Visual neglect as a predictor of functional outcome one year after stroke

A systematic review of vestibular stimulation in post-stroke visual neglect

Unilateral visual neglect is a condition that negatively impacts the lives of many stroke survivors. Studies have investigated different forms of vestibular stimulation as a potential therapy, but evidence is yet to be systematically reviewed. We therefore reviewed the effects of vestibular stimulation on outcomes of neglect and activities of daily living (ADL) for people with visual neglect. We searched relevant databases up until September 2022. Eligible articles included any form of vestibular stimulation, study design, or control condition. Included participants were 18 years or older, presenting with neglect following a haemorrhagic or ischaemic stroke. Relevant outcomes were clinically validated measures of neglect and ADL. Cochrane risk of bias tools were used to assess study quality. Meta-analyses and narrative methods were used to synthesize the data. Our search returned 17 relevant studies comprising 180 participants. Meta-analyses showed no difference between galvanic vestibular stimulation and sham conditions on outcomes, whereas caloric vestibular stimulation led to improvement compared to pre-stimulation scores. Narrative syntheses showed mixed results. Clinical and methodological heterogeneity was found both within and between studies. Overall, results were inconsistent regarding the effects of vestibular stimulation as a treatment for neglect. Further trials are warranted but require more careful methodological planning.

The Association of Personal Neglect with Motor, Activities of Daily Living, and Participation Outcomes after Stroke: A Systematic Review

Despite its potential clinical impact, the association of personal neglect (PN) with motor, activities of daily living (ADL), and participation outcomes after stroke is not well-understood. This first-ever systematic review on the topic therefore evaluates this association, taking into account suggested subtypes of PN, including body representation neglect, somatosensory neglect, motor neglect, and premotor neglect. A systematic literature search was conducted on February 17, 2023 in PubMed, Web of Science, Scopus, PubPsych, and PsycArticles databases. The study adheres to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses, and its protocol was registered on PROSPERO (CRD42020187460). Eleven observational studies were included, gathering 1,400 individuals after stroke (429 showed PN). Results show that individuals with body representation neglect after stroke have significantly decreased movement control and motor strength, lower functional mobility, and ADL independency compared with those without body representation neglect after stroke. Individuals with motor neglect after stroke showed worse motor function and spasticity than to those without motor neglect after stroke. Nonspecified PN (i.e., PN evaluated with an outcome measure that does not allow subcategorization) was related to worse lateropulsion with pushing, longer length of stay and greater odds of being discharged to somewhere other than home. No study evaluated somatosensory and premotor neglect. This review highlights the limited research in this area and emphasizes the need for a more comprehensive PN assessment. However, currently available assessment tools show limited ability to accurately diagnose PN subtypes and future research should prioritize the development of comprehensive diagnostic test batteries.

Clinical and demographic predictors of unilateral spatial neglect recovery after prism therapy among stroke survivors in the sub-acute phase of recovery

BACKGROUND AND AIMS: Unilateral Spatial Neglect (USN) affects the rehabilitation process and leads to poor outcomes after stroke. Factors that influence USN recovery following prism adaptation therapy have not been investigated. This study investigated predictors of USN recovery after prism therapy at the sub-acute phase of recovery. METHODS: This study was a randomized controlled trial. USN was assessed with the Behavioural Inattention Test and Catherine Bergego scale. Seventy-four patients with USN were divided into control and intervention group (prism). The prism group used 20 dioptre prism lenses for repeated aiming for 12 sessions while the control group used neutral lenses for aiming training. Regression analysis was conducted to establish clinical and sociodemographic factors that influence USN recovery. RESULTS: Gender, age, years of education, race, employment status, handedness, type of stroke, time since stroke and site of stroke (p > 0.005) showed no significant influence on USN recovery following PA treatment. Higher Cognitive function (OR  = 1.52, CI = 1.08-2.14, p =  0.016) and group allocationng (being in the prism group) (OR = 63.10, CI =  9.70-410.59, P < 0.001) were found to significantly influence USN recovery following PA treatment session. CONCLUSIONS: A significant modulating effect on general cognitive ability was found in this study. This suggests that prism adaptation therapy's effect on neural activity and spatial neglect depends on the cognitive function of stroke survivors.Trial registration: Pan African Clinical Trial Registry identifier: PACTR201903732473573.

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.

Treating Visual Inattention in Acute Stroke Survivors Using a Therapy Scanning Wall: A Proof-of-Concept Study

Background

Visual inattention is common following right hemisphere stroke, with up to 80% of patients being affected. Visual inattention following stroke is linked to poorer outcomes. There is no clear evidence for how visual inattention should be treated in the hospital inpatient setting.

Objective

To explore the practical implications and possible benefits of using a visual scanning wall in a stroke rehabilitation unit as an assessment and treatment tool for visual inattention.

Methods

This proof-of-concept study recruited stroke survivors with visual inattention. Participants used the scanning wall for scanning training five days a week for two weeks. Assessments using the scanning wall and modified Albert's test were conducted at baseline and at day 14. Both participants and staff delivering the training were asked to complete an acceptability questionnaire.

Results

All participants demonstrated an improvement in the number of pictures identified from baseline to day 14. There was a mean improvement of 9.20 (95% CI 4.77 to 13.63) in the 14 days. This is a statistically significant improvement in the scanning wall score between baseline line and day 14 (p = 0.01). All participants and staff reported the scanning wall as acceptable to use.

Conclusion

This proof-of-concept study has demonstrated the scanning wall could be used to assess for visual inattention in extra personal space. Also, it could be beneficial and is acceptable for the treatment of visual inattention within a hospital inpatient setting for acute stroke survivors.

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.

Visual perceptual deficit screening in stroke survivors: evaluation of current practice in the United Kingdom and Republic of Ireland

PURPOSE

Visual perceptual deficits are frequently underdiagnosed in stroke survivors compared to sensory vision deficits or visual neglect. To better understand this imparity, we evaluated current practice for screening post-stroke visual perceptual deficits.

METHODS

We conducted a survey targeted at professionals working with stroke survivors involved in screening visual perceptual deficits across the United Kingdom and the Republic of Ireland.

RESULTS

Forty orthoptists and 174 occupational therapists responded to the survey. Visual perceptual deficit screening was primarily conducted by occupational therapists (94%), with 75∼100% of stroke survivors screened per month. Respondents lacked consensus on whether several common post-stroke visual deficits were perceptual or not. During the screening, respondents primarily relied on self-reports and observation (94%), while assessment batteries (58%) and screening tools were underutilised (56%) and selected inappropriately (66%). Respondents reported lack of training in visual perception screening (20%) and physical/cognitive condition of stroke survivors (19%) as extremely challenging during screening.

