Posterior Cortical Atrophy with Right Lower Egocentric Quadrantic Neglect and Lower Vertical Allocentric Neglect

Abstract Background/Objectives Whereas rare cases of hemispatial visual neglect have been reported in patients with a neurodegenerative disease, quadrantic visuospatial neglect has not been described. We report a patient with probable posterior cortical atrophy who demonstrated lower right-sided quadrantic visuospatial neglect, together with allocentric vertical neglect. Methods/Results A 68-year-old man initially noted deficits in reading and writing. Subsequently, he developed other cognitive deficits. On vertical line bisections, he deviated upward, and on horizontal line bisections, he deviated to the left. These deviations together suggest that this man’s neglect might be most severe in his right (head/body-centered) lower (below eye level) visual space. When attempting to perform vertical line bisections in all four egocentric quadrants, his upward deviations were largest in the right lower quadrant. On a cancelation test, he revealed bilateral lower (ventral) allocentric neglect but not egocentric neglect. This patient’s magnetic resonance imaging revealed cortical atrophy, most prominent in the left parietal lobe. Discussion Previous research in stroke patients has demonstrated that the parietal lobes are important in mediating attention to contralateral and inferior visual space. The presence of left parietal atrophy may have induced this right lower (ventral) egocentric inattention as well as bilateral ventral allocentric inattention. Although to our knowledge there have been no prior reports of a patient with right lower quadrantic and lower vertical allocentric visuospatial neglect, patients are rarely tested for these forms of neglect, and this patient illustrates the importance of evaluating patients for these and other forms of neglect.

Download Full-text

Latent atrophy factors related to phenotypical variants of posterior cortical atrophy

Neurology ◽

10.1212/wnl.0000000000010362 ◽

2020 ◽

Vol 95 (12) ◽

pp. e1672-e1685 ◽

Cited By ~ 1

Author(s):

Colin Groot ◽

B.T. Thomas Yeo ◽

Jacob W. Vogel ◽

Xiuming Zhang ◽

Nanbo Sun ◽

...

Keyword(s):

Gray Matter ◽

Visual Processing ◽

Space Perception ◽

Object Perception ◽

Cortical Atrophy ◽

Intracranial Volume ◽

Posterior Cortical Atrophy ◽

Modeling Framework ◽

Β Amyloid ◽

The Right

ObjectiveTo determine whether atrophy relates to phenotypical variants of posterior cortical atrophy (PCA) recently proposed in clinical criteria (i.e., dorsal, ventral, dominant-parietal, and caudal) we assessed associations between latent atrophy factors and cognition.MethodsWe employed a data-driven Bayesian modeling framework based on latent Dirichlet allocation to identify latent atrophy factors in a multicenter cohort of 119 individuals with PCA (age 64 ± 7 years, 38% male, Mini-Mental State Examination 21 ± 5, 71% β-amyloid positive, 29% β-amyloid status unknown). The model uses standardized gray matter density images as input (adjusted for age, sex, intracranial volume, MRI scanner field strength, and whole-brain gray matter volume) and provides voxelwise probabilistic maps for a predetermined number of atrophy factors, allowing every individual to express each factor to a degree without a priori classification. Individual factor expressions were correlated to 4 PCA-specific cognitive domains (object perception, space perception, nonvisual/parietal functions, and primary visual processing) using general linear models.ResultsThe model revealed 4 distinct yet partially overlapping atrophy factors: right-dorsal, right-ventral, left-ventral, and limbic. We found that object perception and primary visual processing were associated with atrophy that predominantly reflects the right-ventral factor. Furthermore, space perception was associated with atrophy that predominantly represents the right-dorsal and right-ventral factors. However, individual participant profiles revealed that the large majority expressed multiple atrophy factors and had mixed clinical profiles with impairments across multiple domains, rather than displaying a discrete clinical–radiologic phenotype.ConclusionOur results indicate that specific brain behavior networks are vulnerable in PCA, but most individuals display a constellation of affected brain regions and symptoms, indicating that classification into 4 mutually exclusive variants is unlikely to be clinically useful.

