Differences between left- and right-sided neglect revisited: A large cohort study across multiple domains

Do facilitators and barriers to community ambulation differ among stroke survivors in low resource settings? A cross-sectional study in Nigeria

PURPOSE

Stroke survivors (SSV) in many low- and middle-income countries experience frustrating participation restriction in community ambulation (CA), which impedes community life. This study assessed facilitators and barriers to CA among community-dwelling SSV in a southwest state of Nigeria.

METHODS

This cross-sectional study involved 66 community-dwelling ambulating SSV, purposively recruited from physiotherapy out-patient clinics of selected hospitals in southwest Nigeria. Semi-structured questionnaire containing physical and social environment elements of the ICF domains was administered on respondents. Mobility status at home and community, socio-demographic and clinical data of SSV were also obtained. Responses from open-ended questions were triangulated with appropriate close ended options. Data were analyzed using descriptive statistics and logistic regression at p < 0.05 Alpha value.

RESULTS

Majority of the SSV were independent in their homes (59.1%), used mobility aids (87.9%) and assisted in CA (66.7%). They identified limited physical accessibility by crowds 25 (37.9%), lack of inclined surfaces 40 (95.2%), uneven floors 36 (87.8%), public seating arrangements 33 (78.6%), rain (73.8%) and inability to use services, systems and policies (77.3%) as barriers to CA. Built physical environment was a significant predictor of home (OR = 0.754, p = 0.001) and community mobility (OR = 0.850; p = 0.018), while post-stroke depression was a significant predictor of community mobility (OR = 1.038; p = 0.014).

CONCLUSION

Mobility aids, social attitudes and general support were identified as facilitators, whereas barriers to CA included built physical environment, services and policies, products and technology. Facilitators and barriers to CA are similar to some HIC contexts, perceived difficulties and experiences differ for infrastructural and social reasons among others.

The engagement of temporal attention in left spatial neglect

Previous literature showed how left spatial neglect arises from an asymmetrical distribution of spatial attention. However, it was also suggested that left spatial neglect might be partially caused or at least worsened by non-spatial attention disorders of the right-lateralized stimulus-driven attentional fronto-parietal network. Here, we psychophysically tested the efficiency of temporal attentional engagement of foveal perception through meta-contrast (Experiment 1) and "attentional" masking (Experiment 2) tasks in patients with right-hemisphere stroke with left neglect (N+), without left neglect (N-) and matched healthy controls (C). In both experiments, N+ patients showed higher thresholds, not only than Cs, but also than N- patients. Temporal engagement was clinically impaired in all N+ patients and highly correlated with their typical inability to direct spatial attention towards stimuli on the left side. Our findings suggest that a temporal impairment of attentional engagement is a relevant deficit of left spatial neglect.

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

Purpose

The purpose of this study was to investigate gaze-scanning by pedestrians with homonymous hemianopia (HH) when walking on mid-block sidewalks.

Methods

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.

Results

A total of 7021 gaze scans were obtained from 341 minutes 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.

Conclusions

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.

Modulation of reaching by spatial attention

Attention is needed to perform goal-directed vision-guided movements. We investigated whether the direction of covert attention modulates movement outcomes and dynamics. Right-handed and left-handed volunteers attended to a spatial location while planning a reach toward the same hemifield, the opposite one, or planned a reach without constraining attention. We measured behavioral variables as outcomes of ipsilateral and contralateral reaching and the tangling of behavioral trajectories obtained through principal component analysis as a measure of the dynamics of motor control. We found that the direction of covert attention had significant effects on the dynamics of motor control, specifically during contralateral reaching. Data suggest that motor control was more feedback-driven when attention was directed leftward than when attention was directed rightward or when it was not constrained, irrespectively of handedness. These results may help to better understand the neural bases of asymmetrical neurological diseases like hemispatial neglect.

Virtual reality gameplay classification illustrates the multidimensionality of visuospatial neglect

Brain injuries can significantly impact mental processes and lead to hidden disabilities not easily detectable. Traditional methods for assessing these impacts are imprecise, leading to unreliable prevalence estimates and treatments with uncertain effectiveness. Immersive virtual reality has shown promise for assessment, but its use as a standalone tool is rare. Our research focused on developing and validating a standalone immersive virtual reality classification system for unilateral spatial neglect, a condition common following brain injury characterized by inattention to one side of space. Our study involved 51 brain injury inpatients and 30 controls, all engaging with 'The Attention Atlas', an immersive virtual reality game for testing visual search skills. Our classification system aimed to identify patients with neglect, 'minor atypicality' (indicative of inattention not consistent enough to be labelled as neglect) or non-neglect. This categorization was based on a simple mathematical definition, utilizing gameplay to describe spatial orientation (to the left or right side) and attentional challenge (indicative of search inefficiency). These metrics were benchmarked against a normative model to detect atypical visual search, which refers to gameplay beyond the usual bounds. The combination of neglected side, orientation and challenge factors was used to categorize neglect. We discovered a strong correlation between atypical visual search patterns and neglect risk factors, such as middle cerebral artery stroke, parietal injuries and existing neglect diagnoses (Poisson regression incidence rate ratio = 7.18, 95% confidence interval = 4.41-11.90). In our study, immersive virtual reality-identified neglect in one-fourth of the patients (n = 13, 25.5%), minor atypicality in 17.6% (n = 9) and non-neglect in the majority, 56.9% (n = 29). This contrasts with standard assessments, which detected neglect in 17.6% (n = 9) of cases and had no intermediate category. Our analysis determined six categories of neglect, the most common being left hemispace neglect with above-median orientation and challenge scores. Traditional assessments were not significantly more accurate (accuracy = 84.3%, P = 0.06) than a blanket assumption of non-neglect. Traditional assessments were also relatively insensitive in detecting immersive virtual reality-identified neglect (53.8%), particularly in less severe cases and those involving right-side inattention. Our findings underline the effectiveness of immersive virtual reality in revealing various dimensions of neglect, surpassing traditional methods in sensitivity and detail and operating independently from them. To integrate immersive virtual reality into real-world clinical settings, collaboration with healthcare professionals, patients and other stakeholders is crucial to ensure practical applicability and accessibility.

Application of immersive virtual reality for assessing chronic neglect in individuals with stroke: the immersive virtual road-crossing task

BACKGROUND

Neglect can be a long-term consequence of chronic stroke that can impede an individual's ability to perform daily activities, but chronic and discrete forms can be difficult to detect. We developed and evaluated the "immersive virtual road-crossing task" (iVRoad) to identify and quantify discrete neglect symptoms in chronic stroke patients.

METHOD

The iVRoad task requires crossing virtual intersections and placing a letter in a mailbox placed either on the left or right. We tested three groups using the HTC Vive Pro Eye: (1) chronic right hemisphere stroke patients with (N = 20) and (2) without (N = 20) chronic left-sided neglect, and (3) age and gender-matched healthy controls (N = 20). We analyzed temporal parameters, errors, and head rotation to identify group-specific patterns, and applied questionnaires to measure self-assessed pedestrian behavior and usability.

RESULTS

Overall, the task was well-tolerated by all participants with fewer cybersickness-induced symptoms after the VR exposure than before. Reaction time, left-sided errors, and lateral head movements for traffic from left most clearly distinguished between groups. Neglect patients committed more dangerous crossings, but their self-rated pedestrian behavior did not differ from that of stroke patients without neglect. This demonstrates their reduced awareness of the risks in everyday life and highlights the clinical relevance of the task.

CONCLUSIONS

Our findings suggest that a virtual road crossing task, such as iVRoad, has the potential to identify subtle symptoms of neglect by providing virtual scenarios that more closely resemble the demands and challenges of everyday life. iVRoad is an immersive, naturalistic virtual reality task that can measure clinically relevant behavioral variance and identify discrete neglect symptoms.

