Randomized controlled trial on hemifield eye patching and optokinetic stimulation in acute spatial neglect

The effect of offline anosognosia for hemispatial neglect on neglect rehabilitation in patients with subacute and chronic right hemispheric brain injury. A retrospective cohort study

CLINICAL TRIALS REGISTRATION NUMBER

NCT05145855.

The Neurophysiological Features Associated with Unilateral Spatial Neglect Recovery: A Scoping Review

The purpose of this scoping review is to provide updated information on the neural basis and neurophysiological features associated with unilateral spatial neglect (USN) recovery. We applied the Preferred Reporting Systems for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) framework and identified 16 relevant papers from the databases. Critical appraisal was performed by two independent reviewers using a standardized appraisal instrument developed by the PRISMA-ScR. We identified and categorized investigation methods for the neural basis and neurophysiological features of USN recovery after stroke using magnetic resonance imaging (MRI), functional MRI, and electroencephalography (EEG). This review found two brain-level mechanisms underlying USN recovery at the behavioral level. These include the absence of stroke-related damage to the right ventral attention network during the acute phase and compensatory recruitment of analogous areas of the undamaged opposite hemisphere and prefrontal cortex during visual search tasks in the subacute or later phases. However, the relationship between the neural and neurophysiological findings and improvements in USN-related activities of daily living remains unknown. This review adds to the growing body of evidence regarding the neural mechanisms underlying USN recovery.

Combined optokinetic stimulation and cueing-assisted reading therapy to treat hemispatial neglect: A randomized controlled crossover trial

BACKGROUND

Hemispatial neglect is a disabling cognitive disorder following stroke and effective therapies are required.

OBJECTIVES

To evaluate the effects of combined optokinetic stimulation (OKS) and cueing-assisted reading therapy (READ) on the remission of hemispatial neglect following stroke.

METHODS

Randomized, controlled, two-period, crossover trial conducted at a German neurorehabilitation center. Twenty participants with left neglect following right hemispheric stroke (mean age 66 years (SD 11), mean time since stroke 50 days (SD 33)) finished the trial (12 received OKSREAD first, 8 CONTROL first). The intervention consisted of 15 daily sessions of OKS (20 min) and text reading assisted by a therapist providing cues (20 min). The control treatment was a same-number, same-length neuropsychological treatment not targeting visuospatial attention. Primary outcomes were the change in performance of a customized neuropsychological test battery for neglect (0% worst - 100% best) and a test of neglect-related functional disability (Catherine Bergego Scale, 0 no impairment - 30 severest impairment), assessed before and after each treatment period. Secondary outcomes were performance in the 6 single tests composing the battery (e.g., omissions in text reading, center of cancellation in the Bells test, spatial bias of fixations when freely viewing photographs) and a clinical test of anosognosia.

RESULTS

Overall performance in the neglect test battery improved slightly more after OKSREAD than after CONTROL (d=6%; p=0.002). The remission of neglect-related functional disability did not differ between treatments (d=-2; p=0.291). Ipsilesional fixation bias during free viewing was the only secondary outcome that was improved by OKSREAD as compared to CONTROL (d= -2.8°; p=0.005).

CONCLUSION

At the applied intensity, the combined OKSREAD intervention slightly attenuated the ipsilesional attention bias in persons with neglect, but it did not improve neglect-related functional disability, anosognosia, or other neglect symptoms to a clinically meaningful degree.

CLINICAL TRIAL REGISTRATION

URL: http://www.

CLINICALTRIALS

gov. Unique identifier: NCT04273620.

Gaze-contingent display technology can help to reduce the ipsilesional attention bias in hemispatial neglect following stroke

Background

Hemispatial neglect results from unilateral brain damage and represents a disabling unawareness for objects in the hemispace opposite the brain lesion (contralesional). The patients’ attentional bias for ipsilesional hemispace represents a hallmark of neglect, which results from an imbalanced attentional priority map in the brain. The aim of this study was to investigate whether gaze-contingent display (GCD) technology, reducing the visual salience of objects in ipsilesional hemispace, is able to rebalance this map and increase awareness and exploration of objects in the neglected contralesional hemispace.

