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Cortex; a Journal Devoted To the Study... Jun 2018
Topics: Agnosia; Humans; Neuropsychological Tests
PubMed: 29731103
DOI: 10.1016/j.cortex.2018.04.001 -
Cortex; a Journal Devoted To the Study... Aug 2007Colour agnosia concerns the inability to recognise colours despite intact colour perception, semantic memory for colour information, and colour naming. Patients with...
Colour agnosia concerns the inability to recognise colours despite intact colour perception, semantic memory for colour information, and colour naming. Patients with selective colour agnosia have been described and the deficit is associated with left hemisphere damage. Here we report a case study of a 43-year-old man who was referred to us with a stroke in his right cerebellar hemisphere. During the standard assessment it transpired that he was unable to name coloured patches. Detailed assessment of his colour processing showed that he suffers from a selective colour agnosia. As he claimed to have had this problem all his life, and the fact that the infratentorial infarct that he had incurred was in an area far away from the brain structures that are known to be involved in colour processing, we suggest that he is the first reported case of developmental colour agnosia.
Topics: Adult; Agnosia; Child; Color Perception; Developmental Disabilities; Humans; Language Tests; Male; Recognition, Psychology; Verbal Behavior; Visual Perception
PubMed: 17710826
DOI: 10.1016/s0010-9452(08)70503-3 -
Neurocase Feb 2020In a patient suffering from tactile agnosia a comparison was made (using the ABABAB paradigm) between three blocks of neuropsychological rehabilitation sessions...
In a patient suffering from tactile agnosia a comparison was made (using the ABABAB paradigm) between three blocks of neuropsychological rehabilitation sessions involving off-line anodal transcranial direct current stimulation (anodal-tDCS) and three blocks of rehabilitation sessions without tDCS. During the blocks with anodal-tDCS, the stimulation was administered in counterbalanced order to two sites: i) the perilesional parietal area (specific stimulation) and ii) an occipital area far from the lesion (nonspecific stimulation).Rehabilitation associated with anodal-tDCS (in particular in the perilesional areas) is more efficacious than without stimulation.
Topics: Agnosia; Humans; Male; Middle Aged; Parietal Lobe; Recovery of Function; Touch Perception; Transcranial Direct Current Stimulation
PubMed: 31755352
DOI: 10.1080/13554794.2019.1694951 -
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 -
Annals of the New York Academy of... Nov 2003A review and an experimental study were carried out in search of dissociations between the recognition of music (music agnosia) and that of environmental sounds... (Review)
Review
A review and an experimental study were carried out in search of dissociations between the recognition of music (music agnosia) and that of environmental sounds (auditory agnosia) in stroke patients. The review focused on 45 adequately studied cases published since 1883. The experimental study consisted of administering standard tests of music and environmental sound recognition to 40 unselected patients with unilateral stroke. Among case reports, music was selectively impaired more frequently than environmental sounds, whereas the reverse occurred in the experimental study. In this, right hemisphere lesions tended either to disrupt the apperception of environmental sounds, sparing music entirely, or to disrupt both environmental sounds and melody, sparing rhythm, whereas left hemisphere lesions tended to spare melody and to disrupt rhythm, either selectively or in association with the semantic identification of environmental sounds.
Topics: Adult; Aged; Agnosia; Female; Functional Laterality; Humans; Male; Middle Aged; Music; Stroke
PubMed: 14681117
DOI: 10.1196/annals.1284.005 -
Rinsho Shinkeigaku = Clinical Neurology Nov 2004There are two cortical visual processing streams, the ventral and dorsal stream. The ventral visual stream plays the major role in constructing our perceptual... (Review)
Review
There are two cortical visual processing streams, the ventral and dorsal stream. The ventral visual stream plays the major role in constructing our perceptual representation of the visual world and the objects within it. Disturbance of visual processing at any stage of the ventral stream could result in impairment of visual recognition. Thus we need systematic investigations to diagnose visual agnosia and its type. Two types of category-selective visual agnosia, prosopagnosia and landmark agnosia, are different from others in that patients could recognize a face as a face and buildings as buildings, but could not identify an individual person or building. Neuronal bases of prosopagnosia and landmark agnosia are distinct. Importance of the right fusiform gyrus for face recognition was confirmed by both clinical and neuroimaging studies. Landmark agnosia is related to lesions in the right parahippocampal gyrus. Enlarged lesions including both the right fusiform and parahippocampal gyri can result in prosopagnosia and landmark agnosia at the same time. Category non-selective visual agnosia is related to bilateral occipito-temporal lesions, which is in agreement with the results of neuroimaging studies that revealed activation of the bilateral occipito-temporal during object recognition tasks.