CONCLUSIONS

Visual perceptual deficits are screened post-stroke at a similar rate to sensory vision or visual neglect. Underdiagnosis of visual perceptual deficits may stem from both reliance on subjective and non-standardised screening approaches, and conflicting definitions of visual perception held among clinicians. We recommend increased training provision and use of brief performance-based screening tools.IMPLICATIONS FOR REHABILITATIONLack of agreement among clinicians on what constitutes as visual perceptual or sensory vision deficits may prove problematic, as precise and exact language is often required for clinical decision-making (e.g., referrals).Biases for more familiar visual (perceptual) deficits held among clinicians during the screening process may lead to other visual deficits being missed.To avoid problems being missed, clinicians should aim to use standardised assessments rather than stroke survivor self-report and observations of function when screening for visual perceptual difficulties.

Transcranial direct current stimulation in neglect rehabilitation after stroke: a systematic review

Hemispatial neglect is one of the most frequent attention disorders after stroke. The presence of neglect is associated with longer hospital stays, extended rehabilitation periods, and poorer functional recovery. Transcranial direct current stimulation (tDCS) is a new technique with promising results in neglect rehabilitation; therefore, the objective of this systematic review, performed following the PRISMA guidelines, is to evaluate the effectiveness of tDCS on neglect recovery after stroke. The search was done in MEDLINE (PubMed), Web of Science, Scopus, Cochrane Library, and BioMed Central databases. A total of 311 articles were found; only 11 met the inclusion criteria, including 152 post-stroke patients in total. Methodological quality and risk of bias were assessed for all the studies, and methodological characteristics of the studies, sample sizes, methods, main results, and other relevant data were extracted. tDCS intervention ranged from one to twenty sessions distributed in 1 day to 4 weeks, with intensity ranged from 1 to 2 mA. We found moderate evidence for the efficacy of tDCS in the rehabilitation of hemispatial neglect after a stroke, being more effective in combination with other interventions. Nonetheless, the limited number of studies and some studies' design characteristics makes it risky to draw categorical conclusions. Since scientific evidence is still scarce, further research is needed to determine the advantage of this treatment in acute, sub-acute and chronic stroke patients. Future studies should include larger samples, longer follow-ups, and broader neurophysiological assessments, with the final aim of establishing the appropriate use of tDCS as an adjuvant intervention in neurorehabilitation settings.

Research hotspots and frontiers about role of visual perception in stroke: A bibliometric study

Background

Visual perception is a dynamic process of perceiving the environment through sensory input and transforming sensory input into meaningful concepts related to environmental visual knowledge. Many studies focusing on the role of visual perception after stroke have been published in various journals. However, a bibliometric analysis in the domain of visual perception after stroke is still lacking. This study aimed to deliver a visual analysis to analyze the global trends in research on the role of visual perception after stroke in the last 10 years.

Methods

The literature was derived from the Web of Science core collection database from 2012 to 2021. The collected material was limited to English articles and reviews. CiteSpace and Microsoft Excel were used for bibliographic analysis.

Results

A total of 298 articles were included in the analysis. The annual number of publications increased from 23 to 42 in the last decade. Rehabilitation was the main research hotspot (n = 85). Journal of Physical Therapy Science published the largest number of papers (n = 14). The most influential author, institution, and country were Rowe FJ (n = 17), League of European Research Universities (n = 45), and England (n = 54), respectively. The keywords with the longest burst period are field defect, hemineglect, disorder, and quality of life.

Conclusion

This study analyzes the papers on the role of visual perception after stroke in the past 10 years and provides a new perspective for research in this field. At present, the number of articles in this field is not large and the cooperation network is not close enough. In the future, it is necessary to strengthen the cooperation among various countries, institutions, and authors. In addition, large samples and randomized controlled trials are needed to identify the potential treatments and pathophysiology for visual perceptual impairment after stroke.

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.

Current knowledge and practice of post-stroke unilateral spatial neglect rehabilitation: A cross-sectional survey of South African neurorehabilitation physiotherapists

Background

Unilateral spatial neglect (USN) affects the rehabilitation process leading to poor functional outcomes after stroke. South African physiotherapists’ level of uptake of available evidence in USN rehabilitation and the barriers they encounter are not known.

Objectives

To evaluate knowledge, current practice enablers and barriers to USN management in stroke survivors amongst physiotherapists in South Africa.

Methods

Our cross-sectional survey used a total sampling technique. Questionnaires were sent to neurorehabilitation physiotherapists in South Africa. Descriptive and inferential statistics analysed the data.

Results

The overall knowledge score of USN was 14.11 ± 5.23 of a total of 25. The knowledge was good for definitions of USN; moderate for incidences, causes, screening, diagnosis and prognosis of USN and poor for pharmacological approaches to the management of USN. A significant low positive correlation between respondents’ age (r = 0.46; p = 0.016) and years of practice as a physiotherapist (r = 0.43; p = 0.026) and knowledge of USN was found. The most frequently utilised intervention was constraint-induced movement therapy; the commonly utilised assessment tool was the comb and razor test. ‘Inadequate therapy time’ (55.56%) and ‘lack of relevant equipment for rehabilitation of USN’ (38.89%) were identified as major barriers to USN rehabilitation. Major enablers to USN rehabilitation were the ‘presence of multidisciplinary stroke team in clinical practice’ (83.35%) and ‘availability of adequate staff’ (76.47%).

Conclusion

Physiotherapists demonstrated a fair knowledge of USN although knowledge about pharmacological management of USN was modest. Current practice in post-stroke USN by South African neuro-physiotherapists follows current evidence and practice guidelines.

Clinical implication

Our study shows the level of knowledge and current practice of post-stroke USN rehabilitation. The demonstrated fair knowledge of USN may be improved through training, curriculum modifications or continuing professional development. Identified barriers to the rehabilitation of post-stroke USN can assist health policy, managers and clinicians to improve stroke-specific care.

The Effects of Right Hemisphere Brain Damage on Question-Asking in Conversation

BACKGROUND

Right hemisphere brain damage (RHD) can cause challenges with information gathering. Cognitive processes aid in implicit and explicit information gathering, yet the relationship between these processes and question-asking, the most explicit avenue of information gathering, has not been explored. The purpose of this exploratory descriptive study was to test the hypothesis that adults with RHD differ from controls in the types of questions produced during a conversational discourse task and whether observed differences are associated with cognitive limitations.

