Lateralized occipital degeneration in posterior cortical atrophy predicts visual field deficits
Autor: | Holly Bridge, Gordon T. Plant, Mari N. Maia da Silva, Rebecca S. Millington, Merle James-Galton |
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Rok vydání: | 2017 |
Předmět: |
Male
genetic structures Cognitive Neuroscience Visual dysfunction Corpus callosum lcsh:Computer applications to medicine. Medical informatics Hippocampus Functional Laterality lcsh:RC346-429 Corpus Callosum White matter Perceptual Disorders 03 medical and health sciences Hemianopia 0302 clinical medicine Magnetic resonance imaging medicine Image Processing Computer-Assisted Humans Radiology Nuclear Medicine and imaging lcsh:Neurology. Diseases of the nervous system Aged Occipital lobe Posterior cortical atrophy Neurodegenerative Diseases Regular Article Middle Aged eye diseases Visual field Oxygen medicine.anatomical_structure Diffusion Magnetic Resonance Imaging Neurology Agnosia 030221 ophthalmology & optometry Visual Field Tests lcsh:R858-859.7 Female Neurology (clinical) medicine.symptom Atrophy Visual Fields Psychology Neuroscience 030217 neurology & neurosurgery Parahippocampal gyrus Optic radiation |
Zdroj: | NeuroImage: Clinical, Vol 14, Iss C, Pp 242-249 (2017) NeuroImage : Clinical |
ISSN: | 2213-1582 |
DOI: | 10.1016/j.nicl.2017.01.012 |
Popis: | Background Posterior cortical atrophy (PCA), the visual variant of Alzheimer's disease, leads to high-level visual deficits such as alexia or agnosia. Visual field deficits have also been identified, but often inconsistently reported. Little is known about the pattern of visual field deficits or the underlying cortical changes leading to this visual loss. Methods Multi-modal magnetic resonance imaging was used to investigate differences in gray matter volume, cortical thickness, white matter microstructure and functional activity in patients with PCA compared to age-matched controls. Additional analyses investigated hemispheric asymmetries in these metrics according to the visual field most affected by the disease. Results Analysis of structural data indicated considerable loss of gray matter in the occipital and parietal cortices, lateralized to the hemisphere contralateral to the visual loss. This lateralized pattern of gray matter loss was also evident in the hippocampus and parahippocampal gyrus. Diffusion-weighted imaging showed considerable effects of PCA on white matter microstructure in the occipital cortex, and in the corpus callosum. The change in white matter was only lateralized in the occipital lobe, however, with greatest change in the optic radiation contralateral to the visual field deficit. Indeed, there was a significant correlation between the laterality of the optic radiation microstructure and visual field loss. Conclusions Detailed brain imaging shows that the asymmetric visual field deficits in patients with PCA reflect the pattern of degeneration of both white and gray matter in the occipital lobe. Understanding the nature of both visual field deficits and the neurodegenerative brain changes in PCA may improve diagnosis and understanding of this disease. Highlights • Patients with posterior cortical atrophy show asymmetric visual field deficits manifesting as hemianopia. • Both gray and white matter show lateralized degeneration corresponding to the most affected visual field. • Laterality of microstructure in the optic radiation correlates with visual field loss. |
Databáze: | OpenAIRE |
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