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Revue Neurologique 2017Visual agnosia encompasses all disorders of visual recognition within a selective visual modality not due to an impairment of elementary visual processing or other... (Review)
Review
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). Focal brain injuries provide a unique opportunity to better understand regional brain function, particularly with the use of effective statistical approaches such as voxel-based lesion-symptom mapping (VLSM). The aim of the present work was twofold: (i) to review the various agnosia categories according to the traditional visual dual-pathway model; and (ii) to better assess the anatomical network underlying visual recognition through lesion-mapping studies correlating neuroanatomical and clinical outcomes.
Topics: Agnosia; Brain Injuries; Brain Mapping; Cognition Disorders; Humans; Nerve Net; Neuroimaging; Neuropsychological Tests; Visual Pathways; Visual Perception
PubMed: 28843416
DOI: 10.1016/j.neurol.2017.07.009 -
Brain : a Journal of Neurology Oct 2021
Review
Topics: Agnosia; Humans; Imagination; Pattern Recognition, Visual; Visual Cortex; Visual Perception
PubMed: 33856025
DOI: 10.1093/brain/awab159 -
Cortex; a Journal Devoted To the Study... Apr 2018
Topics: Agnosia; Awareness; Body Dysmorphic Disorders; Body Image; Cerebral Infarction; Delusions; Humans; Recognition, Psychology; Spatial Processing; Terminology as Topic; Visual Perception
PubMed: 29510834
DOI: 10.1016/j.cortex.2018.02.001 -
Current Neurology and Neuroscience... Sep 2016Progressive decline in memory (and other functions) is the defining feature of late-life dementia but affected individuals are often unaware of this impairment. This... (Review)
Review
Progressive decline in memory (and other functions) is the defining feature of late-life dementia but affected individuals are often unaware of this impairment. This article reviews recent research on anosognosia in dementia, including methods of assessing anosognosia, its prevalence and developmental course in dementia, its occurrence in different forms of dementia, neuroimaging findings, and hypothesized component mechanisms. The results suggest that anosognosia is eventually exhibited by nearly all persons with dementia. Its occurrence is robustly associated with common dementia-related pathologies and damage to memory and self-referential brain networks and their interconnections.
Topics: Agnosia; Awareness; Dementia; Humans; Memory; Neuropsychological Tests
PubMed: 27438597
DOI: 10.1007/s11910-016-0684-z -
Handbook of Clinical Neurology 2019The frontal lobes contain a complex set of diverse anatomic regions that form multiple distinct, complex networks with cortical and subcortical regions. Damage to these... (Review)
Review
The frontal lobes contain a complex set of diverse anatomic regions that form multiple distinct, complex networks with cortical and subcortical regions. Damage to these cortical-subcortical networks can have dramatic behavioral consequences, ranging from apathy to impairments in executive functioning. This chapter provides a brief overview of the common syndromes caused by damage to the mediodorsal and dorsolateral prefrontal circuits, followed by a more detailed review of the syndrome-sometimes referred to as pseudopsychopathy or acquired sociopathy-associated with damage to the ventromedial prefrontal circuit.
Topics: Agnosia; Apathy; Emotions; Executive Function; Frontal Lobe; Frontotemporal Dementia; Humans; Motivation; Nerve Net; Neuropsychological Tests
PubMed: 31590727
DOI: 10.1016/B978-0-12-804281-6.00008-2 -
Handbook of Clinical Neurology 2021The term visual agnosia is used to refer to recognition disorders that are confined to the visual modality, that are not due to an impairment in sensory functions, and...
The term visual agnosia is used to refer to recognition disorders that are confined to the visual modality, that are not due to an impairment in sensory functions, and that cannot be explained by other cognitive deficits or by general reduction in intellectual ability. Here, we describe the different types of visual agnosia that have been reported (form agnosia, integrative agnosia, associative agnosia, transformational and orientation agnosia as well as category-specific impairments such as pure alexia and prosopagnosia) and how they relate to the current understanding of visual object recognition. Together with related disorders such as simultanagnosia, texture agnosia, aphantasia, and optic aphasia, these visual perceptual impairments can have severe consequences for those affected. We suggest how in-depth assessment can be carried out to determine the type and the extent of these impairments. In the context of clinical assessment, a step-by-step approach reflecting a posterior to anterior gradient in visual object recognition, from more perceptual to more memory-related processes, is suggested. Individually tailored interventions targeting the identified impairments can be initiated based on the results of the assessment.
Topics: Agnosia; Cognition Disorders; Humans; Neuropsychological Tests; Orientation; Visual Perception
PubMed: 33832675
DOI: 10.1016/B978-0-12-821377-3.00008-8 -
Cortex; a Journal Devoted To the Study... Apr 2021A 66-year-old right-handed female medical doctor suffered two consecutive cardioembolic strokes, initially affecting the right frontal lobe and the right insula,...
