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Elul D, Levin N. The Role of Population Receptive Field Sizes in Higher-Order Visual Dysfunction. Curr Neurol Neurosci Rep 2024:10.1007/s11910-024-01375-6. [PMID: 39266871 DOI: 10.1007/s11910-024-01375-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2024] [Indexed: 09/14/2024]
Abstract
PURPOSE OF REVIEW Population receptive field (pRF) modeling is an fMRI technique used to retinotopically map visual cortex, with pRF size characterizing the degree of spatial integration. In clinical populations, most pRF mapping research has focused on damage to visual system inputs. Herein, we highlight recent work using pRF modeling to study high-level visual dysfunctions. RECENT FINDINGS Larger pRF sizes, indicating coarser spatial processing, were observed in homonymous visual field deficits, aging, and autism spectrum disorder. Smaller pRF sizes, indicating finer processing, were observed in Alzheimer's disease and schizophrenia. In posterior cortical atrophy, a unique pattern was found in which pRF size changes depended on eccentricity. Changes to pRF properties were observed in clinical populations, even in high-order impairments, explaining visual behavior. These pRF changes likely stem from altered interactions between brain regions. Furthermore, some studies suggested that pRF sizes change as part of cortical reorganization, and they can point towards future prognosis.
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Affiliation(s)
- Deena Elul
- fMRI Unit, Neurology Department Hadassah Medical Organization, Faculty of Medicine, The Hebrew University of Jerusalem, POB 12000, Jerusalem, 91120, Israel
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Netta Levin
- fMRI Unit, Neurology Department Hadassah Medical Organization, Faculty of Medicine, The Hebrew University of Jerusalem, POB 12000, Jerusalem, 91120, Israel.
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Malania M, Lin YS, Hörmandinger C, Werner JS, Greenlee MW, Plank T. Training-induced changes in population receptive field properties in visual cortex: Impact of eccentric vision training on population receptive field properties and the crowding effect. J Vis 2024; 24:7. [PMID: 38771584 PMCID: PMC11114612 DOI: 10.1167/jov.24.5.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 02/15/2024] [Indexed: 05/22/2024] Open
Abstract
This study aimed to investigate the impact of eccentric-vision training on population receptive field (pRF) estimates to provide insights into brain plasticity processes driven by practice. Fifteen participants underwent functional magnetic resonance imaging (fMRI) measurements before and after behavioral training on a visual crowding task, where the relative orientation of the opening (gap position: up/down, left/right) in a Landolt C optotype had to be discriminated in the presence of flanking ring stimuli. Drifting checkerboard bar stimuli were used for pRF size estimation in multiple regions of interest (ROIs): dorsal-V1 (dV1), dorsal-V2 (dV2), ventral-V1 (vV1), and ventral-V2 (vV2), including the visual cortex region corresponding to the trained retinal location. pRF estimates in V1 and V2 were obtained along eccentricities from 0.5° to 9°. Statistical analyses revealed a significant decrease of the crowding anisotropy index (p = 0.009) after training, indicating improvement on crowding task performance following training. Notably, pRF sizes at and near the trained location decreased significantly (p = 0.005). Dorsal and ventral V2 exhibited significant pRF size reductions, especially at eccentricities where the training stimuli were presented (p < 0.001). In contrast, no significant changes in pRF estimates were found in either vV1 (p = 0.181) or dV1 (p = 0.055) voxels. These findings suggest that practice on a crowding task can lead to a reduction of pRF sizes in trained visual cortex, particularly in V2, highlighting the plasticity and adaptability of the adult visual system induced by prolonged training.
