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Cortex; a Journal Devoted To the Study... Oct 2021
Topics: Agnosia; Humans; Pattern Recognition, Visual; Visual Perception
PubMed: 34376282
DOI: 10.1016/j.cortex.2021.07.007 -
Expert Review of Neurotherapeutics Mar 2023Posterior Cortical Atrophy (PCA) is a neurodegenerative disorder characterized by impairment of higher-order visual processing in the setting of progressive atrophy of... (Review)
Review
INTRODUCTION
Posterior Cortical Atrophy (PCA) is a neurodegenerative disorder characterized by impairment of higher-order visual processing in the setting of progressive atrophy of the parietal and occipital lobes. The underlying pathology is variable but most commonly Alzheimer's disease. The majority of individuals develop symptoms before 65 years of age; however, delayed diagnosis is common due to misattribution of symptoms to ocular rather than cortical pathology.
AREAS COVERED
The purpose of this review is to provide readers with an in-depth analysis of Posterior Cortical Atrophy syndrome, including clinical, imaging, pathological, and genetic features, management, and treatments.
EXPERT OPINION
Most patients present initially with a relatively pure visuoperceptual-visuospatial syndrome, though other cognitive domains become affected over time. Structural neuroimaging demonstrates parieto-occipital or temporo-occipital predominant atrophy. Cerebrospinal fluid Alzheimer's disease biomarkers, or amyloid/tau PET imaging can help evaluate for underlying Alzheimer's disease, which is the most common underlying neuropathology. The cornerstone of management is focused on nonpharmacologic measures. Early etiologic diagnosis is important with the arrival of disease-modifying therapies, especially for Alzheimer's disease.
Topics: Humans; Alzheimer Disease; Magnetic Resonance Imaging; Neuroimaging; Neurodegenerative Diseases; Atrophy
PubMed: 36920752
DOI: 10.1080/14737175.2023.2190885 -
Handbook of Clinical Neurology 2022Face perception is a socially important but complex process with many stages and many facets. There is substantial evidence from many sources that it involves a large... (Review)
Review
Face perception is a socially important but complex process with many stages and many facets. There is substantial evidence from many sources that it involves a large extent of the temporal lobe, from the ventral occipitotemporal cortex and superior temporal sulci to anterior temporal regions. While early human neuroimaging work suggested a core face network consisting of the occipital face area, fusiform face area, and posterior superior temporal sulcus, studies in both humans and monkeys show a system of face patches stretching from posterior to anterior in both the superior temporal sulcus and inferotemporal cortex. Sophisticated techniques such as fMRI adaptation have shown that these face-activated regions show responses that have many of the attributes of human face processing. Lesions of some of these regions in humans lead to variants of prosopagnosia, the inability to recognize the identity of a face. Lesion, imaging, and electrophysiologic data all suggest that there is a segregation between identity and expression processing, though some suggest this may be better characterized as a distinction between static and dynamic facial information.
Topics: Cerebral Cortex; Facial Recognition; Humans; Magnetic Resonance Imaging; Prosopagnosia; Temporal Lobe
PubMed: 35964972
DOI: 10.1016/B978-0-12-823493-8.00019-5 -
Neuropsychologia Nov 2023We present a comprehensive review of the rare syndrome visual form agnosia (VFA). We begin by documenting its history, including the origins of the term, and the first... (Review)
Review
We present a comprehensive review of the rare syndrome visual form agnosia (VFA). We begin by documenting its history, including the origins of the term, and the first case study labelled as VFA. The defining characteristics of the syndrome, as others have previously defined it, are then described. The impairments, preserved aspects of visual perception, and areas of brain damage in 21 patients who meet these defining characteristics are described in detail, including which tests were used to verify the presence or absence of key symptoms. From this, we note important similarities along with notable areas of divergence between patients. Damage to the occipital lobe (20/21), an inability to recognise line drawings (19/21), preserved colour vision (14/21), and visual field defects (16/21) were areas of consistency across most cases. We found it useful to distinguish between shape and form as distinct constructs when examining perceptual abilities in VFA patients. Our observations suggest that these patients often exhibit difficulties in processing simplified versions of form. Deficits in processing orientation and size were uncommon. Motion perception and visual imagery were not widely tested for despite being typically cited as defining features of the syndrome - although in the sample described, motion perception was never found to be a deficit. Moreover, problems with vision (e.g., poor visual acuity and the presence of hemianopias/scotomas in the visual fields) are more common than we would have thought and may also contribute to perceptual impairments in patients with VFA. We conclude that VFA is a perceptual disorder where the visual system has a reduced ability to synthesise lines together for the purposes of making sense of what images represent holistically.