Topics: Agnosia; Humans
PubMed: 15651309
DOI: No ID Found -
Current Neurology and Neuroscience... Aug 2020Gerstmann (left angular gyrus) syndrome includes the tetrad of finger agnosia (inability to distinguish, name, and recognize the fingers), agraphia (acquired disturbance... (Review)
Review
PURPOSE OF REVIEW
Gerstmann (left angular gyrus) syndrome includes the tetrad of finger agnosia (inability to distinguish, name, and recognize the fingers), agraphia (acquired disturbance in the ability to write), acalculia (loss of the ability to perform arithmetical operations and use numerical concepts), and right-left disorientation (right-left discrimination defect when using language). There is some disagreement regarding its exact localization, but it most likely involves the left angular gyrus with a probable subcortical extension. This article reviews recent research on the clinical aspects of this syndrome.
RECENT FINDINGS
During the last years, just some few new reports of Gerstmann syndrome are found in neurological and neuropsychological literature. Most of the reports are single-case reports. An association between Gerstmann syndrome and the so-called semantic aphasia has been pointed out. Two different explanations to this unusual syndrome have been recently proposed: (1) the pathological process is located in the left parietal white matter disconnecting separate cortical networks and (2) it represents a disturbance in the ability to verbally mediate some spatial knowledge. Although Gerstmann syndrome continues as a controversial syndrome, and most of the reports are single case reports, recently two different explanations have been advance the understanding of this polemic but fascinating syndrome.
Topics: Agnosia; Gerstmann Syndrome; Humans
PubMed: 32852667
DOI: 10.1007/s11910-020-01069-9 -
Danish Medical Bulletin Jan 1972
Topics: Adolescent; Adult; Aged; Agnosia; Brain; Brain Damage, Chronic; Brain Diseases; Brain Injuries; Brain Mapping; Brain Neoplasms; Child; Dominance, Cerebral; Female; Functional Laterality; Humans; Hypophysectomy; Male; Methods; Middle Aged; Motivation; Nervous System; Nervous System Physiological Phenomena; Neurologic Examination; Neurologic Manifestations; Refractory Period, Electrophysiological; Sensation; Touch
PubMed: 5020290
DOI: No ID Found -
Cortex; a Journal Devoted To the Study... Jun 1985A case of unilateral visual agnosia for all types of stimuli limited to the left visual hemifield and associated with a right occipital temporal vascular lesion is...
A case of unilateral visual agnosia for all types of stimuli limited to the left visual hemifield and associated with a right occipital temporal vascular lesion is reported. Questions raised by this case of hemiagnosia as compared to previous ones are discussed.
Topics: Agnosia; Cerebral Infarction; Humans; Male; Middle Aged; Temporal Lobe; Visual Perception
PubMed: 4028746
DOI: 10.1016/s0010-9452(85)80036-8 -
Neuropsychologia Aug 2013As an example of complex auditory signal processing, the analysis of accented speech is potentially vulnerable in the progressive aphasias. However, the brain basis of...
As an example of complex auditory signal processing, the analysis of accented speech is potentially vulnerable in the progressive aphasias. However, the brain basis of accent processing and the effects of neurodegenerative disease on this processing are not well understood. Here we undertook a detailed neuropsychological study of a patient, AA with progressive nonfluent aphasia, in whom agnosia for accents was a prominent clinical feature. We designed a battery to assess AA's ability to process accents in relation to other complex auditory signals. AA's performance was compared with a cohort of 12 healthy age and gender matched control participants and with a second patient, PA, who had semantic dementia with phonagnosia and prosopagnosia but no reported difficulties with accent processing. Relative to healthy controls, the patients showed distinct profiles of accent agnosia. AA showed markedly impaired ability to distinguish change in an individual's accent despite being able to discriminate phonemes and voices (apperceptive accent agnosia); and in addition, a severe deficit of accent identification. In contrast, PA was able to perceive changes in accents, phonemes and voices normally, but showed a relatively mild deficit of accent identification (associative accent agnosia). Both patients showed deficits of voice and environmental sound identification, however PA showed an additional deficit of face identification whereas AA was able to identify (though not name) faces normally. These profiles suggest that AA has conjoint (or interacting) deficits involving both apperceptive and semantic processing of accents, while PA has a primary semantic (associative) deficit affecting accents along with other kinds of auditory objects and extending beyond the auditory modality. Brain MRI revealed left peri-Sylvian atrophy in case AA and relatively focal asymmetric (predominantly right sided) temporal lobe atrophy in case PA. These cases provide further evidence for the fractionation of brain mechanisms for complex sound analysis, and for the stratification of progressive aphasia syndromes according to the signature of nonverbal auditory deficits they produce.
Topics: Agnosia; Aphasia; Auditory Perception; Female; Frontotemporal Dementia; Humans; Middle Aged; Recognition, Psychology; Semantics; Speech
PubMed: 23721780
DOI: 10.1016/j.neuropsychologia.2013.05.013