Download Full-text

Brain structural and functional anomalies associated with simultanagnosia in patients with posterior cortical atrophy

Brain Imaging and Behavior ◽

10.1007/s11682-021-00568-8 ◽

2021 ◽

Author(s):

Yue Cui ◽

Yang Liu ◽

Caishui Yang ◽

Chunlei Cui ◽

Donglai Jing ◽

...

Keyword(s):

Functional Connectivity ◽

Gray Matter ◽

Gray Matter Volume ◽

Cortical Atrophy ◽

Posterior Cortical Atrophy ◽

Matter Volume ◽

Intrinsic Functional Connectivity ◽

Middle Occipital Gyrus ◽

The Right ◽

Left Middle

AbstractSimultanagnosia is a common symptom of posterior cortical atrophy, and its association with brain structural and functional changes remains unclear. In our study, 18 posterior cortical atrophy patients with simultanagnosia, 29 patients with Alzheimer’s disease and 20 cognitively normal controls were recruited and subjected to full neuropsychological evaluation, including simultanagnosia tests, and structural and resting-state functional MRI. The gray matter volume was assessed by voxel-based morphometry, while the intrinsic functional connectivity was evaluated using the reduced gray matter volume regions of interest as the seed. In contrast to the patients with Alzheimer’s disease, those with posterior cortical atrophy showed the following: (1) markedly lower simultanagnosia test scores, (2) an altered regional gray matter volume of the left middle occipital gyrus and ventral occipital areas, and (3) lowered intrinsic functional connectivity with the left middle occipital gyrus, left lingual gyrus and right middle occipital gyrus separately. Additionally, the gray matter volume of the left middle occipital gyrus and left inferior occipital gyrus were each correlated with simultanagnosia in posterior cortical atrophy patients. The intrinsic functional connectivity of the left middle occipital gyrus with the right superior occipital gyrus and that of the right middle occipital gyrus with the left superior parietal gyrus were also correlated with simultanagnosia in posterior cortical atrophy patients. In summary, this study indicated that simultanagnosia is associated with gray matter reductions and decreased functional connectivity in the left middle occipital gyrus and the left inferior occipital gyrus in patients with posterior cortical atrophy.

Download Full-text

F2-01-03: “AM I THE RIGHT WAY UP?”: INVESTIGATING BALANCE PROBLEMS IN POSTERIOR CORTICAL ATROPHY

Alzheimer s & Dementia ◽

10.1016/j.jalz.2019.06.4418 ◽

2019 ◽

Vol 15 ◽

pp. P516-P516

Author(s):

Keir Yong ◽

Amy Peters ◽

Dilek Ocal ◽

David M. Cash ◽

Matthew Bancroft ◽

...

Keyword(s):

Cortical Atrophy ◽

Posterior Cortical Atrophy ◽

The Right ◽

Balance Problems

Download Full-text

AGR - 2 Diagnosis of Posterior Cortical Atrophy Through Inter-Departmental Collaboration

Archives of Clinical Neuropsychology ◽

10.1093/arclin/acz037.02 ◽

2019 ◽

Vol 34 (6) ◽

pp. 831-831

Author(s):

S John ◽

M Silva ◽

N Newman ◽

D Loring

Keyword(s):

Neuropsychological Testing ◽

Cortical Atrophy ◽

White Female ◽

Posterior Cortical Atrophy ◽

Visual Spatial ◽

Field Evidence ◽

Confrontation Naming ◽

Unsteady Gait ◽

History Of ◽

The Right

Abstract Objective We present a patient with rapidly progressive visual decline of 2-year duration that interfered with daily functioning. She was evaluated by neuro-ophthalmology and neurology prior to neuropsychological referral. A series of evaluations led to diagnosis of posterior cortical atrophy, demonstrating the importance of inter-departmental collaboration. Method A 66-year old white female presented with a 2-year history of progressive changes to vision and memory. Medical history included hypertension, dyslipidemia, and a strong family history of optic neuropathy causing blindness. She was diagnosed with a left homonymous hemianopia. MRI revealed "significant cortical atrophy more remarkable on the right temporal, parietal, and occipital regions." She reported dressing apraxia, unsteady gait, declines in reading and writing, and difficulty recalling well-learned information. Results She was a good historian, had fluent speech and no apparent comprehension difficulty. Neuropsychological evaluation revealed relatively preserved language and verbal abilities, including confrontation naming, in the presence of otherwise impaired performances across all domains of functioning. She demonstrated agraphia, acalculia, left-right confusion, and difficulties with motor programming. Perceptual and constructional tasks revealed prominent deficits in visual integration, map orientation, form discrimination, and construction of simple geometric designs. She was perseverative and susceptible to verbal and visual stimulus pull. Conclusions The pattern on neuropsychological testing, with prominent visual spatial and perceptual difficulties, was consistent with posterior cortical atrophy. The decline in visual ability is likely exacerbated but not entirely explained by left hemianopia. Neuropsychological, neuroimaging, and visual field evidence demonstrated posterior cortical atrophy in the absence of positive biomarker evidence, leading to initiation of anti-cholinesterase therapy.