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Affiliation(s)
- Maka Malania
- Institute of Psychology, University of Regensburg, Regensburg, Germany
| | - Yih-Shiuan Lin
- Institute of Psychology, University of Regensburg, Regensburg, Germany
| | | | - John S Werner
- Department of Ophthalmology and Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Mark W Greenlee
- Institute of Psychology, University of Regensburg, Regensburg, Germany
| | - Tina Plank
- Institute of Psychology, University of Regensburg, Regensburg, Germany
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Veronelli L, Daini R, Mannino A, Rossetti A, Gilardone G, Corbo M, Primativo S. Global Processing Deficit in Amnestic Mild Cognitive Impairment. J Alzheimers Dis 2024; 101:1151-1165. [PMID: 39302364 DOI: 10.3233/jad-240375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2024]
Abstract
Background Visuo-perceptual and visuo-attentional disorders, such as global processing deficit and simultanagnosia, are not routinely investigated in prodromal forms of typical Alzheimer's disease, as amnestic mild cognitive impairment (MCI). Objective This study evaluated global processing abilities through Navon's classical paradigm in individuals with amnestic MCI and investigated the related visuo-perceptual and attentional components involved in simultanagnosia. Methods Sixteen consecutive patients with amnestic MCI (6 single-domain, 10 multiple-domain) and 16 matched controls were requested to identify global and local elements of hierarchical Navon letters, and to name large and small solid letters. Results While correctly identifying solid letters, patients with multiple-domain amnestic MCI were less accurate in processing the global level of hierarchical stimuli compared to controls. Single-case analyses suggested that global processing may also be impaired in single-domain amnestic MCI. In addition, patients with pathological performance in the Navon task showed perceptual and/or visual focal attention deficits. Conclusions Early dysfunction of holistic processing can be detected in amnestic MCI. Visuo-perceptual and/or visual focal attention mechanisms, which have been shown to be damaged in Posterior Cortical Atrophy patients with simultanagnosia, may be impaired in individuals with amnestic MCI. Investigation and identification of global processing deficits in MCI could contribute to early diagnosis and longitudinal monitoring of the disease.
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Affiliation(s)
- Laura Veronelli
- Department of Psychology, University of Milano-Bicocca, Milan, Italy
- Department of Neurorehabilitation Sciences, Casa di Cura IGEA, Milan, Italy
| | - Roberta Daini
- Department of Psychology, University of Milano-Bicocca, Milan, Italy
| | - Alice Mannino
- Department of Neurorehabilitation Sciences, Casa di Cura IGEA, Milan, Italy
| | - Alessia Rossetti
- Department of Psychology, University of Milano-Bicocca, Milan, Italy
| | - Giulia Gilardone
- Department of Psychology, University of Milano-Bicocca, Milan, Italy
- Department of Neurorehabilitation Sciences, Casa di Cura IGEA, Milan, Italy
| | - Massimo Corbo
- Department of Neurorehabilitation Sciences, Casa di Cura IGEA, Milan, Italy
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Bick A, McKyton A, Glick-Shames H, Rein N, Levin N. Abnormal network connections to early visual cortex in posterior cortical atrophy. J Neurol Sci 2023; 454:120826. [PMID: 37832379 DOI: 10.1016/j.jns.2023.120826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 10/02/2023] [Accepted: 10/04/2023] [Indexed: 10/15/2023]
Abstract
INTRODUCTION Posterior Cortical Atrophy (PCA), a visual variant of Alzheimer's disease, initially manifests with higher-order visual disorders and parieto/temporo-occipital atrophy. Recent studies have shown remote functional impairment in both distant brain networks and along the calcarine sulcus (V1). Functional alteration in the calcarine differs along its length, reflecting center to periphery visual space differences. Herein, we aim to connect between these two sets of findings by looking at the retinotopic patterns of functional connectivity between large-scale brain networks and V1, comparing patients with normally sighted subjects. METHODS Resting state functional magnetic resonance imaging (fMRI) and T1 anatomical scans were obtained from 11 PCA patients and 17 age-matched healthy volunteers. Default mode network (DMN) and fronto parietal network (FPN) were defined and differences between the networks in patients and healthy controls were evaluated at the whole brain level, specifically their connectivity to V1. RESULTS Connectivity patterns within the DMN and the FPN were similar between the groups, although differences were found in regions within and beyond the networks. Focusing on V1, in the control group we identified the expected pattern of a distributed connectivity along eccentricity, with foveal regions showing stronger connectivity to the FPN and peripheral regions showing stronger connectivity to the DMN. However, in PCA patients we could not identify a clear difference in connectivity along the eccentricities. CONCLUSION Lost specialization of function along the calcarine in PCA patients may have further implications on large-scale networks or vice versa. This impairment, distant from the core pathology, might explain patients' visual disabilities.
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Affiliation(s)
- Atira Bick
- fMRI unit, Neurology department, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Ayelet McKyton
- fMRI unit, Neurology department, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Haya Glick-Shames
- fMRI unit, Neurology department, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Netaniel Rein
- fMRI unit, Neurology department, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Netta Levin
- fMRI unit, Neurology department, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel.
