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Internal Medicine (Tokyo, Japan) Feb 2024A 73-year-old woman with posterior cortical atrophy (PCA) presented with progressive apperceptive visual agnosia, alexia, agraphia, ventral simultanagnosia,...
A 73-year-old woman with posterior cortical atrophy (PCA) presented with progressive apperceptive visual agnosia, alexia, agraphia, ventral simultanagnosia, prosopagnosia, and allocentric (stimulus-centered) left-sided hemispatial neglect. All of these symptoms were attributed to damage to the bilateral occipito-temporal cortices, consistent with ventral variant PCA. While the Pittsburgh compound B uptake was extensively distributed throughout the occipito-parietal (dorsal) and occipito-temporal (ventral) areas, the THK5351 (ligand binding to tau aggregates/astrocyte gliosis) accumulation was limited to the ventral area. These findings suggest that local accumulation of tau proteins and/or astrocyte gliosis over the occipito-temporal cortices can result in ventral variant PCA.
PubMed: 38369357
DOI: 10.2169/internalmedicine.2844-23 -
Journal of Clinical Neurology (Seoul,... May 2024
PubMed: 38627231
DOI: 10.3988/jcn.2023.0468 -
Frontiers in Neuroscience 2024Posterior Cortical Atrophy (PCA) is a syndrome characterized by a progressive decline in higher-order visuospatial processing, leading to symptoms such as space...
INTRODUCTION
Posterior Cortical Atrophy (PCA) is a syndrome characterized by a progressive decline in higher-order visuospatial processing, leading to symptoms such as space perception deficit, simultanagnosia, and object perception impairment. While PCA is primarily known for its impact on visuospatial abilities, recent studies have documented language abnormalities in PCA patients. This study aims to delineate the nature and origin of language impairments in PCA, hypothesizing that language deficits reflect the visuospatial processing impairments of the disease.
METHODS
We compared the language samples of 25 patients with PCA with age-matched cognitively normal (CN) individuals across two distinct tasks: a visually-dependent picture description and a visually-independent job description task. We extracted word frequency, word utterance latency, and spatial relational words for this comparison. We then conducted an in-depth analysis of the language used in the picture description task to identify specific linguistic indicators that reflect the visuospatial processing deficits of PCA.
RESULTS
Patients with PCA showed significant language deficits in the visually-dependent task, characterized by higher word frequency, prolonged utterance latency, and fewer spatial relational words, but not in the visually-independent task. An in-depth analysis of the picture description task further showed that PCA patients struggled to identify certain visual elements as well as the overall theme of the picture. A predictive model based on these language features distinguished PCA patients from CN individuals with high classification accuracy.
DISCUSSION
The findings indicate that language is a sensitive behavioral construct to detect visuospatial processing abnormalities of PCA. These insights offer theoretical and clinical avenues for understanding and managing PCA, underscoring language as a crucial marker for the visuospatial deficits of this atypical variant of Alzheimer's disease.
PubMed: 38379764
DOI: 10.3389/fnins.2024.1342909 -
Neurology Mar 2021We present the case of a 68-year-old woman who developed progressive visuospatial deficits in a period of 18 months, leading to the loss of her independence for...
We present the case of a 68-year-old woman who developed progressive visuospatial deficits in a period of 18 months, leading to the loss of her independence for activities of daily living. After examination, she showed signs of Balint syndrome with optic ataxia, oculomotor apraxia, and simultanagnosia without visual acuity impairment. After brain imaging showing severe bilateral parieto-occipital association cortex atrophy, a diagnosis of posterior cortical atrophy was made according to the 2017 International Consortium's criteria.
Topics: Aged; Apraxias; Ataxia; Atrophy; Brain; Cerebral Cortex; Cogan Syndrome; Female; Humans; Occipital Lobe; Parietal Lobe; Vision Disorders
PubMed: 32928969
DOI: 10.1212/WNL.0000000000010849 -
Investigative Ophthalmology & Visual... Sep 2020Posterior cortical atrophy (PCA) is a rare neurodegenerative syndrome manifesting with visuospatial processing impairment. We recently suggested that abnormal population...