METHOD

Adults with RHD (n = 15) and controls (n = 15) participated in a 5-min "first-encounter conversation" and were assessed for attention, memory, executive functioning (EF), visuospatial skills, and language domains using the Cognitive Linguistic Quick Test (CLQT). Questions produced during the conversation were coded and tallied by type: polar (yes/no), content (wh-), or alternative (A or B) using Computerized Language Analysis programs. Groups were compared on total questions used, use of questions by type, and CLQT domain scores; associations were computed between cognitive domain scores and question types.

RESULTS

Compared with controls, adults with RHD used half as many questions overall and scored significantly lower on the attention, executive function, and visuospatial domains of the CLQT. For the RHD group, there was a significant correlation between EF scores and the production of content and polar questions.

CONCLUSIONS

The frequency of question-asking is important to understanding the communication profile in adults with RHD. Executive function, attention, and, to a lesser extent, visuospatial capabilities may contribute to question-asking behaviors in conversation in this population. The RHD Framework for Asking Questions is proposed to illustrate the potential areas of deficit in the question-asking process after RHD.

Feasibility study of immersive virtual prism adaptation therapy with depth-sensing camera using functional near-infrared spectroscopy in healthy adults

Prism Adaptation (PA) is used to alleviate spatial neglect. We combined immersive virtual reality with a depth-sensing camera to develop virtual prism adaptation therapy (VPAT), which block external visual cues and easily quantify and monitor errors than conventional PA. We conducted a feasibility study to investigate whether VPAT can induce behavioral adaptations by measuring after-effect and identifying which cortical areas were most significantly activated during VPAT using functional near-infrared spectroscopy (fNIRS). Fourteen healthy subjects participated in this study. The experiment consisted of four sequential phases (pre-VPAT, VPAT-10°, VPAT-20°, and post-VPAT). To compare the most significantly activated cortical areas during pointing in different phases against pointing during the pre-VPAT phase, we analyzed changes in oxyhemoglobin concentration using fNIRS during pointing. The pointing errors of the virtual hand deviated to the right-side during early pointing blocks in the VPAT-10° and VPAT-20° phases. There was a left-side deviation of the real hand to the target in the post-VPAT phase, demonstrating after-effect. The most significantly activated channels during pointing tasks were located in the right hemisphere, and possible corresponding cortical areas included the dorsolateral prefrontal cortex and frontal eye field. In conclusion, VPAT may induce behavioral adaptation with modulation of the dorsal attentional network.

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.

Spatial Neglect Subtypes, Definitions and Assessment Tools: A Scoping Review

Objective: The objective of this scoping review was to capture the reported definitions for the subtypes of neglect post stroke and map the range of assessment tools employed for each neglect subtype.

Methods: EMBASE, Emcare, Medline, and psychINFO were searched from database inception. Searching included all allied terms and mesh headings for stroke, spatial neglect, measurement, screening tools, psychometric properties. Two reviewers independently screened studies for inclusion. Primary studies with documented protocols of a spatial neglect tool for adults post stroke, with some aspect of validity or reliability were included. Two reviewers independently reviewed the documented protocols of each tool to determine the underlying subtypes and disagreements were resolved through discussion.

Results: There were 371 articles included with 292 tools used for the screening or diagnosis of neglect. The majority of studies (67%) included a tool that did not specify the neglect subtype being assessed, therefore an analysis of the underlying subtypes for each tool is presented.

Conclusions: There is no consistency with the terms used to refer to the syndrome of spatial neglect with over 200 different terms used within the included studies to refer to the syndrome as a whole or one of its subtypes. It is essential to unify the terminology and definition for each neglect subtype. There are hundreds of neglect tools available, however many are not able to differentiate presenting subtypes. It is important for clinicians and researchers to critically evaluate the neglect tools being used for the screening and diagnosis of neglect.

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.

FOPR test: a virtual reality-based technique to assess field of perception and field of regard in hemispatial neglect

BACKGROUND

We previously proposed a novel virtual reality-based method to assess human field of perception (FOP) and field of regard (FOR), termed the FOPR test. This study assessed the diagnostic validity of the FOPR test for hemispatial neglect (HSN).

METHODS

We included 19 stroke patients with a lesion in the right hemisphere and with HSN (HSN+SS), 22 stroke patients with a lesion in the right hemisphere and without HSN (HSN-SS), and 22 healthy controls aged 19-65 years. The success rate (SR) and response time (RT) in the FOPR test for both FOP and FOR were assessed (FOP-SR, FOR-SR, FOP-RT, and FOR-RT, respectively). Using a Bland-Altman plot, agreements between the FOPR test and conventional tests were confirmed, and the FOPR test accuracy was verified using the support vector machine (SVM). Measured values were analysed using ANOVA and Kruskall-Wallis tests for group comparison.

RESULTS

The Bland-Altman plot showed good agreement between FOPR test and conventional tests; individuals within 95% agreement limits were within the range of 94.8-100.0%. The SVM classification accuracy, using FOP and FOR variables from the left hemispace, ranged from 83.3 to 100.0% in a binary classification (HSN vs non-HSN). The FOPR test demonstrated differences in SR and RT for both FOP and FOR across the groups.

CONCLUSION

The FOPR test was valid for the HSN diagnosis and provided quantitative and intuitive information regarding visuospatial function. Furthermore, it might enhance our understanding of visuospatial function including HSN by applying the time relative component and concepts of perception and exploration, FOP and FOR.

TRIAL REGISTRATION

NCT03463122. Registered 13 March 2018, retrospectively registered.

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.

Dual-Task in Large Perceptual Space Reveals Subclinical Hemispatial Neglect

OBJECTIVE

Both clinically observable and subclinical hemispatial neglect are related to functional disability. The aim of the present study was to examine whether increasing task complexity improves sensitivity in assessment and whether it enables the identification of subclinical neglect.

METHOD

We developed and compared two computerized dual-tasks, a simpler and a more complex one, and presented them on a large, 173 × 277 cm screen. Participants in the study included 40 patients with unilateral stroke in either the left hemisphere (LH patient group, n = 20) or the right hemisphere (RH patient group, n = 20) and 20 healthy controls. In addition to the large-screen tasks, all participants underwent a comprehensive neuropsychological assessment. The Bells Test was used as a traditional paper-and-pencil cancellation test to assess neglect.

RESULTS

RH patients made significantly more left hemifield omission errors than controls in both large-screen tasks. LH patients' omissions did not differ significantly from those of the controls in either large-screen task. No significant group differences were observed in the Bells Test. All groups' reaction times were significantly slower in the more complex large-screen task compared to the simpler one. The more complex large-screen task also produced significantly slower reactions to stimuli in the left than in the right hemifield in all groups.

CONCLUSIONS

The present results suggest that dual-tasks presented on a large screen sensitively reveal subclinical neglect in stroke. New, sensitive, and ecologically valid methods are needed to evaluate subclinical neglect.

