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https://www.readbyqxmd.com/read/29165034/congenital-prosopagnosia-without-object-agnosia-a-literature-review
#1
Jacob Geskin, Marlene Behrmann
A longstanding controversy concerns the functional organization of high-level vision, and the extent to which the recognition of different classes of visual stimuli engages a single system or multiple independent systems. We examine this in the context of congenital prosopagnosia (CP), a neurodevelopmental disorder in which individuals, without a history of brain damage, are impaired at face recognition. This paper reviews all CP cases from 1976 to 2016, and explores the evidence for the association or dissociation of face and object recognition...
November 22, 2017: Cognitive Neuropsychology
https://www.readbyqxmd.com/read/29145186/the-kl%C3%A3-ver-bucy-syndrome
#2
Douglas J Lanska
In 1937, Heinrich Klüver and Paul Bucy described a dramatic behavioral syndrome in monkeys after bilateral temporal lobectomy. The full Klüver-Bucy syndrome (KBS) - hyperorality, placidity, hypermetamorphosis, dietary changes, altered sexual behavior, and visual agnosia - is evident within 3 weeks following operation. Some KBS features (i.e., hyperorality, placidity, hypermetamorphosis) persist indefinitely, whereas others gradually resolve over several years. Klüver and Bucy were initially unaware of an earlier report of KBS by Sanger Brown and Edward Schäfer in 1888...
2018: Frontiers of Neurology and Neuroscience
https://www.readbyqxmd.com/read/29145178/minor-hemisphere-major-syndromes
#3
Antonio Carota, Julien Bogousslavsky
A right "minor hemisphere" does not exist as the right hemisphere is dominant for awareness (nosognosia), spatial attention, emotional regulation, facial and voice expressions, visual recognition, and topographical orientation. Without the right hemisphere, the world would be flat, deprived of general and spatial attentions, pointing preferentially to the right side of the space, lacking visual experiences and emotions, exhibiting diminished awareness of the self and environment. Clinical-related syndromes of the right hemisphere are unilateral spatial neglect, object and face visual agnosia, the anosognosia for hemiparesis and/or hemianopia, misidentification syndromes, mania, and other obsessions for the food and the body...
2018: Frontiers of Neurology and Neuroscience
https://www.readbyqxmd.com/read/29093537/perceptual-integration-and-attention-in-human-extrastriate-cortex
#4
Francesca Strappini, Gaspare Galati, Marialuisa Martelli, Enrico Di Pace, Sabrina Pitzalis
Visual crowding is a perceptual phenomenon with far-reaching implications in both perceptual (e.g., object recognition and reading) and clinical (e.g., developmental dyslexia and visual agnosia) domains. Here, we combined event-related fMRI measurements and wide-field brain mapping methods to investigate whether the BOLD response evoked by visual crowding is modulated by different attentional conditions. Participants underwent two sessions of psychophysical training outside the scanner, and then fMRI BOLD activity was measured simultaneously in early visual areas (including the visual word form area, VWFA), while they viewed strongly-crowded and weakly-crowded Gabor patches in attended and unattended conditions...
November 1, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29076767/relationship-between-somatosensory-event-related-potential-n140-aberrations-and-hemispatial-agnosia-in-patients-with-stroke-a-preliminary-study
#5
Tomoyuki Ueno, Yasushi Hada, Yukiyo Shimizu, Thoru Yamada
PURPOSE: The somatosensory event-related potential N140 is thought to be related to selective attention. This study aimed to compare the somatosensory event-related potential N140 in healthy subjects to that in patients with stroke to determine whether N140 and attentiveness are associated in patients with stroke with or without hemispatial agnosia. MATERIALS AND METHODS: Normal somatosensory event-related potential N140 values were determined using data from ten healthy subjects...
