Visual Spatial Neglect Research Articles

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.

Feasibility of Computerized Visuomotor Integration System for Visual Field Defects and Spatial Neglect in Poststroke Patients.

To develop a computerized visuomotor integration system for assessment and training of visual perception impairments and evaluate its safety and feasibility in patients with a stroke. Visual field defects and spatial neglect lead to substantial poststroke impairment. Most diagnostic assessments are anchored in traditional methods, and clinical effects of rehabilitation treatments are limited. The CoTras Vision system included two evaluations and four training modules. The evaluation modules were based on the Albert's test and Star cancellation test, and training modules were based on visual tracking, central-peripheral integration, and visuomotor perception techniques. Bland-Altman plots for agreement with the traditional paper-and-pencil test were performed, and the modified Intrinsic Motivation Inventory, Patient Satisfaction Questionnaire, and Simulator Sickness Questionnaire were conducted. Ten patients with acute stroke completed the study. Bland-Altman plots revealed good agreements for Albert's test (mean difference, -0.3±4.5) and Star cancellation test (mean difference, 0.3±0.7). The mean±standard deviation scores of the modified Intrinsic Motivation Inventory, Patient Satisfaction Survey, and Simulator Sickness Questionnaire were 84.7±30.6, 40.5±7.9, and 34.0±34.5 respectively. The CoTras Vision system is feasible and safe in patients with stroke. Most patients had a high degree of motivation to use the system and did not experience severe adverse events. Further studies are needed to confirm its usefulness in stroke patients with visual field defects and hemineglect symptoms. Furthermore, a large, well-designed, randomized controlled trial will be needed to confirm the treatment effect of the CoTras Vision system.

Assessment of visual and auditory spatial neglect in immersive virtual reality: A case study

Assessment of visual and auditory spatial neglect in immersive virtual reality: A case study

MULTIDIMENSIONAL PROfiLES OF COGNITIVE DETERIORATION AND RECOVERY ASSOCIATED WITH GLIOBLASTOMA SURGERY

Abstract AIMS Patients with glioblastoma suffer a high incidence of cognitive deficits. Cognition is the result of multiple neural mechanisms and glioblastoma is diffusely infiltrative with the capacity to invade multiple functional areas in the brain. We hypothesise that cognitive deterioration and recovery in these patients will be multidimensional in nature and therefore different components of cognition will show distinct recovery profiles following surgery. METHOD 28 patients with high-grade glioma, recruited at a single centre underwent preoperative (T0), early postoperative (within one week) (T1) and delayed (six to eight weeks) (T2) testing of their cognition with a neurocognitive screening tests; Oxford Cognitive Screen and Cambridge Attention, Memory and Perception Screen (OCS-Bridge) tool. Varimax principal component analysis was performed to determine if there are low-dimensional domains of cognition examined by the tests. Changes in cognitive scores between time points was calculated and correlated with principal component scores (PCs). RESULTS We found six principal components which explained 71% of the variance in OCS scores. and six different com- ponents explained 63% of the variance in Bridge scores. Cognitive deterioration was largely multidimensional with few significant correlations between PC change scores at T1 except tests loading on to visual field and spatial neglect. Cognitive recovery measured with T2 change scores were not significantly correlated between attention, praxis and language domains and between verbal working memory and visual memory and attention. CONCLUSIONS Longitudinal cognitive signatures of deterioration and recovery are heterogenous between patients. This high- lights the importance of targeting potentially distinct neural mechanisms for the rehabilitation of these patients.

Neural substrates in patients with visual-spatial neglect recovering from right-hemispheric stroke.

Visual-spatial attention disorder after stroke seriously affects recovery and quality of life in stroke patients. Previous studies have shown that some patients recovery rapidly from visual-spatial neglect (VSN), but the brain networks underlying this recovery are not well understood. Using functional magnetic resonance imaging, we aimed to identify network differences between patients who rapidly recovered from VSN and those with persistent VSN. The study included 30 patients with VSN who suffered subacute stroke. Patients were examined 2-4 weeks after stroke onset and 4 weeks after the initial assessment. At the last evaluation, patients in the persistent VSN (n = 15) and rapid recovery (n = 15) groups underwent paper-and-pencil tests. We defined the bilateral frontal eye fields, bilateral intraparietal sulcus in the dorsal attention network, and right temporoparietal junction and ventral frontal cortex areas in the ventral attention network as regions of interest (ROI) and measured whole-brain ROI-based functional connectivity (FC) and amplitude of low-frequency fluctuations (ALFF) in subacute right-hemisphere stroke patients. VSN recovery was associated with changes in the activation of multiple bilateral attentional brain regions. Specifically, persistent VSN was associated with lower FC in the right superior frontal gyrus, right inferior temporal gyrus, right medial orbitofrontal cortex, left precuneus, right inferior parietal gyrus, right medial frontal gyrus, right rectus gyrus, left superior frontal gyrus, left middle cingulate gyrus, right superior temporal pole, right postcentral gyrus, and right posterior cingulate gyrus compared to that in those with rapid recovery, whereas ALFF in the left cerebellum were decreased in patients with persistent VSN. Our results demonstrate that the DAN rather than the VAN, plays a more important role in recovery from VSN, and that the cerebellum is involved in recovery. We believe that our results supplement those of previous studies on recovery from VSN.