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Invernizzi A, Haak KV, Carvalho JC, Renken RJ, Cornelissen FW. Bayesian connective field modeling using a Markov Chain Monte Carlo approach. Neuroimage 2022; 264:119688. [PMID: 36280097 DOI: 10.1016/j.neuroimage.2022.119688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 09/17/2022] [Accepted: 10/14/2022] [Indexed: 11/09/2022] Open
Abstract
The majority of neurons in the human brain process signals from neurons elsewhere in the brain. Connective Field (CF) modelling is a biologically-grounded method to describe this essential aspect of the brain's circuitry. It allows characterizing the response of a population of neurons in terms of the activity in another part of the brain. CF modelling translates the concept of the receptive field (RF) into the domain of connectivity by assessing, at the voxel level, the spatial dependency between signals in distinct cortical visual field areas. Thus, the approach enables to characterize the functional cortical circuitry of the human cortex. While already very useful, the present CF modelling approach has some intrinsic limitations due to the fact that it only estimates the model's explained variance and not the probability distribution associated with the estimated parameters. If we could resolve this, CF modelling would lend itself much better for statistical comparisons at the level of single voxels and individuals. This is important when trying to gain a detailed understanding of the neurobiology and pathophysiology of the visual cortex, notably in rare cases. To enable this, we present a Bayesian approach to CF modeling (bCF). Using a Markov Chain Monte Carlo (MCMC) procedure, it estimates the posterior probability distribution underlying the CF parameters. Based on this, bCF quantifies, at the voxel level, the uncertainty associated with each parameter estimate. This information can be used in various ways to increase confidence in the CF model predictions. We applied bCF to BOLD responses recorded in the early human visual cortex using 3T fMRI. We estimated both the CF parameters and their associated uncertainties and show they are only weakly correlated. Moreover, we show how bCF facilitates the use of effect size (beta) as a data-driven parameter that can be used to select the most reliable voxels for further analysis. Finally, to further illustrate the functionality gained by bCF, we apply it to perform a voxel-level comparison of a single, circular symmetric, Gaussian versus a Difference-of-Gaussian model. We conclude that our bCF framework provides a comprehensive tool to study human functional cortical circuitry in health and disease.
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Affiliation(s)
- Azzurra Invernizzi
- Laboratory for Experimental Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Cognitive Neuroscience Center, Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, Groningen, the Netherlands; Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Koen V Haak
- Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Joana C Carvalho
- Laboratory of Preclinical MRI, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Remco J Renken
- Cognitive Neuroscience Center, Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, Groningen, the Netherlands
| | - Frans W Cornelissen
- Laboratory for Experimental Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Cognitive Neuroscience Center, Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, Groningen, the Netherlands
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Wu J, Wang C, Wang L, Wang Y, Yang J, Yan T, Suo D, Wang L, Liu X, Zhang J. Development of a Piezoelectric Actuated Tactile Stimulation Device for Population Receptive Field Mapping in Human Somatosensory Cortex With fMRI. J Magn Reson Imaging 2022; 56:1055-1065. [PMID: 35324031 DOI: 10.1002/jmri.28173] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Multichannel tactile stimulation devices is need to investigate human finger population receptive field (pRF) characteristics in the primary somatosensory cortex during functional magnetic resonance imaging (fMRI). PURPOSE To accurately characterize right-hand somatosensory representation based on the Bayesian pRF model. STUDY TYPE Prospective. POPULATION A water phantom and six healthy participants (four males, mean 23.8 years old). FIELD STRENGTH/SEQUENCE T1-weighted magnetization-prepared rapid gradient-echo, T2*-weighted echo planar imaging at 3 T. ASSESSMENT The piezoelectric actuated tactile stimulation device consisted of execution unit and control unit. The output performance of the device was measured by a laser displacement sensor. The effect of the device on images' signal-to-noise ratio (SNR) was measured by phantom experiments. The activation representation arrangement order, relative volumes, and receptive field size of the right hand were assessed during the along-digits and cross-digits paradigms. STATISTICAL TESTS The normality of the data was tested by the Shapiro-Wilk method. A paired-sample t test was performed to test pRF characteristics for all digit pairings. The significance level was set to P = 0.05 (false discovery rate [FDR] correct). RESULTS Percussive stimulation provided by the piezoelectric actuated tactile stimulator had a stable displacement (2.64 mm) over a wide range of vibration frequencies (0-30 Hz). The output delay of the device was 1 millisecond. The device did not affect the image's SNR (without the device: SNR = 138.24 ± 7.87, temporal SNR [TSNR] = 440.03 ± 52.08. With the device: SNR = 138.06 ± 8.44, TSNR = 438.52 ± 56.38. PSNR = 0.88, PTSNR = 0.46). Representations of right-hand fingers showed the same arrangement order in both experiments (D1-D5 arranged along the central sulcus). However, the relative volumes of D3 showed significant differences in S1 (P = 0.003). Among four subareas, the relative volumes of D3 were significantly different in area 1 (P = 0.047). DATA CONCLUSION This developed stimulator, through experimental verification, could play a role in pRF mapping exploration. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY STAGE: 1.
