 лет, толщины молекулярного слоя - у детей 3 лет жизни. Правосторонняя асимметрия характерна для толщины зернистого слоя у детей 3 лет и поперечника коры, в целом, у детей 6 лет. Толщина коры и слоев в области парамедианной дольки мозжечка по среднегрупповым показателям достигает уровня взрослых людей к 9 годам. Выводы. Толщина коры мозжечка и ее слоев в области дольки H VII B увеличивается гетерохронно и гетеродинамически в правом и левом полушариях мозжечка у детей на первом году жизни, а также в периоды раннего, первого и второго детства. Уменьшения поперечника коры и слоев в парамедианной дольке мозжечка у детей от рождения до 12 лет не обнаружено. Objective - to study the age-related changes in the thickness of the cortex and its layers in the paramedian lobule of the cerebellum in children. Material and methods. The work was performed on postmortem material (62 cerebellums) obtained from children aged from birth to 12 years who died from injuries but without brain damage. The thickness of the cortex, as well as the thickness of its molecular and granular layers, were measured using computer morphometry on the Nissl-stained frontal histological sections of the cortex taken bilaterally in the region of the paramedian (gracile) lobule (HVIIB) at the top of the folia of cerebellum. Analysis of quantitative data was performed at annual intervals. Results. In the paramedian lobule of the cerebellum, the increase in the thickness of the cortex occured in four stages: in the right hemisphere - from birth to 1, 3, 5 and 9 years, in the left hemisphere - to 1, 5, 7 and 9 years. Left-sided asymmetry of the cortical thickness of the cerebellum was observed in 1 and 2-year old children, the thickness of the molecular layer - in 3-year old children. Right-sided asymmetry was characteristic for the thickness of the granular layer in 3-year old children and a cross-section of the cortex in 6-year old children. The thickness of the cortex and layers in the area of the paramedian lobule of the cerebellum on the average group indicators reached the level of adults by 9 years. Conclusions. The thickness of the cerebellar cortex and its layers in the area of the lobule HVIIB increased heterochronically and heterogeneously in the right and left hemispheres of the cerebellum in children of the first year of life, and in the periods of early, first and second childhood. No reduction in the diameter of the cortex and layers in the paramedian lobule of the cerebellum of children from birth to 12 years was found.

Functional and structural MRI correlates of executive functions in multiple sclerosis

2021 ◽  
pp. 135245852110331
Author(s):  
Olga Marchesi ◽  
Raffaello Bonacchi ◽  
Paola Valsasina ◽  
Paolo Preziosa ◽  
Elisabetta Pagani ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Working Memory ◽  
A Priori ◽  
Structural Mri ◽  
Wisconsin Card Sorting Test ◽  
Cognitive Networks ◽  
Superior Cerebellar Peduncle ◽  
Card Sorting ◽  
Cerebellar Peduncle ◽  
Magnetic Resonance Imaging Mri

Background: Executive dysfunctions, including difficulties in attention, working memory, planning, and inhibition affect 15%–28% of multiple sclerosis (MS) patients. Objectives: To investigate structural and functional magnetic resonance imaging (MRI) abnormalities underlying executive function (EF) in MS patients. Methods: A total 116 MS patients and 65 controls underwent resting-state (RS) and diffusion-weighted sequences and neuropsychological examination, including Wisconsin Card Sorting Test (WCST) to test EF. Brain RS cognitive networks and fractional anisotropy (FA) from a priori selected white matter tracts were derived. Associations of WCST scores with RS functional connectivity (FC) and FA abnormalities were investigated. Results: In MS patients, predictors of working memory/updating were: lower corpus callosum (CC) FA, lower left working-memory network (WMN), right WMN RS FC for worse performance; lower executive control network (ECN), higher default-mode network (DMN), and salience network (SN) RS FC for better performance ( R2 = 0.35). Predictors of attention were lower CC genu FA, lower left WMN, and DMN RS FC for worse performance; higher left WMN and ECN RS FC for better performance ( R2 = 0.24). Predictors of worse shifting/inhibition were lower CC genu and superior cerebellar peduncle (SCP) FA, lower left WMN RS FC for worse performance; and higher ECN RS FC for better performance ( R2 = 0.24). Conclusions: CC and SCP microstructural damage and RS FC abnormalities in cognitive networks underlie EF frailty in MS.

