Patterns of spontaneous recovery of neglect and associated disorders in acute right brain-damaged patients

Preserved recognition of basic visual features despite lack of awareness of shape: Evidence from a case of neglect

Human visual experience of objects comprises a combination of visual features, such as color, position, and shape. Spatial attention is thought to play a role in creating a coherent perceptual experience, integrating visual information coming from a given location, but the mechanisms underlying this process are not fully understood. Deficits of spatial attention in which this integration process does not occur normally, such as neglect, can provide insights regarding the mechanisms of spatial attention in visual object recognition. In this study, we describe a series of experiments conducted with an individual with neglect, DH. DH presents characteristic lack of awareness of the left side of individual objects, evidenced by poor object and face recognition, and impaired word reading. However, he exhibits intact recognition of color within the boundaries of the same objects he fails to recognize. Furthermore, he can also report the orientation and location of a colored region on the neglected left side despite lack of awareness of the shape of the region. Overall, DH shows selective lack of awareness of shape despite intact processing of basic visual features in the same spatial location. DH's performance raises intriguing questions and challenges about the role of spatial attention in the formation of coherent object percepts and visual awareness.

A scoping review and critique of the Input-Output subtyping dimension of spatial neglect

Spatial neglect is a common and debilitating disorder after stroke whereby individuals have difficulty reporting, orienting, and/or responding to the contralesional side of space. Given the heterogeneity of neglect symptom presentation, various neglect subtypes have been proposed to better characterize the disorder. This review focuses on the distinction between Input neglect (i.e., difficulty perceiving and/or attending to contralesional stimuli) and Output neglect (i.e., difficulty planning and/or executing movements toward contralesional stimuli). Conceptualizations of Input and Output neglect have varied considerably. We provide a novel summary of the terminology, measurement approaches, and neural correlates of these subtypes. A protocol detailing our systematic scoping review strategy is registered on the Open Science Framework (https://osf.io/bvtxf/). For feasibility and greater comparability across studies, we limited our inclusion criteria to tasks focused on visual stimuli and upper-limb movements. A total of 110 articles were included in the review. Subtyping tasks were categorized based on whether they mainly manipulated aspects of the input (i.e., congruence of visual input with motor output, presence of visual input) or the output (i.e., modality, goal, or direction of output) to produce an Input-Output subtype dissociation. We used our review results to identify four main critiques of this literature: 1) lack of consistency/clarity in conceptual models; 2) methodological issues of dissociating Input and Output subtypes; 3) a need for updated neural theories; and 4) barriers to clinical application. We discuss the lessons learned from this subtyping dimension that can be applied to future research on neglect subtype assessment and treatment.

Effects of a Stimulus Response Task Using Virtual Reality on Unilateral Spatial Neglect: A Randomized Controlled Trial

OBJECTIVE

To investigate the effects of a stimulus response task using virtual reality (VR) for unilateral spatial neglect (USN).

DESIGN

Double-blind randomized controlled trial.

SETTING

Acute phase hospital where stroke patients are hospitalized.

PARTICIPANTS

The participants were 42 patients (N=42) with right-hemisphere cerebral damage who had been experiencing USN in their daily lives. They were randomly assigned to 3 groups: a stimulus response task with a background shift (SR+BS group), a stimulus response task without a background shift (SR group), and an object gazing task (control group).

INTERVENTIONS

The stimulus response task was to search for balloons that suddenly appeared on the VR screen. A background shift was added to highlight the search in the neglected space. The control task was to maintain a controlled gaze on a balloon that appeared on the VR screen. The intervention period was 5 days.

MAIN OUTCOME MEASURES

The primary outcome was the participants' scores on a stimulus-driven attention test (SAT) using the reaction time. The stimuli of the SAT were divided into 6 blocks of 3 lines on each side (-3 to +3). The secondary outcomes were their scores on the Behavioral Intention Test conventional, Catherine Bergego Scale, and straight ahead pointing tests.

RESULTS

In the SAT, there were significant interaction effects of reaction time between time and group factors in left-2, right+2, and right+3. The SR+BS and SR groups showed significant improvements in the reaction time of left-2 and right+3 compared with the control group. Moreover, the SR+BS group showed a significant improvement in the reaction time of left-2, which was the neglected space, compared with the SR group. However, there were no significant interaction effects of Behavioral Intention Test conventional, Catherine Bergego Scale, and straight ahead pointing.

CONCLUSIONS

Our results suggest that the use of stimulus response tasks using VR combined with background shifts may improve left-sided USN.

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.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Identifying profiles of stroke patients benefitting from additional training: a latent class analysis approach

OBJECTIVE

To identify profiles of stroke patient benefitting from additional training, using latent class analysis.