Methods

Using remote eye-tracking, we recorded gaze positions in 19 patients with left hemispatial neglect following right-hemisphere stroke and 22 healthy control subjects, while they were watching static naturalistic scenes. There were two task conditions, free viewing (FV) or goal-directed visual search (VS), and four modification conditions including the unmodified original picture, a purely static modification and two differently strong modifications with an additional gaze-contingent mask (GC-LOW, GC-HIGH), that continuously reduced color saturation and contrast of objects in the right hemispace.

Results

The patients’ median gaze position (Center of Fixation) in the original pictures was markedly deviated to the right in both tasks (FV: 6.8° ± 0.8; VS: 5.5° ± 0.7), reflecting the neglect-typical ipsilesional attention bias. GC modification significantly reduced this bias in FV (GC-HIGH: d = − 3.2 ± 0.4°; p < 0.001). Furthermore, in FV and VS, GC modification increased the likelihood to start visual exploration in the (neglected) left hemifield by about 20%. This alleviation of the ipsilesional fixation bias was not associated with an improvement in detecting left-side targets, in contrast, the GC mask even decreased and slowed the detection of right-side targets. Subjectively, patients found the intervention pleasant and most of the patients did not notice any modification.

Conclusions

GCD technology can be used to positively influence visual exploration patterns in patients with hemispatial neglect. Despite an alleviation of the neglect-related ipsilesional fixation bias, a concomitant functional benefit (improved detection of contralesional targets) was not achieved. Future studies may investigate individualized GCD-based modifications as augmented reality applications during the activities of daily living.

A Complex Intervention Integrating Prism Adaptation and Neck Vibration for Unilateral Neglect in Patients of Chronic Stroke: A Randomised Controlled Trial

Unilateral neglect in patients of chronic stroke reduces the quality of life and interferes with activities of daily living (ADL). This study aimed to investigate the effects of a complex rehabilitative programme that integrates prism adaptation (PA) and neck vibration (NV) for unilateral neglect in patients of chronic stroke. Thirty-six patients were randomised among the PA + NV group (Group A, n = 12), the NV-only group (Group B, n = 12), and the PA-only group (Group C, n = 12). The intervention was performed for 50 min/day, with five sessions per week, for 4 weeks. Albert's test and the Catherine Bergego Scale were used to measure the effects of each intervention on unilateral neglect, whereas the modified Barthel Index was used to assess the effect on ADL. All three groups exhibited a reduction in unilateral neglect and an improvement in activities of daily living after the intervention (p < 0.05). Notably, Group A (PA + NV) exhibited a significantly greater level of reduction in unilateral neglect than the other groups (p < 0.05); however, the improvement in ADL did not significantly vary across the three groups (p > 0.05). This novel complex intervention comprising PA + NV is recommended for the rehabilitation, in the clinical setting, of patients of chronic stroke with unilateral neglect.

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.

Prism Adaptation and Optokinetic Stimulation Comparison in the Rehabilitation of Unilateral Spatial Neglect

Prism adaptation (PA) is one of the most effective treatments for the rehabilitation of unilateral spatial neglect. Optokinetic stimulation (OKS) has also been demonstrated to be effective in ameliorating symptoms of neglect. The aim of this study is to compare the effectiveness of these two methods in a group of neglect patients using a crossover design. A group of 13 post-acute brain-damaged patients with unilateral spatial neglect, who had never been rehabilitated, were treated using PA and OKS. Each treatment was applied for 10 sessions, twice a day, to all patients with both treatments in crossed order (i.e., PA followed by OKS or vice versa). Neuropsychological assessments were performed: before the first (T1), at the end of the first/beginning of the second (T2) and at the end of the second training sessions (T3), and two weeks after the end of treatment (T4). Both procedures produced a significant improvement in clinical tests at T2, independent of the type of training. The results suggest that either PA or OKS induces a significant amelioration of neglect in right brain-damaged patients, mainly in the first block of treatment. Since no differences between treatments were found, they could be applied in clinical practice, according to the requirements of the individual patient.

Robot-Assisted Arm Training in Stroke Individuals With Unilateral Spatial Neglect: A Pilot Study

Background: Robot-assisted arm training (RAT) is an innovative exercise-based therapy that provides highly intensive, adaptive, and task-specific training, yet its effects for stroke individuals with unilateral spatial neglect remain to be explored. The study was aimed to investigate the effects of RAT on unilateral spatial neglect, arm motor function, activities of daily living, and social participation after stroke.

