Unilateral Neglect Research Articles

Structural Coupling System for Cognitive Modeling in Immersive VR Assessment Tasks

Unilateral spatial neglect (USN) is a disorder characterized by the inability to attend to the space opposite the cerebral hemisphere lesion, significantly hindering daily activities. Due to the complex neural circuitry of the brain, understanding the mechanisms of USN has proven challenging. In clinical settings, the Behavioral Inattention Test (BIT), a paper-based examination, is commonly used to assess USN. However, improved scores on this test do not necessarily guarantee functional improvement, as it solely evaluates performance in a two-dimensional space. To address this limitation, various approaches utilizing information and communication technology (ICT) and measurement devices in rehabilitation engineering have been proposed. However, related studies have focused on analyzing motor responses to specific sensory stimuli, and the assessment measures often fail to capture a patient’s symptoms in dynamic environments. Therefore, this study proposes a methodology for modeling human spatial cognition. This cognitive architecture utilizes a structural coupling system that integrates parameters from multiple computational intelligence subsystems. In this study, we constructed a simulation environment capable of replicating the movements of patients with USN using empirical data collected from actual experiments. Furthermore, in this simulation environment, we developed patient agents that incorporated the proposed cognitive architecture. The experimental results suggest that hypothesis testing concerning attention mechanisms can be applied through the performance of patient agents within the simulation environment.

DEALING WITH TWO SYNCHRONOUS LESIONS

Introduction Multiple synchronous intracranial lesions present a significant diagnostic and therapeutic challenge, in most cases appearing as metastatic tumors or same-cell type tumors. Case Report We report the case of a 73-year-old patient admitted in our department with light left hemiparesis (MRC MMT 4/5), light left hypoesthesia and transitory and remitted state of temporo-spatial confusion that debuted around six weeks prior to presentation. The neurological exam confirmed the sensorimotor deficit and displayed the existence of left neglect syndrome. The patient’s MRI revealed a giant temporo-parieto-occipital mass almost 7 cm in diameter that appeared to have an intraventricular starting point and showed a relatively homogeneous contrast enhancement with significant mass effect. A concomitant superficial parieto-temporal lesion was also noted. Both lesions were excised in a successive manner from superficial to deep, using a right parieto-temporal craniotomy. While the giant mass had a yellowish color and an extremely hard consistency, the superficial one was easily suctionable and had a grey-reddish color and was extremely well vascularized, raising the suspicion of concomitant brain lesions of different histology. Postoperatively the patient underwent a routine thoracic CT scan in the context of a position related soft tissue injury that revealed the existence of two pulmonary lesions, further deepening our suspicion of concomitant brain lesions of different histology. Conclusions Although extremely rare, the appearance of two histologically distinct brain lesions in patients with no evidence of a genetic condition should be taken into consideration especially in the context of intraoperative differences in order to successfully guide the patients’ follow-up treatment.

Patient-specific visual neglect severity estimation for stroke patients with neglect using EEG.

We aim to assess the severity of spatial neglect through detailing patients' field of view (FOV) using EEG. Spatial neglect, a prevalent neurological syndrome in stroke patients, typically results from unilateral brain injuries, leading to inattention to the contralesional space. Commonly used Neglect detection methods like the Behavioral Inattention Test - Conventional (BIT-C) lack the capability to assess the full extent and severity of neglect. Although the Catherine Bergego Scale (CBS) provides valuable clinical information, it does not detail the specific field of view affected in neglect patients. Building on our previously developed EEG-based Brain-Computer Interface (BCI) system, AREEN (AR-guided EEG-based Neglect Detection, Assessment, and Rehabilitation System), we aim to map neglect severity across a patient's field of view. We have demonstrated that AREEN can assess neglect severity in a patient-agnostic manner. However, its effectiveness in patient-specific scenarios, which is crucial for creating a generalizable plug-and-play system, remains unexplored. This paper introduces a novel EEG-based combined Spatio-Temporal Network (ESTNet) that processes both time and frequency domain data to capture essential frequency band information associated with spatial neglect. We also propose a field of view correction system using Bayesian fusion, leveraging AREEN's recorded response times for enhanced accuracy by addressing noisy labels within the dataset. Extensive testing of ESTNet on our proprietary dataset has demonstrated its superiority over benchmark methods, achieving 79.62% accuracy, 76.71% sensitivity, and 86.36% specificity. Additionally, we provide saliency maps to enhance model explainability and establish clinical correlations. These findings underscore ESTNet's potential combined with Bayesian fusion-based FOV correction as an effective tool for generalized neglect assessment in clinical setting.