DESIGN

Retrospective observational study.

PATIENTS

Patients with stroke (n = 6,875) admitted to 42 recovery rehabilitation units in Japan between January 2005 and March 2016 who were registered in the Japan Association of Rehabilitation Database.

METHODS

The main outcome measure was the difference in Functional Independence Measure (FIM) scores between admission and discharge (referred to as "gain"). The effect of additional training, categorized as usual care (no additional training), self-exercise, training with hospital staff, or both exercise (combining self-exercise and training with hospital staff), was assessed through multiple regression analyses of latent classes.

RESULTS

Applying inclusion and exclusion criteria, 1185 patients were classified into 7 latent classes based on their admission characteristics (class size n = 82 (7%) to n = 226 (19%)). Patients with class 2 characteristics (right hemiparesis and modified dependence in the motor-FIM and cognitive-FIM) had positive FIM gain with additional training (95% confidence interval (95% CI) 0.49-3.29; p < 0.01). One-way analysis of variance revealed that training with hospital staff (95% CI 0.07-16.94; p < 0.05) and both exercises (95% CI 5.38-15.13; p < 0.01) led to a significantly higher mean FIM gain than after usual care.

CONCLUSION

Additional training in patients with stroke with right hemiparesis and modified dependence in activities of daily living was shown to improve activities of daily living. Training with hospital staff combined with self-exercise is a promising rehabilitation strategy for these patients.

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.

Moderate-Severe TBI as a Progressive Disorder: Patterns and Predictors of Cognitive Declines in the Chronic Stages of Injury

BACKGROUND

Moderate-severe traumatic brain injury (TBI) has been associated with progressive cognitive decline in the chronic injury stages in a small number of studies.

OBJECTIVE

This study aimed to (i) replicate our previous findings of decline from 1 to 3+ years post-injury in a larger, non-overlapping sample and (ii) extend these findings by examining the proportion of decliners in 2 earlier time windows, and by investigating novel predictors of decline.

METHODS

N = 48 patients with moderate-severe TBI underwent neuropsychological assessment at 2, 5, 12 months, and 30+ months post-injury. We employed the Reliable Change Index (RCI) to evaluate decline, stability and improvement across time and logistic regression to identify predictors of decline (demographic/cognitive reserve; injury-related).

RESULTS

The proportions of patients showing decline were: 12.5% (2-5 months post-injury), 17% (5-12 months post-injury), and 27% (12-30+ months post-injury). Measures of verbal retrieval were most sensitive to decline. Of the predictors, only left progressive hippocampal volume loss from 5 to 12 months post-injury significantly predicted cognitive decline from 12 to 30+ months post-injury.

CONCLUSIONS

Identical to our previous study, 27% of patients declined from 12 to 30+ months post-injury. Additionally, we found that the further from injury, the greater the proportion of patients declining. Importantly, earlier progressive hippocampal volume loss predicted later cognitive decline. Taken together, the findings highlight the need for ongoing research and treatment that target these deleterious mechanisms affecting patients in the chronic stages of moderate-severe TBI.

Key constructs of body awareness impairments post-stroke: a scoping review of assessment tools and interventions

PURPOSE

To summarise body awareness assessment tools and interventions relevant for stroke rehabilitation using a framework that categorises key body awareness constructs, disorders and impairments.

MATERIALS AND METHODS

Online electronic databases and trial registries were searched from inception until July 2021, in addition to hand searching reference lists of included studies and reviews. Study selection included any study design where the investigation involved assessing and/or intervening in body awareness following stroke. Data were extracted based on predefined criteria by two independent reviewers and mapped to the emergent framework.

RESULTS

The final analysis included 144 papers that reported 43 assessment tools and 8 types of interventions for body awareness. Consensus was reached on a synthesised body awareness framework. This comprised specific impairments and disorders, constructs, sub-categories and main categories leading to the overarching term of body awareness. Clinical and psychometric properties of the assessment tools were not reported or poorly evaluated, and the interventions lacked robust study designs and rigorous methods.

CONCLUSIONS

The framework produced will enable future research and clinical practice to be based on consistent concepts and definitions. Clinicians can also use this information to cautiously select assessment tools and/or interventions but are reminded of the limitations identified in this review.Implications for rehabilitationThere is limited understanding, compounded by inconsistent terminology and definitions regarding body awareness after stroke.A synthesized framework to define key constructs and definitions of body awareness is proposed.Assessment tools and interventions reported in the literature are mapped to the proposed framework.Psychometric properties of available tools are reported.Significant work remains to refine concepts of body awareness, develop and evaluate assessment tools and interventions.

