scholarly journals Neuropsychological Perspective on Dyslexia

2021 ◽  
Author(s):  
María-José González-Valenzuela ◽  
Isaías Martín-Ruiz
Keyword(s):  
White Matter ◽  
Visual Perception ◽  
Corpus Callosum ◽  
Learning Disability ◽  
Phonological Processing ◽  
Clinical Manifestations ◽  
Brain Areas ◽  
Magnocellular System ◽  
Definition Of ◽  
Specific Learning

The aim of this chapter is to offer a neuropsychological approach to dyslexia. Firstly, the definition of dyslexia is addressed, as a specific learning disability that is neuropsychological in origin. Secondly, the clinical manifestations of dyslexia are discussed: academic, cognitive-linguistic, and socio-emotional. Thirdly, the main clinical explanations are explored, based on genetic theories (familial and twin heritability) and neurological theories, mainly neuroanatomical (brain asymmetry, corpus callosum morphology, cerebellar morphology, and variations in grey/white matter) and neurophysiological hypotheses (magnocellular system, connectivity between brain areas, and functional activity of brain areas). Finally, the main bases of an adequate neuropsychological intervention are detailed, such as training in visual perception, auditory perception, phonological processing, and orthographic processing.

Deficits in musical rhythm perception in children with specific learning disabilities

2021 ◽  
pp. 1-7
Author(s):  
Vasudha Hande ◽  
Shantala Hegde
Keyword(s):  
Learning Disabilities ◽  
Learning Disability ◽  
Language Processing ◽  
Phonological Processing ◽  
Specific Learning Disability ◽  
Specific Learning Disabilities ◽  
Target Language ◽  
Rhythm Perception ◽  
Musical Rhythm ◽  
Specific Learning

BACKGROUND: A specific learning disability comes with a cluster of deficits in the neurocognitive domain. Phonological processing deficits have been the core of different types of specific learning disabilities. In addition to difficulties in phonological processing and cognitive deficits, children with specific learning disability (SLD) are known to also found have deficits in more innate non-language-based skills like musical rhythm processing. OBJECTIVES: This paper reviews studies in the area of musical rhythm perception in children with SLD. An attempt was made to throw light on beneficial effects of music and rhythm-based intervention and their underlying mechanism. METHODS: A hypothesis-driven review of research in the domain of rhythm deficits and rhythm-based intervention in children with SLD was carried out. RESULTS: A summary of the reviewed literature highlights that music and language processing have shared neural underpinnings. Children with SLD in addition to difficulties in language processing and other neurocognitive deficits are known to have deficits in music and rhythm perception. This is explained in the background of deficits in auditory skills, perceptuo-motor skills and timing skills. Attempt has been made in the field to understand the effect of music training on the children’s auditory processing and language development. Music and rhythm-based intervention emerges as a powerful intervention method to target language processing and other neurocognitive functions. Future studies in this direction are highly underscored. CONCLUSIONS: Suggestions for future research on music-based interventions have been discussed.

Corpus Callosum Microstructural Alterations In Children With Memory Related Learning Disability: A Diffusion Tensor Imaging Study

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Abeer Maghawry Abd elhameed ◽  
Shaimaa Abdelsattar Mohammad ◽  
Neveen Hassan Nashaat ◽  
Amgad Samy Abdel-Rahman ◽  
Ehab Ragaa Abdol Raouf
Keyword(s):  
Learning Disabilities ◽  
White Matter ◽  
Corpus Callosum ◽  
Learning Disability ◽  
Diffusion Tensor ◽  
Digit Span ◽  
Clinical Test ◽  
Control Subjects ◽  
Healthy Control ◽  
With Memory

Abstract Purpose The purpose of this study is to assess the corpus callosum microstructural changes in children with memory related learning disability. Methods DTI was performed in 20 patients with memory related learning disabilities (MRLD +) and 22 matched healthy control subjects (MRLD -) aged 7– 13 years. Fractional anisotropy (FA), axial diffusivity, radial diffusivity (RD) and trace were calculated for corpus callosum. Comparison between patients with memory related learning disabilities (MRLD +) and healthy control subjects (MRLD -) was performed. DTI metrics were correlated to clinical digit span backward scores in (MRLD +) group. A pvalue less than .05 was considered significant. Results The corpus callosum showed a highly significant higher FA and lower diffusivity indices in (MRLD +) group compared to the (MRLD -) group (p < 0.001). No significant correlation between the clinical test “digit span backward” scores and DTI metrics of the corpus callosum was found. Conclusion Changes in DTI metrics of corpus callosum in patients with memory related learning disabilities reflects white matter micro-structural changes. Higher FA values and lower diffusivity indices do not necessarily indicate healthier white matter but, can indicate pathology.