Download Full-text

Symbols

Information Modeling: The EXPRESS Way ◽

10.1093/oso/9780195087147.003.0026 ◽

1994 ◽

Author(s):

Douglas Schenck ◽

Peter Wilson

Keyword(s):

Information Model ◽

Lower Half ◽

Data Type ◽

Vertical Line ◽

Horizontal Line ◽

Model Composition ◽

Formal Parameter ◽

The Right

EXPRESS-G has three basic kinds of symbol; defintion, relation, and composition. Definition and relation symbols are used to define the contents and structure of an information model. Composition symbols enable the diagrams to be spread across many physical pages. A definition symbol is a rectangle enclosing the name of the thing being defined. The type of the definition is denoted by the style of the box. Symbols are provided for EXPRESS simple types, defined types, entity types and schemas. The EXPRESS language offers a number of predefined simple types, namely Binary, Boolean, Integer, Logical, Number, Real and String. These are the terminal types of the language. The symbol for them is a solid rectangle with a double vertical line at its right end. The name of the type is enclosed within the box, as shown in Figure 18.1. The EXPRESS Generic pseudotype is not represented in EXPRESS-G as it is only used as a formal parameter to a function or procedure, and EXPRESS-G does not have these. The symbols for the select, enumeration and defined data type are dashed boxes as shown in Figure 18.2. • The symbol for a defined data type is a dashed box enclosing the name of the type. • The symbol for a select type is a dashed box with a double vertical line at the left end, enclosing the name of the select. • The symbol for an enumeration type is a dashed box with a double vertical line at the right end, enclosing the name of the enumeration. Although an enumeration is not a terminal of the EXPRESS language (because its definition includes the enumerated things), it is a terminal of the EXPRESS-G language. Figure 18.3 shows the symbol for an entity, which is a solid rectangle enclosing the name of the entity. The symbol for a schema is shown in Figure 18.3. It is a solid rectangle divided in half by a horizontal line. The name of the schema is written in the upper half of the rectangle. The lower half of the symbol is empty. EXPRESS-G does not support any notation for either function or procedure definitions.

Download Full-text

Evaluation of two infants with myotonic dystrophy by the McFie's diagram from the results of WISC

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x1998000400018 ◽

1998 ◽

Vol 56 (3B) ◽

pp. 633-638 ◽

Cited By ~ 1

Author(s):

CRISTINA MARIA DUARTE WIGG ◽

LUIZ ANTONIO ALVES DURO

Keyword(s):

Myotonic Dystrophy ◽

Left Hemisphere ◽

Parietal Lobe ◽

Psychological Test ◽

Intelligence Scale ◽

Verbal Skills ◽

Parietal Lobes ◽

Visual Spatial ◽

The Right ◽

Impairment Severity

In this paper the authors disclose the result of a research carried out on two brothers whose parents were first cousins, being the gene transmitted by the father. The psychological test Wechsler Intelligence Scale of Children (WISC) was used in two occasions in order to assess the verbal and non-verbal skills. FRM and IRM were nine and eleven-year-old respectively, in the first examination, being the former thirteen and the latter fifteen-year-old on the second one. A comparison between the McFie's diagram and the WISC scores was made: the McFie's diagram showed the impairment severity in each cortical lobe when the left hemisphere was compared with the right one. The McFie's diagram was made from WISC's scores: the McFie's diagram showed the impairment severity in each cortical lobe when the left hemisphere was compared with the right one. On the second examination the performance was worse than in the first, mainly in the non-verbal aspects. The IRM's diagram showed a reduction in the right frontal and parietal lobes. In the FRM's diagram a reduction in the left frontal, temporal and parietal lobes, and also, in the right parietal lobe was found. The visual-spatial constructive aspects showed greatest impairment in this result.