Methods: In a pilot randomized controlled trial, individuals with unilateral spatial neglect after right hemisphere stroke were equally allocated to intervention group and control group, 45-min training daily, 5 days/week, for 4 weeks. Outcome measures included the Behavioral Inattention Test-conventional section (BIT-C), Catherine Bergego Scale (CBS), Fugl-Meyer Assessment for Upper Extremity (FMA-UE), Modified Barthel Index (MBI), and World Health Organization Disability Assessment Schedule Version 2.0 (WHODAS 2.0).

Results: From November 2018 to February 2021, 20 stroke patients (mean age 47.40 ± 8.47) were enrolled in the study. Robot-assisted arm training was feasible and safe for individuals with unilateral spatial neglect. Both groups had significant improvements in all outcome measures. Participants assigned to RAT therapy had significantly greater improvements in BIT-C (difference, 7.70; 95% CI, 0.55–14.85, P = 0.04), FMA-UE (difference, 5.10; 95% CI, 1.52–8.68, P = 0.01), and WHODAS 2.0 (difference, −7.30; 95% CI, −12.50 to −2.10, P = 0.01). However, the change scores on CBS and MBI demonstrated no significance between the groups.

Conclusion: Our findings provide preliminary support for introducing robot-assisted arm training to remediate unilateral spatial neglect after stroke. The training program focusing on neglect of contralateral space and affected upper extremity may be effective in neglect symptoms, motor function recovery, and social participation, while not generalizing into improvements in activities of daily living.

Clinical Trial Registration: Chinese Clinical Trial Registry (http://www.chictr.org.cn/) on 17 October 2019, identifier: ChiCTR1900026656.

Non-pharmacological interventions for spatial neglect or inattention following stroke and other non-progressive brain injury

BACKGROUND

People with spatial neglect after stroke or other brain injury have difficulty attending to one side of space. Various rehabilitation interventions have been used, but evidence of their benefit is unclear.

OBJECTIVES

The main objective was to determine the effects of non-pharmacological interventions for people with spatial neglect after stroke and other adult-acquired non-progressive brain injury.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched October 2020), the Cochrane Central Register of Controlled Trials (CENTRAL; last searched October 2020), MEDLINE (1966 to October 2020), Embase (1980 to October 2020), the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1983 to October 2020), and PsycINFO (1974 to October 2020). We also searched ongoing trials registers and screened reference lists.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of any non-pharmacological intervention specifically aimed at spatial neglect. We excluded studies of general rehabilitation and studies with mixed participant groups, unless separate neglect data were available.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Review authors categorised the interventions into eight broad types deemed to be applicable to clinical practice through iterative discussion: visual interventions, prism adaptation, body awareness interventions, mental function interventions, movement interventions, non-invasive brain stimulation, electrical stimulation, and acupuncture. We assessed the quality of evidence for each outcome using the GRADE approach.

MAIN RESULTS

We included 65 RCTs with 1951 participants, all of which included people with spatial neglect following stroke. Most studies measured outcomes using standardised neglect assessments. Fifty-one studies measured effects on ADL immediately after completion of the intervention period; only 16 reported persisting effects on ADL (our primary outcome). One study (30 participants) reported discharge destination, and one (24 participants) reported depression. No studies reported falls, balance, or quality of life. Only two studies were judged to be entirely at low risk of bias, and all were small, with fewer than 50 participants per group. We found no definitive (phase 3) clinical trials. None of the studies reported any patient or public involvement. Visual interventions versus any control: evidence is very uncertain about the effects of visual interventions for spatial neglect based on measures of persisting functional ability in ADL (2 studies, 55 participants) (standardised mean difference (SMD) -0.04, 95% confidence interval (CI) -0.57 to 0.49); measures of immediate functional ability in ADL; persisting standardised neglect assessments; and immediate neglect assessments. Prism adaptation versus any control: evidence is very uncertain about the effects of prism adaptation for spatial neglect based on measures of persisting functional ability in ADL (2 studies, 39 participants) (SMD -0.29, 95% CI -0.93 to 0.35); measures of immediate functional ability in ADL; persisting standardised neglect assessments; and immediate neglect assessments. Body awareness interventions versus any control: evidence is very uncertain about the effects of body awareness interventions for spatial neglect based on measures of persisting functional ability in ADL (5 studies, 125 participants) (SMD 0.61, 95% CI 0.24 to 0.97); measures of immediate functional ability in ADL; persisting standardised neglect assessments; immediate neglect assessments; and adverse events. Mental function interventions versus any control: we found no trials of mental function interventions for spatial neglect reporting on measures of persisting functional ability in ADL. Evidence is very uncertain about the effects of mental function interventions on spatial neglect based on measures of immediate functional ability in ADL and immediate neglect assessments. Movement interventions versus any control: we found no trials of movement interventions for spatial neglect reporting on measures of persisting functional ability in ADL. Evidence is very uncertain about the effects of body awareness interventions on spatial neglect based on measures of immediate functional ability in ADL and immediate neglect assessments. Non-invasive brain stimulation (NIBS) versus any control: evidence is very uncertain about the effects of NIBS on spatial neglect based on measures of persisting functional ability in ADL (3 studies, 92 participants) (SMD 0.35, 95% CI -0.08 to 0.77); measures of immediate functional ability in ADL; persisting standardised neglect assessments; immediate neglect assessments; and adverse events. Electrical stimulation versus any control: we found no trials of electrical stimulation for spatial neglect reporting on measures of persisting functional ability in ADL. Evidence is very uncertain about the effects of electrical stimulation on spatial neglect based on immediate neglect assessments. Acupuncture versus any control: we found no trials of acupuncture for spatial neglect reporting on measures of persisting functional ability in ADL. Evidence is very uncertain about the effects of acupuncture on spatial neglect based on measures of immediate functional ability in ADL and immediate neglect assessments.