Topics: Humans; Pattern Recognition, Visual; Visual Perception; Vision, Ocular; Visual Fields; Vision Disorders; Agnosia
PubMed: 37634886
DOI: 10.1016/j.neuropsychologia.2023.108666 -
Cortex; a Journal Devoted To the Study... May 2023COVID-19 can cause psychological problems including loss of smell and taste, long-lasting memory, speech, and language impairments, and psychosis. Here, we provide the...
COVID-19 can cause psychological problems including loss of smell and taste, long-lasting memory, speech, and language impairments, and psychosis. Here, we provide the first report of prosopagnosia following symptoms consistent with COVID-19. Annie is a 28-year-old woman who had normal face recognition prior to contracting COVID-19 in March 2020. Two months later, she noticed face recognition difficulties while experiencing symptom relapses and her deficits with faces have persisted. On two tests of familiar face recognition and two tests of unfamiliar face recognition, Annie showed clear impairments. In contrast, she scored normally on tests assessing face detection, face identity perception, object recognition, scene recognition, and non-visual memory. Navigational deficits frequently co-occur with prosopagnosia, and Annie reports that her navigational abilities are substantially worse than before she became ill. Self-report survey data from 54 respondents with long COVID showed that a majority reported reductions in visual recognition and navigation abilities. In summary, Annie's results indicate that COVID-19 can produce severe and selective neuropsychological impairments similar to deficits seen following brain damage, and it appears that high-level visual impairments are not uncommon in people with long COVID.
Topics: Humans; Female; Adult; Prosopagnosia; Post-Acute COVID-19 Syndrome; COVID-19; Face; Recognition, Psychology; Pattern Recognition, Visual
PubMed: 36966620
DOI: 10.1016/j.cortex.2023.01.012 -
Current Neurology and Neuroscience... Sep 2021Historical and contemporary treatments of visual agnosia and neglect regard these disorders as largely unrelated. It is thought that damage to different neural processes... (Review)
Review
PURPOSE OF REVIEW
Historical and contemporary treatments of visual agnosia and neglect regard these disorders as largely unrelated. It is thought that damage to different neural processes leads directly to one or the other condition, yet apperceptive variants of agnosia and object-centered variants of neglect share remarkably similar deficits in the quality of conscious experience. Here we argue for a closer association between "apperceptive" variants of visual agnosia and "object-centered" variants of visual neglect. We introduce a theoretical framework for understanding these conditions based on "scale attention", which refers to selecting boundary and surface information at different levels of the structural hierarchy in the visual array.
RECENT FINDINGS
We review work on visual agnosia, the cortical structures and cortico-cortical pathways that underlie visual perception, visuospatial neglect and object-centered neglect, and attention to scale. We highlight direct and indirect pathways involved in these disorders and in attention to scale. The direct pathway involves the posterior vertical segments of the superior longitudinal fasciculus that are positioned to link the established dorsal and ventral attentional centers in the parietal cortex with structures in the inferior occipitotemporal cortex associated with visual apperceptive agnosia. The connections in the right hemisphere appear to be more important for visual conscious experience, whereas those in the left hemisphere appear to be more strongly associated with the planning and execution of visually guided grasps directed at multi-part objects such as tools. In the latter case, semantic and functional information must drive the selection of the appropriate hand posture and grasp points on the object. This view is supported by studies of grasping in patients with agnosia and in patients with neglect that show that the selection of grasp points when picking up a tool involves both scale attention and semantic contributions from inferotemporal cortex. The indirect pathways, which include the inferior fronto-occipital and horizontal components of the superior longitudinal fasciculi, involve the frontal lobe, working memory and the "multiple demands" network, which can shape the content of visual awareness through the maintenance of goal- and task-based abstractions and their influence on scale attention. Recent studies of human cortico-cortical pathways necessitate revisions to long-standing theoretical views on visual perception, visually guided action and their integrations. We highlight findings from a broad sample of seemingly disparate areas of research to support the proposal that attention to scale is necessary for typical conscious visual experience and for goal-directed actions that depend on functional and semantic information. Furthermore, we suggest that vertical pathways between the parietal and occipitotemporal cortex, along with indirect pathways that involve the premotor and prefrontal cortex, facilitate the operations of scale attention.