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Affiliation(s)
- Jinglong Wu
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing, China.,Research Center for Medical Artificial Intelligence, Shenzhen Institutes of Advanced Technology, Chinese Academy of Science, Shenzhen, China
| | - Chenyu Wang
- Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama, Japan
| | - Luyao Wang
- School of Life Science, Shanghai University, Shanghai, China
| | - Yutong Wang
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing, China
| | - Jiajia Yang
- Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama, Japan.,Section on Functional Imaging Methods, National Institute of Mental Health, Bethesda, Maryland, USA
| | - Tianyi Yan
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Dingjie Suo
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Li Wang
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Xin Liu
- Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Jian Zhang
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing, China
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Klink PC, Chen X, Vanduffel V, Roelfsema P. Population receptive fields in non-human primates from whole-brain fMRI and large-scale neurophysiology in visual cortex. eLife 2021; 10:67304. [PMID: 34730515 PMCID: PMC8641953 DOI: 10.7554/elife.67304] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 10/24/2021] [Indexed: 01/07/2023] Open
Abstract
Population receptive field (pRF) modeling is a popular fMRI method to map the retinotopic organization of the human brain. While fMRI-based pRF maps are qualitatively similar to invasively recorded single-cell receptive fields in animals, it remains unclear what neuronal signal they represent. We addressed this question in awake nonhuman primates comparing whole-brain fMRI and large-scale neurophysiological recordings in areas V1 and V4 of the visual cortex. We examined the fits of several pRF models based on the fMRI blood-oxygen-level-dependent (BOLD) signal, multi-unit spiking activity (MUA), and local field potential (LFP) power in different frequency bands. We found that pRFs derived from BOLD-fMRI were most similar to MUA-pRFs in V1 and V4, while pRFs based on LFP gamma power also gave a good approximation. fMRI-based pRFs thus reliably reflect neuronal receptive field properties in the primate brain. In addition to our results in V1 and V4, the whole-brain fMRI measurements revealed retinotopic tuning in many other cortical and subcortical areas with a consistent increase in pRF size with increasing eccentricity, as well as a retinotopically specific deactivation of default mode network nodes similar to previous observations in humans.
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Affiliation(s)
| | - Xing Chen
- Vision and Cognition, Netherlands Institute for Neuroscience, Amsterdam, Netherlands
| | | | - Pieter Roelfsema
- Vision and Cognition, Netherlands Institute for Neuroscience, Amsterdam, Netherlands
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Halbertsma HN, Bridge H, Carvalho J, Cornelissen FW, Ajina S. Visual Field Reconstruction in Hemianopia Using fMRI Based Mapping Techniques. Front Hum Neurosci 2021; 15:713114. [PMID: 34447301 PMCID: PMC8382851 DOI: 10.3389/fnhum.2021.713114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 07/21/2021] [Indexed: 11/21/2022] Open
Abstract
PURPOSE A stroke that includes the primary visual cortex unilaterally leads to a loss of visual field (VF) representation in the hemifield contralateral to the damage. While behavioral procedures for measuring the VF, such as perimetry, may indicate that a patient cannot see in a particular area, detailed psychophysical testing often detects the ability to perform detection or discrimination of visual stimuli ("blindsight"). The aim of this study was to determine whether functional magnetic resonance imaging (fMRI) could be used to determine whether perimetrically blind regions of the VF were still represented in VF maps reconstructed on the basis of visually evoked neural activity. METHODS Thirteen patients with hemianopia and nine control participants were scanned using 3T MRI while presented with visual stimulation. Two runs of a dynamic "wedge and ring" mapping stimulus, totaling approximately 10 min, were performed while participants fixated centrally. Two different analysis approaches were taken: the conventional population receptive field (pRF) analysis and micro-probing (MP). The latter is a variant of the former that makes fewer assumptions when modeling the visually evoked neural activity. Both methods were used to reconstruct the VF by projecting modeled activity back onto the VF. Following a normalization step, these "coverage maps" can be compared to the VF sensitivity plots obtained using perimetry. RESULTS While both fMRI-based approaches revealed regions of neural activity within the perimetrically "blind" sections of the VF, the MP approach uncovered more voxels in the lesioned hemisphere in which a modest degree of visual sensitivity was retained. Furthermore, MP-based analysis indicated that both early (V1/V2) and extrastriate visual areas contributed equally to the retained sensitivity in both patients and controls. CONCLUSION In hemianopic patients, fMRI-based approaches for reconstructing the VF can pick up activity in perimetrically blind regions of the VF. Such regions of the VF may be particularly amenable for rehabilitation to regain visual function. Compared to conventional pRF modeling, MP reveals more voxels with retained visual sensitivity, suggesting it is a more sensitive approach for VF reconstruction.