AUTHORS' CONCLUSIONS

The effectiveness of non-pharmacological interventions for spatial neglect in improving functional ability in ADL and increasing independence remains unproven. Many strategies have been proposed to aid rehabilitation of spatial neglect, but none has yet been sufficiently researched through high-quality fully powered randomised trials to establish potential or adverse effects. As a consequence, no rehabilitation approach can be supported or refuted based on current evidence from RCTs. As recommended by a number of national clinical guidelines, clinicians should continue to provide rehabilitation for neglect that enables people to meet their rehabilitation goals. Clinicians and stroke survivors should have the opportunity, and are strongly encouraged, to participate in research. Future studies need to have appropriate high-quality methodological design, delivery, and reporting to enable appraisal and interpretation of results. Future studies also must evaluate outcomes of importance to patients, such as persisting functional ability in ADL. One way to improve the quality of research is to involve people with experience with the condition in designing and running trials.

Can auditory cues improve visuo-spatial neglect? Results of two pilot studies

Although neglect is known to be a multimodal deficit, current interventions often address the visual modality only. Experimental studies, however, found that neglect patients can partially overcome their spatial inattention temporarily when being exposed to auditory cues that move towards the neglected side of space. Two pilot studies investigated the impact of dynamic auditory cueing on egocentric neglect severity in a clinical-therapeutic setting. In both studies, the patient groups received 15 sessions of intervention. Study 1, designed as double-blinded trial with a historical control group, targeted severely impaired early-acute patients who listened to music or audio books which were presented as moving dynamically from right to left. Results showed a reduction in egocentric neglect severity that persisted after therapy termination in the intervention but not in the historical control group. In study 2, based on the comparison with reported effect sizes of previous studies, dynamic meaningful auditory cues and optokinetic stimulation were combined in a computer-based training. Both studies found a significant reduction of neglect severity. Results provide evidence for the reduction of egocentric neglect severity after repetitive auditory cueing therapy in both severely and moderately impaired patients. Our promising findings should be verified thoroughly in randomized-controlled trials.

Unilateral Spatial Neglect After Stroke: Current Insights

INTRODUCTION

Unilateral spatial neglect (USN) is a disorder of contralesional space awareness which often follows unilateral brain lesion. Since USN impairs awareness of contralesional space/body and often of concomitant motor disorders, its presence represents a negative prognostic factor of functional recovery. Thus, the disorder needs to be carefully diagnosed and treated. Here, we attempted to present a clear and concise picture of current insights in the comprehension and rehabilitation of USN.

METHODS

We first provided an updated overview of USN clinical and neuroanatomical features and then highlighted recent progresses in the diagnosis and rehabilitation of the disease. In relation to USN rehabilitation, we conducted a MEDLINE literature research on three of the most promising interventions for USN rehabilitation: prismatic adaptation (PA), non-invasive brain stimulation (NIBS), and virtual reality (VR). The identified studies were classified according to the strength of their methods.