A 66-year-old right-handed female medical doctor suffered two consecutive cardioembolic strokes, initially affecting the right frontal lobe and the right insula, followed by a lesion in the left temporal lobe. The patient presented with distinctive phenomenology of general auditory agnosia with anosognosia for the deficit. She did not understand verbal requests and her answers to oral questions were fluent but unrelated to the topic. However, she was able to correctly answer written questions, name objects, and fluently describe their purpose, which is characteristic for verbal auditory agnosia. She was also unable to recognise environmental sounds or to recognise and repeat any melody. These inabilities represent environmental sound agnosia and amusia, respectively. Surprisingly, she was not aware of the problem, not asking any questions regarding her symptoms, and avoiding discussing her inability to understand spoken language, which is indicative of anosognosia. The deficits in our patient followed a distinct pattern of recovery. The verbal auditory agnosia was the first to resolve, followed by environmental sound agnosia. Amusia persisted the longest. The patient was clinically assessed from the first day of symptom onset and the evolution of symptoms was video documented. We give a detailed account of the patient's behaviour and provide results of audiological and neuropsychological evaluations. We discuss the anatomy of auditory agnosia and anosognosia relevant to the case. This case study may serve to better understand auditory agnosia in clinical settings. It is important to distinguish auditory agnosia from Wernicke's aphasia, because use of written language may enable normal communication.
Topics: Aged; Agnosia; Aphasia; Aphasia, Wernicke; Female; Humans; Neuropsychological Tests; Temporal Lobe
PubMed: 33647851
DOI: 10.1016/j.cortex.2020.12.025 -
Handbook of Clinical Neurology 2018This chapter offers a perspective on the origin, operational definition, historic vicissitudes, and current status of Gerstmann syndrome. The main issues and controversy... (Review)
Review
This chapter offers a perspective on the origin, operational definition, historic vicissitudes, and current status of Gerstmann syndrome. The main issues and controversy accompanying Gerstmann syndrome throughout the years are reviewed. The clinical picture of Gerstmann syndrome as it emerges from a series of modern-day pure cases is described. In current clinical practice, a diagnosis of Gerstmann syndrome indicates the concomitant presence of four acquired symptoms: finger agnosia, acalculia, left-right disorientation, and agraphia. Finally, based on empiric work conducted in recent years, the chapter concludes with a new interpretation of Gerstmann syndrome. If seen as an instance of intraparietal disconnection, this classic parietal syndrome will acquire fresh clinical and theoretic significance.
Topics: Gerstmann Syndrome; History, 20th Century; History, 21st Century; Humans
PubMed: 29519471
DOI: 10.1016/B978-0-444-63622-5.00020-6 -
Journal of Neuro-ophthalmology : the... Sep 2018There 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... (Review)
Review
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).
EVIDENCE ACQUISITION
This article reviews pertinent literature, concentrating on recent developments in basic science research and studies of individual patients.
RESULTS
An overview of the current understanding of higher cerebral visual processing is followed by a discussion of the various disorders listed above.
CONCLUSIONS
There has been considerable progress in the understanding of how the extrastriate visual cortex is organized, specifically in relation to functionally specialized visual areas. This permits a better understanding of the individual visual agnosias resulting from damage to these areas.
Topics: Agnosia; Humans; Visual Cortex; Visual Perception
PubMed: 28945627
DOI: 10.1097/WNO.0000000000000556 -
Archives of Clinical Neuropsychology :... Dec 2014Gerstmann's syndrome includes the clinical tetrad of finger agnosia, agraphia, acalculia, and right-left confusion. Some disagreement remains with regard to the exact... (Review)
Review
Gerstmann's syndrome includes the clinical tetrad of finger agnosia, agraphia, acalculia, and right-left confusion. Some disagreement remains with regard to the exact localization of the syndrome, but most probable it involves the left angular gyrus with a subcortical extension. Several authors have suggested that a defect in mental spatial rotations could simultaneously account for acalculia, right-left disorientation, and finger agnosia. It has been also suggested that semantic aphasia is always associated with acalculia; as a matter of fact, left angular gyrus has a significant involvement in semantic processing. In this paper, it is proposed that Gerstmann's syndrome should include: acalculia, finger agnosia, right-left disorientation, and semantic aphasia, but not agraphia. When the pathology extends toward the superior parietal gyrus, agraphia can be found. A fundamental defect (i.e., an impairment in verbally mediated spatial operations) could explain these apparently unrelated clinical signs.
Topics: Gerstmann Syndrome; Humans
PubMed: 25377466
DOI: 10.1093/arclin/acu056