Unilateral Spatial Neglect May Not Be Detected by Performance-Based Functional Neglect Assessment

IMPORTANCE

Unilateral spatial neglect (neglect) poststroke is disabling. It is critical that people with neglect are identified so that treatment can be provided to maximize independence. However, there is some evidence to suggest that existing assessments may not adequately measure neglect. It is unclear whether assessments also fail to identify people with neglect entirely.

OBJECTIVE

To determine whether there are stroke survivors who self-report neglect symptoms that are not detected by therapist-rated assessments and to compare self-report and therapist-ratings.

DESIGN

Cross-sectional study.

SETTING

U.S. university research center.

PARTICIPANTS

Unilateral stroke survivors (N = 133).

INTERVENTION

Not applicable.

OUTCOMES AND MEASURES

The Catherine Bergego Scale (CBS) was administered to participants and scored by a trained occupational therapist. The parallel self-evaluation anosognosia form was also administered to participants to self-report and rate neglect symptoms.

RESULTS

Forty-eight participants (36.1%) were classified as without neglect on the basis of therapist-rated total CBS scores, yet 30 (62.5%) of these 48 participants reported symptoms of neglect on the CBS self-evaluation anosognosia form. There was a significant difference (p < .001) between therapist-rated and self-rated total CBS scores.

CONCLUSIONS AND RELEVANCE

Our results indicate that many stroke survivors report some level of disability associated with neglect yet do not meet the criteria to be classified as having neglect according to a commonly used therapist-rated performance-based measure. Plain-Language Summary: The findings of this study contribute to the evidence that existing assessments used by occupational therapists to measure performance-based neglect may not always detect neglect symptoms comprehensively in people poststroke. The finding also suggest that we may be missing neglect symptoms entirely. Occupational therapists should consider using various methods to assess for neglect, including patient self-report and comprehensive occupational profiles. Clinicians should also thoroughly screen all clients with stroke for neglect, regardless of lesion location.

Identifying Spatial Neglect in Chronic Right Hemisphere Stroke Survivors Using the RHDBank Outcomes

PURPOSE

The chronicity of spatial neglect (SN) and the utility of existing diagnostic measures used by speech-language pathologists remain poorly understood. In this retrospective study, we examined how the RHDBank test battery informs the identification of SN after right hemisphere brain damage (RHD) during the chronic phase of recovery.

METHOD

Data from 29 right hemisphere stroke survivors were extracted from the RHDBank, including SN tests, for which we performed laterality index scoring: a 51-item demographic survey, the Apples Test, the Indented Paragraph Test, and the clock drawing task from the Cognitive Linguistic Quick Test (CLQT). Two groups (SN+ and SN-) were identified using the Apples Test. A hierarchical cluster analysis explored CLQT performance clusters in association with SN, and group comparisons of demographic variables and test scores were conducted.

RESULTS

Ten patients were identified as having SN+ (34%) using the Apples Test. The Indented Paragraph Test and the CLQT's clock drawing test identified only two of the 20 stroke survivors with SN+. Cluster analyses showed that domain and task scores on the CLQT carried information to classify participants into SN+ and SN- in concordance with performance on the Apples Test. Participants in the SN+ cluster had moderately impaired attention and executive function skills and mildly impaired visuospatial skills.

CONCLUSIONS

The Apples Test differentiated SN in a group of chronic right hemisphere stroke survivors. Using multiple measures from the CLQT seemed to capture a greater range of problems than clock drawing and paragraph reading tests alone. Therefore, the RHDBank test battery as a whole-and in part the CLQT, Apples Test, and Indented Paragraph Test-can detect certain subtypes of SN in the chronic deficit profile after RHD and is a starting point for diagnostic integration by speech-language pathologists.

Comprehensive voxel-wise, tract-based, and network lesion mapping reveals unique architectures of right and left visuospatial neglect

Visuospatial neglect is a common, post-stroke cognitive impairment which is widely considered to be a disconnection syndrome. However, the patterns of disconnectivity associated with visuospatial neglect remain unclear. Here, we had 480 acute stroke survivors [age = 72.8 (SD = 13.3), 44.3% female, 7.5 days post-stroke (SD = 11.3)] undertake routine clinical imaging and standardised visuospatial neglect testing. The data were used to conduct voxel-wise, tract-level, and network-level lesion-mapping analyses aimed at localising the neural correlates of left and right egocentric (body-centred) and allocentric (object-centred) visuospatial neglect. Only minimal anatomical homogeneity was present between the correlates of right and left egocentric neglect across all analysis types. This finding challenges previous work suggesting that right and left visuospatial neglect are anatomically homologous, and instead suggests that egocentric neglect may involve damage to a shared, but hemispherically asymmetric attention network. By contrast, egocentric and allocentric neglect was associated with disconnectivity in a distinct but overlapping set of network edges, with both deficits related to damage across the dorsal and ventral attention networks. Critically, this finding suggests that the distinction between egocentric and allocentric neglect is unlikely to reflect a simple dichotomy between dorsal versus ventral networks dysfunction, as is commonly asserted. Taken together, the current findings provide a fresh perspective on the neural circuitry involved in regulating visuospatial attention, and provide important clues to understanding the cognitive and perceptual processes involved in this common and debilitating neuropsychological syndrome.

Rethinking Remapping: Circuit Mechanisms of Recovery after Stroke

Stroke is one of the most common causes of disability, and there are few treatments that can improve recovery after stroke. Therapeutic development has been hindered because of a lack of understanding of precisely how neural circuits are affected by stroke, and how these circuits change to mediate recovery. Indeed, some of the hypotheses for how the CNS changes to mediate recovery, including remapping, redundancy, and diaschisis, date to more than a century ago. Recent technological advances have enabled the interrogation of neural circuits with ever greater temporal and spatial resolution. These techniques are increasingly being applied across animal models of stroke and to human stroke survivors, and are shedding light on the molecular, structural, and functional changes that neural circuits undergo after stroke. Here we review these studies and highlight important mechanisms that underlie impairment and recovery after stroke. We begin by summarizing knowledge about changes in neural activity that occur in the peri-infarct cortex, specifically considering evidence for the functional remapping hypothesis of recovery. Next, we describe the importance of neural population dynamics, disruptions in these dynamics after stroke, and how allocation of neurons into spared circuits can restore functionality. On a more global scale, we then discuss how effects on long-range pathways, including interhemispheric interactions and corticospinal tract transmission, contribute to post-stroke impairments. Finally, we look forward and consider how a deeper understanding of neural circuit mechanisms of recovery may lead to novel treatments to reduce disability and improve recovery after stroke.

Prevalence, Severity and Impact of Visuospatial Neglect in Geriatric Stroke Rehabilitation, a Cross-Sectional Study

OBJECTIVES

Visuospatial neglect (VSN) is a common cognitive deficit of lateralized attention after stroke and can have a negative influence on patients' daily activities, community participation, and caregiver burden. VSN prevalence has been investigated in several mixed-age populations, but rarely in only an older population. As the population in geriatric rehabilitation (GR) is understudied and VSN may influence rehabilitation goals in GR (return home), we examined the prevalence of VSN as well as associations between VSN (severity) and population characteristics and the impact of VSN on functioning, length of stay, and discharge destination after GR.

DESIGN

Multicenter cross-sectional study.

SETTING AND PARTICIPANTS

Stroke patients admitted to GR.

METHODS

Three VSN tests (Star cancelation task, Line bisection task, and Catherine Bergego Scale) were administered in the first 2 weeks of GR admission. To examine VSN severity, a composite score was calculated based on scores of the 3 tests.

RESULTS

A total of 114 stroke patients were included [55.3% female; mean age 80.2 (SD 8.0) years]. VSN prevalence was 47.4%, in which allocentric and egocentric neglect were more prevalent than VSN during activities of daily living. Participants with VSN spent more days in GR compared to participants without VSN (median 68.5 vs 35.5 days) and had fewer home returns. In addition, VSN participants showed less mobility, lower cognitive functioning, and less independence during self-care compared to participants without VSN. Mobility, self-care, cognition, duration of rehabilitation, and home return were negatively associated with VSN severity.