A Quantitative, Digital Method to Analyze Human Figure Drawings as a Tool to Assess Body Representations Distortions in Stroke Patients

OBJECTIVE

Human figure drawings are widely used in clinical practice as a qualitative indication of Body Representations (BRs) alterations in stroke patients. The objective of this study is to present and validate the use of a new app called QDraw for the quantitative analysis of drawings and to investigate whether this analysis can reveal distortions of BRs in chronic stroke patients.

RESULTS

QDraw has proven to generate reliable data as compared to manual scoring and in terms of inter-rater reliability, as shown by the high correlation coefficients. Moreover, human figure drawings from chronic stroke patients demonstrated a distortion of upper limb perception, as shown by a significantly higher arm length asymmetry compared to legs, whereas no difference was found in healthy controls.

CONCLUSIONS

The present study supports the use of quantitative, digital methods (the QDraw app) to analyze human figure drawings as a tool to evaluate BRs distortions in stroke patients.

Broken Ring enVision Search (BReViS): A New Clinical Test of Attention to Assess the Effect of Layout and Crowding on Visual Search

The assessment of attention in neuropsychological patients could be performed with visual search tests. The Broken Rings enVision Search test (BReViS) here proposed represents a novel open access paper-and-pencil tool in which layout and crowding are varied among four cards. These manipulations allow the assessment of different components of attention: a selective component, the visuo-spatial orientation of attention, and the focal attention, involved in a crowding phenomenon. Our purpose was to determine the characteristics of the BReViS test, provide specific normative data, and assess these components across the lifespan. The test was administered to a sample of 550 participants aged between 20 and 79 years old and to a series of patients. Three indexes targeting different components of visuo-spatial attention (selective attention, strategic orientation of visual attention, focal attention) were obtained by combining execution times and accuracy together with the total errors. The results showed that age, education and gender influenced, in different combinations, the four indexes, for which specific norms were developed. Regression-based norms were provided in percentiles and equivalent scores. All patients showed pathological scores and specific patterns of attentional deficits. The BreViS test proved to be a free and easy valuable tool which can be used in the clinical environment to assess attentional deficits in neuropsychological patients.

Barriers to patient recruitment in a poststroke neurorehabilitation multicenter trial in Brazil

There is a high demand for stroke rehabilitation in the Brazilian public health system, but most studies that have addressed rehabilitation for unilateral spatial neglect (USN) after stroke have been performed in high-income countries. Therefore, the aim of this study was to analyze USN patient recruitment in a multicenter noninvasive brain stimulation clinical trial performed in Brazil and to provide study design recommendations for future studies. We evaluated the reasons for exclusion of patients from a multicenter, randomized, double-blinded clinical trial of rehabilitation of USN patients after stroke. Clinical and demographic variables were compared between the included and excluded patients. A descriptive statistical analysis was performed. Only 173 of the 1953 potential neglect patients (8.8%) passed the initial screening. After screening evaluation, 87/173 patients (50.3%) were excluded for clinical reasons. Cognitive impairment led to the exclusion of 21/87 patients (24.1%). Low socioeconomic status led to the exclusion of 37/173 patients (21.4%). Difficulty obtaining transportation to access treatment was the most common reason for their exclusion (16/37 patients, 43.3%). The analyzed Brazilian institutions have potential for conducting studies of USN. The recruitment of stroke survivors with USN was restricted by the study design and limited financial support. A history of cognitive impairment, intracranial stenting or craniectomy, and lack of transportation were the most common barriers to participating in a multicenter noninvasive brain stimulation trial among patients with USN after stroke.

Development and 5-year Evaluation of Diagnosis-Specific Protocols for Visual Neuro-Rehabilitation in a Multicenter Inpatient Rehabilitation Network

Objective

To provide a retrospective evaluation of a new eye and vision rehabilitation care pathway in a U.S. multi-site inpatient rehabilitation network involving the occupational therapy (OT) staff and a consulting doctor of optometry (OD) specializing in vision rehabilitation.

Design

Retrospective study.

Setting

Two Inpatient Rehabilitation Facilities (IRFs) and 1 Long Term Acute Care Hospital (LTACH).

Participants

There were 2083 records reviewed (44% women, avg. age 59 years). The most common diagnoses were hemispatial neglect (19.2%), homonymous field defects (18.5%), and oculomotor cranial nerve palsies (16.7%) (N=2083).

Interventions

Clinical care was reviewed where diagnosis-specific protocols were developed and training was provided to OTs in order to reinforce OD-prescribed interventions during daily treatment sessions, including (1) third, fourth, and sixth ocular cranial nerve palsies (OCNPs) with prisms fitted for full time, postural adaptation training, and oculomotor re-education using pursuits, saccades, head-rotations, and binocular vision exercises including alternate cover and vergence; (2) homonymous hemianopia with training awareness of field loss, eccentric viewing, and fitting of Peli lens for optical field expansion; and (3) prism adaptation therapy (PAT) for left hemispatial neglect.