Environmental therapy: interface design strategies for color graphics to assist navigational tasks in patients with visuospatial disorders through an analytic hierarchy process based on CIE color perception.

Environmental therapy theory has been applied in the research of disease prevention, and the effectiveness of using color and graphic designs to assist patients with spatial orientation has been confirmed. Visual-spatial impairments are common symptoms associated with cognitive decline. However, the interaction and driving factors between these impairments and spatial color and graphic designs remain unclear. This paper first discusses the correlation between the characteristics of visual-spatial impairments and environmental factors and then investigates the color preferences of such patients based on the CIE 1976 color system and the Analytic Hierarchy Process (AHP). Subsequently, the paper explores spatial design strategies conducive to spatial orientation from the perspective of adaptability to pathological characteristics, utilizing case study analysis. (1) Pathological characteristics of visual-spatial impairments (such as difficulties in spatial orientation and spatial neglect) are related to environmental factors; (2) Emotional attachment factors play a key role in patients' perception of satisfaction with environmental colors; (3) Color associations have the potential to strengthen spatial memory. Additionally, interface designs with high luminance, low saturation, and clear color differentiation facilitate patients' recognition of space. This paper posits that spatial interface design is a feasible approach to assist with spatial orientation, and it achieves this through a mediating process that progresses from influencing visual stimuli to cognitive memory and then to behavioral orientation. The article provides insights into the operational feasibility of this method.

Risk-taking behaviour and executive functions, a major component of the risk of fall factors after recent stroke.

This study investigated the weight of different cognitive disorders on patient behaviour influencing the risk of falls after recent stroke. Survey and retrospective monocentric study. 74 professionals/108 patients. Survey of professionals to ask for their thoughts concerning the weight of different cognitive disorders on the risk of falls and a retrospective study of patients post-stroke to determine whether these cognitive deficits could distinguish fallers from non-fallers. Univariate and multivariate logistic regression analyses were conducted. In part 1, major cognitive disorders identified were anosognosia, confusion, inattention, precipitation, and unilateral spatial neglect. In part 2, 25 patients (23%) were fallers. After adjustment for length of rehabilitation stay and disease severity, on multivariate analysis, the cognitive disorders significantly associated with risk of falls were anosognosia (odds ratio 16), precipitation (13.3), inattention (8.3), and perseveration (4.9). Unilateral spatial neglect was not independently associated. Aphasia did not play a role. Some cognitive disorders, easily identified before any neuropsychological assessment, strongly modify patient behaviour in terms of risk of falls. It is proposed that these disorders should not be considered as an additional factor along with physical and general factors but rather as a multiplying factor applied to the others.

Novel SERPINC1 Mutation in a Brazilian Patient with Sudden-onset Sagittal Sinus Thrombosis Caused by Congenital Antithrombin Deficiency

A 19-year-old Brazilian man visited the emergency department of our hospital complaining of nausea and fever. He presented with left hemispatial neglect. Magnetic resonance imaging led to a diagnosis of sagittal sinus thrombosis. Blood tests showed decreased antithrombin (ATIII) activity, and ATIII deficiency was diagnosed. He was treated with heparin sodium and warfarin. Genetic counseling through medical interpreters was recommended, and the patient and his mother consented to genetic testing, which revealed a novel mutation variant of the SERPINC1 gene. Genetic counseling is important to connect patients to genetic testing, even if language barriers are present.