Download Full-text

Magnetoencephalography reveals differences in brain activations for fast and slow responses to simple multiplications

Scientific Reports ◽

10.1038/s41598-021-97927-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Giorgio Arcara ◽

Rachele Pezzetta ◽

S. Benavides-Varela ◽

G. Rizzi ◽

S. Formica ◽

...

Keyword(s):

Parietal Lobe ◽

Brain Activity ◽

Angular Gyrus ◽

Single Digit ◽

Parietal Lobes ◽

Neurophysiological Studies ◽

Dorsolateral Prefrontal ◽

The Right ◽

Left Angular Gyrus ◽

Open Question

AbstractDespite decades of studies, it is still an open question on how and where simple multiplications are solved by the brain. This fragmented picture is mostly related to the different tasks employed. While in neuropsychological studies patients are asked to perform and report simple oral calculations, neuroimaging and neurophysiological studies often use verification tasks, in which the result is shown, and the participant must verify the correctness. This MEG study aims to unify the sources of evidence, investigating how brain activation unfolds in time using a single-digit multiplication production task. We compared the participants' brain activity—focusing on the parietal lobes—based on response efficiency, dividing their responses in fast and slow. Results showed higher activation for fast, as compared to slow, responses in the left angular gyrus starting after the first operand, and in the right supramarginal gyrus only after the second operand. A whole-brain analysis showed that fast responses had higher activation in the right dorsolateral prefrontal cortex. We show a timing difference of both hemispheres during simple multiplications. Results suggest that while the left parietal lobe may allow an initial retrieval of several possible solutions, the right one may be engaged later, helping to identify the solution based on magnitude checking.

Download Full-text

Simple Multiplication in the Brain: A MEG Study Comparing Fast and Slow Responses

10.21203/rs.3.rs-599967/v1 ◽

2021 ◽

Author(s):

Arcara G. ◽

Pezzetta R. ◽

Benavides-Varela S. ◽

Rizzi G. ◽

Formica S. ◽

...

Keyword(s):

Parietal Lobe ◽

Brain Activity ◽

Angular Gyrus ◽

Single Digit ◽

Parietal Lobes ◽

Neurophysiological Studies ◽

Dorsolateral Prefrontal ◽

The Right ◽

Left Angular Gyrus ◽

The Brain

Abstract Despite decades of studies, it is still an open question on how and where simple multiplication is solved by the brain. This fragmented picture is mostly related to the different tasks employed. Although in neuropsychological studies patients are asked to perform and report simple oral calculations, neuroimaging and neurophysiological studies often use verification tasks, in which the result is shown, and the participant must verify the correctness. This MEG study aims to unify the sources of evidence, investigating how brain activation unfolds in time using a single-digit multiplication production task. We compared the participants’ brain activity – focusing on the parietal lobes - based on response efficiency, dividing their responses in fast and slow. Results showed a higher activation for fast, as compared to slow, responses in the left angular gyrus starting after the first operand, and in the right supramarginal gyrus only after the second operand. A whole-brain analysis showed that fast responses had higher activation in the right dorsolateral prefrontal cortex. We show a timing difference of both hemispheres during simple multiplications. Results suggest that while the left parietal lobe may allow an initial retrieval of several possible solutions, the right one may be engaged later, helping to identify the solution based on magnitude checking.