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.
Topics: Atrophy; Brain Mapping; Female; Gray Matter; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Neurodegenerative Diseases; Visual Cortex; Visual Pathways
PubMed: 32897377
DOI: 10.1167/iovs.61.11.8 -
Cognitive and Behavioral Neurology :... Jun 2023A selective impairment for making hand postures that are required to use specific tools has rarely been reported in individuals with acquired brain injury, and such an...
A selective impairment for making hand postures that are required to use specific tools has rarely been reported in individuals with acquired brain injury, and such an impairment has not been documented at all in individuals with degenerative disorders. We describe an individual with posterior cortical atrophy and probable corticobasal syndrome who was unable to use tools because of an inability to make the proper hand posture required for each tool. This individual was, however, able to use the tools properly once her hand postures were corrected, and her ability to manipulate the tools (ie, timing, arm posture, and amplitude) was intact. Also, she had no difficulty with a test of her manipulation knowledge. Areas of hypoperfusion observed by single-photon emission computerized tomography included the anterior intraparietal sulcus in the left parietal lobe, which is an area that has been proposed to control hand postures. This selective impairment might be explained by the reasoning-based hypothesis for apraxia, which attributes hand posture errors in the absence of manipulation errors to dysfunction in one of the three independent pathways that subserve tool use, rather than the manipulation-based hypothesis for apraxia, which attributes hand posture errors to impaired manipulation knowledge. This is the first case with a degenerative disorder that revealed a selective impairment for making hand postures for tool use, which might be explained mainly by apraxia of hand postures along with visuospatial dysfunction (simultanagnosia) and/or sensory disturbance.
Topics: Female; Humans; Corticobasal Degeneration; Apraxias; Posture; Neurodegenerative Diseases; Atrophy
PubMed: 36961317
DOI: 10.1097/WNN.0000000000000339 -
Neurological Sciences : Official... May 2021Selective bilateral lesions of the parietal-occipital lobes can lead to an uncommon and incompletely understood clinical entity, Balint' syndrome, which consists of...
BACKGROUND
Selective bilateral lesions of the parietal-occipital lobes can lead to an uncommon and incompletely understood clinical entity, Balint' syndrome, which consists of simultanagnosia, oculomotor apraxia, optic ataxia and difficulty in perceiving distances between objects.
CASE PRESENTATION
We herein report a rare presentation of Balint's syndrome in a 65-year-old woman suffering from stroke and SARS-CoV2 infection.
CONCLUSION
During SARS-CoV2 pandemic, Italian physicians were forced to work with less instrumental diagnostic resources, relying on their clinical knowledge mostly. The aim of this case report is to highlight the importance of performing a precise neurological evaluation, particularly during these challenging times: it might avoid incorrect diagnosis and favour the discovery of rare clinical diseases.
Topics: Aged; Apraxias; COVID-19; Female; Humans; Physicians; RNA, Viral; SARS-CoV-2
PubMed: 33400067
DOI: 10.1007/s10072-020-04934-0 -
Behavioral and Brain Functions : BBF Apr 2024One important role of the TPJ is the contribution to perception of the global gist in hierarchically organized stimuli where individual elements create a global visual...
One important role of the TPJ is the contribution to perception of the global gist in hierarchically organized stimuli where individual elements create a global visual percept. However, the link between clinical findings in simultanagnosia and neuroimaging in healthy subjects is missing for real-world global stimuli, like visual scenes. It is well-known that hierarchical, global stimuli activate TPJ regions and that simultanagnosia patients show deficits during the recognition of hierarchical stimuli and real-world visual scenes. However, the role of the TPJ in real-world scene processing is entirely unexplored. In the present study, we first localized TPJ regions significantly responding to the global gist of hierarchical stimuli and then investigated the responses to visual scenes, as well as single objects and faces as control stimuli. All three stimulus classes evoked significantly positive univariate responses in the previously localized TPJ regions. In a multivariate analysis, we were able to demonstrate that voxel patterns of the TPJ were classified significantly above chance level for all three stimulus classes. These results demonstrate a significant involvement of the TPJ in processing of complex visual stimuli that is not restricted to visual scenes and that the TPJ is sensitive to different classes of visual stimuli with a specific signature of neuronal activations.