RESULTS

The last years have witnessed a relative decrement of interest in the study of neuropsychological disorders of spatial awareness in USN, but a relative increase in the study of potential interventions for its rehabilitation. Although optimal protocols still need to be defined, high-quality studies have demonstrated the efficacy of PA, TMS and tDCS interventions for the treatment of USN. In addition, preliminary investigations are suggesting the potentials of GVS and VR approaches for USN rehabilitation.

CONCLUSION

Advancing neuropsychological and neuroscience tools to investigate USN pathophysiology is a necessary step to identify effective rehabilitation treatments and to foster our understanding of neurofunctional bases of spatial cognition in the healthy brain.

The Management of Stroke Rehabilitation: A Synopsis of the 2019 U.S. Department of Veterans Affairs and U.S. Department of Defense Clinical Practice Guideline

DESCRIPTION

In June 2019, the U.S. Department of Veterans Affairs (VA) and U.S. Department of Defense (DoD) approved an update of the joint clinical practice guideline for rehabilitation after stroke. This synopsis summarizes the key recommendations from this guideline.

METHODS

In February 2018, the VA/DoD Evidence-Based Practice Work Group convened a joint VA/DoD guideline development effort that included clinical stakeholders and stroke survivors and conformed to the National Academy of Medicine (formerly the Institute of Medicine) tenets for trustworthy clinical practice guidelines. The guideline panel identified key questions, systematically searched and evaluated the literature, and developed 2 algorithms and 42 key recommendations using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. Stroke survivors and their family members were invited to share their perspectives to further inform guideline development.

RECOMMENDATIONS

The guideline recommendations provide evidence-based guidance for the rehabilitation care of patients after stroke. The recommendations are applicable to health care providers in both primary care and rehabilitation. Key features of the guideline are recommendations in 6 areas: timing and approach; motor therapy; dysphagia; cognitive, speech, and sensory therapy; mental health therapy; and other functions, such as returning to work and driving.

Rehabilitation in acute stroke from the point of view of evidence-based medicine: possibilities of drug treatment

The review highlights the fundamental principles of early rehabilitation in ischemic stroke, the benefits and risks of early and very early patient mobilization. It presents data on the efficiency of CIMT-kinesiotherapy and mirror therapy in restoring upper extremity function, as well as procedures for nonpharmacological correction of spatial neglect syndrome. The effect on the rehabilitation of concomitant Alzheimer's disease is analyzed. The areas of pharmacological potentiation of poststroke rehabilitation, the efficiency of cerebrolysin in particular, are considered.

"Sequential multimodality stimulation" for post-stroke-hemineglect: Feasibility and outcome in a pilot randomized controlled trial

OBJECTIVE

To test the feasibility and efficacy of multimodality stimulation combined with motor tasking as a corrective strategy for hemineglect following right hemispheric ischemic strokes.

MATERIAL AND METHODS

A prospective randomized controlled single blinded clinical trial was conducted over eighteen months from January 2017. All patients with right hemispheric ischemic strokes were screened for hemineglect and those fulfilling criteria were recruited and randomized. Patients under the therapy group (TG) received the intervention based on a structured protocol in addition to standard physiotherapy. The control group (CG) received standard physiotherapy alone. NIHSS, mRS and Neuropsychological test scores were recorded at different time points. The primary outcome measures (neuropsychological test scores) were compared between the two groups (Student's t-test to find out the difference in outcome measures) at one and three months post-stroke.

RESULTS

Of the 14 patients recruited, data from 12 were available for analysis, 5 patients in TG and 7 in CG. There was a trend for better hemineglect and functional outcomes in TG.

CONCLUSION

Multimodality stimulation, in addition to standard physiotherapy, is feasible and potentially results in better neurocognitive and functional recovery following right hemispheric ischemic strokes. However, larger studies are warranted to prove these preliminary observations beyond doubt.