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Affiliation(s)
- Hinke N. Halbertsma
- Laboratory for Experimental Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Holly Bridge
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Joana Carvalho
- Champalimaud Centre for the Unknown, Champalimaud Foundation, Lisbon, Portugal
| | - Frans W. Cornelissen
- Laboratory for Experimental Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Sara Ajina
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Department of Neurorehabilitation, National Hospital for Neurology and Neurosurgery, London, United Kingdom
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Abstract
PURPOSE OF REVIEW Non-amnestic (or atypical) presentations of neurodegenerative dementias are underrecognized and underdiagnosed, including posterior cortical atrophy (PCA) syndrome, which is characterized by prominent visuospatial and visuoperceptual dysfunction at presentation. It is most commonly due to Alzheimer's disease pathology, while Lewy body disease, corticobasal degeneration, and prion disease are neuropathological entities that are less frequently associated with PCA. The diagnosis of PCA is often delayed, to the detriment of the patient, and awareness and understanding of PCA will improve detection, prognostication, and treatment. RECENT FINDINGS The natural history of PCA appears to be distinct from typical Alzheimer's disease and significant heterogeneity exists within the PCA syndrome, with the underlying causes of this heterogeneity beginning to be explored. Functional and molecular imaging can assist in better understanding PCA, particularly assessment of network disruptions that contribute to clinical phenotypes. Cerebrospinal fluid biomarkers are useful to detect underlying pathology, but measures of retinal thickness are less promising. There are currently no adequate treatment options for PCA. SUMMARY Continued efforts to characterize PCA are needed, and greater awareness and understanding of atypical presentations of neurodegenerative dementias could serve to elucidate pathobiological mechanisms of underlying disease.
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de Best PB, Abulafia R, McKyton A, Levin N. Convergence Along the Visual Hierarchy Is Altered in Posterior Cortical Atrophy. Invest Ophthalmol Vis Sci 2020; 61:8. [PMID: 32897377 PMCID: PMC7488212 DOI: 10.1167/iovs.61.11.8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 08/17/2020] [Indexed: 12/14/2022] Open
Abstract
Purpose Posterior cortical atrophy (PCA) is a rare neurodegenerative syndrome manifesting with visuospatial processing impairment. We recently suggested that abnormal population receptive field properties are associated with the symptoms of PCA patients. Specifically, simultanagnosia, the inability to perceive multiple items simultaneously, can be explained by smaller peripheral population receptive fields, and foveal crowding, in which nearby distractors interfere with object perception, may result from larger foveal population receptive fields. These effects occurred predominantly in V1, even though atrophy mainly involves high-order areas. In this study, we used connective field modeling to better understand these inter-area interactions. Methods We used functional magnetic resonance imaging to scan six PCA patients and eight controls while they viewed drifting bar stimuli. Resting-state data were also collected. Connective field modeling was applied for both conditions: once when the source was V1 and the targets were extrastriate areas and once for the opposite direction. The difference between the two was defined as convergence magnitude. Results With stimulus, the convergence magnitude of the controls increased along the visual pathway, suggesting that spatial integration from V1 becomes larger up the visual hierarchy. No such slope was found in the PCA patients. The difference between the groups originated mainly from the dorsal pathway. Without stimulus, the convergence magnitude was negative, slightly more so for the PCA patients, with no slope, suggesting constant divergence along the visual hierarchy. Conclusions Atrophy in one part of the visual system can affect other areas within the network through complex intervisual area interactions, resulting in modulation of population receptive field properties and an ensemble of visuocognitive function impairments.