CONCLUSIONS AND IMPLICATIONS

VSN is very prevalent in the GR stroke population. VSN severely hampers older people during daily activities and their rehabilitation process and, therefore, has a major personal and societal impact. Accordingly, systematic assessment of VSN in the early phase of geriatric rehabilitation with multiple VSN screening tests is recommended.

Uncovering the (un)attended: Pupil light responses index persistent biases of spatial attention in neglect

Visuospatial neglect is a frequent and disabling disorder, mostly after stroke, that presents in impaired awareness to stimuli on one side of space. Neglect causes disability and functional dependence, even long after the injury. Improving measurements of the core attentional deficit might hold the key for better understanding of the condition and development of treatment. We present a rapid, pupillometry-based method that assesses automatic biases in (covert) attention, without requiring behavioral responses. We exploit the phenomenon that pupil light responses scale with the degree of covert attention to stimuli, and thereby reveal what draws (no) attention. Participants with left-sided neglect after right-sided lesions following stroke (n = 5), participants with hemianopia/quadrantanopia following stroke (n = 11), and controls (n = 22) were presented with two vertical bars, one of which was white and one of which was black, while fixating the center. We varied which brightness was left and right, respectively across trials. In line with the hypotheses, participants with neglect demonstrated biased pupil light responses to the brightness on the right side. Participants with hemianopia showed similar biases to intact parts of the visual field, whilst controls exhibited no bias. Together, this demonstrates that the pupil light response can reveal not only visual, but also attentional deficits. Strikingly, our pupillometry-based bias estimates were not in agreement with neuropsychological paper-and-pencil assessments conducted on the same day, but were with those administered in an earlier phase post-stroke. Potentially, we pick up on persistent biases in the covert attentional system that participants increasingly compensate for in classical neuropsychological tasks and everyday life. The here proposed method may not only find clinical application, but also advance theory and aid the development of successful restoration therapies by introducing a precise, longitudinally valid, and objective measurement that might not be affected by compensation.

Profiling Daily Life Performance Recovery in the Early Subacute Phase After Stroke Using a Graphical Modeling Approach

Background Laboratory-based assessments have shown that stroke recovery is heterogeneous between patients and affected domains such as motor and language function. However, laboratory-based assessments are not ecologically valid and do not necessarily reflect patients' daily life performance. Therefore, we aimed to give an innovative view on stroke recovery by profiling daily life performance recovery across domains in patients with early subacute stroke and determine their interrelatedness, taking stroke localization into account. Methods and Results Daily life performance was observed at neurorehabilitation admission and weekly thereafter until discharge, using a scale containing 7 daily life domains. Graphical modeling was applied to investigate the conditional independence between recovery of these domains depending on stroke localization. There were 592 patients analyzed. Four clusters of interrelated domains were identified within the first 6 weeks poststroke. The first cluster included recovery in learning and applying knowledge, general tasks and demands, and domestic life. The second cluster comprised recovery in self-care and general tasks and demands. The third cluster included recovery in mobility and self-care; it incorporated interpersonal interactions and relationships in left supratentorial stroke, and learning and applying knowledge in right supratentorial stroke. The final cluster included only communication recovery. Conclusions Daily life recovery dynamics early poststroke show that although impairments in body functions are anatomically determined, their impact on performance is comparable. Second, some, but by no means all, domains show an interrelated recovery. Domains requiring cognitive abilities are especially interrelated and seem to be essential for concomitant recovery in mobility and domestic life.

Prism Adaptation Treatment for Right-Sided and Left-Sided Spatial Neglect: A Retrospective Case-Matched Study

Objective

To compare the effectiveness of prism adaptation treatment (PAT) between patients with right- and left-sided spatial neglect (SN).

Design

Retrospective case-matched design.

Setting

Inpatient rehabilitation hospitals and facilities.

Participants

A total of 118 participants were selected from a clinical dataset of 4256 patients from multiple facilities across the United States. Patients with right-sided SN (median age: 71.0 [63.5-78.5] years; 47.5% female; 84.8% stroke, 10.1% traumatic/nontraumatic brain injury) were matched 1:1 with patients with left-sided SN (median age: 70.0 [63.0-78.0] years; 49.2% female; 86.4% stroke, 11.8% traumatic/nontraumatic brain injury) based on age, neglect severity, overall functional ability at admission, and number of PAT sessions completed during their hospital stay.

Intervention

Prism adaptation treatment.

Main Outcome Measures

Primary outcomes were pre-post change on the Kessler Foundation Neglect Assessment Process (KF-NAP) and the Functional Independence Measure (FIM). Secondary outcomes were whether the minimal clinically important difference was achieved for pre-post change on the FIM.

Results

We found greater KF-NAP gain for patients with right-sided SN than those with left-sided SN (Z = 2.38, P=.018). We found no differences between patients with right-sided and left-sided SN for Total FIM gain (Z=-0.204, P=.838), Motor FIM gain (Z=-0.331, P=.741), or Cognitive FIM gain (Z=-0.191, P=.849).

Conclusions

Our findings suggest PAT is a viable treatment for patients with right-sided SN just as it is for patients with left-sided SN. Therefore, we suggest prioritizing PAT within the inpatient rehabilitation setting as a treatment to improve SN symptoms regardless of brain lesion side.

Disconnectomics to unravel the network underlying deficits of spatial exploration and attention

Spatial attention and exploration are related to a predominantly right hemispheric network structure. However, the areas of the brain involved and their exact role is still debated. Spatial neglect following right hemispheric stroke lesions has been frequently viewed as a model to study these processes in humans. Previous investigations on the anatomical basis on spatial neglect predominantly focused on focal brain damage and lesion-behaviour mapping analyses. This approach might not be suited to detect remote areas structurally spared but which might contribute to the behavioural deficit. In the present study of a sample of 203 right hemispheric stroke patients, we combined connectome lesion-symptom mapping with multivariate support vector regression to unravel the complex and disconnected network structure in spatial neglect. We delineated three central nodes that were extensively disconnected from other intrahemispheric areas, namely the right superior parietal lobule, the insula, and the temporal pole. Additionally, the analysis allocated central roles within this network to the inferior frontal gyrus (pars triangularis and opercularis), right middle temporal gyrus, right temporal pole and left and right orbitofrontal cortices, including interhemispheric disconnection. Our results suggest that these structures-although not necessarily directly damaged-might play a role within the network underlying spatial neglect in humans.

Increased scene complexity during free visual exploration reveals residual unilateral neglect in recovered stroke patients

Unilateral neglect is a common cognitive syndrome after stroke, which is defined as a spatially specific unawareness of the contralesional space. The syndrome is caused by disruptions of attentional networks in the brain, which impair the patients' ability to direct attention towards the contralesional space. During recovery, patients often learn to compensate by voluntarily directing their attention to the neglected side at the expense of cognitive resources. In this study, we examined the impact of the complexity of visual input on free visual exploration behavior of unilateral neglect and apparently recovered patients. We asked whether increasing scene complexity would allow the detection of residual unilateral neglect in recovered patients by increasing the amount of cognitive resources needed for visual processing and limiting capacities for compensation. Using virtual reality, we analyzed the spatial distribution of gaze of unilateral neglect patients, patients who had, according to conventional diagnostics, recovered from the syndrome, stroke patients with no history of unilateral neglect, and age-matched healthy controls. We manipulated the complexity of an immersive virtual scene presented on head mounted displays. We identified the orientation bias towards the ipsilesional side as a sensitive and specific marker of unilateral neglect, which was present in unilateral neglect and recovered patients but absent in stroke patients with no history of unilateral neglect and controls. Increasing scene complexity exacerbated the orientation shift in unilateral neglect patients and revealed that three out of nine (33%) recovered patients had a high probability of suffering from residual unilateral neglect as estimated by a generalized linear model using the median horizontal gaze position as a predictor.