October 27, 2017: International Journal of Neuroscience
https://www.readbyqxmd.com/read/29051913/patients-with-dementia-are-easy-victims-to-predators
#6
R C Hamdy, J V Lewis, R Copeland, A Depelteau, A Kinser, T Kendall-Wilson, K Whalen
Patients with dementia, especially Alzheimer's disease and particularly those in early stages, are susceptible to become victims of predators: Their agnosia (see Case 1) prevents them from detecting and accurately interpreting subtle signals that otherwise would have alerted them that they are about to fall for a scam. Furthermore, their judgment is impaired very early in the disease process, often before other symptoms manifest themselves and usually before a diagnosis is made. Patients with early stages of dementia are therefore prime targets for unscrupulous predators, and it behooves caregivers and health care professionals to ensure the integrity of these patients...
January 2017: Gerontology & Geriatric Medicine
https://www.readbyqxmd.com/read/28951167/still-holding-after-all-these-years-an-action-perception-dissociation-in-patient-df
#7
Tzvi Ganel, Melvyn A Goodale
Patient DF, who has bilateral damage in the ventral visual stream, is perhaps the best known individual with visual form agnosia in the world, and has been the focus of scores of research papers over the past twenty-five years. The remarkable dissociation she exhibits between a profound deficit in perceptual report and a preserved ability to generate relatively normal visuomotor behaviour was early on a cornerstone in Goodale and Milner's (1992) two visual systems hypothesis. In recent years, however, there has been a greater emphasis on the damage that is evident in the posterior regions of her parietal cortex in both hemispheres...
September 23, 2017: Neuropsychologia
https://www.readbyqxmd.com/read/28949822/preserved-expert-object-recognition-in-a-case-of-unilateral-visual-agnosia
#8
Johannes Rennig, Sonja Cornelsen, Helmut Wilhelm, Marc Himmelbach, Hans-Otto Karnath
We examined a stroke patient (HWS) with a unilateral lesion of the right medial ventral visual stream, involving the right fusiform and parahippocampal gyri. In a number of object recognition tests with lateralized presentations of target stimuli, HWS showed significant symptoms of hemiagnosia with contralesional recognition deficits for everyday objects. We further explored the patient's capacities of visual expertise that were acquired before the current perceptual impairment became effective. We confronted him with objects he was an expert for already before stroke onset and compared this performance with the recognition of familiar everyday objects...
September 26, 2017: Journal of Cognitive Neuroscience
https://www.readbyqxmd.com/read/28945627/the-visual-agnosias-and-related-disorders
#9
Sameen Haque, Michael S Vaphiades, Christian J Lueck
BACKGROUND: There are many disorders of higher visual processing that result from damage to specific areas of the cerebral cortex that have a specific role in processing certain aspects (modalities) of vision. These can be grouped into those that affect the ventral, or "what?", pathway (e.g., object agnosia, cerebral achromatopsia, prosopagnosia, topographagnosia, and pure alexia), and those that affect the dorsal, or "where?", pathway (e.g., akinetopsia, simultanagnosia, and optic ataxia)...
September 22, 2017: Journal of Neuro-ophthalmology: the Official Journal of the North American Neuro-Ophthalmology Society
https://www.readbyqxmd.com/read/28861031/visual-dysfunction-in-posterior-cortical-atrophy
#10
REVIEW
Mari N Maia da Silva, Rebecca S Millington, Holly Bridge, Merle James-Galton, Gordon T Plant
Posterior cortical atrophy (PCA) is a syndromic diagnosis. It is characterized by progressive impairment of higher (cortical) visual function with imaging evidence of degeneration affecting the occipital, parietal, and posterior temporal lobes bilaterally. Most cases will prove to have Alzheimer pathology. The aim of this review is to summarize the development of the concept of this disorder since it was first introduced. A critical discussion of the evolving diagnostic criteria is presented and the differential diagnosis with regard to the underlying pathology is reviewed...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28843416/visual-agnosia-and-focal-brain-injury
#11
REVIEW
O Martinaud
Visual agnosia encompasses all disorders of visual recognition within a selective visual modality not due to an impairment of elementary visual processing or other cognitive deficit. Based on a sequential dichotomy between the perceptual and memory systems, two different categories of visual object agnosia are usually considered: 'apperceptive agnosia' and 'associative agnosia'. Impaired visual recognition within a single category of stimuli is also reported in: (i) visual object agnosia of the ventral pathway, such as prosopagnosia (for faces), pure alexia (for words), or topographagnosia (for landmarks); (ii) visual spatial agnosia of the dorsal pathway, such as cerebral akinetopsia (for movement), or orientation agnosia (for the placement of objects in space)...