Detection of Stroke-Induced Visual Neglect and Target Response Prediction Using Augmented Reality and Electroencephalography.

We aim to build a system incorporating electroencephalography (EEG) and augmented reality (AR) that is capable of identifying the presence of visual spatial neglect (SN) and mapping the estimated neglected visual field. An EEG-based brain-computer interface (BCI) was used to identify those spatiospectral features that best detect participants with SN among stroke survivors using their EEG responses to ipsilesional and contralesional visual stimuli. Frontal-central delta and alpha, frontal-parietal theta, Fp1 beta, and left frontal gamma were found to be important features for neglect detection. Additionally, temporal analysis of the responses shows that the proposed model is accurate in detecting potentially neglected targets. These targets were predicted using common spatial patterns as the feature extraction algorithm and regularized discriminant analysis combined with kernel density estimation for classification. With our preliminary results, our system shows promise for reliably detecting the presence of SN and predicting visual target responses in stroke patients with SN.

Impaired visual search in posterior cortical atrophy vs. typical Alzheimer's disease

BackgroundPosterior cortical atrophy (PCA) is a neurocognitive disorder characterized by difficulty localizing in space. Recognizing PCA is important because it is usually missed early in its course and may result from a number of neurological disorders other than Alzheimer's disease (AD). ObjectiveThis study aimed to clarify whether impaired visual search tasks of spatial localization distinguished patients with PCA from those with other more typical dementias as well as from healthy control (HC) subjects. MethodsTwelve patients meeting neuroimaging-supported Consensus Criteria for PCA, 12 comparably advanced patients with amnestic-predominant typical AD (tAD), and 24 HC participants were compared on tests of untimed and timed visual search, spatial neglect, mental rotation, environmental orientation, visuospatial construction, and face recognition. ResultsOnly abnormalities in untimed and timed visual search and environmental orientation distinguished the PCA patients from both the tAD group and the HC group without also distinguishing the tAD patients from HC's. The PCA patients also had a tendency to greater difficulty scanning left hemispace compared to HC's. Visuospatial constructions, although worse in PCA, and face recognition were impaired in both dementia groups. ConclusionsThese findings support the concept of PCA as a disorder of spatial processing and localization, indicating that visual search tasks are particularly sensitive and specific for detecting PCA and distinguishing it from more typical dementia syndromes.

Carotid artery plaques and unilateral spatial neglect in the elderly.

The causes for falls in the elderly are varied, and visual spatial neglect could be 1 contributing factor. Further, the presence of a carotid artery plaque, especially on the right side, might influence the visual spatial attention of the elderly.Our aim was to identify the intrinsic association between carotid plaques and lateralization of spatial attention in the elderly. Further, we sought to understand and potentially prevent the consequences of unilateral spatial neglect such as injury from falls.Participants aged 64 to 93 years were divided into a group with carotid artery plaque(s) of the right side or both sides (BOTH, n = 38; and 9/ 38 were right side only) and a group without right-side carotid artery plaque(s) (LEFT, n = 53). Participants were asked to perform a line bisection task and undergo doppler ultrasonography examinations.Contrary to expectations, compared to LEFT, the mean index and net scores of the line bisection errors in BOTH were significantly less leftward, but the mean diameter of the right-side common carotid artery in BOTH was significantly larger.Our results indicate that the presence of carotid plaque(s) might be linked to increased risk of falls in the elderly. The attenuated spatial neglect in participants with right-side carotid artery plaque(s) might be due to compensatory carotid artery dilatation.