Aligning formal and functional assessments of Visuospatial Neglect: A mixed-methods study

ABSTRACTThe occurrence of visuospatial neglect acts as a key predictor of recovery outcome following stroke. However, the specific behavioural profiles associated with various neglect subtypes are not well understood. This study aims to identify real-world functional impairments associated with neglect, to determine whether functional impairment profiles differ across patients with egocentric and allocentric neglect, and to investigate how neglect severity predicts functional impairments.Notes from 290 stroke patients' occupational therapy functional assessments were qualitatively and quantitatively analysed in the context of neglect type and severity as reported by the OCS Cancellation Task. Overall, neglect patients had more references to having difficulty initiating tasks, finding items, exhibiting spatial inattention, and having difficulty using both arms than patients without neglect. The proportion of theme references did not differ significantly across patients with egocentric and allocentric neglect. The quantitative severity of egocentric neglect was acted as a significant predictor of reference occurrence over and above stroke severity within difficulty finding items, spatial inattention, body inattention, and upper limb use.This study expands on previous findings by identifying real-world functional impairments differentiating patients with and without neglect. This data provides novel insight into the impact of neglect on functional abilities.

Right Unilateral Spatial Neglect Improves with Intrinsic Motivation

Background. In the acute phase of stroke, it is well known that the incidence and severity of unilateral spatial neglect (USN) are more significant in the right hemisphere injuries. Still, the detection of USN in left hemisphere injuries has been increasing in recent years. This trend is because behavioral assessments have prevented the exclusion of patients who are difficult to assess for USN or apathy using conventional paper-and-pencil tests (e.g., aphasia). Right USN and post-stroke apathy share many common lesions. Therefore, clinical symptoms may overlap, but little validation considers this. Case Study. A man (62 years old) determined to have the right USN and apathy was treated for six weeks in 3 terms. In the first term (weeks 1 to 2), the patient was treated for the right USN by conventional therapy. In the second term (3–4 weeks), treatment for right USN and apathy by goal-directed therapy based on affinity behavior was implemented. In the third term (5–6 weeks), goal-directed therapy based on affinity behavior was discontinued, and treatment was returned to conventional therapy only. In the second term (goal-directed therapy based on affinity behavior), the improvement in patients' apathy (clinical assessment for spontaneity) was more significant than the effect size in the third term (conventional therapy). There were no significant differences in USN (catherine bergego scale) and intrinsic motivation (pittsburgh rehabilitation participation scale). However, the effect size in the second term tended to be larger than in the third term (conventional therapy). Clinical Rehabilitation Impact. This report aims to demonstrate the limitations of current treatment for cases determined to have both right USN and apathy. Second, to assess the extent to which this new intervention can complement the limitations of current treatment.

Computer-based assessment of unilateral spatial neglect: A systematic review

Background

To date, no gold standard exists for the assessment of unilateral spatial neglect (USN), a common post-stroke cognitive impairment, with limited sensitivity provided by currently used clinical assessments. Extensive research has shown that computer-based (CB) assessment can be more sensitive, but these have not been adopted by stroke services yet.

Objective

We conducted a systematic review providing an overview of existing CB tests for USN to identify knowledge gaps and positive/negative aspects of different methods. This review also investigated the benefits and barriers of introducing CB assessment tasks to clinical settings and explored practical implications for optimizing future designs.

Methodology

We included studies that investigated the efficacy of CB neglect assessment tasks compared to conventional methods in detecting USN for adults with brain damage. Study identification was conducted through electronic database searches (e.g., Scopus), using keywords and standardized terms combinations, without date limitation (last search: 08/06/2022). Literature review and study selection were based on prespecified inclusion criteria. The quality of studies was assessed with the quality assessment of diagnostic accuracy studies tool (Quadas-2). Data synthesis included a narrative synthesis, a table summarizing the evidence, and vote counting analysis based on a direction of effect plot.

Results

A total of 28 studies met the eligibility criteria and were included in the review. According to our results, 13/28 studies explored CB versions of conventional tasks, 11/28 involved visual search tasks, and 5/28 other types of tasks. The vote counting analysis revealed that 17/28 studies found CB tasks had either equal or higher sensitivity than conventional methods and positive correlation with conventional methods (15/28 studies). Finally, 20/28 studies showed CB tasks effectively detected patients with USN within different patient groups and control groups (17/28).

Conclusions

The findings of this review provide practical implications for the implementation of CB assessment in the future, offering important information to enhance a variety of methodological issues. The study adds to our understanding of using CB tasks for USN assessment, exploring their efficacy and benefits compared to conventional methods, and considers their adoption in clinical environments.

Resting-state electroencephalography changes in poststroke patients with visuospatial neglect

Background

This study aimed to explore the electrophysiological characteristics of resting-state electroencephalography (rsEEG) in patients with visuospatial neglect (VSN) after stroke.

Methods

A total of 44 first-event sub-acute strokes after right hemisphere damage (26 with VSN and 18 without VSN) were included. Besides, 18 age-matched healthy participants were used as healthy controls. The resting-state electroencephalography (EEG) of 64 electrodes was recorded to obtain the power of the spectral density of different frequency bands. The global delta/alpha ratio (DAR), DAR over the affected hemispheres (DAR_AH), DAR over the unaffected hemispheres (DAR_UH), and the pairwise-derived brain symmetry index (pdBSI; global and four bands) were compared between groups and receiver operating characteristic (ROC) curve analysis was conducted. The Barthel index (BI), Fugl-Meyer motor function assessment (FMA), and Berg balance scale (BBS) were used to assess the functional state of patients. Visuospatial neglect was assessed using a battery of standardized tests.

Results

We found that patients with VSN performed poorly compared with those without VSN. Analysis of rsEEG revealed increased delta and theta power and decreased alpha and beta power in stroke patients with VSN. Compared to healthy controls and poststroke non-VSN patients, patients with VSN showed a higher DAR (P < 0.001), which was significantly positively correlated with the BBS (DAR: r = –0.522, P = 0.006; DAR_AH: r = –0.521, P = 0.006; DAR_UH: r = –0.494, P = 0.01). The line bisection task was positively correlated with DAR (r = 0.458, P = 0.019) and DAR_AH (r = 0.483, P = 0.012), while the star cancellation task was only positively correlated with DAR_AH (r = 0.428, P = 0.029). DAR_AH had the best discriminating value between VSN and non-VSN, with an area under the curve (AUC) of 0.865. Patients with VSN showed decreased alpha power in the parietal and occipital areas of the right hemisphere. A higher parieto-occipital pdBSI_alpha was associated with a worse line bisection task (r = 0.442, P = 0.024).

Conclusion

rsEEG may be a useful tool for screening for stroke patients with visuospatial neglect, and DAR and parieto-occipital pdBSI_alpha may be useful biomarkers for visuospatial neglect after stroke.

Impacts of Prism Adaptation Treatment on Spatial Neglect and Rehabilitation Outcome: Dosage Matters

We examined whether number of prism adaptation treatment (PAT) sessions in regular clinical practice would predict spatial neglect (SN) improvement and rehabilitation outcomes. We reviewed clinical records from 16 U.S. rehabilitation hospitals where neurological patients were assessed for SN using the Catherine Bergego Scale (CBS) and if SN was detected, and may have received PAT. Multiple linear regression was used to predict CBS Change (indicating SN improvement) in 520 patients who received PAT while considering age, sex, diagnosis, time post diagnosis, CBS at baseline, neglected side of space, and length of stay. Another set of regression models including the same variables and adding Function Independent Measure (FIM®) at admission was used to predict FIM Gains (indicating rehabilitation outcomes) in 1720 patients receiving PAT or not. We found that greater number of PAT sessions predicted greater CBS Change, especially in patients with moderate-to-severe neglect. Number of PAT sessions also positively correlated with Total FIM, Motor FIM, and Cognitive FIM Gains regardless of SN severity classification at baseline. Furthermore, number of PAT sessions predicted CBS Change and FIM Gains among patients completing ≤8 PAT sessions but not among patients with ≥8 sessions, who however, showed greater CBS Change with increased PAT frequency (i.e., fewer days between two consecutive sessions). Receiving more once-daily PAT sessions predicted greater improvement in SN and rehabilitation outcomes. Receiving PAT at a higher frequency for 8 or more sessions predicted better SN improvement. Thus, dosage matters. The study provides practice-based evidence that PAT is appropriate for inpatient rehabilitation.