August 23, 2017: Revue Neurologique
https://www.readbyqxmd.com/read/28828534/finger-tapping-and-verbal-fluency-post-tap-test-improvement-in-inph-its-value-in-differential-diagnosis-and-shunt-treatment-outcomes-prognosis
#12
Evangelia Liouta, Stylianos Gatzonis, Theodosis Kalamatianos, Aristotelis Kalyvas, Christos Koutsarnakis, Faidon Liakos, Christos Anagnostopoulos, Spyridon Komaitis, Dimitris Giakoumettis, George Stranjalis
BACKGROUND: Idiopathic normal pressure hydrocephalus (INPH) diagnosis is challenging as it can be mimicked by other neurological conditions, such as neurodegenerative dementia and motor syndromes. Additionally, outcomes after lumbar puncture (LP) tap test and shunt treatment may vary due to the lack of a common protocol in INPH assessment. The present study aimed to assess whether a post-LP test amelioration of frontal cognitive dysfunctions, characterizing this syndrome, can differentiate INPH from similar neurological conditions and whether this improvement can predict INPH post-shunt outcomes...
August 21, 2017: Acta Neurochirurgica
https://www.readbyqxmd.com/read/28764909/a-novel-psen1-s230n-mutation-causing-early-onset-alzheimer-s-disease-associated-with-prosopagnosia-hoarding-and-parkinsonism
#13
John M Ringman, Maria Casado, Victoria Van Berlo, Judy Pa, Nelly Joseph-Mathurin, Anne M Fagan, Tammie Benzinger, Randall J Bateman, John C Morris
We describe clinical and biomarker findings in an index patient with the onset of Alzheimer's disease (AD) symptoms at age 57 and a family history consistent with an autosomal dominant pattern of inheritance. She had the atypical early features of visual agnosia and prosopagnosia followed by hoarding behavior and Parkinsonism. Structural MRI revealed global atrophy that was most severe in the lateral temporal lobes and insular cortex bilaterally. CSF biomarker assessment showed Aβ42, p-tau181, and total tau levels consistent with AD...
September 14, 2017: Neuroscience Letters
https://www.readbyqxmd.com/read/28747411/stroke-of-the-inferiomedial-temporal-lobe-causing-word-agnosia
#14
Hardi Hassan, Huq Ehsanula, Mahendra Pattanshetti
A 69-year-old man presented with sudden loss of ability to recognise written words and remember the meaning of words and names. He could not name the town he lived in nor name his children. It was difficult for him to remember the meaning of concrete and abstract nouns. His speech fluency and understanding of casual talks were normal. He remembered that he had a conversation with his family that morning, but not the exact content. He was referred to the transient ischaemic attack clinic by his general practitioner as he scored low on the abbreviated mental test score...
July 26, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/28732749/body-representation-disorders-predict-left-right-orientation-impairments-after-stroke-a%C3%A2-voxel-based-lesion-symptom-mapping-study
#15
Haike E van Stralen, H Chris Dijkerman, J Matthijs Biesbroek, Hugo J Kuijf, H Maarten A van Gemert, David Sluiter, L Jaap Kappelle, Martine J E van Zandvoort
INTRODUCTION: Deficits in the ability to distinguish between the left and right side of the body can severely impair daily life functioning. The current study examined the relation between left right orientation (LRO) impairments and somatosensory related deficits, ranging from primary somatosensory impairments to body representation impairments, in patients who suffered a recent stroke. We also examined which areas in the brain are associated with LRO impairments using a Voxel-based Lesion Symptom Mapping (VLSM) analysis...