Current practice and challenges in screening for visual perception deficits after stroke: a qualitative study

PURPOSE

We document current clinical practice and needs in screening for visual perception problems after stroke to inform development of new screening tools.

MATERIALS AND METHODS

We interviewed 12 occupational therapists and 13 orthoptists. Interviews were thematically analysed using the Value Proposition Canvas, a model which establishes challenges and facilitators in what people want to achieve.

RESULTS

Participants' understanding of visual perception varied and often included sensory and cognitive deficits. Occupational therapists commonly screened for visual field deficits and hemispatial neglect, while other aspects of visual cognition were rarely assessed. A positive screening result triggered an orthoptic referral. Screening generally occurred during functional assessments and/or with in-house developed tools. Challenges to practice were: lack of time, lack of training, environmental and stroke survivor factors (e.g., aphasia), insufficient continuation of care, and test characteristics (e.g., not evidence-based). Facilitators were: quick and practical tools, experienced staff or tools with minimal training requirements, a streamlined care pathway.

CONCLUSIONS

Screening employs non-standardised assessments and rarely covers higher visual perceptual deficits. We demonstrates the need for an evidence-based visual perception screen, which should ideally be 15 min or less, be portable, and require minimal equipment. The screen should be suitable for bedside testing and aphasia-friendly.Implications for rehabilitationThere is a high demand for training on what visual perception deficits are and how to screen for them.Building local relationships between orthoptists and occupational therapists is perceived as highly beneficial for providing good vision and visual perception care for stroke survivors.Occupational therapists should be alert for visual perceptual deficits in their patients preferably through systematic screening with standardised assessments such as the shortened version of the Rivermead Perceptual Assessment Battery or Occupational Therapy Adult Perceptual Screening Test.

Relationship Between Line Bisection Test Time and Hemispatial Neglect Prognosis in Patients With Stroke: A Prospective Pilot Study

Objective

To determine the relationship between line bisection test (LBT) performance time and prognosis of hemispatial neglect (HSN) in stroke patients.

Methods

Data on stroke patients with HSN were prospectively collected. After patient recruitment and eligibility screening, the LBT, Motor-Free Visual Perception Test 3rd edition, and Korean version of Mini-Mental State Examination were performed at the time of admission and 4 weeks thereafter. The LBT performance time was also measured. All patients received conventional rehabilitation for 4 weeks. Based on the improvements in their LBT grades, the patients were divided into improved and non-improved groups. The evaluation results of the two groups were compared using Mann–Whitney U-tests and logistic regression was performed to predict the independence of each outcome.

Results

In total, 26 stroke patients with HSN were included, with 13 patients in each group. Significant differences were observed in the baseline LBT performance times between the improved and non-improved groups (p<0.05). Logistic regression analysis revealed associations between HSN prognosis, and baseline LBT performance time (odds ratio=0.95; 95% confidence interval, 0.90–1.00; p<0.05) and baseline Motor-Free Visual Perception Test 3rd edition (odds ratio=1.20; 95% confidence interval, 1.01–1.43; p<0.05).

Conclusion

A significant relationship was observed between the baseline LBT performance time and HSN 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.

The ventral attention network: the mirror of the language network in the right brain hemisphere

Resting-state functional MRI (RfMRI) analyses have identified two anatomically separable fronto-parietal attention networks in the human brain: a bilateral dorsal attention network and a right-lateralised ventral attention network (VAN). The VAN has been implicated in visuospatial cognition and, thus, potentially in the unilateral spatial neglect associated with right hemisphere lesions. Its parietal, frontal and temporal endpoints are thought to be structurally supported by undefined white matter tracts. We investigated the white matter tract connecting the VAN. We used three approaches to study the structural anatomy of the VAN: (a) independent component analysis on RfMRI (50 subjects), defining the endpoints of the VAN, (b) tractography in the same 50 healthy volunteers, with regions of interest defined by the MNI coordinates of cortical areas involved in the VAN used in a seed-based approach and (c) dissection, by Klingler's method, of 20 right hemispheres, for ex vivo studies of the fibre tracts connecting VAN endpoints. The VAN includes the temporoparietal junction and the ventral frontal cortex. The endpoints of the superior longitudinal fasciculus in its third portion (SLF III) and the arcuate fasciculus (AF) overlap with the VAN endpoints. The SLF III connects the supramarginal gyrus to the ventral portion of the precentral gyrus and the pars opercularis. The AF connects the middle and inferior temporal gyrus and the middle and inferior frontal gyrus. We reconstructed the structural connectivity of the VAN and considered it in the context if the pathophysiology of unilateral neglect and right hemisphere awake brain surgery.

Multisensory stimulation for the rehabilitation of unilateral spatial neglect

Unilateral spatial neglect (USN) is a neuropsychological syndrome, typically caused by lesions of the right hemisphere, whose features are the defective report of events occurring in the left (contralesional) side of space and the inability to orient and set up actions leftwards. Multisensory integration mechanisms, largely spared in USN patients, may temporally modulate spatial orienting. In this pilot study, the effects of an intensive audio-visual Multisensory Stimulation (MS) on USN were assessed, and compared with those of a treatment that ameliorates USN, Prismatic Adaptation (PA). Twenty USN stroke patients received a 2-week treatment (20 sessions, twice per day) of MS or PA. The effects of MS and PA were assessed by a set of neuropsychological clinical tests (target cancellation, line bisection, sentence reading, personal neglect, complex drawing) and the Catherine Bergego Scale for functional disability. Results showed that MS brought about an amelioration of USN deficits overall comparable to that induced by PA; personal neglect was improved only by MS, not by PA. The clinical gains of the MS treatment were not influenced by duration of disease and lesion volume, and they persisted up to one month post-treatment. In conclusion, MS represents a novel and promising rehabilitation procedure for USN.