Download Full-text

Granular Cell Tumor in the Brain of a Dog

Brazilian Journal of Veterinary Pathology ◽

10.24070/bjvp.1983-0246.v14i1p80-87 ◽

2021 ◽

Vol 14 (1) ◽

pp. 80-87

Author(s):

Marisa Maglaty ◽

Kevin Woolard

Keyword(s):

Parietal Lobe ◽

Granular Cell ◽

Clinical History ◽

Brain Parenchyma ◽

Sleep State ◽

Parietal Lobes ◽

Cluster Seizures ◽

Enzyme Elevation ◽

The Right ◽

The Brain

Diagnostic Exercise from The Latin Comparative Pathology Group. Clinical History: 10 year-old, female spayed, Golden Retriever/Poodle mix. This patient had a mass removed laparoscopically from the right adrenal gland (cortical adenoma) and was started on a low dose of prednisone post-operatively. Eight days post-op, she began having cluster seizures and was started on levetiracetam therapy. The following day, the dog was moderately obtunded and stumbling. On neurological examination, mild generalized ataxia was noted along with decreased menace OS, and delayed proprioception in the left pelvic and left thoracic limbs. CBC and chemistry values were unremarkable except for a mild hepatic enzyme elevation. EEG showed seizure-like activity and abnormal brain waves resembling sleep state while awake. MRI revealed an eccentric right-sided mass extending over the frontal and parietal lobes with subtentorial herniation. Due to poor prognosis, euthanasia was elected. Necropsy and Microscopic Findings: Tenuously adhered to the right parietal lobe of the brain and the dura mater is a soft, round, white, plaque-like mass measuring 3.5 x 3.0 x 0.3 cm. The mass is friable and poorly-demarcated from surrounding brain parenchyma. A portion of the mass adheres to the supradjacent surface of the calvarium.

Download Full-text

Data-driven detection of latent atrophy factors related to phenotypical variants of posterior cortical atrophy

10.1101/679225 ◽

2019 ◽

Author(s):

Colin Groot ◽

B.T. Thomas Yeo ◽

Jacob W Vogel ◽

Xiuming Zhang ◽

Nanbo Sun ◽

...

Keyword(s):

Gray Matter ◽

Visual Processing ◽

Amyloid Β ◽

Space Perception ◽

Object Perception ◽

Data Driven ◽

Cortical Atrophy ◽

Intracranial Volume ◽

Posterior Cortical Atrophy ◽

The Right

AbstractPosterior cortical atrophy is a clinical-radiological syndrome characterized by visual processing deficits and atrophy in posterior parts of the brain, most often caused by Alzheimer’s disease pathology. Recent consensus criteria describe four distinct phenotypical variants of posterior cortical atrophy defined by clinical and radiological features; i) object perception/occipitotemporal (ventral), ii) space perception/temporoparietal (dorsal), iii) non-visual/dominant parietal and iv) primary visual (caudal). We employed a data-driven approach to identify atrophy factors related to these proposed variants in a multi-center cohort of 119 individuals with posterior cortical atrophy (age: 64 SD 7, 38% male, MMSE: 21 SD 5, 71% amyloid-β positive, 29% amyloid-β status unknown). A Bayesian modelling framework based on latent Dirichlet allocation was used to compute four latent atrophy factors in accordance with the four proposed variants. The model uses standardized gray matter density images as input (adjusted for age, sex, intracranial volume, field strength and whole-brain gray matter volume) and provides voxelwise probabilistic maps for all atrophy factors, allowing every individual to express each factor to a degree without a priori classification. The model revealed four distinct yet partially overlapping atrophy factors; right-dorsal, right-ventral, left-ventral, and limbic. Individual participant profiles revealed that the vast majority of participants expressed multiple factors, rather than predominantly expressing a single factor. To assess the relationship between atrophy factors and cognition, neuropsychological test scores covering four posterior cortical atrophy-specific cognitive domains were assessed (object perception, space perception, non-visual parietal functions and primary visual processing) and we used general linear models to examine the association between atrophy factor expression and cognition. We found that object perception and primary visual processing were associated with atrophy that predominantly reflects the right-ventral factor. Furthermore, space perception was associated with atrophy that predominantly represents the right-ventral and right-dorsal factors. Similar to the atrophy factors, most participants had mixed clinical profiles with impairments across multiple domains. However, when selecting four participants with an isolated impairment, we observed atrophy patterns and factor expressions that were largely in accordance with the hypothesized variants. Taken together, our results indicate that variants of posterior cortical atrophy exist but these constitute phenotypical extremes and most individuals fall along a broad clinical-radiological spectrum, indicating that classification into four mutually exclusive variants is unlikely to be clinically useful.

Download Full-text