scholarly journals Early-Onset Parkinson Disease Screening in Patients From Nigeria

2021 ◽  
Vol 11 ◽  
Author(s):  
Lukasz M. Milanowski ◽  
Olajumoke Oshinaike ◽  
Benjamin J. Broadway ◽  
Jennifer A. Lindemann ◽  
Alexandra I. Soto-Beasley ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Parkinson Disease ◽  
Neurodegenerative Diseases ◽  
Early Onset ◽  
Local Population ◽  
Age At Onset ◽  
Compound Heterozygous ◽  
Loss Of Function ◽  
African Countries ◽  
Age Related

Introduction: Nigeria is one of the most populated countries in the world; however, there is a scarcity of studies in patients with age-related neurodegenerative diseases, such as Parkinson disease (PD). The aim of this study was to screen patients with PD including a small cohort of early-onset PD (EOPD) cases from Nigeria for PRKN, PINK1, DJ1, SNCA multiplication, and LRRK2 p.G2019S.Methods: We assembled a cohort of 109 Nigerian patients with PD from the four main Nigerian tribes: Yoruba, Igbo, Edo, and Hausa. Fifteen cases [14 from the Yoruba tribe (93.3%)] had EOPD (defined as age-at-onset &lt;50 years). All patients with EOPD were sequenced for the coding regions of PRKN, PINK1, and DJ1. Exon dosage analysis was performed with a multiplex ligation-dependent probe amplification assay, which also included a SNCA probe and LRRK2 p.G2019S. We screened for LRRK2 p.G2019S in the entire PD cohort using a genotyping assay. The PINK1 p.R501Q functional analysis was conducted.Results: In 15 patients with EOPD, 22 variants were observed [PRKN, 9 (40.9%); PINK1, 10 (45.5%); and DJ1, 3 (13.6%)]. Three (13.6%) rare, nonsynonymous variants were identified, but no homozygous or compound heterozygous carriers were found. No exonic rearrangements were present in the three genes, and no carriers of SNCA genomic multiplications or LRRK2 p.G2019S were identified. The PINK1 p.R501Q functional analysis revealed pathogenic loss of function.Conclusion: More studies on age-related neurodegenerative diseases are needed in sub-Saharan African countries, including Nigeria. Population-specific variation may provide insight into the genes involved in PD in the local population but may also contribute to larger studiesperformed in White and Asian populations.

scholarly journals Neuroimaging Anomalies in Community-Dwelling Asymptomatic Adults With Very Early-Stage White Matter Hyperintensity

2021 ◽  
Vol 13 ◽  
Author(s):  
Shuai Guan ◽  
Xiangyu Kong ◽  
Shifei Duan ◽  
Qingguo Ren ◽  
Zhaodi Huang ◽  
...  
Keyword(s):  
White Matter ◽  
Functional Mri ◽  
Resting State ◽  
Early Stage ◽  
Structural Mri ◽  
Resting State Fmri ◽  
Community Dwelling ◽  
White Matter Hyperintensity ◽  
Age Related ◽  
Comparative Results

White matter hyperintensity (WMH) is common in healthy adults in their 60s and can be seen as early as in their 30s and 40s. Alterations in the brain structural and functional profiles in adults with WMH have been repeatedly studied but with a focus on late-stage WMH. To date, structural and functional MRI profiles during the very early stage of WMH remain largely unexplored. To address this, we investigated multimodal MRI (structural, diffusion, and resting-state functional MRI) profiles of community-dwelling asymptomatic adults with very early-stage WMH relative to age-, sex-, and education-matched non-WMH controls. The comparative results showed significant age-related and age-independent changes in structural MRI-based morphometric measures and resting-state fMRI-based measures in a set of specific gray matter (GM) regions but no global white matter changes. The observed structural and functional anomalies in specific GM regions in community-dwelling asymptomatic adults with very early-stage WMH provide novel data regarding very early-stage WMH and enhance understanding of the pathogenesis of WMH.