Rehabilitation interventions of unilateral spatial neglect based on the functional outcome measure: A systematic review and meta-analysis

ABSTRACTThis review aimed to examine the bottom-up and top-down rehabilitation intervention effectiveness based on the functional outcome measure as immediate effect and long-term effect for unilateral spatial neglect conditions. The RCT studies were collected by searching in three databases J-Stage, PubMed, and PEDro from 2008 through 2018. The studies which used the following instruments: BI, CBS, FMA, and FIM, as the functional outcome with the PEDro score of six and above, were eligible for inclusion. A total of 492 participants in 13 studies included from 291 studies initially identified. The meta-analysis for overall ES revealed that BI and CBS had a significant mean of SMD = 0.65 (95% CI, 0.23-1.07; p = 0.003; I2 = 65%), and SMD = -0.23 (95% CI, -0.45 to -0.01; p = 0.04; I2 = 35%) respectively, while FMA and FIM had an insignificant mean of SMD = 0.14 (95% CI, -0.08-0.37; p = 0.22; I2 = 0%), and SMD = -0.22 (95% CI, -0.69-0.25; p = 0.37; I2 = 0%) respectively. Based on the results, although indicated the heterogeneity representation across studies, it showed that the top-down intervention approach of high-frequency rTMS was more effective in enhancing the functional abilities and ADL of unilateral spatial neglect patients on the immediate effects but not necessarily in the long-term effects.

The mobility assessment course: A ready-to-use dynamic measure of visuospatial neglect

The Mobility Assessment Course (MAC) is a tool to measure visuospatial neglect in a dynamic fashion. Although the MAC has been shown to dissociate between patients with and without neglect, it remains unclear whether it is applicable in clinical settings. We evaluated the MAC regarding its (1) feasibility as a diagnostic tool as part of standard care, (2) construct validity, and (3) underlying constructs and potential confounders. A consecutive sample of stroke patients admitted to inpatient rehabilitation completed the MAC, shape cancellation, line bisection, and/or Catherine Bergego Scale (CBS) as part of the standard assessment. To assess feasibility, we computed the percentage of patients who completed the MAC. Construct validity was tested by evaluating MAC performance between patients with and without neglect and controls. Finally, a regression analysis was conducted to assess underlying constructs and potential confounders of MAC performance (i.e., level of mobility and lesion side). The MAC was completed by 82% of patients (N = 182/223; of whom 145 completed all tasks). Patients with neglect performed worse on the MAC (indicating more severe neglect) compared to patients without neglect and controls. The MAC had a lower sensitivity and higher specificity than paper-and-pencil tasks and the CBS. Performance on shape cancellation, line bisection, and CBS were predictors of MAC performance. Level of mobility and lesion side did not predict MAC scores, indicating that these factors do not confound its reliability. To conclude, the MAC is an easy-to-implement tool to evaluate neglect in a dynamic manner, which can be administered in addition to conventional paper-and-pencil tasks.

Effects of visual-motor illusion in stroke hemiplegic patients with left-side personal neglect: A report of two cases

Personal neglect is the neglect of self-body space, which often occurs in patients with unilateral spatial neglect (USN), but lacks a dedicated rehabilitation. The purpose of this study was to investigate the effects of visual-motor illusion (VMI) on two-stroke hemiplegic patients with left-side personal neglect. Case 1 was a 53-year-old man diagnosed with a right lenticulostriate artery infarction. Case 2 was a 76-year-old woman diagnosed with a right middle cerebral artery infarction. USN symptoms were not observed in either patient in the desk USN assessment, but personal neglect and USN symptoms in daily life were observed in both patients. Intervention effects were verified using an ABA design, comprising a 5-day three-phase (A1, B, A2). In phase B, VMI was performed on the paralyzed upper limb for 10 min in addition to conventional physical therapy. Outcomes measures were the Fluff test, Catherine Bergego Scale (CBS), Fugl-Meyer Assessment (FMA), and Functional Independence Measure (FIM). In both patients, no improvements were noted in FMA, but improvements were observed in the Fluff test, CBS, and FIM in phase B; these effects were retained in phase A2. Therefore, VMI may have contributed to improvements in Personal neglect and USN symptoms in daily life.

Predicting home discharge after inpatient rehabilitation of stroke patients with aphasia

The early identification of the discharge setting from Inpatient Rehabilitation Facilities is a primary goal in stroke-related research because of its clinical and socio-economic relevance. Several features have been identified as significant predictors of the discharge setting. Within cognitive deficits, aphasia is known to be a common and disabling condition that could influence rehabilitation outcome. However, it is often set as an exclusion criterion in stroke research. This study aims to investigate the predictive power of clinical variables, in particular specific language disturbances and nonlinguistic cognitive deficits, for discharge setting in post-acute stroke patients with aphasia after intensive multidisciplinary rehabilitation. In a sample of 158 patients, demographic, motor, language, and nonverbal cognitive data were retrospectively considered for the prediction of the discharge to home vs. another institutional setting. Univariate analysis identified relevant differences between groups and the significant variables were included in a logistic regression model. The results showed that better functional motor status, absence of dysphagia and unimpaired nonlinguistic cognitive profile independently predict the discharge to home. In particular, nonverbal cognitive functioning seemed to be specifically relevant within the aphasic population. The findings could be helpful for setting up the rehabilitation priorities and an adequate discharge arrangement.

Multiverse to inform neurological research: an example using recovery outcome of neglect

OBJECTIVE

Multiverse analysis provides an ideal tool for understanding how inherent, yet ultimately arbitrary methodological choices impact the conclusions of individual studies. With this investigation, we aimed to demonstrate the utility of multiverse analysis for evaluating generalisability and identifying potential sources of bias within studies employing neurological populations.

METHODS

Multiverse analysis was used to evaluate the robustness of the relationship between post-stroke visuospatial neglect and poor long-term recovery outcome within a sample of 1113 (age = 72.5, 45.1% female) stroke survivors. A total of 25,600 t-test comparisons were run across 400 different patient groups defined using various combinations of valid inclusion criteria based on lesion location, stroke type, assessment time, neglect impairment definition, and scoring criteria across 16 standardised outcome measures.

RESULTS

Overall, 33.9% of conducted comparisons yielded significant results. 99.9% of these significant results fell below the null specification curve, indicating a highly robust relationship between neglect and poor recovery outcome. However, the strength of this effect was not constant across all comparison groups. Comparisons which included < 100 participants, pre-selected patients based on lesion type, or failed to account for allocentric neglect impairment were found to yield average effect sizes which differed substantially. Similarly, average effect sizes differed across various outcome measures with the strongest average effect in comparisons involving an activities of daily living measure and the weakest in comparisons employing a depression subscale.

CONCLUSIONS

This investigation demonstrates the utility of multiverse analysis techniques for evaluating effect robustness and identifying potential sources of bias within neurological research.

Right and left neglect are not anatomically homologous: A voxel-lesion symptom mapping study

Visuospatial neglect is a heterogenous syndrome which can occur following damage to either right or left hemisphere areas. This study employs voxel-lesion symptom mapping to identify the neural correlates of left and right egocentric and allocentric neglect in a large acute stroke cohort. A cohort of 446 acute stroke survivors (age = 26-95, 44% female) completed neuropsychological neglect assessment and routine clinical imaging. Similar to previous investigations, left egocentric and left allocentric neglect were associated with damage to distinct clusters of voxels within the posterior parietal and temporo-parietal junction areas. Unlike previous investigations, right egocentric neglect was found to most strongly associated with damage to more posterior voxels within left occipital cortical areas. Right allocentric neglect was found to be most strongly associated with damage to the anterior limb of the left internal capsule. Interestingly, the right hemisphere homologues of the areas implicated in right-lateralised neglect were not overlapping with those associated with left neglect impairment. This dissociation was present across both egocentric and allocentric neglect impairment. The results of this investigation suggest that right egocentric/allocentric neglect should not be characterised as a consequence of damage to left-hemisphere homologues of the right hemisphere attentional systems. These findings support the characterisation of visuospatial neglect as a heterogenous cluster of impairments rather than a unitary syndrome and provide novel insight into the neural correlates of spatial attention.

