Brain networks in posterior cortical atrophy: A single case tractography study and literature review

Migliaccio, Raffaella; Agosta, Federica; Toba, Monica N.; Samri, Dalila; Corlier, Fabian; Souza, Leonardo Cruz de; Chupin, Marie; Sharman, Michael; Gorno‐Tempini, Maria Luisa; Dubois, Bruno; Filippi, Massimo; Bartolomeo, Paolo

doi:10.1016/j.cortex.2011.10.002

Cited by 60 publications

(52 citation statements)

References 76 publications

(94 reference statements)

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“…Our results are partly concordant with recent findings that APOE‐ε4 carriers show different brain activity during scene perception (Shine, Hodgetts, Postans, Lawrence, & Graham, 2015), and anatomically match previously reported cases of AD‐related visuoperceptual deficits (Chan et al., 2015) and studies of posterior cortical atrophy (Crutch et al., 2012; Migliaccio et al., 2012). …”

Section: Discussionmentioning

confidence: 99%

Functional brain network centrality is related to APOE genotype in cognitively normal elderly

et al. 2018

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IntroductionAmyloid plaque deposition in the brain is an early pathological change in Alzheimer's disease (AD), causing disrupted synaptic connections. Brain network disruptions in AD have been demonstrated with eigenvector centrality (EC), a measure that identifies central regions within networks. Carrying an apolipoprotein (APOE)‐ε4 allele is a genetic risk for AD, associated with increased amyloid deposition. We studied whether APOE‐ε4 carriership is associated with EC disruptions in cognitively normal individuals.MethodsA total of 261 healthy middle‐aged to older adults (mean age 56.6 years) were divided into high‐risk (APOE‐ε4 carriers) and low‐risk (noncarriers) groups. EC was computed from resting‐state functional MRI data. Clusters of between‐group differences were assessed with a permutation‐based method. Correlations between cluster mean EC with brain volume, CSF biomarkers, and psychological test scores were assessed.ResultsDecreased EC in the visual cortex was associated with APOE‐ε4 carriership, a genetic risk factor for AD. EC differences were correlated with age, CSF amyloid levels, and scores on the trail‐making and 15‐object recognition tests.ConclusionOur findings suggest that the APOE‐ε4 genotype affects brain connectivity in regions previously found to be abnormal in AD as a sign of very early disease‐related pathology. These differences were too subtle in healthy elderly to use EC for single‐subject prediction of APOE genotype.

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Section: Discussionmentioning

confidence: 99%

Functional brain network centrality is related to APOE genotype in cognitively normal elderly

et al. 2018

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“…One study assessing structural connectivity in early-onset AD, however, did not find specific frontal involvement. 103 Posterior cortical atrophy has been consistently associated with reduced connectivity to the visual network, 101,104,105 and logopenic PPA with language network disruption. 101,106-108 One study investigating functional networks in late-onset AD identified the anterior temporal network as being specifically involved in this form, 102 although further confirmation is required.…”

Section: Alzheimer Disease Variantsmentioning

confidence: 99%

Brain connectivity in neurodegenerative diseases—from phenotype to proteinopathy

et al. 2014

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Functional and structural connectivity measures, as assessed by means of functional and diffusion MRI, are emerging as potential intermediate biomarkers for Alzheimer disease (AD) and other disorders. This Review aims to summarize current evidence that connectivity biomarkers are associated with upstream and downstream disease processes (molecular pathology and clinical symptoms, respectively) in the major neurodegenerative diseases. The vast majority of studies have addressed functional and structural connectivity correlates of clinical phenotypes, confirming the predictable correlation with topography and disease severity in AD and frontotemporal dementia. In neurodegenerative diseases with motor symptoms, structural--but, to date, not functional--connectivity has been consistently found to be associated with clinical phenotype and disease severity. In the latest studies, the focus has moved towards the investigation of connectivity correlates of molecular pathology. Studies in cognitively healthy individuals with brain amyloidosis or genetic risk factors for AD have shown functional connectivity abnormalities in preclinical disease stages that are reminiscent of abnormalities observed in symptomatic AD. This shift in approach is promising, and may aid identification of early disease markers, establish a paradigm for other neurodegenerative disorders, shed light on the molecular neurobiology of connectivity disruption and, ultimately, clarify the pathophysiology of neurodegenerative diseases.

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“…Most frequent and severe drawing disorders are found in posterior cortical atrophy (PCA), which is associated with prominent visuospatial impairments and relative preservation of memory, insight, and judgment [105]. PCA is associated with atrophy in the occipital, parietal, and posterior temporal lobes [106], but recently a lesion of long white-matter tracts, including the superior and inferior longitudinal fasciculi and the inferior fronto-occipital fasciculus, has also been documented [107]. This early-onset AD-related pathology gives rise to complex visuospatial difficulties, such as visuoperceptual impairments [108], optic ataxia, simultanagnosia, gaze apraxia (often with the complete spectrum of Balint syndrome), and even egocentric [109,110] or allocentric [111] unilateral spatial neglect.…”

Section: Drawing Disabilities In Early and Late Onset Forms Of Admentioning

confidence: 99%

Drawing Disorders in Alzheimer’s Disease and Other Forms of Dementia

Trojano

Gainotti

2016

JAD

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Abstract. Drawing is a multicomponential process that can be impaired by many kinds of brain lesions. Drawing disorders are very common in Alzheimer's disease and other forms of dementia, and can provide clinical information for the distinction of the different dementing diseases. In our review we started from an overview of the neural and cognitive bases of drawing, and from a recollection of the drawing tasks more frequently used for assessing individuals with dementia. Then, we analyzed drawing disorders in dementia, paying special attention to those observed in Alzheimer's disease, from the prodromal stages of the amnesic mild cognitive impairment to the stages of full-blown dementia, both in the sporadic forms with late onset in the entorhino-hippocampal structures and in those with early onset in the posterior neocortical structures. We reviewed the drawing features that could differentiate Alzheimer's disease from vascular dementia and from the most frequent forms of degenerative dementia, namely frontotemporal dementia and Lewy body disease. Finally, we examined some peculiar aspects of drawing disorders in dementia, such as perseverations, rotations, and closing-in. We argue that a careful analysis of drawing errors helps to differentiate the different forms of dementia more than overall accuracy in drawing.

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Brain networks in posterior cortical atrophy: A single case tractography study and literature review

Cited by 60 publications

References 76 publications

Functional brain network centrality is related to APOE genotype in cognitively normal elderly

Functional brain network centrality is related to APOE genotype in cognitively normal elderly

Brain connectivity in neurodegenerative diseases—from phenotype to proteinopathy

Drawing Disorders in Alzheimer’s Disease and Other Forms of Dementia

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