A Meta-Analysis of Neuropsychological Predictors of Outcome Following Stroke and Other Non-Traumatic Acquired Brain Injuries in Adults

A number of cognitive abilities have been reported to predict outcome following a non-traumatic acquired brain injury (ABI) in adults. However, the results are inconsistent. Furthermore, the unique and combined capacity of these cognitive abilities to predict ABI outcome has not been evaluated. Consequently, we employed meta-analysis and multiple regression to evaluate the capacity of various neuropsychological domains to predict two separate outcome variables in adults: (1) activities of daily living; and (2) quality of life. Based on the activities of daily living meta-analysis (N = 2384), we estimated the following significant bivariate effects: memory (r = .31, 95% CI: .20/.41]), language (r = .33, 95% CI:.26/.40), attention (r = .38, 95% CI: .30/.46]), executive functions (r = .29, 95% CI: .19/.39]), and visuospatial abilities (r = .41, 95% CI: .34/ .48). Based on the quality of life meta-analysis (N = 1037), we estimated the following significant bivariate effects: memory (r = .12, 95% CI: .03/.20]), language (r = .19, 95% CI: .06/ .32), attention (r = .30, 95% CI: .16/.44]), executive functions (r = .24, 95% CI: .12/.37) and visuospatial/constructional abilities (r = .30, 95% CI: .14/.46). Meta-analytic structural equation modelling (metaSEM) identified two significant, unique predictors of activities of daily living, attention and visuospatial abilities, and the model accounted for 21% of the variance (multiple R² = .21, 95%CI: .16/.26). For the corresponding quality of life metaSEM, no statistically significant unique predictors were identified, however, a significant multiple correlation was observed, multiple R² = .11 (95%CI: 04/.18). We conclude that practitioners may be able to predict, with some degree of accuracy, functional outcome following a stroke and other non-traumatic ABI in adults. We also provide some critical commentary on the nature and quality of the measures used in this area of research to represent the cognitive dimensions of interest.

Right hemisphere ventral stream for emotional prosody identification: Evidence from acute stroke

OBJECTIVE

To determine whether right ventral stream and limbic structures (including posterior superior temporal gyrus [STG], STG, temporal pole, inferior frontal gyrus pars orbitalis, orbitofrontal cortex, amygdala, anterior cingulate, gyrus, and the sagittal stratum) are implicated in emotional prosody identification.

METHODS

Patients with MRI scans within 48 hours of unilateral right hemisphere ischemic stroke were enrolled. Participants were presented with 24 sentences with neutral semantic content spoken with happy, sad, angry, afraid, surprised, or bored prosody and chose which emotion the speaker was feeling based on tone of voice. Multivariable linear regression was used to identify individual predictors of emotional prosody identification accuracy from a model, including percent damage to proposed right hemisphere structures, age, education, and lesion volume across all emotions (overall emotion identification) and 6 individual emotions. Patterns of recovery were also examined at the chronic stage.

RESULTS

The overall emotion identification model was significant (adjusted r ² = 0.52; p = 0.043); greater damage to right posterior STG (p = 0.038) and older age (p = 0.009) were individual predictors of impairment. The model for recognition of fear was also significant (adjusted r ² = 0.77; p = 0.002), with greater damage to right amygdala (p = 0.047), older age (p < 0.001), and less education (p = 0.005) as individual predictors. Over half of patients with chronic stroke had residual impairments.

CONCLUSIONS

Right posterior STG in the right hemisphere ventral stream is critical for emotion identification in speech. Patients with stroke with damage to this area should be assessed for emotion identification impairment.

Interoceptive awareness in focal brain-damaged patients

BACKGROUND

Interoception is the basic process enabling evaluation of one's own internal state of body, but its alteration in brain-damaged patients has not been adequately investigated. Our study aimed to investigate awareness of visceral and somatosensorial sensations in brain-damaged patients with unilateral stroke.

METHODS

Sixty patients (22 with left brain damage, LP; 25 with right brain damage without neglect, RPN-; and 13 with right brain-damage and extrapersonal and/or personal neglect, RPN+) and 45 healthy controls (HC) completed the Self-Awareness Questionnaire (SAQ), a self-report tool for assessing interoceptive awareness with two domains related to visceral (VD) and somatosensory feelings (SD), respectively.

RESULTS

Comparing the SAQ subdomains scores between three groups of patients (LP, RPN-, and RPN+) and HC, we found that RPN+ had significantly lower scores on VD than HC and LP, whereas no significant difference was found on scores of SD between groups.

CONCLUSION

Our results support the hypothesis of a right-hemispheric dominance for "interoceptive neural network" suggesting that processing of visceral sensations would be located mainly in the right hemisphere. Therefore, a careful assessment of interoceptive awareness in clinical practice would be useful to improve rehabilitation and to engage patients with deficit of interoceptive awareness in developing greater accuracy of body signals.

Spatial Neglect in Stroke: Identification, Disease Process and Association with Outcome During Inpatient Rehabilitation

We established spatial neglect prevalence, disease profile and amount of therapy that inpatient stroke survivors received, and outcomes at discharge using Sentinel Stroke National Audit Programme (SSNAP) data. We used data from 88,664 National Health Service (NHS) admissions in England, Wales and Northern Ireland (July 2013–July 2015), for stroke survivors still in hospital after 3 days with a completed baseline neglect National Institute for Health Stroke Scale (NIHSS) score. Thirty percent had neglect (NIHSS item 11 ≥ 1) and they were slightly older (78 years) than those without neglect (75 years). Neglect was observed more commonly in women (33 vs. 27%) and in individuals with a premorbid dependency (37 vs. 28%). Survivors of mild stroke were far less likely to present with neglect than those with severe stroke (4% vs. 84%). Those with neglect had a greatly increased length of stay (27 vs. 10 days). They received a comparable amount of average daily occupational and physiotherapy during their longer inpatient stay but on discharge a greater percentage of individuals with neglect were dependent on the modified Rankin scale (76 vs. 57%). Spatial neglect is common and associated with worse clinical outcomes. These results add to our understanding of neglect to inform clinical guidelines, service provision and priorities for future research.

Brain Activations During Optokinetic Stimulation in Acute Right-Hemisphere Stroke Patients and Hemispatial Neglect: An fMRI Study

Objective. Leftward optokinetic stimulation (OKS) is a promising therapeutic approach for right-hemisphere stroke patients with left hemispatial neglect. We questioned whether the putative neural basis is an activation of frontoparietal brain regions involved in the control of eye movements and spatial attention. Methods. We used functional magnetic resonance imaging to investigate brain activations during OKS in acute right-hemisphere stroke patients (RHS, n = 19) compared with healthy control subjects (HC, n = 9). Based on neuropsychological testing we determined the ipsilesional attention bias in all RHS patients, 11 showed manifest hemispatial neglect. Results. In HC subjects, OKS in either direction led to bilateral activation of the visual cortex (V1-V4), frontal (FEF) and supplementary (SEF) eye fields, intraparietal sulcus (IPS), basal ganglia, and thalamus. RHS patients' activations were generally reduced compared with HC. Nevertheless, leftward OKS bilaterally activated the visual cortex (V1-V4), FEF, SEF, IPS, and thalamus. The neural response to OKS was negatively correlated with patients' behavioral impairment: The greater the individual attention bias/neglect the weaker the brain activations. Conclusion. In RHS patients, leftward OKS activates frontoparietal regions (FEF, IPS) that are spared from structural brain damage and functionally involved in both oculomotor control and spatial attention. This may provide a neural basis for the known therapeutic effects of OKS on hemispatial neglect. In acute stroke stages, reduced activation levels correlating with neglect severity indicate functional downregulation of the underlying dorsal attention network. Therefore, chronic RHS patients with less severe neglect after recovery of network disturbances may be more suitable candidates for OKS rehabilitation.

