scholarly journals Voxel and surface based whole brain analysis shows reading skill associated grey matter abnormalities in dyslexia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Teija Kujala ◽  
Aleksi J. Sihvonen ◽  
Anja Thiede ◽  
Peter Palo-oja ◽  
Paula Virtala ◽  
...  

AbstractDevelopmental dyslexia (DD) is the most prevalent neurodevelopmental disorder with a substantial negative influence on the individual’s academic achievement and career. Research on its neuroanatomical origins has continued for half a century, yielding, however, inconsistent results, lowered total brain volume being the most consistent finding. We set out to evaluate the grey matter (GM) volume and cortical abnormalities in adult dyslexic individuals, employing a combination of whole-brain voxel- and surface-based morphometry following current recommendations on analysis approaches, coupled with rigorous neuropsychological testing. Whilst controlling for age, sex, total intracranial volume, and performance IQ, we found both decreased GM volume and cortical thickness in the left insula in participants with DD. Moreover, they had decreased GM volume in left superior temporal gyrus, putamen, globus pallidus, and parahippocampal gyrus. Higher GM volumes and cortical thickness in these areas correlated with better reading and phonological skills, deficits of which are pivotal to DD. Crucially, total brain volume did not influence our results, since it did not differ between the groups. Our findings demonstrating abnormalities in brain areas in individuals with DD, which previously were associated with phonological processing, are compatible with the leading hypotheses on the neurocognitive origins of DD.

2021 ◽  
Author(s):  
Teija Kujala ◽  
Aleksi Sihvonen ◽  
Anja Thiede ◽  
Peter Palo-Oja ◽  
Paula Virtala ◽  
...  

Abstract Developmental dyslexia (DD) is the most prevalent neurodevelopmental disorder with a substantial negative influence on the individual’s academic achievement and career. Research on its neuroanatomical origins has continued for half a century, yielding, however, inconsistent results, lowered total brain volume being the most consistent finding. We set out to evaluate the grey matter (GM) volume and cortical abnormalities in adult dyslexic individuals, employing a combination of whole-brain voxel- and surface-based morphometry following current recommendations on analysis approaches, coupled with rigorous neuropsychological testing. Whilst controlling for age, sex, total intracranial volume, and performance IQ, we found both decreased GM volume and cortical thickness in the left insula in participants with DD. Moreover, they had decreased GM volume in left superior temporal gyrus, putamen, globus pallidus, and parahippocampal gyrus. Higher GM volumes and cortical thickness in these areas correlated with better reading and phonological skills, deficits of which are pivotal to DD. Crucially, total brain volume did not influence our results, since it did not differ between the groups. Our findings demonstrating abnormalities in brain areas in individuals with DD, which previously were associated with phonological processing, are compatible with the leading hypotheses on the neurocognitive origins of DD.


2021 ◽  
Author(s):  
Eilidh MacNicol ◽  
Paul Wright ◽  
Eugene Kim ◽  
Irene Brusini ◽  
Oscar Esteban ◽  
...  

Age-specific resources mitigate biases in human MRI processing arising from structural changes across the lifespan. There are fewer age-specific resources for preclinical imaging, and they only represent developmental periods rather than adulthood. Since rats recapitulate many facets of human aging, it was hypothesized that brain volume and each tissue’s relative contribution to total brain volume would change with age in the adult rat. However, the currently available tissue probability maps, which provide a priori information for tissue volume estimation, provide inaccurate grey matter probabilities in subcortical structures, particularly the thalamus. Consequently, age-specific templates and tissue probability maps were generated from a longitudinal study that scanned a cohort of rats at 3, 5, 11, and 17 months old. Mixed-effects models assessed the effect of age on brain, grey matter, white matter, and CSF volumes, and the relative tissue proportions. Grey and white matter volume increased with age, and the tissue proportions relative to total brain volume varied throughout adulthood. Furthermore, we present evidence of a systematic underestimation of thalamic grey matter volume with existing resources, which is mitigated with the use of age-specific tissue probability maps since the derived estimates better matched histological evidence. To reduce age-related biases in image pre-processing, a set of rat brain resources from across the adult lifespan is consequently released to expand the preclinical MRI community’s fundamental resources.