Topics: Agnosia; Humans; Perceptual Disorders; Visual Pathways; Visual Perception
PubMed: 34586544
DOI: 10.1007/s11910-021-01139-6 -
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 -
Alzheimer's Research & Therapy Jul 2023Alzheimer's disease (AD) is a common age-related neurodegenerative disease in the central nervous system and is the primary cause of dementia. It is clinically... (Review)
Review
Alzheimer's disease (AD) is a common age-related neurodegenerative disease in the central nervous system and is the primary cause of dementia. It is clinically characterized by the memory impairment, aphasia, apraxia, agnosia, visuospatial and executive dysfunction, behavioral changes, and so on. Incidence of this disease was bound up with age, genetic factors, cardiovascular and cerebrovascular dysfunction, and other basic diseases, but the exact etiology has not been clarified. MicroRNAs (miRNAs) are small endogenous non-coding RNAs that were involved in the regulation of post-transcriptional gene expression. miRNAs have been extensively studied as noninvasive potential biomarkers for disease due to their relative stability in bodily fluids. In addition, they play a significant role in the physiological and pathological processes of various neurological disorders, including stroke, AD, and Parkinson's disease. MiR-155, as an important pro-inflammatory mediator of neuroinflammation, was reported to participate in the progression of β-amyloid peptide and tau via regulating immunity and inflammation. In this review, we put emphasis on the effects of miR-155 on AD and explore the underlying biological mechanisms which could provide a novel approach for diagnosis and treatment of AD.
Topics: Humans; Alzheimer Disease; Neurodegenerative Diseases; MicroRNAs; Amyloid beta-Peptides; Risk Factors
PubMed: 37452431
DOI: 10.1186/s13195-023-01264-z -
Geriatrie Et Psychologie... Sep 2019Visual perception is humans' preferred way for taking information on the surrounding world. Visual perception is frequently impaired in patients with Alzheimer's... (Review)
Review
Visual perception is humans' preferred way for taking information on the surrounding world. Visual perception is frequently impaired in patients with Alzheimer's disease, lessening patients' quality of life, and making evaluation of other cognitive deficits more complicated. Our review covers the recent literature describing visual perception deficits in patients suffering from Alzheimer's disease by classifying them according to their neuroanatomical correspondence: retina, visual pathway, subcortical structures, occipital visual cortex, occipito-temporal "what" and occipito-parietal "where" pathways. Overall, both low-level and high-level visual perception disorders seem quite common in Alzheimer's disease, including, on a low-level, loss of visual field, decreased acuity and contrast sensitivity, and impaired color vision, and on a high-level, impaired color vision, motion perception, visuospatial deficits, object agnosia, prosopagnosia and impaired recognition of facial emotional expressions. Professionals working with Alzheimer's disease should be aware of visuoperceptual deficits, which could impair the quality of life of the patients, and distort the results of neuropsychological tests using visual material. Moreover, some tests assessing visual perception could be of interest for early diagnosis of the disease.
Topics: Aged; Aged, 80 and over; Alzheimer Disease; Humans; Neuropsychological Tests; Perceptual Disorders; Vision Disorders; Visual Pathways; Visual Perception
PubMed: 31449049
DOI: 10.1684/pnv.2019.0815 -
Journal of Alzheimer's Disease : JAD 2021D. Frank Benson and colleagues first described the clinical and neuropathological features of posterior cortical atrophy (PCA) from patients in the UCLA Neurobehavior... (Review)
Review
BACKGROUND
D. Frank Benson and colleagues first described the clinical and neuropathological features of posterior cortical atrophy (PCA) from patients in the UCLA Neurobehavior Program.
OBJECTIVE
We reviewed the Program's subsequent clinical experience with PCA, and its potential for clarifying this relatively rare syndrome in comparison to the accumulated literature on PCA.
METHODS
Using the original criteria derived from this clinic, 65 patients with neuroimaging-supported PCA were diagnosed between 1995 and 2020.
RESULTS
On presentation, most had visual localization complaints and related visuospatial symptoms, but nearly half had memory complaints followed by symptoms of depression. Neurobehavioral testing showed predominant difficulty with visuospatial constructions, Gerstmann's syndrome, and Balint's syndrome, but also impaired memory and naming. On retrospective application of the current Consensus Criteria for PCA, 59 (91%) met PCA criteria with a modification allowing for "significantly greater visuospatial over memory and naming deficits." There were 37 deaths (56.9%) with the median overall survival of 10.3 years (95% CI: 9.6-13.6 years), consistent with a slow neurodegenerative disorder in most patients.
CONCLUSION
Together, these findings recommend modifying the PCA criteria for "relatively spared" memory, language, and behavior to include secondary memory and naming difficulty and depression, with increased emphasis on the presence of Gerstmann's and Balint's syndromes.
Topics: Agnosia; Alzheimer Disease; Atrophy; Biomarkers; Diagnosis, Differential; Female; Gerstmann Syndrome; Humans; Male; Middle Aged; Neuroimaging; Neuropsychological Tests; Occipital Lobe; Parietal Lobe
PubMed: 34057092
DOI: 10.3233/JAD-210368