Visual processing features in patients with visual spatial neglect recovering from right-hemispheric stroke

ObjectiveVisual spatial neglect (VSN) is a disorder of spatial-temporal attention, often as a result of traumatic brain injury, including stroke. Accumulating evidence suggests that the recovery from VSN follows a very predictable pattern. In this study, we aimed to determine the specific electrophysiology readout that might have predictive value for recovery from VSN in the typical early events, including the recovery rate of visual processing, within the first four weeks of recovery. MethodsThis was a prospective study of 18 right ischemic stroke patients with VSN who performed a visual cue-target task within 3 days after stroke. The patients were divided into two groups according to their outcome. We compared behavioral data, the amplitudes and latencies of ERP components（P1, N1, and P300） between patients with persistent-VSN (P-VSN) and those with rapid recovery-VSN (R-VSN). ResultsThe amplitudes and latencies of the P1 and N1 components were not significantly influenced by the validity of the cue-based expectancy (all p > 0.05). However, a longer mean P300 latency evoked an effective cue (p < 0.001), and there was a significant difference between the P-VSN and R-VSN groups when using the left target (left hemisphere, p = 0.014; right hemisphere, p = 0.027). The recovery rate found in our study (18.75% at four weeks after stroke) was lower than that of previously reported studies. ConclusionsOur findings support the use of the event-related potential as a tool for investigating rapid recovery from VSN after stroke and suggest that other factors, such as an asymmetrical omission toward the contralateral side or impairment in the temporal processing capacity, might also be potential biomarkers of recovery.

The motor activity in acute cerebral stroke based on the Performance Oriented Mobility Assessment test modified by M. T inetti (1986), functional stress tests and screening assessment of visual-spatial disorders

Objective. The article presents the survey data of 80 patients in the acute period of cerebral stroke who were treated in the department of the primary vascular center. Design and methods. Upon recommendations of the motor activity, the patients with acute stroke were screened for the presence of neglect. The choice of motor activity was based on the Performance Oriented Mobility Assessment test in the modification of M. Tinetti (1986) and the results of functional stress tests. Results. There were no complications or falls at the hospital when adequate vegetative support and a high score at Performance Oriented Mobility Assessment in the modification of M. Tinetti (1986) were present, as well as in the absence of visual-spatial inability. The patients with the significant visual-spatial neglect showed higher risk of falls, even with adequate vegetative support and postural stability. Results. We demonstrated the possibility, as well as the prognostic value of the Performance Oriented Mobility Assessment in the modification of M. Tinetti (1986) and functional stress tests along with the assessment of visual-spatial neglect in planning the early motor rehabilitation of patients with cerebral stroke. In addition, we developed an algorithm for the motor rehabilitation planning.

Neglect syndrome after ischemic stroke: diagnosis, treatment options

The purpose of the study: the study of clinical efficacy and safety of the Neuromidin® in the rehabilitation period in patients with primary ischemic stroke, its eff ect on motor, cognitive function, level of household adaptation, depending on the presence or absence of neglekt syndrome and "push-syndrome". 60 patients aged 49 to 82 years in the recovery period of ischemic stroke were examined (30 patients — the main group: treatment with the addition of Neuromidin®; 30 patients — control group: standard treatment without adding Neuromidin®). Investigation of motor, cognitive, and sensitive disorders was carried out with the use of clinical scales. The effectiveness of the treatment was evaluated in the absence of signs of neglekt syndrome and "push-syndrome", reduction of motor and cognitive impairment. Patients with neglekt syndrome showed greater dependence on third-party care and more severe cognitive impairment than in patients who had not been diagnosed neglekt syndrome. After treatment, the majori ty of patients achieved elimination of neglekt syndrome, but in the group where patients received Neuromidin®, the number of such patients was higher. In addition, patients in the main group improved cognitive function. The use of Neuromidin® in complex rehabilitation measures in patients with ischemic stroke contributes to the restoration of lost functions, reduces the phenomena of visual-spatial neglect, positively affects self-care and improves the quality of life of patients and their relatives.

Development of the Halifax Visual Scanning Test: A New Measure of Visual-Spatial Neglect for Personal, Peripersonal, and Extrapersonal Space.