2021 ◽  
Author(s):  
Su Wang ◽  
Jan M. Friedman ◽  
Per Suppa ◽  
Ralph Buchert ◽  
Victor-Felix Mautner

Abstract Background: Neurofibromatosis 1 (NF1) is a rare autosomal dominant disease characterized by increased Schwann cell proliferation in peripheral nerves. Several small studies of brain morphology in children with NF1 have found increased total brain volume, total white matter volume and/or corpus callosum area. Several studies (mostly in children with NF1) also attempted to correlate changes in brain morphology and volume with cognitive or behavioural abnormalities, though findings were inconsistent. We aimed to characterize alterations in brain volumes by three-dimensional (3D) MRI in adults with NF1 in major intracranial sub-regions. We also aimed to assess the effect of age on these volumes and correlated brain white matter and grey matter volumes with neuropsychometric findings in adults with NF1.Methods: We obtained brain volume measurements using 3D magnetic resonance imaging for 351 adults with NF1 and, as a comparison group, 43 adults with neurofibromatosis 2 (NF2) or Schwannomatosis. We assessed a subset of 19 adults with NF1 for clinical severity of NF1 features and neurological problems and conducted psychometric testing for attention deficiencies and intelligence quotient. We compared brain volumes between NF1 patients and controls and correlated volumetric measurements to clinical and psychometric features in the NF1 patients. Results:Total brain volume and total and regional white matter volumes were all significantly increased in adults with NF1. Grey matter volume decreased faster with age in adults with NF1 than in controls. Greater total brain volume and white matter volume were correlated with lower attention deficits and higher intelligence quotients in adults with NF1.Conclusion:Our findings are consistent with the hypothesis that dysregulation of brain myelin production is a cardinal manifestation of NF1 and that these white matter changes may be functionally important in affected adults.


2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Niklas Klasson ◽  
Erik Olsson ◽  
Carl Eckerström ◽  
Helge Malmgren ◽  
Anders Wallin

Author(s):  
P. Yugander ◽  
M. Jagannath

Autism Spectrum Disorder (ASD) is widely developing neurodevelopmental disorder. The ASD is a lifelong neurodevelopmental disorder that effects the social interaction and behavior of human beings. In this review, we presented structural magnetic resonance imaging (sMRI) studies that were examined in structural brain abnormalities of ASD patients. To date sMRI results were distinct, due to the diversity of the ASD itself. The accelerated brain volume is the uniform finding of ASD. However, the recent investigation reports have started to interpret the structural abnormalities of ASD patient’s brain. The most common abnormalities found in total brain volume, cerebellum, amygdala, hippocampal, basal ganglia, insula, gray and white matter. Limited sMRI research has been done on less than 2 years ASD children. Future research should include autistic children less than 2 years along with functional MRI and diffusion tensor imaging.


Neurology ◽  
2017 ◽  
Vol 88 (5) ◽  
pp. 449-455 ◽  
Author(s):  
Michelle Luciano ◽  
Janie Corley ◽  
Simon R. Cox ◽  
Maria C. Valdés Hernández ◽  
Leone C.A. Craig ◽  
...  

Objective:To assess the association between Mediterranean-type diet (MeDi) and change in brain MRI volumetric measures and mean cortical thickness across a 3-year period in older age (73–76 years).Methods:We focused on 2 longitudinal brain volumes (total and gray matter; n = 401 and 398, respectively) plus a longitudinal measurement of cortical thickness (n = 323), for which the previous cross-sectional evidence of an association with the MeDi was strongest. Adherence to the MeDi was calculated from data gathered from a food frequency questionnaire at age 70, 3 years prior to the baseline imaging data collection.Results:In regression models adjusting for relevant demographic and physical health indicators, we found that lower adherence to the MeDi was associated with greater 3-year reduction in total brain volume (explaining 0.5% of variance, p < 0.05). This effect was half the size of the largest covariate effect (i.e., age). Cross-sectional associations between MeDi and baseline MRI measures in 562 participants were not significant. Targeted analyses of meat and fish consumption did not replicate previous associations with total brain volume or total gray matter volume.Conclusions:Lower adherence to the MeDi in an older Scottish cohort is predictive of total brain atrophy over a 3-year interval. Fish and meat consumption does not drive this change, suggesting that other components of the MeDi or, possibly, all of its components in combination are responsible for the association.


2020 ◽  
pp. 1-10 ◽  
Author(s):  
Michael A. Mooney ◽  
Priya Bhatt ◽  
Robert J. M. Hermosillo ◽  
Peter Ryabinin ◽  
Molly Nikolas ◽  
...  