From competition to cooperation: Visual neglect across the hemispheres

Visuospatial neglect is a frequent and disabling consequence of injuries to the right hemisphere. Patients with neglect show signs of impaired attention for left-sided events, which depends on dysfunction of fronto-parietal networks. After unilateral injury, such as stroke, these networks and their contralateral homologs can reorganize following multiple potential trajectories, which can be either adaptive or maladaptive. This article presents possible factors influencing the profile of evolution of neglect towards recovery or chronicity, and highlights potential mechanisms that may constrain these processes in time and space. The integrity of white matter pathways within and between the hemisphere appears to pose crucial connectivity constraints for compensatory brain plasticity from remote brain regions. Specifically, the availability of a sufficient degree of inter-hemispheric connectivity might be critical to shift the role of the undamaged left hemisphere in spatial neglect, from exerting maladaptive effects, to promoting compensatory activity.

Recovery of Visuospatial Neglect Subtypes and Relationship to Functional Outcome Six Months After Stroke

Background/Objective. This study aims to investigate how complex visuospatial neglect behavioural phenotypes predict long-term outcomes, both in terms of neglect recovery and broader functional outcomes after 6 months post-stroke. Methods. This study presents a secondary cohort study of acute and 6-month follow-up data from 400 stroke survivors who completed the Oxford Cognitive Screen's Cancellation Task. At follow-up, patients also completed the Stroke Impact Scale questionnaire. These data were analysed to identify whether any specific combination of neglect symptoms is more likely to result in long-lasting neglect or higher levels of functional impairment, therefore warranting more targeted rehabilitation. Results. Overall, 98/142 (69%) neglect cases recovered by follow-up, and there was no significant difference in the persistence of egocentric/allocentric (X2 [1] = .66 and P = .418) or left/right neglect (X2 [2] = .781 and P = .677). Egocentric neglect was found to follow a proportional recovery pattern with all patients demonstrating a similar level of improvement over time. Conversely, allocentric neglect followed a non-proportional recovery pattern with chronic neglect patients exhibiting a slower rate of improvement than those who recovered. A multiple regression analysis revealed that the initial severity of acute allocentric, but not egocentric, neglect impairment acted as a significant predictor of poor long-term functional outcomes (F [9,300] = 4.742, P < .001 and adjusted R2 = .098). Conclusions. Our findings call for systematic neuropsychological assessment of both egocentric and allocentric neglect following stroke, as the occurrence and severity of these conditions may help predict recovery outcomes over and above stroke severity alone.

Visual field improvement in neglect after virtual reality intervention: a single-case study

A patient suffering from visuo-spatial neglect was investigated as a special interest case during a study on the effectiveness of "restorative approaches" after visual field loss. This patient trained with our newly developed Virtual Reality (VR) system "Salzburg Visual Field Trainer" for 254 days. Perimetric results show a visual field expansion of 48.8% (left eye) and 36.8% (right eye) translating to an improvement of approximately 5.5° to 10.5° of visual angle. Further, subjective self-report shows improvements of up to 317% in visual field functionality. Our results indicate that patients suffering from visuo-spatial neglect could benefit from a VR-based restorative intervention.

How We Assess Spatial Neglect Matters: Prevalence of Spatial Neglect as Measured by the Catherine Bergego Scale and Impact on Rehabilitation Outcomes

OBJECTIVE

The aim of this study was to determine the prevalence and functional impact of unilateral spatial neglect on right hemisphere stroke patients in an inpatient rehabilitation facility using a multidimensional, functionally based behavioral measure (Catherine Bergego Scale [CBS]).

DESIGN

This was a retrospective cohort study of 742 consecutive admissions of patients with right hemispheric stroke to an inpatient rehabilitation facility. Spatial neglect was assessed using the CBS. Functional impact of neglect was measured by hospital length of stay, Functional Independence Measure change per day, discharge destination, and number of falls.

RESULTS

As measured by the CBS, 86% of the right hemisphere stroke patients had symptoms of spatial neglect. Moderate and severe neglect was associated with less Functional Independence Measure change per day and lower rates of community discharge. The presence of neglect was not significantly associated with fall rate or length of hospital stay after controlling for admission Functional Independence Measure scores and age. The "difficulty looking left" CBS item had the strongest relationship with total CBS scores and effectively predicted Functional Independence Measure change per day and discharge destination.

CONCLUSIONS

Using a sensitive measure, the CBS, rates of spatial neglect are extremely high in right hemisphere stroke patients entering inpatient rehabilitation. Both identification and determination of neglect severity are extremely important given their significant relationship to rehabilitation outcomes and discharge destinations.

TO CLAIM CME CREDITS

Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME.

CME OBJECTIVES

Upon completion of this article, the reader should be able to (1) describe why carefully assessing spatial neglect in right hemisphere stroke patients is important; (2) identify multiple dimensions of spatial neglect assessed by the Catherine Bergego Scale and how this approach differs from traditional paper and pencil assessment methods; and (3) describe the relationship between spatial neglect as measured by the Catherine Bergego Scale and functional outcomes of right hemisphere stroke patients in inpatient rehabilitation settings.

LEVEL

Advanced.

ACCREDITATION

The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Barriers and Facilitators to Rehabilitation Care of Individuals With Spatial Neglect: A Qualitative Study of Professional Views

Objective

To identify barriers and facilitators to achieving optimal inpatient rehabilitation outcome among individuals with spatial neglect (SN).

Design

Cross-sectional, semistructured focus group discussions.

Setting

Rehabilitation hospitals.

Participants

A total of 15 occupational therapists and 14 physical therapists treating patients with SN on 3 campuses of a rehabilitation hospital system (N=29). Six focus group sessions were conducted and audio-recorded for transcription.

Interventions

Not applicable.

Main Outcome Measures

Not applicable.

Results

Participants identified several patient-related characteristics that posed barriers to treatment, including the symptoms of SN itself, cognitive issues, physical weakness, comorbidities, and reduced therapy engagement. Supportive family members were considered a key facilitator, but lack of preparedness to assume caregiving roles, poor understanding of SN and rehabilitation goals, and inadequate levels of involvement were family-related barriers to successful treatment. Participants expressed that having resources and technologies available at their center to support SN treatment facilitated positive outcomes and perceived limited staff knowledge and skills and poor interclinician communication as barriers to treatment. At the health care system level, barriers included a lack of responsive measures of SN progress and insurer-related issues. Strong continuity of care between transitions was considered an important factor for enabling effective treatment.

Conclusions

Barriers and facilitators to the current practice of SN care were identified from occupational and physical therapists’ point of view. Opportunities exist to promote identified facilitators and minimize barriers to improve SN rehabilitation. The present study makes a unique contribution in identifying specific needs for innovative interventions that involve family support and training, promotion of interdisciplinary collaboration, development of interprofessional vocabulary, and continuous treatment and follow-up assessment for SN through care transitions.

Editorial for special issue on neglect rehabilitation

It is clear already that in current and future years more people will suffer from stroke, whether related to COVID-19 or not, and given its prevalence, many more people's lives will be affected by neglect. Here we hope to have contributed to its possible amelioration with highlights of the latest thinking on neglect diagnosis, prevalence and treatment.

Visual and motor neglect: Clinical and neurocognitive aspects

Attention allows us to prioritize the processing of external information according to our goals, but also to cope with sudden, unforeseen events. Attention processes rely on the coordinated activity of large-scale brain networks. At the cortical level, these systems are mainly organized in fronto-parietal networks, with functional and anatomical asymmetries in favor of the right hemisphere. Dysfunction of these right-lateralized networks often produce severe deficit of spatial attention, such as visual neglect. Other brain-damaged patients avoid moving the limbs contralateral to their brain lesion, even in the absence of sensorimotor deficits (motor neglect). This paper first summarizes past and current evidence on brain networks of attention; then, it presents clinical and experimental findings on visual and motor neglect, and on the possible mechanisms of clinical recovery.