Topics: Humans; Parietal Lobe; Magnetic Resonance Imaging; Recognition, Psychology; Neuroimaging; Multivariate Analysis; Photic Stimulation; Pattern Recognition, Visual; Visual Perception; Brain Mapping
PubMed: 38637870
DOI: 10.1186/s12993-024-00233-2 -
Topics in Stroke Rehabilitation May 2022For the first time, we administered reversing prism exposure to treat optic ataxia in a single patient with Balint-Holmes Syndrome (BHS), who also underwent specific...
OBJECTIVE
For the first time, we administered reversing prism exposure to treat optic ataxia in a single patient with Balint-Holmes Syndrome (BHS), who also underwent specific trainings for simultanagnosia and ocular apraxia.
METHOD AND RESULTS
By an introduction and withdrawal experimental design, we observed that the active treatment periods improved patient's visuospatial defects and functional autonomy.
CONCLUSIONS
We thus provided a proof of principle supporting the use of reversing prism exposure in optic ataxia within an integrated and personalized rehabilitative approach for BHS.
Topics: Apraxias; Ataxia; Cogan Syndrome; Eye Movements; Humans; Parietal Lobe; Perceptual Disorders; Stroke
PubMed: 33960916
DOI: 10.1080/10749357.2021.1923319 -
BMC Neurology Jan 2021Glucocerebrosidase (GBA) heterozygous variants are the most important genetic risk factor for the development of alpha-synucleinopathies (i.e., Parkinson's disease and...
BACKGROUND
Glucocerebrosidase (GBA) heterozygous variants are the most important genetic risk factor for the development of alpha-synucleinopathies (i.e., Parkinson's disease and Dementia with Lewy Bodies). Herein, we report for the first time on a patient with a clinical diagnosis of Posterior Cortical Atrophy, carrier of the common GBA heterozygous variant N370S (c.1226A > G).
CASE PRESENTATION
A 44-year-old woman with positive familial history for Dementia with Lewy Bodies disclosed three related signs characterizing the Balint's syndrome: ocular apraxia, optic ataxia and simultanagnosia. Over 2-year follow up, overt gaze apraxia (psychic paralysis of gaze) appeared leading to functional blindness. Given her young age at onset and positive familial history, she underwent a next-generation-sequencing (NGS) based screening of a panel of 32 genes related to neurodegenerative conditions within the ANAMNESYS (An origiNal Approach to study faMiliarity in NEurodegenerative SYndromeS) study. NGS demonstrated the N370S variant in the GBA gene (rs76763715), confirmed by Sanger sequencing. This is a relatively common variant, with predicted mild impact, already reported to occur in 2.4% of PD Italian patients; however, neither this nor other GBA variants have ever been reported to date in patients with Posterior Cortical Atrophy. Glucocerebrosidase activity was investigated and found to be significantly reduced (4.72 nmol/h/mg) compared to healthy controls as well as patients affected by neurodegenerative diseases, further supporting pathogenicity of the GBA variant.
CONCLUSIONS
We report on a patient with a clinical diagnosis of Posterior Cortical Atrophy, carrier of the GBA heterozygous variant N370S (c.1226A > G; p.Asn409Ser) determining reduced GCase activity. This report also confirms the role of NGS-based targeted gene analysis in detecting peculiar clinical phenotypes associated with known pathogenic mutations and reinforces the knowledge that carriers of genetic variants often present phenotypic overlaps across different neurodegenerative syndromes, highlighting the limitations of current clinical diagnostic criteria in defining boundaries between distinct conditions and the difficulties of clinicians in reaching the best clinical diagnosis.
Topics: Adult; Age of Onset; Atrophy; Female; Glucosylceramidase; Heterozygote; Humans; Italy; Mutation; Neurodegenerative Diseases; Phenotype
PubMed: 33435912
DOI: 10.1186/s12883-020-02023-5