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Affiliation(s)
- Pieter B. de Best
- fMRI Unit, Neurology Department, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ruth Abulafia
- fMRI Unit, Neurology Department, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ayelet McKyton
- fMRI Unit, Neurology Department, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Netta Levin
- fMRI Unit, Neurology Department, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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Olds JJ, Hills WL, Warner J, Falardeau J, Alasantro LH, Moster ML, Egan RA, Cornblath WT, Lee AG, Frishberg BM, Turbin RE, Katz DM, Charley JA, Pelak VS. Posterior Cortical Atrophy: Characteristics From a Clinical Data Registry. Front Neurol 2020; 11:358. [PMID: 32581988 PMCID: PMC7297208 DOI: 10.3389/fneur.2020.00358] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/14/2020] [Indexed: 12/02/2022] Open
Abstract
Background: Posterior cortical atrophy (PCA) is a neurodegenerative syndrome that presents with higher-order visual dysfunction with relative sparing of memory and other cognitive domains, and it is most commonly associated with Alzheimer's disease pathology. There is a lack of data regarding the presentation of PCA to non-cognitive specialists. Therefore, we collected clinical data from neuro-ophthalmologists regarding the presentation of PCA to their practices and compared data to published cohorts and a published survey of cognitive specialists. Methods: Members of the North American Neuro-Ophthalmology Society Listserv (NANOSnet) were invited to complete an online, retrospective, chart-review data-entry survey regarding their patients with PCA, and REDCap was used for data collection. Results: Data for 38 patients were entered by 12 neuro-ophthalmologists. Patient mean age at presentation was 67.8 years, and 74% of patients were women. Difficulty reading was reported at presentation by 91% of patients, and poor performance on color vision, stereopsis, and visual field testing (performed reliably by 36/38 patients) were common findings. Most patients who were treated were treated with donepezil and/or memantine. Conclusions: Compared to published data from cognitive specialists, patients presenting to neuro-ophthalmology with PCA were more likely to be older and female and have a reading complaint. Reliable visual field testing was the norm with homonymous defects in the majority of patients. The neuro-ophthalmologist plays an important role in diagnosing PCA in older adults with unexplained visual signs and symptoms, and future studies of PCA should involve multiple specialists in order to advance our understanding of PCA and develop effective treatments.
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Affiliation(s)
- Jennifer J Olds
- Department of Ophthalmology, Keesler Air Force Base, Biloxi, MS, United States
| | - William L Hills
- Department of Neurology & Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States
| | - Judith Warner
- Department of Ophthalmology & Neurology, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, United States
| | - Julie Falardeau
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States
| | - Lori Haase Alasantro
- Department of Neuroscience, The Neurology Center of Southern California, University of California San Diego School of Medicine, Carlsbad, CA, United States
| | - Mark L Moster
- Department of Neurology and Ophthalmology, Wills Eye Hospital and Thomas Jefferson University, Philadelphia, PA, United States
| | - Robert A Egan
- Eye & Vascular Neurology, LLC, Carlton, OR, United States
| | - Wayne T Cornblath
- Department of Ophthalmology, Visual Sciences & Neurology, W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, MI, United States
| | - Andrew G Lee
- Department of Ophthalmology, Blanton Eye Institute, Houston Methodist Hospital, Houston, TX, United States
| | - Benjamin M Frishberg
- Department of Neuroscience, The Neurology Center of Southern California, University of California San Diego School of Medicine, Carlsbad, CA, United States
| | - Roger E Turbin
- Division of Neuro-ophthalmology and Orbital Surgery, Rutgers New Jersey Medical School, Institute of Ophthalmology and Visual Sciences, Newark, NJ, United States
| | - David M Katz
- Bethesda Neurology, LLC, Department of Ophthalmology & Neurology, Howard University Hospital, Georgetown University Hospital, Washington, DC, United States
| | - John A Charley
- Retired Private Practice Ophthalmologist, Pittsburgh, PA, United States
| | - Victoria S Pelak
- Department of Neurology & Ophthalmology, UCHealth Sue Anschutz-Rodgers Eye Center and the Neurosciences Center, University of Colorado School of Medicine, Aurora, CO, United States
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