The effect of cerebellar lesıons on language in Turkısh speakıng indıvıduals

ABSTRACT Background The cerebellum is approximately 10% of the brain volume and is responsible for attention, language, emotion and cognitive functions. Linguistic processing difficulties and cognitive impairments may be observed in individuals with cerebellar lesions depending on the location and severity of the damage. There is no study evaluating language in Turkish-speaking individuals with cerebellar lesions. Objective To determine the differences in linguistic and visuospatial skills of Turkish speaking individuals with cerebellar lesions compared to control groups, including a right hemisphere lesion group and a healthy control group. Method Fifteen patients with cerebellar lesion (without hemispatial neglect and dysarthria), 15 patients with right hemisphere lesion due to right arter cerebri media (without hemispatial neglect) and 15 healthy control were included. To clarify the language impairment specific to cerebellar lesions, we also included individuals with right hemisphere lesions, which are typically assumed not to present with aphasia. The Language Assessment Test for Aphasia (ADD), Benton Judgment of Line Orientation Test, Benton Facial Recognition Test, Single Letter Deletion Test were used. The “Accident Scene” picture was used for collecting narrative speech samples. After a three group comparison a post-hoc pairwise analysis was performed. Results Among the microstructural parameters in the narrative language analysis, the effort ratio was significantly higher in the cerebellar lesion group compared to the healthy control group. Among the non-verbal cognitive tests, the Benton Facial Recognition Test score was significantly lower in the cerebellar and right hemisphere lesion group compared to the healthy control group. Total score, naming and grammar scores in the ADD test were significantly lower in the cerebellar lesion group compared with the healthy control group. There was no difference between cerebellar and right hemisphere lesions in terms of ADD score, ADD subtests and narrative parameters. Conclusion In Turkish-speaking individuals with cerebellar lesions, verbal productivity may be interrupted by effort behaviours, and standard aphasia assessment tests may reveal impaired grammar and naming performance without a diagnosis of aphasia. In addition to reduced efficiency in verbal production, facial recognition may be impaired. We found no difference between individuals with lesions in the cerebellum and right hemisphere. This suggests that ischemic damage may affect different components of language independently of the diagnosis of aphasia.

Ecological assessment of unilateral spatial neglect in immersive virtual reality: A multiple-case study to assess the feasibility and relevance of a Baking Tray Task

ABSTRACT The assessment of unilateral spatial neglect (USN) primarily relies on paper-and-pencil tests, which do not fully represent daily life difficulties. To address this limitation, ecological tests, like the Baking Tray Test (BTT), have been developed. However, the original BTT identifies the presence of USN without providing information on its severity. In this aim, a new severity measure, the Centre of Mass (CoM), has been proposed, but its calculation in real environments poses challenges. Immersive virtual reality (VR) offers a promising solution for implementing a BTT in which measures are automatically calculated. This study aimed to assess the feasibility and relevance of an immersive VR BTT. Nineteen right brain-damaged patients with and without USN and 25 healthy participants were included. Group analyses showed an equivalence between the two BTT versions. Individual analyses revealed that all USN patients, except one, had pathological results in both versions. They also underlined pathological scores in patients without USN signs on paper-and-pencil tests. Finally, the CoM strongly correlated with paper-and-pencil tests and appeared to be a good indicator of USN severity. These findings support the relevance of implementing the BTT in an immersive VR version, suggesting its potential to enhance USN assessment.

Effects of postural and kinesthetic awareness on static standing balance and plantar pressure in chronic stroke: a randomized controlled trial.

To determine effects of postural and kinesthetic awareness on plantar pressure and static standing stability in chronic stroke patients. The cross-sectional single-blind study was conducted at the University of Lahore Teaching Hospital, Lahore, Pakistan, from January 19 to March 2, 2023, and comprised stroke patients of both genders. aged 45-60 years having visual spatial neglect. They were randomised into control group A and experimental group B. Group A received routine physical therapy, while group B additionally received postural and kinesthetic awareness sessions. Static component of the Berg balance scale was used to measure balance, and PoData Stabiliometeric plate ("Chinesport, Italy") to measure plantar pressure. Data was analysed using SPSS version 25. Of the 52 patients, 26(50%) were in group A with mean age 51.97±4.37 years and mean weight 79.48±5.7kg. The remaining 26(50%) patients were in group B with mean age 50.69±4.41 years and mean weight 78.27±4.55kg. The outcome measures were significantly better in group B compared to group A (p<0.05). Postural and kinesthetic awareness could possibly be a well-grounded rehabilitative strategy that may support and enhance the balance of individuals with chronic stroke. The study was registered at the United States National Institutes of Health (ClinicalTrials.gov) with registration number NCT05915195.

Spotlighting the Neglect of Balinese Women's and Children's Rights in Custody Court Decisions

The Balinese society adheres to a patrilineal kinship system in which men are considered the successors of the lineage. This system often serves as the rationale for awarding child custody to fathers in divorce cases, frequently disregarding the rights of the mother and the best interests of the child. This study examines the implications of the patrilineal kinship system on divorce proceedings, the criteria used by judges in child custody decisions among the Balinese, and the potential for reconstructing child custody arrangements to prioritize the child's best interests. It is a legal research that examines the normative issues regarding child custody in a patrilineal society with a gender perspective. This paper suggests that decisions regarding child custody should refer to the child's best interests principle and gender responsiveness. In the event of a divorce, a wife is typically returned to her parents by her husband's extended family, a process known as “mulih deha”, which effectively reverts her to the status of a girl, implying she has no children and does not retain any marital property. Societal culture holds that a child is considered secure in the father's household, even if the paternal grandparents provide care. This entrenched belief system discourages Balinese women from pursuing child custody. A co-parenting model, allowing both parents to remain actively involved, can help reconstruct child custody arrangements to serve the child's best interests better.