June 7, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
https://www.readbyqxmd.com/read/28730259/clinical-manifestations-and-morphological-changes-in-one-case-with-post-stroke-kl%C3%A3-ver-bucy-syndrome
#16
Nicolae Cătălin Hreniuc, Carmen NeamŢu, Mircea Florin Sferdian, Cristina Georgiana Ghib Para, Cris Virgiliu Precup, Ioan Ioiart
We present the case of a 71-year-old right-handed male, admitted to the Department of Neurology, Emergency County Hospital of Arad, Romania, on November 2015, with a rare case of Klüver-Bucy syndrome (KBS), following an ischemic stroke of the right temporal lobe, which was previously diagnosed in December 2014 and was treated accordingly. At the moment of second hospital admission, the patient was found somnolent and confused at home, with traumatic signs of biting of the tongue and urine emission. A couple days after admission, our patient became alert and presented hypersexuality, hypermetamorphosis, increased oral tendency, behavior changes including apathy with loss of anger and fear, and a very increased appetite, transient visual agnosia and right-left disorientation...
2017: Romanian Journal of Morphology and Embryology, Revue Roumaine de Morphologie et Embryologie
https://www.readbyqxmd.com/read/28669762/space-specific-deficits-in-visual-orientation-discrimination-caused-by-lesions-in-the-midbrain-stimulus-selection-network
#17
Eric I Knudsen, Jason S Schwarz, Phyllis F Knudsen, Devarajan Sridharan
Perceptual decisions require both analysis of sensory information and selective routing of relevant information to decision networks. This study explores the contribution of a midbrain network to visual perception in chickens. Analysis of visual orientation information in birds takes place in the forebrain sensory area called the Wulst, as it does in the primary visual cortex (V1) of mammals. In contrast, the midbrain, which receives parallel retinal input, encodes orientation poorly, if at all. We discovered, however, that small electrolytic lesions in the midbrain severely impair a chicken's ability to discriminate orientations...
July 24, 2017: Current Biology: CB
https://www.readbyqxmd.com/read/28559827/pure-amorphagnosia-without-tactile-object-agnosia
#18
Shinichirou Kubota, Mai Yamada, Hideyo Satoh, Akira Satoh, Mitsuhiro Tsujihata
A 54-year-old female showed amorphagnosia without ahylognosia and tactile agnosia 40 days after the onset of right cerebral infarction. Her basic somatosensory functions were normal. The appreciation of substance qualities (hylognosia) was preserved, but the patient's inability to recognize the size and shape (morphagnosia) was confined to 2- and 3-dimensional shapes (amorphagnosia) in the left hand. However, the patient's ability to recognize real daily objects was well preserved. Brain MRI after admission showed ischemic lesions confined to the right pre- and postcentral gyri and the medial frontal cortex on DWI and FLAIR images...
January 2017: Case Reports in Neurology
https://www.readbyqxmd.com/read/28545844/rise-and-fall-of-the-two-visual-systems-theory
#19
Yves Rossetti, Laure Pisella, Robert D McIntosh
Among the many dissociations describing the visual system, the dual theory of two visual systems, respectively dedicated to perception and action, has yielded a lot of support. There are psychophysical, anatomical and neuropsychological arguments in favor of this theory. Several behavioral studies that used sensory and motor psychophysical parameters observed differences between perceptive and motor responses. The anatomical network of the visual system in the non-human primate was very readily organized according to two major pathways, dorsal and ventral...
May 23, 2017: Annals of Physical and Rehabilitation Medicine
https://www.readbyqxmd.com/read/28532578/impaired-peripheral-reaching-and-on-line-corrections-in-patient-df-optic-ataxia-with-visual-form-agnosia
#20
Stéphanie Rossit, Monika Harvey, Stephen H Butler, Larissa Szymanek, Stéphanie Morand, Simona Monaco, Robert D McIntosh
An influential model of vision suggests the presence of two visual streams within the brain: a dorsal occipito-parietal stream which mediates action and a ventral occipito-temporal stream which mediates perception. One of the cornerstones of this model is DF, a patient with visual form agnosia following bilateral ventral stream lesions. Despite her inability to identify and distinguish visual stimuli, DF can still use visual information to control her hand actions towards these stimuli. These observations have been widely interpreted as demonstrating a double dissociation from optic ataxia, a condition observed after bilateral dorsal stream damage in which patients are unable to act towards objects that they can recognize...
April 22, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
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