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.

Robot Diagnosis Test for Egocentric and Allocentric Hemineglect

OBJECTIVE

Patients with hemineglect fail to respond to egocentric stimuli or allocentric parts of stimuli contralateral to the brain lesion. The clinical diagnosis of hemineglect mainly involves evaluation of the egocentric form, while less sensitive standardized tests exist for other forms. Our global aim is to develop an innovative integrative robot measure, the MonAmour test, combining the assessment of egocentric, allocentric and motor hemineglect. Here, we present the egocentric and allocentric evaluations.

METHODS

Thirty-five first stroke patients (25 hemineglect) and 56 age-matched healthy controls were assessed on the index test (MonAmour) and on three reference standard tests (Bells test, Apples test and Neglect subtest of the Test for Attentional Performance). Based on controls' performance, normative data were created. Validity was evaluated between the MonAmour and the reference standard tests through correlations and test sensitivity/specificity. Reliability of the MonAmour was measured with test-retest and minimal detectable change.

RESULTS

Results demonstrated moderate to strong correlations between the MonAmour and the reference standard tests (r = .40-.88, p < .001 - p = .016). The sensitivity was high (50%-96%), with accurate diagnosis of patients with hemineglect, and reliability was excellent (Intraclass Correlation Coefficient = .79-.95, p < .001).

CONCLUSIONS

The MonAmour robot test is a valid, sensitive and reliable tool that can diagnose egocentric and allocentric hemineglect. Future studies will deepen the assessment and understanding of the different forms of hemineglect by testing the motor component of the test in order to use this accurate and integrative measure in daily clinical routine.

REGISTRATION

ClinicalTrials.gov(NCT02543424).

Musical Neglect Training for Chronic Persistent Unilateral Visual Neglect Post-stroke

Unilateral visual neglect from right hemispheric stroke is a condition that reduces a person's ability to attend to and process stimuli in their left visual field, resulting in neglect and inattention to the left side of their environment. This perceptual processing deficit can negatively affect individuals' daily living which in turn reduces functional independence. Musical Neglect Training (MNT) has been developed based on previous research evidence to improve left visual field processing. Two individuals with persistent chronic unilateral visual neglect participated in this study. Participants underwent six individual MNT sessions. Active MNT was used involving exercises on musical equipment (tone bars) to complete musical patterns emphasizing attentional focus toward the neglect visual field. Two standardized assessments (Albert's and Line Bisection Test) were used. The assessments were administered immediately before and after each of the 6 MNT sessions to assess the within-session effect of MNT. Follow-up testing was done 1 week after their 6th session to examine the longer-lasting effects of MNT. Paired t-test and Wilcoxon signed rank test were used to examine results. Both participants showed significant improvement pre vs. posttest on the Albert's Test but not on the Line Bisection Test. The current study presents the positive potential of MNT for patients with chronic persistent visual neglect. In particular, effects were shown for exploratory visuomotor neglect (Albert's test), but not for egocentric perceptive neglect (Line Bisection Test), and substantiated for within-session effects only. The predictable auditory stimulus patterns associated with object sequences (tone bars) to provide feedback, direct spatial attention and orientation, and initiate intention for movement into the neglect field may offer specific advantages to reduce persistent perceptual attention deficits.

A New Standardization of the Bells Test: An Italian Multi-Center Normative Study

Objective: The Bells Test is a cancelation task that is widely used for the diagnosis of unilateral spatial neglect (USN). With the aim of fostering more reliable use of this instrument, we set out to develop new norms adjusted for the possible influence of age, gender and education. We worked on the original version of the test.

Methods: Normative data were collected from 401 healthy participants aged between 20 and 80 years. Individual factors that could affect performance (i.e., gender, age, and years of education) were considered. We computed several indices on the Bells Test including an asymmetry score, an accuracy score and execution time. Multiple regression analyses (for time measures) and generalized linear models (for accuracy measures) were used to check for the influence of individual predictors of performance on the Bells Test.

Results: Data indicated a significant influence of age on the accuracy score and execution time variables and a marginally significant effect of education on the accuracy score variable. Wherever appropriate, cut-offs are provided for the three dependent scores on the Bells Test corrected for age and education.

Conclusion: Based on a large normative sample, the present study provides new normative data on the Bells Test, which could lead to its reliable use in the diagnosis of USN.

The ipsilesional attention bias in right-hemisphere stroke patients as revealed by a realistic visual search task: Neuroanatomical correlates and functional relevance

OBJECTIVE

Right-hemisphere stroke may cause an ipsilesional attention bias and left hemispatial neglect. Computerized time-limited tasks are more sensitive than conventional paper-pencil tests in detecting these spatial attention deficits. However, their frequency in the acute stage of stroke, the neuroanatomical basis and functional relevance for patients' everyday life are unclear.

METHOD

A realistic visual search task is introduced, in which eye movements are recorded while the patient searches for paperclips among different everyday objects on a computer display. The "desk task" performance of 34 acute right-hemisphere stroke patients was compared to established paper-pencil tests for neglect and the Posner reaction time task, and finally correlated to structural brain lesions.

RESULTS

Most of the patients, even those without clinical neglect signs and with normal paper-pencil test performance, exhibited a clear ipsilesional attention bias in the desk task. This bias was highly correlated to the left-right asymmetry in the Posner task and to neglect-related functional impairment scores. Lesion-symptom mapping revealed task-specific differences: deficits in the desk task were associated with lesions of the superior temporal gyrus, contralesional unawareness in the Posner task with ventral frontal cortex lesions and paper-pencil cancellation bias with damage to the inferior parietal lobe. Neglect behavior was further associated with distinct frontoparietal white matter tract disconnections (inferior longitudinal fasciculus, superior longitudinal fasciculus, arcuate).

CONCLUSIONS

Results from the novel desk task indicate a functional relevance of spatial attention deficits in right-hemisphere stroke patients, even if they are "subclinical." This should be considered especially in patients without obvious clinical neglect signs. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Adaptation to poststroke visual field loss: A systematic review

AIM

To provide a systematic overview of the factors that influence how a person adapts to visual field loss following stroke.