Automatic Neuroimage Processing and Analysis in Stroke-A Systematic Review

This article presents a systematic review of the current computational technologies applied to medical images for the detection, segmentation, and classification of strokes. Besides, analyzing and evaluating the technological advances, the challenges to be overcome and the future trends are discussed. The principal approaches make use of artificial intelligence, digital image processing and analysis, and various other technologies to develop computer-aided diagnosis (CAD) systems to improve the accuracy in the diagnostic process, as well as the interpretation consistency of medical images. However, there are some points that require greater attention such as low sensitivity, optimization of the algorithm, a reduction of false positives, and improvement in the identification and segmentation processes of different sizes and shapes. Also, there is a need to improve the classification steps of different stroke types and subtypes. Furthermore, there is an additional need for further research to improve the current techniques and develop new algorithms to overcome disadvantages identified here. The main focus of this research is to analyze the applied technologies for the development of CAD systems and verify how effective they are for stroke detection, segmentation, and classification. The main contributions of this review are that it analyzes only up-to-date studies, mainly from 2015 to 2018, as well as organizing the various studies in the area according to the research proposal, i.e., detection, segmentation, and classification of the types of stroke and the respective techniques used. Thus, the review has great relevance for future research, since it presents an ample comparison of the most recent works in the area, clearly showing the existing difficulties and the models that have been proposed to overcome such difficulties.

[Top-down and bottom-up approaches for the treatment of unilateral spatial neglect in stroke patients: A systematic review]

OBJECTIVE

To evaluate the effectiveness of top-down and bottom-up approaches in the rehabilitation of unilateral spatial neglect in stroke patients.

METHODOLOGY

We carried out a systematic review of randomized controlled trials from January of 2013 to March of 2017. The following databases were searched: Scopus, Science Direct, Web of Science, Pubmed and CINHAL. The methodological quality, level of scientific evidence and the strength of recommendation were evaluated.

RESULTS

We included 13 studies (294 subjects): nine studies (188 patients) carried out therapies with a bottom-up approach such us eye patching, virtual reality, optokinetic stimulation, transcranial magnetic stimulation and prism adaption; three studies (94 patients) evaluated therapies with a top-down approach such us visual scanning, sensory feedback and mental practice; one study incorporated both approaches. Nine of these studies showed improvements in spatial neglect scales; five of these used bottom-up approaches, another three used top-down approaches and the remaining study combined both approaches. Disability was evaluated by nine studies, and only three reported improvements. Three studies reported significant improvements in motor function in the intervention groups.

CONCLUSIONS

Top-down and bottom-up approaches could improve unilateral spatial neglect, disability and motor function in patients with stroke.

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.

Interventions for visual field defects in people with stroke

BACKGROUND

Visual field defects are estimated to affect 20% to 57% of people who have had a stroke. Visual field defects can affect functional ability in activities of daily living (commonly affecting mobility, reading and driving), quality of life, ability to participate in rehabilitation, and depression and anxiety following stroke. There are many interventions for visual field defects, which are proposed to work by restoring the visual field (restitution); compensating for the visual field defect by changing behaviour or activity (compensation); substituting for the visual field defect by using a device or extraneous modification (substitution); or ensuring appropriate diagnosis, referral and treatment prescription through standardised assessment or screening, or both.

OBJECTIVES

To determine the effects of interventions for people with visual field defects after stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register, the Cochrane Eyes and Vision Group Trials Register, CENTRAL, MEDLINE, Embase, CINAHL, AMED, PsycINFO, and PDQT Databse, and clinical trials databases, including ClinicalTrials.gov and WHO Clinical Trials Registry, to May 2018. We also searched reference lists and trials registers, handsearched journals and conference proceedings, and contacted experts.

SELECTION CRITERIA

Randomised trials in adults after stroke, where the intervention was specifically targeted at improving the visual field defect or improving the ability of the participant to cope with the visual field loss. The primary outcome was functional ability in activities of daily living and secondary outcomes included functional ability in extended activities of daily living, reading ability, visual field measures, balance, falls, depression and anxiety, discharge destination or residence after stroke, quality of life and social isolation, visual scanning, adverse events, and death.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened abstracts, extracted data and appraised trials. We undertook an assessment of methodological quality for allocation concealment, blinding of outcome assessors, method of dealing with missing data, and other potential sources of bias. We assessed the quality of evidence for each outcome using the GRADE approach.