scholarly journals Neurobiological Differences Between Aggression and Agitation in Persons with DementiaAffiliation

2019 ◽  
Vol 2 (4) ◽  
pp. 28-36
Author(s):  
Ladislav Volicer
Keyword(s):  
White Matter ◽  
Cell Count ◽  
Neurofibrillary Tangles ◽  
Brain Perfusion ◽  
Behavioral Symptoms ◽  
Brain Areas ◽  
White Matter Changes ◽  
People With Dementia ◽  
Methodological Problems ◽  
Definition Of

Background Controversy exists about definition of agitation and especially about inclusion of aggression as a part of agitation in people with dementia. Methods: Papers describing neurobiological indices related to behavioral symptoms of dementia were reviewed. Papers comparing indices in persons exhibiting aggression and persons exhibiting agitation were selected for this review. Results The survey found seven papers which compared neuroanatomical indices and three papers which compared neurochemical indices. The neuroanatomical indices differentiating agitation and aggression included changes in brain perfusion, sizes of brain areas, distribution of neurofibrillary tangles, and white matter changes. The neurochemical indices differentiating agitation and aggression included relationships with neurotransmitter variables and the cell count in the locus coeruleus. Conclusion Despite the small number of papers and some methodological problems, the presented information clearly indicates that aggression and agitation are two distinct unrelated syndromes in persons with dementia.

scholarly journals Relationship between Stereoscopic Vision, Visual Perception, and Microstructure Changes of Corpus Callosum and Occipital White Matter in the 4-Year-Old Very Low Birth Weight Children

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Przemko Kwinta ◽  
Izabela Herman-Sucharska ◽  
Anna Leśniak ◽  
Małgorzata Klimek ◽  
Paulina Karcz ◽  
...  
Keyword(s):  
Birth Weight ◽  
White Matter ◽  
Visual Perception ◽  
Corpus Callosum ◽  
Very Low Birth Weight ◽  
Diffusion Tensor ◽  
Stereoscopic Vision ◽  
Developmental Test ◽  
Brain Microstructure

Aim.To assess the relationship between stereoscopic vision, visual perception, and microstructure of the corpus callosum (CC) and occipital white matter, 61 children born with a mean birth weight of 1024 g (SD 270 g) were subjected to detailed ophthalmologic evaluation, Developmental Test of Visual Perception (DTVP-3), and diffusion tensor imaging (DTI) at the age of 4.Results. Abnormal stereoscopic vision was detected in 16 children. Children with abnormal stereoscopic vision had smaller CC (CC length:53±6 mm versus61±4 mm;p<0.01; estimated CC area:314±106 mm2versus446±79 mm2;p<0.01) and lower fractional anisotropy (FA) values in CC (FA value of rostrum/genu:0.7±0.09versus0.79±0.07;p<0.01; FA value of CC body:0.74±0.13versus0.82±0.09;p=0.03). We found a significant correlation between DTVP-3 scores, CC size, and FA values in rostrum and body. This correlation was unrelated to retinopathy of prematurity.Conclusions. Visual perceptive dysfunction in ex-preterm children without major sequelae of prematurity depends on more subtle changes in the brain microstructure, including CC. Role of interhemispheric connections in visual perception might be more complex than previously anticipated.

Assessment of White Matter Lesions in Parkinson's Disease: Voxel-based Analysis and Tract-based Spatial Statistics Analysis of Parkinson's Disease with Mild Cognitive Impairment

2020 ◽  
Vol 17 (4) ◽  
pp. 480-486
Author(s):  
Wei Pu ◽  
Xudong Shen ◽  
Mingming Huang ◽  
Zhiqian Li ◽  
Xianchun Zeng ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
White Matter ◽  
Corpus Callosum ◽  
Fractional Anisotropy ◽  
Spatial Statistics ◽  
Diffusion Tensor ◽  
Tract Based Spatial Statistics