METHOD

A systematic review was undertaken (data search period 1861-2016) inclusive of systematic reviews, randomized controlled trials, controlled trials, cohort studies, observational studies, and case controlled studies. Studies including adult subjects with hemifield visual field loss, which occured as a direct consequence of stroke, were included. Search terms included a range of MESH terms as well as alternative terms relating to stroke, visual field loss, visual functions, visual perception, and adaptation. Articles were selected by two authors independently, and data were extracted by one author, being verified by the second. All included articles were assessed for risk of bias and quality using checklists appropriate to the study design.

RESULTS

Forty-seven articles (2,900 participants) were included in the overall review, categorized into two sections. Section one included seventeen studies where the reviewers were able to identify a factor they considered as likely to be important for the process of adaptation to poststroke visual field loss. Section two included thirty studies detailing interventions for visual field loss that the reviewers deemed likely to have an influence on the adaptation process. There were no studies identified which specifically investigated and summarized the factors that influence how a person adapts to visual field loss following stroke.

CONCLUSION

There is a substantial amount of evidence that patients can be supported to compensate and adapt to visual field loss following stroke using a range of strategies and methods. However, this systematic review highlights the fact that many unanswered questions in the area of adaptation to visual field loss remain. Further research is required on strategies and methods to improve adaptation to aid clinicians in supporting these patients along their rehabilitation journey.

Mapping visuospatial attention: the greyscales task in combination with repetitive navigated transcranial magnetic stimulation

BACKGROUND

Visuospatial attention is executed by the frontoparietal cortical areas of the brain. Damage to these areas can result in visual neglect. We therefore aimed to assess a combination of the greyscales task and repetitive navigated transcranial magnetic stimulation (rTMS) to identify cortical regions involved in visuospatial attention processes. This pilot study was designed to evaluate an approach in a cohort of healthy volunteers, with the future aim of using this technique to map brain tumor patients before surgery. Ten healthy, right-handed subjects underwent rTMS mapping of 52 cortical spots in both hemispheres. The greyscales task was presented tachistoscopically and was time-locked to rTMS pulses. The task pictures showed pairs of horizontal rectangles shaded continuously from black at one end to white at the other, mirror-reversed. On each picture the subject was asked to report which of the two greyscales appeared darker overall. The responses were categorized into "leftward" and "rightward," depending on whether the subject had chosen the rectangle with the darker end on the left or the right. rTMS applied to cortical areas involved in visuospatial attention is supposed to affect lateral shifts in spatial bias. These shifts result in an altered performance on the greyscales task compared to the baseline performance without rTMS stimulation.

RESULTS

In baseline conditions, 9/10 subjects showed classic pseudoneglect to the left. Leftward effects also occurred more often in mapping conditions. Yet, calculated rightward deviations were strikingly greater in magnitude (p < 0.0001). Overall, the right hemisphere was found to be more suggestible than the left hemisphere. Both rightward and leftward deviation scores were higher for the rTMS of this brain side (p < 0.0001). Right hemispheric distributions accord well with current models of visuospatial attention (Corbetta et al. Nat Neurosci 8(11):1603-1610, 2005). We observed leftward deviations triggered by rTMS within superior frontal and posterior parietal areas and rightward deviations within inferior frontal areas and the temporoparietal junction (TPJ).

CONCLUSION

The greyscales task, in combination with rTMS, yields encouraging results in the examination of the visuospatial attention function. Future clinical implications should be evaluated.

Randomised, double-blind, placebo-controlled crossover study of single-dose guanfacine in unilateral neglect following stroke

OBJECTIVE

Unilateral neglect is a poststroke disorder that impacts negatively on functional outcome and lacks established, effective treatment. This multicomponent syndrome is characterised by a directional bias of attention away from contralesional space, together with impairments in several cognitive domains, including sustained attention and spatial working memory. This study aimed to test the effects of guanfacine, a noradrenergic alpha-2A agonist, on ameliorating aspects of neglect.

METHODS

Thirteen right hemisphere stroke patients with leftward neglect were included in a randomised, double-blind, placebo-controlled proof-of-concept crossover study that examined the effects of a single dose of guanfacine. Patients were tested on a computerised, time-limited cancellation paradigm, as well as tasks that independently assessed sustained attention and spatial working memory.

RESULTS

On guanfacine, there was a statistically significant improvement in the total number of targets found on the cancellation task when compared with placebo (mean improvement of 5, out of a possible 64). However, there was no evidence of a change in neglect patients' directional attention bias. Furthermore, Bayesian statistical analysis revealed reliable evidence against any effects of guanfacine on search organisation and performance on our sustained attention and spatial working memory tasks.

CONCLUSIONS

Guanfacine improves search in neglect by boosting the number of targets found but had no effects on directional bias or search organisation, nor did it improve sustained attention or working memory on independent tasks. Further work is necessary to determine whether longer term treatment with guanfacine may be effective for some neglect patients and whether it affects functional outcome measures.

TRIAL REGISTRATION NUMBER

NCT00955253.

Evoking visual neglect-like deficits in healthy volunteers - an investigation by repetitive navigated transcranial magnetic stimulation

In clinical practice, repetitive navigated transcranial magnetic stimulation (rTMS) is of particular interest for non-invasive mapping of cortical language areas. Yet, rTMS studies try to detect further cortical functions. Damage to the underlying network of visuospatial attention function can result in visual neglect-a severe neurological deficit and influencing factor for a significantly reduced functional outcome. This investigation aims to evaluate the use of rTMS for evoking visual neglect in healthy volunteers and the potential of specifically locating cortical areas that can be assigned for the function of visuospatial attention. Ten healthy, right-handed subjects underwent rTMS visual neglect mapping. Repetitive trains of 5 Hz and 10 pulses were applied to 52 pre-defined cortical spots on each hemisphere; each cortical spot was stimulated 10 times. Visuospatial attention was tested time-locked to rTMS pulses by a landmark task. Task pictures were displayed tachistoscopically for 50 ms. The subjects' performance was analyzed by video, and errors were referenced to cortical spots. We observed visual neglect-like deficits during the stimulation of both hemispheres. Errors were categorized into leftward, rightward, and no response errors. Rightward errors occurred significantly more often during stimulation of the right hemisphere than during stimulation of the left hemisphere (mean rightward error rate (ER) 1.6 ± 1.3 % vs. 1.0 ± 1.0 %, p = 0.0141). Within the left hemisphere, we observed predominantly leftward errors rather than rightward errors (mean leftward ER 2.0 ± 1.3 % vs. rightward ER 1.0 ± 1.0 %; p = 0.0005). Visual neglect can be elicited non-invasively by rTMS, and cortical areas eloquent for visuospatial attention can be detected. Yet, the correlation of this approach with clinical findings has to be shown in upcoming steps.