MAIN RESULTS

Twenty studies (732 randomised participants, with data for 547 participants with stroke) met the inclusion criteria for this review. However, only 10 of these studies compared the effect of an intervention with a placebo, control, or no treatment group, and eight had data which could be included in meta-analyses. Only two of these eight studies presented data relating to our primary outcome of functional abilities in activities of daily living. One study reported evidence relating to adverse events.Three studies (88 participants) compared a restitutive intervention with a control, but data were only available for one study (19 participants). There was very low-quality evidence that visual restitution therapy had no effect on visual field outcomes, and a statistically significant effect on quality of life, but limitations with these data mean that there is insufficient evidence to draw any conclusions about the effectiveness of restitutive interventions as compared to control.Four studies (193 participants) compared the effect of scanning (compensatory) training with a control or placebo intervention. There was low-quality evidence that scanning training was more beneficial than control or placebo on quality of life, measured using the Visual Function Questionnaire (VFQ-25) (two studies, 96 participants, mean difference (MD) 9.36, 95% confidence interval (CI) 3.10 to 15.62). However, there was low or very-low quality evidence of no effect on measures of visual field, extended activities of daily living, reading, and scanning ability. There was low-quality evidence of no significant increase in adverse events in people doing scanning training, as compared to no treatment.Three studies (166 participants) compared a substitutive intervention (a type of prism) with a control. There was low or very-low quality evidence that prisms did not have an effect on measures of activities of daily living, extended activities of daily living, reading, falls, or quality of life, and very low-quality evidence that they may have an effect on scanning ability (one study, 39 participants, MD 9.80, 95% CI 1.91 to 17.69). There was low-quality evidence of an increased odds of an adverse event (primarily headache) in people wearing prisms, as compared to no treatment.One study (39 participants) compared the effect of assessment by an orthoptist to standard care (no assessment) and found very low-quality evidence that there was no effect on measures of activities of daily living.Due to the quality and quantity of evidence, we remain uncertain about the benefits of assessment interventions.

AUTHORS' CONCLUSIONS

There is a lack of evidence relating to the effect of interventions on our primary outcome of functional ability in activities of daily living. There is limited low-quality evidence that compensatory scanning training may be more beneficial than placebo or control at improving quality of life, but not other outcomes. There is insufficient evidence to reach any generalised conclusions about the effect of restitutive interventions or substitutive interventions (prisms) as compared to placebo, control, or no treatment. There is low-quality evidence that prisms may cause minor adverse events.

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).

A Systematic Review and Meta-Analysis of Rehabilitative Interventions for Unilateral Spatial Neglect and Hemianopia Poststroke From 2006 Through 2016

OBJECTIVE

To evaluate the effectiveness of activity-based, nonactivity-based, and combined activity- and nonactivity-based rehabilitative interventions for individuals presenting with unilateral spatial neglect (USN) and hemianopia.

DATA SOURCES

We searched CINAHL, Cochrane Library, EMBASE, MEDLINE, and PubMed from 2006 to 2016.

STUDY SELECTION

Randomized controlled trials (RCTs) with a score of 6 or more in the Physiotherapy Evidence Database Scale that examined the effects of activity-based and nonactivity-based rehabilitation interventions for people with USN or hemianopia. Two reviewers selected studies independently.

DATA EXTRACTION

Extracted data from the published RCTs. Mean differences (MD) or standardized mean differences (SMD), and 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed using the I² statistic.

DATA SYNTHESIS

A total of 20 RCTs for USN and 5 for hemianopia, involving 594 and 206 stroke participants respectively, were identified. Encouraging results were found in relation to activity-based interventions for visual scanning training and compensatory training for hemianopia (MD=5.11; 95% confidence intervals [95% CI], 0.83-9.4; P=.019; I²=25.16% on visual outcomes), and optokinetic stimulation and smooth pursuit training for USN (SMD=0.49; 95% CI, 0.01-0.97; P=.045; I²=49.35%) on functional performance in activities of daily living, (SMD=0.96; 95% CI, 0.09-1.82; P=.031; I²=89.57%) on neglect.

CONCLUSIONS

Activity-based interventions are effective and commonly used in the treatment of USN and hemianopia. Nonactivity-based and combined approaches, for both impairments, have not been refuted, because more studies are required for substantiated conclusions to be drawn.

Early Rehabilitation After Stroke: a Narrative Review

PURPOSE OF REVIEW

Despite current rehabilitative strategies, stroke remains a leading cause of disability in the USA. There is a window of enhanced neuroplasticity early after stroke, during which the brain's dynamic response to injury is heightened and rehabilitation might be particularly effective. This review summarizes the evidence of the existence of this plastic window, and the evidence regarding safety and efficacy of early rehabilitative strategies for several stroke domain-specific deficits.