Using augmented reality to assess spatial neglect: The Free Exploration Test (FET).

To capture the distortion of exploratory activity typical of patients with spatial neglect, traditional diagnostic methods and new virtual reality applications use confined workspaces that limit patients' exploration behavior to a predefined area. Our aim was to overcome these limitations and enable the recording of patients' biased activity in real, unconfined space. We developed the Free Exploration Test (FET) based on augmented reality technology. Using a live stream via the back camera on a tablet, patients search for a (non-existent) virtual target in their environment, while their exploration movements are recorded for 30 s. We tested 20 neglect patients and 20 healthy participants and compared the performance of the FET with traditional neglect tests. In contrast to controls, neglect patients exhibited a significant rightward bias in exploratory movements. The FET had a high discriminative power (area under the curve = 0.89) and correlated positively with traditional tests of spatial neglect (Letter Cancellation, Bells Test, Copying Task, Line Bisection). An optimal cut-off point of the averaged bias of exploratory activity was at 9.0° on the right; it distinguished neglect patients from controls with 85% sensitivity. FET offers time-efficient (execution time: ∼3 min), easy-to-apply, and gamified assessment of free exploratory activity. It supplements traditional neglect tests, providing unrestricted recording of exploration in the real, unconfined space surrounding the patient.

Ventral Variant Posterior Cortical Atrophy with Occipito-temporal Accumulation of Tau Proteins/Astrocyte Gliosis.

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.

Teaching NeuroImage: Short-Lasting Egocentric and Allocentric Visual Neglect After Right-Middle Cerebral Artery Stroke.

Teaching NeuroImage: Short-Lasting Egocentric and Allocentric Visual Neglect After Right-Middle Cerebral Artery Stroke.

Effects of Visual Assist Signals on Unilateral Spatial Neglect and Its Measurement

Effects of Visual Assist Signals on Unilateral Spatial Neglect and Its Measurement

Overview of Neuro-Ophthalmic Findings in Leukodystrophies.

Background: Leukodystrophies are a group of rare genetic diseases that primarily affect the white matter of the central nervous system. The broad spectrum of metabolic and pathological causes leads to manifestations at any age, most often in childhood and adolescence, and a variety of symptoms. Leukodystrophies are usually progressive, resulting in severe disabilities and premature death. Progressive visual impairment is a common symptom. Currently, no overview of the manifold neuro-ophthalmologic manifestations and visual impact of leukodystrophies exists. Methods: Data from 217 patients in the Hamburg leukodystrophy cohort were analyzed retrospectively for neuro-ophthalmologic manifestations, age of disease onset, and magnetic resonance imaging, visual evoked potential, and optical coherence tomography findings and were compared with data from the literature. Results: In total, 68% of the patients suffered from neuro-ophthalmologic symptoms, such as optic atrophy, visual neglect, strabismus, and nystagmus. Depending on the type of leukodystrophy, neuro-ophthalmologic symptoms occurred early or late during the course of the disease. Magnetic resonance imaging scans revealed pathologic alterations in the visual tract that were temporally correlated with symptoms. Conclusions: The first optical coherence tomography findings in Krabbe disease and metachromatic leukodystrophy allow retinal assessments. Comprehensive literature research supports the results of this first overview of neuro-ophthalmologic findings in leukodystrophies.

Perspectives of Decision Support System TeleRehab in the Management of Post-Stroke Telerehabilitation.

Stroke is the main cause of disability among adults. Decision-making in stroke rehabilitation is increasingly complex; therefore, the use of decision support systems by healthcare providers is becoming a necessity. However, there is a significant lack of software for the management of post-stroke telerehabilitation (TR). This paper presents the results of the developed software "TeleRehab" to support the decision-making of clinicians and healthcare providers in post-stroke TR. We designed a Python-based software with a graphical user interface to manage post-stroke TR. We searched Scopus, ScienceDirect, and PubMed databases to obtain research papers with results of clinical trials for post-stroke TR and to form the knowledge base of the software. The findings show that TeleRehab suggests recommendations for TR to provide practitioners with optimal and real-time support. We observed feasible outcomes of the software based on synthetic data of patients with balance problems, spatial neglect, and upper and lower extremities dysfunctions. Also, the software demonstrated excellent usability and acceptability scores among healthcare professionals.