Visual-spatial neglect is a common attentional disorder after right-hemisphere stroke and is associated with poor rehabilitation outcomes. The presence of neglect symptoms has been reported to vary across personal, peripersonal, and extrapersonal space. Currently, no measure is available to assess neglect severity equally across these spatial regions and may be missing subsets of symptoms or patients with neglect entirely. We sought to provide initial construct validity for a novel assessment tool that measures neglect symptoms equally for these spatial regions: the Halifax Visual Scanning Test (HVST). In Study I, the HVST was compared to conventional measures of neglect and functional outcome scores (wheelchair navigation) in 15 stroke inpatients and 14 healthy controls. In Study II, 19 additional controls were combined with the control data from Study I to establish cutoffs for impairment. Patterns of neglect in the stroke group were examined. In Study I, performance on all HVST subtests were correlated with the majority of conventional subtests and wheelchair navigation outcomes. In Study II, neglect-related deficits in visual scanning showed dissociations across spatial regions. Four inpatients exhibited symptoms of neglect on the HVST that were not detected on conventional measures, one of which showed symptoms in personal and extrapersonal space exclusively. The HVST appears a useful measure of neglect symptoms in different spatial regions that may not be detected with conventional measures and that correlates with functional wheelchair performance. Preliminary control data are presented and further research to add to this normative database appears warranted.

Intermittent θ burst stimulation modulates resting-state functional connectivity in the attention network and promotes behavioral recovery in patients with visual spatial neglect

Functional connectivity changes in the attention network are viewed as a physiological signature of visual spatial neglect (VSN). The left dorsal lateral prefrontal cortex (LDLPFC) is known to initiate and monitor top-down attentional control and dynamically adjust behavioral performance. This study aimed to investigate whether increasing the activity of the LDLPFC through intermittent θ burst stimulation (iTBS) could modulate the resting-state functional connectivity in the attention network and facilitate recovery from VSN. Patients with right hemisphere stroke and VSN were randomly assigned to two groups matched for clinical characteristics and given a 10-day treatment. On each day, all patients underwent visual scanning training and motor function training and received iTBS over the LDLPFC either at 80% resting motor threshold (RMT) or at 40% RMT before the trainings. MRI, the line bisection test, and the star cancelation test were performed before and after treatment. Patients who received iTBS at 80% RMT showed a large-scale reduction in the resting-state functional connectivity extent, largely in the right attention network, and more significant improvement of behavioral performance compared with patients who received iTBS at 40% RMT. These results support that the LDLPFC potentially plays a key role in the modulation of attention networks in neglect. Increasing the activity of the LDPLPFC through iTBS can facilitate recovery from VSN in patients with stroke.

Diagnostic validity of line bisection in the acute phase of stroke

The line bisection task is commonly depicted as a valid diagnostic tool to help differentiate between primary visual field defects and spatial neglect. However, recent studies have addressed possible drawbacks in the acute phase after stroke onset. We investigated these critical assumptions in a large and homogeneous sample of 180 acute stroke patients. Line bisection, cancellation performance, copying, and primary visual field defects were assessed in 180 acute right-hemispheric stroke patients. Effects of visual field defects and concurrent spatial neglect on line bisection were analyzed by multiple regression to account for possible additive and interactive effects. The relation between line bisection and other tests applied in spatial neglect was explored by factorial analysis. We found no evidence for the existence of a contralesional ‘hemianopic line bisection error’ in acute patients with primary visual field defects. Such patients even showed a more pronounced ipsilesional line bisection error. Second, the factorial analysis revealed that the line bisection task on the one hand and cancellation/copying tasks on the other were represented by different factors, indicating that they make different cognitive demands. In the acute phase of stroke, line bisection does not appear to be a valid task to diagnose neither primary visual field defects nor spatial neglect (the latter as defined by its core symptoms (cf., Karnath and Rorden, 2012) which are typically captured with cancellation/copying tasks).

SV3. Modulation of hemifield effects in visual-spatial attention by transcranial direct current stimulation

Introduction A bilateral field advantage (BFA), that is enhanced visual processing when stimuli are aligned across both visual hemifields, corresponds to a hemispheric resource model of parallel visual attentional processing, suggesting more attentional resources for bilateral displays. Several studies have shown that the BFA extends beyond early stages of visual attentional processing. Visual-short-term-memory (VSTM) capacity was higher when stimuli are distributed bilaterally rather than unilaterally and repetitive transcranial magnetic stimulation (rTMS) over the right precuneus diminished the BFA (Kraft et al., 2014). Methods: Here we tested whether the BFA can be modulated by simultaneous anodal and cathodal transcranial direct current stimulation applied either over the left and right occipital cortex (O1/O2) or over the left and right parietal cortex (P3/P4). Twenty healthy subjects were tested using a whole report paradigm based on the Theory of Visual Attention (TVA; Bundesen, 1990). Results and Conclusion: This approach allowed us measuring VSTM capacity and visual processing speed variability in unilateral and bilateral displays. It is discussed how this approach can modulate the inter-hemispheric parietal and occipital balance and whether it can be used in therapeutic settings, e.g. in patients with visual deficits or spatial neglect.