The assessment of hemineglect syndrome with cancellation tasks: a comparison between the Bells test and the Apples test

Unilateral spatial neglect (USN) is a frequent consequence of acquired brain injury, especially following right hemisphere damage. Traditionally, unilateral spatial neglect is assessed with cancellation tests such as the Bells test. Recently, a new cancellation test, the Apples test, has been proposed. The present study aims at comparing the accuracy of these two tests in detecting hemispatial neglect, on a sample of 56 right hemisphere stroke patients with a diagnosis of USN. In order to evaluate the agreement between the Apples and Bells tests, Cohen's kappa and McNemar's test were used to assess differences between the two methods of evaluation. Poor agreement and statistically significant differences emerged between the Apples and Bells tests. Overall, the Apples test was significantly more sensitive than the Bells test in detecting USN. Based on these results, the use of the Apples test for peripersonal neglect assessment is therefore highly recommended.

Binocular rivalry after right-hemisphere stroke: Effects of attention impairment on perceptual dominance patterns

Binocular rivalry is when perception fluctuates while the stimuli, consisting of different images presented to each eye, remain unchanged. The fluctuation rate and predominance ratio of these images are regarded as information source for understanding properties of consciousness and perception. We administered a binocular rivalry task to 26 right-hemisphere stroke patients and 26 healthy control participants, using stimuli such as simple Gabor anaglyphs. Each single Gabor image was of unequal spatial frequency compared to its counterpart, allowing assessment of the effect of relative spatial frequency on rivalry predominance. Results revealed that patients had significantly decreased alternation rate compared to healthy controls, with severity of patients' attention impairment predicting alternation rates. The patient group had higher predominance ratio for high compared to low relative spatial frequency stimuli consistent with the hypothesis that damage to the right hemisphere may disrupt processing of relatively low spatial frequencies. Degree of attention impairment also predicted the effect of relative spatial frequencies. Lastly, both groups showed increased predominance rates in the right eye compared to the left eye. This right eye dominance was more pronounced in patients than controls, suggesting that right hemisphere stroke may additionally affect eye predominance ratios.

Artistic Skills Recovery and Compensation in Visual Artists after Stroke

Background

Art is a characteristic of mankind, which requires superior central nervous processing and integration of motor functions with visual information. At the present time, a significant amount of information related to neurobiological basis of artistic creation has been derived from neuro-radiological cognitive studies, which have revealed that subsequent to tissue destruction, the artists continue to create art. The current study aims to review the most important cases of visual artists with stroke and to discuss artistic skills recovery and compensation as well as artistic style after stroke.

Methods

The role of various central nervous system regions in artistic creation was reviewed on the basis of previously published functional studies. Our PubMed search (1995–2015) has identified 10 famous artists with right cerebral stroke as well as 5 with left cerebral stroke who survived and continued to create art after stroke. As the artists included in this review lived at various times during the twentieth century and in different countries, clinical information related to their case was limited. However, it appears that artistic skills recovery and compensation appear within days after stroke. Some of the artists would subsequently change their artistic style. All these elements have been evaluated within the context of specific clinical cases.

Conclusion

The poststroke artistic skills recovery and compensation with development of a new style or the opposite, regaining the previous prestroke style, represents a significant element of clinical importance in medical rehabilitation as well as neuroesthetics, which requires further evaluation. At the present time, the molecular mechanisms of artistic creation are poorly understood, and more standardized clinical and experimental studies are needed.

Risk Factors for Symptoms of Depression and Anxiety One Year Poststroke: A Longitudinal Study

OBJECTIVE

To estimate the relative contribution of psychological factors next to sociodemographic and premorbid/stroke-related factors to the risk of developing symptoms of depression and anxiety after stroke.

DESIGN

Multicenter, longitudinal cohort study.

SETTING

Patients after stroke from 6 general hospitals.

PARTICIPANTS

Patients (N=331) were included at stroke onset and followed up 2 and 12 months after stroke.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Sociodemographic and premorbid/stroke-related information was recorded during hospital admission, whereas psychological characteristics were determined with postal questionnaires 2 months poststroke. Symptoms of depression and anxiety were assessed with the Hospital Anxiety and Depression Scale (HADS) 2 and 12 months poststroke. Multivariable logistic analysis was performed to analyze the influence of sociodemographic, premorbid/stroke-related, and psychological characteristics on depressive symptoms (depression subscale of HADS >7) and symptoms of anxiety (anxiety subscale of HADS >7) 1 year after stroke.

RESULTS

Early depression, stroke severity, posterior cerebral artery stroke, and neuroticism independently explained the variance of depressive symptoms 1 year poststroke (discriminative power, 83%; adjusted R(2) value, 36%). Neuroticism and early anxiety independently explained the variance of symptoms of anxiety 1 year poststroke (discriminative power, 88%; adjusted R(2) value, 44%). Based on these predictive models, nomograms were constructed to visually reflect the individual contribution of each risk factor to the development of long-term mood disorders after stroke.

CONCLUSIONS

Psychological characteristics are important risk factors for poststroke symptoms of depression and anxiety.

Structural white-matter connections mediating distinct behavioral components of spatial neglect in right brain-damaged patients

Spatial neglect is a neuropsychological syndrome in which patients fail to perceive and orient to stimuli located in the space contralateral to the lesioned hemisphere. It is characterized by a wide heterogeneity in clinical symptoms which can be grouped into distinct behavioral components correlating with different lesion sites. Moreover, damage to white-matter (WM) fiber tracts has been suggested to disconnect brain networks that mediate different functions associated with spatial cognition and attention. However, it remains unclear what WM pathways are associated with functionally dissociable neglect components. In this study we examined nine patients with a focal right hemisphere stroke using a series of neuropsychological tests and diffusion tensor imaging (DTI) in order to disentangle the role of specific WM pathways in neglect symptoms. First, following previous work, the behavioral test scores of patients were factorized into three independent components reflecting perceptual, exploratory, and object-centered deficits in spatial awareness. We then examined the structural neural substrates of these components by correlating indices of WM integrity (fractional anisotropy) with the severity of deficits along each profile. Several locations in the right parietal and frontal WM correlated with neuropsychological scores. Fiber tracts projecting from these locations indicated that posterior parts of the superior longitudinal fasciculus (SLF), as well as nearby callosal fibers connecting ipsilateral and contralateral parietal areas, were associated with perceptual spatial deficits, whereas more anterior parts of SLF and inferior fronto-occipital fasciculus (IFOF) were predominantly associated with object-centered deficits. In addition, connections between frontal areas and superior colliculus were found to be associated with the exploratory deficits. Our results provide novel support to the view that neglect may result from disconnection lesions in distributed brain networks, but also extend these notions by highlighting the role of dissociable circuits in different functional components of the neglect syndrome. However these preliminary findings require replication with larger samples of patients.