Intrarater Reliability of Catherine Bergego Scale and Albert’s Test in Chronic Stroke Patients With Unilateral Spatial Neglect

Intrarater Reliability of Catherine Bergego Scale and Albert’s Test in Chronic Stroke Patients With Unilateral Spatial Neglect

Gaze Scanning on Mid-Block Sidewalks by Pedestrians With Homonymous Hemianopia With or Without Spatial Neglect.

The purpose of this study was to investigate gaze-scanning by pedestrians with homonymous hemianopia (HH) when walking on mid-block sidewalks. Pedestrians with right homonymous hemianopia (RHH), and left homonymous hemianopia (LHH) without and with left spatial neglect (LHSN) walked on city streets wearing a gaze-tracking system. Gaze points were obtained by combining head movement and eye-in-head movement. Mixed-effects regression models were used to compare horizontal gaze scan magnitudes and rates between the side of the hemi-field loss (BlindSide) and the seeing side (SeeingSide), among the three subject groups, and between mid-block walking and street crossing segments. A total of 7021 gaze scans were obtained from 341minutes of mid-block walking videos by 19 participants (6 with LHH, 7 with RHH, and 6 with LHSN). The average gaze magnitude and scanning rate in mid-block segments were significantly higher towards the BlindSide than the SeeingSide in LHH (magnitude larger by 1.9° (degrees), P = 0.006; scan rate higher by 4.2 scans/minute, P < 0.001) and RHH subjects (magnitude larger by 3.3°, P < 0.001; scan rate higher by 3.2 scans/minute, P = 0.002), but they were not significantly different in LHSN subjects. The scanning rate, in terms of scans/minute (mean, 95% confidence interval [CI]) was significantly lower in LHSN subjects (mean = 6.9, 95% CI = 5.6-8.7) than LHH (mean = 10.2, 95% CI = 8.0-13.1; P = 0.03) and RHH (mean = 11.1, 95% CI = 9.0-13.7; P = 0.007) subjects. Compared to street-crossings, the scan rate during the mid-block segments was lower by 3.5 scans/minute (P < 0.001) and the gaze magnitude was smaller by 3.8° (P < 0.001) over the 3 groups. Evidence of compensatory scanning suggests a proactive, top-down mechanism driving gaze in HH. The presence of spatial neglect (SN) appeared to negatively impact the top-down process.

Streams of conscious visual experience

Consciousness, a cornerstone of human cognition, is believed to arise from complex neural interactions. Traditional views have focused on localized fronto-parietal networks or broader inter-regional dynamics. In our study, we leverage advanced fMRI techniques, including the novel Functionnectome framework, to unravel the intricate relationship between brain circuits and functional activity shaping visual consciousness. Our findings underscore the importance of the superior longitudinal fasciculus within the fronto-parietal fibers, linking conscious perception with spatial neglect. Additionally, our data reveal the critical contribution of the temporo-parietal fibers and the splenium of the corpus callosum in connecting visual information with conscious representation and their verbalization. Central to these networks is the thalamus, posited as a conductor in synchronizing these interactive processes. Contrasting traditional fMRI analyses with the Functionnectome approach, our results emphasize the important explanatory power of interactive mechanisms over localized activations for visual consciousness. This research paves the way for a comprehensive understanding of consciousness, highlighting the complex network of neural connections that lead to awareness.

Quantifying the Use of Space in the Clock Drawing Test: Validity in Hemispatial Neglect.

The Clock Drawing Test (CDT) is a widely used test for cognitive screening as its execution taps into a large number of cognitive functions. Because of the involvement of visuospatial abilities, the CDT is also commonly used to assess hemispatial neglect. In the present study, we introduce a new quantitative scoring method for the CDT that aims to measure the use of space for each half of the clock face and asymmetries of space use. Two measures are introduced: the explored space (ES) and used space (US) for each half of the clock, as well as two derived asymmetry indices. Such new measures were applied to CDTs of four groups of participants: right brain-damaged patients without visuospatial neglect, two groups of right brain-damaged patients with varying degrees of visuospatial neglect, and a group of neurologically healthy participants. Analyses showed that only neglect patients explored and used the left clock half significantly less than the right one. This result was also confirmed by the asymmetry indices, where neglect patients showed a stronger rightward bias. For neglect patients, the US asymmetry index correlated with the patients' scores on the neuropsychological tests. The analyses of receiver operating characteristic curves showed that left US and left ES scores had good accuracy in categorizing neglect patients. The present work provides new quantitative indices of CDT space usage in hemispatial neglect. Cutoffs are provided for clinical practice.