scholarly journals Mathematical Models for Tumor Growth and the Reduction of Overtreatment

2018 ◽  
Vol 80 (01) ◽  
pp. 072-078 ◽  
Author(s):  
Berdine Heesterman ◽  
John-Melle Bokhorst ◽  
Lisa de Pont ◽  
Berit Verbist ◽  
Jean-Pierre Bayley ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Mathematical Models ◽  
Goodness Of Fit ◽  
Mean Squared Error ◽  
Age At Onset ◽  
Growth Curves ◽  
Magnetic Resonance Images ◽  
Coefficient Of Determination ◽  
Growth Data ◽  
Significant Difference

Background To improve our understanding of the natural course of head and neck paragangliomas (HNPGL) and ultimately differentiate between cases that benefit from early treatment and those that are best left untreated, we studied the growth dynamics of 77 HNPGL managed with primary observation. Methods Using digitally available magnetic resonance images, tumor volume was estimated at three time points. Subsequently, nonlinear least squares regression was used to fit seven mathematical models to the observed growth data. Goodness of fit was assessed with the coefficient of determination (R 2) and root-mean-squared error. The models were compared with Kruskal–Wallis one-way analysis of variance and subsequent post-hoc tests. In addition, the credibility of predictions (age at onset of neoplastic growth and estimated volume at age 90) was evaluated. Results Equations generating sigmoidal-shaped growth curves (Gompertz, logistic, Spratt and Bertalanffy) provided a good fit (median R 2: 0.996–1.00) and better described the observed data compared with the linear, exponential, and Mendelsohn equations (p < 0.001). Although there was no statistically significant difference between the sigmoidal-shaped growth curves regarding the goodness of fit, a realistic age at onset and estimated volume at age 90 were most often predicted by the Bertalanffy model. Conclusions Growth of HNPGL is best described by decelerating tumor growth laws, with a preference for the Bertalanffy model. To the best of our knowledge, this is the first time that this often-neglected model has been successfully fitted to clinically obtained growth data.

Age-Related Changes in the Allocation of Vertical Attention

2018 ◽  
Vol 24 (10) ◽  
pp. 1121-1124 ◽  
Author(s):  
Aleksandra Mańkowska ◽  
Kenneth M. Heilman ◽  
John B. Williamson ◽  
Michał Harciarek
Keyword(s):  
Spatial Attention ◽  
Right Hemisphere ◽  
Ventral Stream ◽  
Midsagittal Plane ◽  
Visual Stream ◽  
Leftward Bias ◽  
Healthy Elderly ◽  
Age Related ◽  
The Right ◽  
Dorsal Visual Stream

AbstractObjectives: Healthy individuals often have a leftward and upward attentional spatial bias; however, there is a reduction of this leftward bias with aging. The right hemisphere mediates leftward spatial attention and age-related reduction of right hemispheric activity may account for this reduced leftward bias. The right hemisphere also appears to be responsible for upward bias, and this upward bias might reduce with aging. Alternatively, whereas the dorsal visual stream allocates attention downward, the ventral stream allocates attention upward. Since with aging there is a greater atrophy of the dorsal than ventral stream, older participants may reveal a greater upward bias. The main purpose of this study was to learn if aging influences the vertical allocation of spatial attention. Methods: Twenty-six young (17 males; mean age 44.62±2.57 years) and 25 healthy elderly (13 males; mean age 72.04±.98 years), right-handed adults performed line bisections using 24 vertical lines (24 cm long and 2 mm thick) aligned with their midsagittal plane. Results: Older adults had a significantly greater upward bias than did younger adults. Conclusions: Normal upward attentional bias increases with aging, possibly due to an age-related reduction of the dorsal attentional stream that is responsible for the allocation of downward attention. (JINS, 2018, 24, 1121–1124)

Sign in / Sign up

Export Citation Format

Share Document