Prevalence of spatial neglect post-stroke: A systematic review

OBJECTIVE

Spatial neglect (SN) impedes stroke rehabilitation progress, slows functional recovery, and increases caregiver stress and burden. The estimation of SN prevalence varies widely across studies.

BACKGROUND

We aimed to establish the prevalence of SN based on the injured cerebral hemisphere, recovery stage post-stroke, and diagnostic methodology.

MATERIALS AND METHODS

All journal articles published up to February 27, 2019 from CINAHL, PsycINFO, PubMed and Web of Science were searched. We selected original research articles that described observational studies, included both individuals with left brain damage (LBD) and those with right brain damage (RBD) post-stroke, and reported specific diagnostic methods for SN. All authors reached consensus for the final selection of 41 articles. Time post-stroke, patient selection criteria, study setting, SN diagnostic methods were extracted.

RESULTS

A total of 6324 participants were included: 3411 (54%) with RBD and 2913 (46%) with LBD. Without considering time post-stroke or diagnostic methods, the occurrence rate of SN was 29% (38% after RBD and 18% after LBD). Using ecological assessments resulted in higher prevalence than using tests not directly related to daily life activities (53% vs. 24%). Using methods based on a single-cutoff criterion led to lower occurrence of SN than using multi-test methods (27% vs. 33%). The prevalence decreased from the acute to chronic stage post-stroke.

CONCLUSIONS

The estimated prevalence of SN after unilateral stroke is 30%. SN is more common after RBD than after LBD, but SN after LBD is still quite common. Using ecological assessments and multi-test methods to detect SN is preferred to using a single-cutoff criterion of a test that is not directly related to daily function. The decrease in SN prevalence over time is evident, but the exact prevalence in later stages cannot be estimated. More research is needed to better understand chronic SN.

How does the number of targets affect visual search performance in visuospatial neglect?

INTRODUCTION

Impairments in visual search are a common symptom in visuospatial neglect (VSN). The severity of the lateralized attention bias in visual search tasks can vary depending on the number of distractors: the more distractors, the more targets are missed. However, little is known about how the number of targets affect search performance in VSN. The aim of the current study was to examine the effect of the number of targets on hit rate in VSN.

METHODS

We included 23 stroke patients with right-brain damage and VSN, 55 with right-brain damage without VSN, and 49 with left-brain damage without VSN, all admitted for inpatient rehabilitation. In a visual search task, patients had to find and tap targets, presented along with non-targets. The location and number of targets varied from trial to trial, allowing the evaluation of the effects of number and location of targets on hit rate.

RESULTS

VSN patients detected a lower percentage of targets when more targets were present. For patients with right-brain damage without VSN, adding targets only reduced the hit rate of the most contralesional target. No effect of number of targets on hit rate was seen in patients with left-brain damage. Additionally, VSN patients found less contralesional targets than ipsilesional targets, made more delayed revisits, and had an initial rightward bias when compared to the other groups. There were no differences in search time, search consistency, or immediate revisits between groups. There was a moderate positive relation between the hit rate asymmetry score in our search task and conventional paper-and-pencil VSN tasks, and neglect behavior in daily life.

CONCLUSIONS

In VSN patients, a higher number of targets reduces the hit rate. The reduced hit rate in visual search evoked by additional targets should be taken into account when assessing visual search in VSN.

Non-Spatial Impairments Affect False-Positive Neglect Diagnosis Based on Cancellation Tasks

OBJECTIVE

To diagnose egocentric neglect after stroke, the spatial bias of performance on cancellation tasks is typically compared to a single cutoff. This standard procedure relies on the assumption that the measurement error of cancellation performance does not depend on non-spatial impairments affecting the total number of cancelled targets. Here we assessed the impact of this assumption on false-positive diagnoses.

METHOD

We estimated false positives by simulating cancellation data using a binomial model. Performance was summarised by the difference in left and right cancelled targets (R-L) and the Centre of Cancellation (CoC). Diagnosis was based on a fixed cutoff versus cutoffs adjusted for the total number of cancelled targets and on single test performance versus unanimous or proportional agreement across multiple tests. Finally, we compared the simulation findings to empirical cancellation data acquired from 651 stroke patients.

RESULTS

Using a fixed cutoff, the rate of false positives depended on the total number of cancelled targets and ranged from 10% to 30% for R-L scores and from 10% to 90% for CoC scores. The rate of false positives increased even further when diagnosis was based on proportional agreement across multiple tests. Adjusted cutoffs and unanimous agreement across multiple tests were effective at controlling false positives. For empirical data, fixed versus adjusted cutoffs differ in estimation of neglect prevalence by 13%, and this difference was largest for patients with non-spatial impairments.

CONCLUSIONS

Our findings demonstrate the importance of considering non-spatial impairments when diagnosing neglect based on cancellation performance.

Number Processing Error as a Clinical Manifestation of Hemispatial Neglect Following Hypoxic Brain Injury: a Case Report

Hemispatial neglect is a symptom where patients do not show response to stimuli on the contralesional side of their brain lesion. Although it is most common in the context of hemispheric stroke, several pathological processes including neurodegenerative disease, neoplasia, and trauma may cause this. Prevalence of hemispatial neglect is unknown and rarely reported among patients with hypoxic brain injury. Also, hemispatial neglect accompanying neglect dyslexia is rather hard to be recognized and symptoms involving numbers are exceptionally rare. We report a patient with hypoxic brain injury following cardiac arrest who showed signs of neglect dyslexia for numbers that provided a primary clue for the diagnosis of left hemispatial neglect. Early detection of different forms of cognitive dysfunction of hypoxic brain injury is highly essential in providing early neurorehabilitation for better prognosis.

Keeping an eye on visual search patterns in visuospatial neglect: A systematic review

Patients with visuospatial neglect exhibit a failure to detect, respond, or orient towards information located in the side of space opposite to their brain lesion. To extend our understanding of the underlying cognitive processes involved in neglect, some studies have used eye movement measurements to complement behavioural data. We provide a qualitative synthesis of studies that have used eye-tracking in patients with neglect, with a focus on highlighting the utility of examining eye movements and reporting what eye-tracking has revealed about visual search patterns in these patients. This systematic review includes twenty studies that met the eligibility criteria. We extracted information pertaining to patient characteristics (e.g., age, type of stroke, time since stroke), neglect test(s) used, type of stimuli (e.g., static, dynamic), eye-tracker specifications (e.g., temporal and spatial resolution), and eye movement measurements (e.g., saccade amplitude, fixation duration). Five key themes were identified. First, eye-tracking is a useful tool to complement pen-and-paper neglect tests. Second, the lateral asymmetrical bias in eye movement patterns observed during active exploration also occurred while at rest. Third, the lateral asymmetrical bias was evident not only in the horizontal plane but also in the vertical plane. Fourth, eye movement patterns were modulated by stimulus- and task-related factors (e.g., visual salience, local perceptual features, image content, stimulus duration, presence of distractors). Fifth, measuring eye movements in patients with neglect is useful for determining and understanding other cognitive impairments, such as spatial working memory. To develop a fuller, and a more accurate, picture of neglect, future research would benefit from eye movement measurements.

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

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.

Numeric input operation on electronic devices among individuals with visuospatial working memory impairment

ABSTRACTIn human-computer interactions, higher-level visuospatial function is likely needed to effectively use the interface. The aim of this study is to clarify whether individuals with visuospatial defects can use electronic devices effectively. We quantitatively and qualitatively analyzed the ability of seven individuals with Bálint syndrome and seven individuals with left-unilateral spatial neglect (USN) to input a digit sequence into a flat touch interface. Control groups consisted of seven individuals with memory deficits and 11 healthy individuals. Participants with Bálint syndrome took longer and had more hesitations than the USN group and the two control groups to input numerical sequences (Steel-Dwass test, p < .01). In addition, participants with Bálint syndrome had a high percentage of hesitations for exploration of the button array on the interface relative to USN and the memory deficit group (Fisher's exact test, p < .05). Regarding neuropsychological data, participants with Bálint syndrome had a lower score for visuospatial working memory than participants with USN and the memory deficits control group (Steel-Dwass test, p < .01). The results shed some light on the relation between visuospatial working memory deficits and the spatial perception of interface layouts and spatial control during electronic device operation.