Objective: Application of diffusion tensor imaging (DTI) to explore the changes of FA value in patients with Parkinson's disease (PD) with mild cognitive impairment. Methods: 27 patients with PD were divided into PD with mild cognitive impairment (PD-MCI) group (n = 7) and PD group (n = 20). The original images were processed using voxel-based analysis (VBA) and tract-based spatial statistics (TBSS). Results: The average age of pd-mci group was longer than that of PD group, and the course of disease was longer than that of PD group. Compared with PD group, the voxel based analysis-fractional anisotropy (VBA-FA) values of PD-MCI group decreased in the following areas: bilateral frontal lobe, bilateral temporal lobe, bilateral parietal lobe, bilateral subthalamic nucleus, corpus callosum, and gyrus cingula. Tract-based spatial statistics-fractional anisotropy (TBSS-FA) values in PD-MCI group decreased in bilateral corticospinal tract, anterior cingulum, posterior cingulum, fornix tract, bilateral superior thalamic radiation, corpus callosum(genu, body and splenium), bilateral uncinate fasciculus, bilateral inferior longitudinal fasciculus, bilateral superior longitudinal fasciculus, bilateral superior fronto-occipital fasciculus, bilateral inferior fronto-occipital fasciculus, and bilateral parietal-occipital tracts. The mean age of onset in the PD-MCI group was greater than that in the PD group, and the disease course was longer than that in the PD group. Conclusion: DTI-based VBA and TBSS post-processing methods can detect abnormalities in multiple brain areas and white matter fiber tracts in PD-MCI patients. Impairment of multiple cerebral cortex and white matter fiber pathways may be an important causes of cognitive dysfunction in PD-MCI.

Specific Learning Disabilities

2018 ◽  
Author(s):  
Christopher J. Lonigan
Keyword(s):  
Learning Disabilities ◽  
Learning Disability ◽  
Language Proficiency ◽  
Medical Condition ◽  
Neurodevelopmental Disorder ◽  
Opportunity To Learn ◽  
Specific Learning Disability ◽  
Specific Learning Disabilities ◽  
Low Achievement ◽  
Specific Learning

Specific learning disability is a common neurodevelopmental disorder affecting about 5–8% of the school-aged population. A key concept in specific learning disabilities is unexpected low achievement. An individual whose achievement in reading, math, or writing is both low and less than what would be expected based on developmental capacity and opportunity to learn and whose low achievement cannot be explained by a sensory impairment, limited language proficiency, or other impairing medical condition is considered to have a specific learning disability. This chapter provides an overview of issues and challenges involved in the identification and diagnosis of a specific learning disability, and it provides information on prevalence, epidemiology, and interventions for specific learning disabilities. Response-to-instruction models of identification hold promise for the identification of individuals with a specific learning disability, and they provide a means for the identification of false positives while enhancing the instructional context for children at risk.

scholarly journals Topographic patterns of white matter hyperintensities are associated with multimodal neuroimaging biomarkers of Alzheimer’s disease

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Malo Gaubert ◽  
Catharina Lange ◽  
Antoine Garnier-Crussard ◽  
Theresa Köbe ◽  
Salma Bougacha ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
White Matter ◽  
Glucose Metabolism ◽  
Corpus Callosum ◽  
Gray Matter ◽  
Fdg Pet ◽  
White Matter Hyperintensities ◽  
Gray Matter Volume ◽  
Matter Volume

Abstract Background White matter hyperintensities (WMH) are frequently found in Alzheimer’s disease (AD). Commonly considered as a marker of cerebrovascular disease, regional WMH may be related to pathological hallmarks of AD, including beta-amyloid (Aβ) plaques and neurodegeneration. The aim of this study was to examine the regional distribution of WMH associated with Aβ burden, glucose hypometabolism, and gray matter volume reduction. Methods In a total of 155 participants (IMAP+ cohort) across the cognitive continuum from normal cognition to AD dementia, FLAIR MRI, AV45-PET, FDG-PET, and T1 MRI were acquired. WMH were automatically segmented from FLAIR images. Mean levels of neocortical Aβ deposition (AV45-PET), temporo-parietal glucose metabolism (FDG-PET), and medial-temporal gray matter volume (GMV) were extracted from processed images using established AD meta-signature templates. Associations between AD brain biomarkers and WMH, as assessed in region-of-interest and voxel-wise, were examined, adjusting for age, sex, education, and systolic blood pressure. Results There were no significant associations between global Aβ burden and region-specific WMH. Voxel-wise WMH in the splenium of the corpus callosum correlated with greater Aβ deposition at a more liberal threshold. Region- and voxel-based WMH in the posterior corpus callosum, along with parietal, occipital, and frontal areas, were associated with lower temporo-parietal glucose metabolism. Similarly, lower medial-temporal GMV correlated with WMH in the posterior corpus callosum in addition to parietal, occipital, and fontal areas. Conclusions This study demonstrates that local white matter damage is correlated with multimodal brain biomarkers of AD. Our results highlight modality-specific topographic patterns of WMH, which converged in the posterior white matter. Overall, these cross-sectional findings corroborate associations of regional WMH with AD-typical Aß deposition and neurodegeneration.

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