Investigation of Psen1&2 Genes in Early Onset Alzheimer’s Disease Patients

Investigation of Psen1&2 Genes in Early Onset Alzheimer’s Disease Patients

The central role of the temporo-parietal junction and the superior longitudinal fasciculus in supporting multi-item competition: Evidence from lesion-symptom mapping of extinction

The present study examined the relations between the lesions linked to visual and tactile extinction (VE and TE), and those related to visual field defects and spatial neglect. Continuous variations in patients’ performance were used to assess the link between behavioural scores and integrity of both grey and white matter (GM and WM). We found both common and distinct neural substrates associated with extinction and neglect. Damage to angular and middle occipital gyri, superior temporal sulcus (STS) and insula were linked to VE. Lesions involving the supramarginal gyrus (SMG), intraparietal sulcus, middle frontal and superior temporal gyri (MFG and STG) were associated exclusively with spatial neglect. Lesions affecting the temporo-parietal junction (TPJ), the middle temporal region, middle frontal area (BA46) as well as the insula and putamen were linked to both spatial neglect and VE. Analysis of the relations between VE and TE highlighted the TPJ as the common site for both modalities. These findings suggest that the TPJ plays a general role in identifying salient events in the sensory environment across multiple modalities. Furthermore, WM analyses pointed to superior longitudinal fasciculus (SLF) as critical for interconnecting components of the visuospatial attention network. We demonstrated that functional disconnections resulting from SLF damage contribute to altered performance on attention tasks measuring not only neglect but also VE and TE. We propose that the SLF supports interactions between functionally specialized regions involved in attentional control across multiple sensory modalities.

Spatial attention to thermal pain stimuli in subjects with visual spatial hemi-neglect: Extinction, mislocalization and misidentification of stimulus modality

One approach to the study of disordered spatial attention is to carry out tests of extinction, in which stimuli are detected on the left when they are presented on the left alone, but not when both sides are stimulated simultaneously in a dual simultaneous stimulation (DSS) protocol. Extinction has been documented for multiple sensory modalities, but not for thermal pain stimuli, to our knowledge. We now test the hypothesis that subjects with visual spatial neglect (hemi-neglect) will have alterations in thermal pain sensation which are related to abnormal spatial attention. The results demonstrate that thermal pain extinction of hot and cold pain stimuli occurs in a proportion of subjects with hemi-neglect. In the subjects with visual spatial hemi-neglect but without thermal pain extinction, the sensation of the thermal pain stimulus on the affected (left) side was not extinguished but was often localized to the unaffected (right) side, and the submodality of the stimulus (cold or hot) was often misidentified. Ratios indicating the magnitude of extinction, mislocalization and misidentification were significantly larger on the left side of subjects with visual spatial neglect than in healthy controls or in controls with stroke but without hemineglect. The proportion of subjects with thermal pain extinction, mislocalization, or misidentification was significantly higher in subjects with hemi-neglect than those in either control group. These results demonstrate that disordered attention exerts a powerful effect upon the perception of both the location and the quality of thermal pain stimuli.

Impact of Visual-Spatial Neglect on Stroke Functional Outcomes, Discharge Destination and Maintenance of Improvement Post-Discharge

This study evaluated basic functional mobility in 25 patients with stroke and visual-spatial neglect during inpatient rehabilitation and early follow-up. Seven patients with neglect and 12 patients without neglect were discharged home and the rest to institutions. Patients without neglect achieved higher outcomes in a shorter time (mean 52 and 79 days respectively). All patients discharged home continued to improve at least up to 5 weeks post-discharge. The patients discharged to institutions achieved lower outcomes overall and quickly deteriorated to admission levels post-discharge. The results inform occupational therapy practice in the areas of assessment, discharge planning, destination and expected functional mobility outcomes in the community.

Ipsilateral ptosis as main feature of tuberothalamic artery infarction

Tuberothalamic artery infarction (TTAI) results mainly in a myriad of neuropsychological symptoms such as memory impairment, euphoria, apathy, verbal perseverations, constructional apraxia and lack of spontaneity. Language disturbances, acalculia, buccofacial and limb apraxia occur prominently after left TTAI while visual spatial processing deficits and hemispatial neglect occur prominently after the right one. Some cases of TTAI causing Horner's syndrome in addition of these wide-ranging neurobehavioral symptoms have been reported. Here, we report a case of TTAI with an ipsilateral ptosis as main clinical manifestation. This finding suggests that a Horner's syndrome can be the main feature of TTAI when neuropsychological manifestations are inconspicuous.