Abstract Background Mechanistic endophenotypes can inform process models of psychopathology and aid interpretation of genetic risk factors. Smaller total brain and subcortical volumes are associated with attention-deficit hyperactivity disorder (ADHD) and provide clues to its development. This study evaluates whether common genetic risk for ADHD is associated with total brain volume (TBV) and hypothesized subcortical structures in children. Methods Children 7–15 years old were recruited for a case–control study (N = 312, N = 199 ADHD). Children were assessed with a multi-informant, best-estimate diagnostic procedure and motion-corrected MRI measured brain volumes. Polygenic scores were computed based on discovery data from the Psychiatric Genomics Consortium (N = 19 099 ADHD, N = 34 194 controls) and the ENIGMA + CHARGE consortium (N = 26 577). Results ADHD was associated with smaller TBV, and altered volumes of caudate, cerebellum, putamen, and thalamus after adjustment for TBV; however, effects were larger and statistically reliable only in boys. TBV was associated with an ADHD polygenic score [β = −0.147 (−0.27 to −0.03)], and mediated a small proportion of the effect of polygenic risk on ADHD diagnosis (average ACME = 0.0087, p = 0.012). This finding was stronger in boys (average ACME = 0.019, p = 0.008). In addition, we confirm genetic variation associated with whole brain volume, via an intracranial volume polygenic score. Conclusion Common genetic risk for ADHD is not expressed primarily as developmental alterations in subcortical brain volumes, but appears to alter brain development in other ways, as evidenced by TBV differences. This is among the first demonstrations of this effect using molecular genetic data. Potential sex differences in these effects warrant further examination.


Stroke ◽  
2020 ◽  
Vol 51 (9) ◽  
Author(s):  
Amy Brodtmann ◽  
Mohamed Salah Khlif ◽  
Natalia Egorova ◽  
Michele Veldsman ◽  
Laura J. Bird ◽  
...  

Background and Purpose: Brain atrophy can be regarded as an end-organ effect of cumulative cardiovascular risk factors. Accelerated brain atrophy is described following ischemic stroke, but it is not known whether atrophy rates vary over the poststroke period. Examining rates of brain atrophy allows the identification of potential therapeutic windows for interventions to prevent poststroke brain atrophy. Methods: We charted total and regional brain volume and cortical thickness trajectories, comparing atrophy rates over 2 time periods in the first year after ischemic stroke: within 3 months (early period) and between 3 and 12 months (later period). Patients with first-ever or recurrent ischemic stroke were recruited from 3 Melbourne hospitals at 1 of 2 poststroke time points: within 6 weeks (baseline) or 3 months. Whole-brain 3T magnetic resonance imaging was performed at 3 time points: baseline, 3 months, and 12 months. Eighty-six stroke participants completed testing at baseline; 125 at 3 months (76 baseline follow-up plus 49 delayed recruitment); and 113 participants at 12 months. Their data were compared with 40 healthy control participants with identical testing. We examined 5 brain measures: hippocampal volume, thalamic volume, total brain and hemispheric brain volume, and cortical thickness. We tested whether brain atrophy rates differed between time points and groups. A linear mixed-effect model was used to compare brain structural changes, including age, sex, years of education, a composite cerebrovascular risk factor score, and total intracranial volume as covariates. Results: Atrophy rates were greater in stroke than control participants. Ipsilesional hemispheric, hippocampal, and thalamic atrophy rates were 2 to 4 times greater in the early versus later period. Conclusions: Regional atrophy rates vary over the first year after stroke. Rapid brain volume loss in the first 3 months after stroke may represent a potential window for intervention. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02205424.


2015 ◽  
Vol 38 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Yiran Chen ◽  
Hosung Kim ◽  
Robert Bok ◽  
Subramaniam Sukumar ◽  
Xin Mu ◽  
...  

Hyperpolarized 13C magnetic resonance imaging has recently been used to dynamically image metabolism in vivo. This technique provides the capability to investigate metabolic changes in mouse brain development over multiple time points. In this study, we used 13C magnetic resonance spectroscopic imaging and hyperpolarized 13C-1-labeled pyruvate to analyze its conversion into lactate. We also applied T2-weighted anatomical imaging to examine brain volume changes starting from postnatal day 18 (P18). We combined these results with body weight measurements for a comprehensive interpretation of mouse brain maturation. Both the produced lactate level and pyruvate to lactate conversion rate decreased with increasing age in a linear manner. Total brain volume remained the same after P18, even though body weight continued to grow exponentially. Our results have shown that the rate of metabolism of 13C-1 pyruvate to lactate in brain is high in the young mouse and decreases with age. The brain at P18 is still relatively immature and continues to develop even as the total brain volume remains the same.


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