RECENT FINDINGS

Overall, trials of rehabilitation in the first 2 weeks after stroke are scarce. In the realm of very early mobilization, one large and one small trial found potential harm from mobilizing patients within the first 24 h after stroke, and only one small trial found benefit in doing so. For the upper extremity, constraint-induced movement therapy appears to have benefit when started within 2 weeks of stroke. Evidence for non-invasive brain stimulation in the acute period remains scant and inconclusive. For aphasia, the evidence is mixed, but intensive early therapy might be of benefit for patients with severe aphasia. Mirror therapy begun early after stroke shows promise for the alleviation of neglect. Novel approaches to treating dysphagia early after stroke appear promising, but the high rate of spontaneous improvement makes their benefit difficult to gauge. The optimal time to begin rehabilitation after a stroke remains unsettled, though the evidence is mounting that for at least some deficits, initiation of rehabilitative strategies within the first 2 weeks of stroke is beneficial. Commencing intensive therapy in the first 24 h may be harmful.

Rehabilitation of unilateral neglect: Evidence-based medicine

BACKGROUND

In the last decades, several rehabilitation methods have been developed to improve spatial neglect. These can be classified according to their theoretical basis: (i) enhance awareness of neglect behaviour through a top-down mechanism; (ii) low-level bottom-up sensory stimulation; (iii) modulation of inhibitory processes; (iv) increase arousal.

OBJECTIVE

The purpose of this study was to provide an overview of the evidence on the effectiveness of rehabilitation procedures for unilateral neglect.

METHOD

A systematic search was performed to look for all randomised controlled trials aimed at reducing left spatial neglect that included a functional assessment. In addition, recent review papers and meta-analyses were analysed.

RESULTS

Thirty-seven randomized controlled trials were found (12 bottom-up; 12 top-down; 1 interhemispheric competition; 12 combination of approaches) that included 1027 patients with neglect. Although there are some encouraging results, overall, the level of evidence remains low. Poor methodological quality and small sample sizes are major limitations in many published trials.

CONCLUSION

There is a need for well-conducted, large-scale randomised controlled trials that incorporate blinded assessments, evaluation of the generalization to activities of daily living and long-term follow-up.

The ecological assessment of unilateral neglect

Conventional paper-and-pencil tests of unilateral neglect are of limited ecological validity. To address this issue, a number of assessment procedures have been proposed to provide clinicians and researchers with more ecologically valid assessments of unilateral neglect, which may be useful to plan rehabilitation and to measure the generalization of the effects of rehabilitation to daily life. We present here an overview of the different assessment measures available in the literature. The most widely used scales are the Behavioural Inattention Test (BIT), the semi-structured scales for assessment of personal and extra-personal neglect, the Subjective Neglect Questionnaire, the Baking Tray Task, the wheelchair obstacle course, the ADL-based neglect battery, and the Catherine Bergego Scale (CBS). The CBS is probably, to date, the most widely used behavioural assessment instrument for unilateral neglect. It has been found to be reliable, valid, and sensitive to change during rehabilitation. It also enables the assessment of awareness of the consequences of unilateral neglect in daily life skills.

Classifiers for Ischemic Stroke Lesion Segmentation: A Comparison Study

MOTIVATION

Ischemic stroke, triggered by an obstruction in the cerebral blood supply, leads to infarction of the affected brain tissue. An accurate and reproducible automatic segmentation is of high interest, since the lesion volume is an important end-point for clinical trials. However, various factors, such as the high variance in lesion shape, location and appearance, render it a difficult task.

METHODS

In this article, nine classification methods (e.g. Generalized Linear Models, Random Decision Forests and Convolutional Neural Networks) are evaluated and compared with each other using 37 multiparametric MRI datasets of ischemic stroke patients in the sub-acute phase in terms of their accuracy and reliability for ischemic stroke lesion segmentation. Within this context, a multi-spectral classification approach is compared against mono-spectral classification performance using only FLAIR MRI datasets and two sets of expert segmentations are used for inter-observer agreement evaluation.

RESULTS AND CONCLUSION

The results of this study reveal that high-level machine learning methods lead to significantly better segmentation results compared to the rather simple classification methods, pointing towards a difficult non-linear problem. The overall best segmentation results were achieved by a Random Decision Forest and a Convolutional Neural Networks classification approach, even outperforming all previously published results. However, none of the methods tested in this work are capable of achieving results in the range of the human observer agreement and the automatic ischemic stroke lesion segmentation remains a complicated problem that needs to be explored in more detail to improve the segmentation results.