The Visual Scanning Test: a newly developed neuropsychological tool to assess and target rehabilitation of extrapersonal visual unilateral spatial neglect

PURPOSE

Visual unilateral spatial neglect (VUSN) is a neuropsychological condition commonly experienced after stroke whereby patients are unable to attend to stimuli on the controlesional side of their space. VUSN can occur in the personal, peripersonal, and/or extrapersonal portion of patient's space. Traditional paper-and-pencil neuropsychological tests are widely used to evaluate VUSN, but they assess peripersonal VUSN. Instead, personal and extrapersonal neglect are less easily evaluated. The aim of this study was to present normative values for the Visual Scanning Test (VST), a new neuropsychological tool to quantitatively assess the extrapersonal VUSN.

METHODS

Eighty-six healthy subjects took part in the study (61 female), with a mean age of 52.8 years (SD = 17.0) and a mean of 14.0 years of education (SD = 5.2). The VST involved a visual search for a target between similar visual distractors, projected in the far space. The test was administered twice to each participant, with an interval of 2 weeks. From the recorded data, it was possible to obtain indexes related to the reaction times and to the accuracy of the performance on the VST.

RESULTS

Multiple linear regression analysis revealed that age and education significantly influenced VST-derived indexes. From the regression analysis, a correction grid for raw scores was built. Adjusted scores were then ranked, and by means of a non-parametric procedure, tolerance limits (both outer and inner one-sided) were defined.

CONCLUSIONS

The present study provided normative data for the VST in an Italian population useful for both clinical and research purposes.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03931798.

Improved Accuracy on Lateralized Spatial Judgments in Healthy Aging

OBJECTIVES

Healthy young adults often demonstrate a leftward spatial bias called "pseudoneglect" which often diminishes with aging. One hypothesis for this phenomenon is an age-related deterioration in right hemisphere functions (right hemi-aging). If true, then a greater rightward bias should be evident on all spatial attention tasks regardless of content. Another hypothesis is a decrease in asymmetrical hemispheric activation with age (HAROLD). If true, older participants may show reduced bias in all spatial tasks, regardless of leftward or rightward biasing of specific spatial content.

METHODS

Seventy right-handed healthy participants, 33 younger (21-40) and 37 older (60-78), were asked to bisect solid and character-letter lines as well as to perform left and right trisections of solid lines.

RESULTS

Both groups deviated toward the left on solid line bisections and left trisections. Both groups deviated toward the right on right trisections and character line bisections. In all tasks, the older participants were more accurate than the younger participants.

CONCLUSIONS

The finding that older participants were more accurate than younger participants across all bisection and trisection conditions suggests a decrease in the asymmetrical hemispheric activation of these specialized networks important in the allocation of contralateral spatial attention or spatial action intention.

Does stroke laterality predict major depression and cognitive impairment after stroke? Two-year prospective evaluation in the EMMA study

Depression and cognitive impairment are common conditions following stroke. We aimed to evaluate stroke laterality as predictor of post-stroke depression (PSD) and cognitive impairment (PCI) in a stroke cohort. Major depression (Patient Health Questionnaire-9, score ≥ 10) and cognitive impairment (Modified Telephone Interview for Cognitive Status, score < 14) were evaluated at 6 months and yearly up to 2 years. Survival analyses were performed by Kaplan-Meier curves and Cox logistic regression models, adjusted for potential confounders (cumulative hazard ratio, HR; 95% confidence interval, CI), for the likelihood of subsequent PSD or PCI progression at 6 months and 2 years, according to stroke laterality (right hemisphere-reference). Among 100 stroke patients, we found 19% had PSD and 38% had PCI 2 years after stroke. Most participants (53%) presented right-sided stroke. However, right-sided stroke was not associated with PSD or PCI. Overall, left-sided stroke was an independent and long-term predictor of PCI, but not of major depression. Left-sided stroke was associated with a high probability of PCI (42.6% and 53.2%, respectively at 6 months and 2 years, p-log-rank: 0.002). The HR of PCI due to left-sided stroke was 3.25 (95%CI, 1.30-8.12) at 6 months and remained almost the same at 2 years (HR,3.22;95%CI, 1.43-7.28). The risk of having worse cognition status increased by >3 times, 2 years after stroke. The results support the hypothesis that involvement of networks in the left, but not in the right hemisphere, contribute to long-term cognitive impairment. Lesion laterality did not influence the risk of PSD.

Using machine learning-based lesion behavior mapping to identify anatomical networks of cognitive dysfunction: Spatial neglect and attention

Previous lesion behavior studies primarily used univariate lesion behavior mapping techniques to map the anatomical basis of spatial neglect after right brain damage. These studies led to inconsistent results and lively controversies. Given these inconsistencies, the idea of a wide-spread network that might underlie spatial orientation and neglect has been pushed forward. In such case, univariate lesion behavior mapping methods might have been inherently limited in detecting the presumed network due to limited statistical power. By comparing various univariate analyses with multivariate lesion-mapping based on support vector regression, we aimed to validate the network hypothesis directly in a large sample of 203 newly recruited right brain damaged patients. If the exact same correction factors and parameter combinations (FDR correction and dTLVC for lesion size control) were used, both univariate as well as multivariate approaches uncovered the same complex network pattern underlying spatial neglect. At the cortical level, lesion location dominantly affected the temporal cortex and its borders into inferior parietal and occipital cortices. Beyond, frontal and subcortical gray matter regions as well as white matter tracts connecting these regions were affected. Our findings underline the importance of a right network in spatial exploration and attention and specifically in the emergence of the core symptoms of spatial neglect.

Impact of visuospatial neglect post-stroke on daily activities, participation and informal caregiver burden: A systematic review

OBJECTIVES

Visuospatial neglect (VSN) is a common cognitive disorder after stroke. The primary aim of this systematic review was to provide an overview of the impact of VSN in 3 aspects: (1) activities of daily living (ADL), (2) participation, and (3) caregiver burden. The second aim was to investigate the differences in studies focusing on populations with mean age<65 versus≥65 years.

METHODS

PubMed, EMBASE, Web of Science, Cochrane Library, Emcare, PsychINFO, Academic Search Premier and CENTRAL were searched systematically. Quality was assessed with the Mixed Methods Appraisal Tool.

RESULTS

Of the 115 included studies, 104 provided outcomes on ADL, 15 on participation (4 studies with mean age≥65), and 2 on caregiver burden (1 study with mean age≥65). Quality assessment yielded scores ranging from 0 to 100%. VSN had a negative impact on ADL (i.e., independence during ADL and performance in self-care, household tasks, reading, writing, walking, wheelchair navigation) and participation (i.e., driving, community mobility, orientation, work). The impact of VSN on fulfilling social roles was unclear. VSN had a negative effect on caregiver burden. We found no clear age-related differences.

CONCLUSIONS AND IMPLICATIONS

VSN has a negative impact not only on patients' independence but particularly on the performance of ADL. Despite the far fewer studies of VSN as compared with ADL, VSN also seems to hamper participation and increase caregiver burden, but further research is needed. Because of the large impact, VSN should be systematically and carefully assessed during rehabilitation. A considerable number of different instruments were used to diagnose VSN. Diagnosing VSN at more than one level [function (i.e., pen-and-paper test), activities, and participation] is strongly recommended. Consensus is needed on how to assess VSN and its negative impact for research and rehabilitation practice.

SYSTEMATIC REVIEW REGISTRATION NO

PROSPERPO Registration No. CRD42018087483.