Main Outcome Measures

Frequency of diagnoses.

Hypothesis

Diagnoses with developed protocols were most common. Secondarily, feasibility and efficacy by anonymous OT survey.

Results

2083 vision consults were performed over 5 years. The most common diagnoses were hemispatial neglect (n=399, 19.2%), homonymous field defects (n=386, 18.5%), and OCNPs (n=347, 16.7%). None of the OTs reported the protocols were infeasible and 63% (IQR 38%-69%) reported their patients benefited from the interventions. The survey suggested prism for OCNPs helped in 42%, and Peli lens and PAT both helped in 38%.

Conclusions

Data support the feasibility of this inpatient eye and vision rehabilitation care pathway which may be used as a foundation for creating or refining similar programs elsewhere. Uniform administration of IRF-based visual neuro-rehabilitation care could provide a substrate for future clinical trials to evaluate efficacy.

The process by which patients become aware of unilateral spatial neglect: A qualitative study

Unilateral spatial neglect (USN), which can occur post-stroke, significantly impacts patients' daily lives. We explored the process by which patients become aware of the facets of their USN from the acute to subacute phase using a qualitative method. Participant observations, semi-structured interviews, and medical-record surveys were conducted with eight patients with USN and thirty healthcare professionals. We identified three themes regarding the patients' USN awareness process: inconsistency between present symptoms and perception of the left side, reconsidering the reasons for a vagueness on the left side, and acceptance of neglecting the left side. Additionally, healthcare professionals' support consisted of four strategies: assessing patients' perception of stimuli on their left side, compensating for patients' behaviours, promoting awareness of USN, and promoting activities that involve the use of residual functions after a cerebrovascular accident. Patients with USN gradually became aware of their deficits through interactions with others, and they responded by creating and practicing their own self-developed management strategies. These findings indicate that recovery from USN requires a series of experiences and social interactions. A comprehensive understanding of the process of awareness and adaption to USN from onset to recovery can help provide support for patients with USN.

Assess and rehabilitate body representations via (neuro)robotics: An emergent perspective

The perceptions of our own body (e.g., size and shape) do not always coincide with its real characteristics (e.g., dimension). To track the complexity of our perception, the concept of mental representations (model) of the body has been conceived. Body representations (BRs) are stored in the brain and are maintained and updated through multiple sensory information. Despite being altered in different clinical conditions and being tightly linked with self-consciousness, which is one of the most astonishing features of the human mind, the BRs and, especially, the underlying mechanisms and functions are still unclear. In this vein, here we suggest that (neuro)robotics can make an important contribution to the study of BRs. The first section of the study highlights the potential impact of robotics devices in investigating BRs. Far to be exhaustive, we illustrate major examples of its possible exploitation to further improve the assessment of motor, haptic, and multisensory information building up the BRs. In the second section, we review the main evidence showing the contribution of neurorobotics-based (multi)sensory stimulation in reducing BRs distortions in various clinical conditions (e.g., stroke, amputees). The present study illustrates an emergent multidisciplinary perspective combining the neuroscience of BRs and (neuro)robotics to understand and modulate the perception and experience of one's own body. We suggest that (neuro)robotics can enhance the study of BRs by improving experimental rigor and introducing new experimental conditions. Furthermore, it might pave the way for the rehabilitation of altered body perceptions.

Body and peripersonal space representations in chronic stroke patients with upper limb motor deficits

The continuous stream of multisensory information between the brain and the body during body–environment interactions is crucial to maintain the updated representation of the perceived dimensions of body parts (metric body representation) and the space around the body (the peripersonal space). Such flow of multisensory signals is often limited by upper limb sensorimotor deficits after stroke. This would suggest the presence of systematic distortions of metric body representation and peripersonal space in chronic patients with persistent sensorimotor deficits. We assessed metric body representation and peripersonal space representation in 60 chronic stroke patients with unilateral upper limb motor deficits, in comparison with age-matched healthy controls. We also administered a questionnaire capturing explicit feelings towards the affected limb. These novel measures were analysed with respect to patients’ clinical profiles and brain lesions to investigate the neural and functional origin of putative deficits. Stroke patients showed distortions in metric body representation of the affected limb, characterized by an underestimation of the arm length and an alteration of the arm global shape. A descriptive lesion analysis (subtraction analysis) suggests that these distortions may be more frequently associated with lesions involving the superior corona radiata and the superior frontal gyrus. Peripersonal space representation was also altered, with reduced multisensory facilitation for stimuli presented around the affected limb. These deficits were more common in patients reporting pain during motion. Explorative lesion analyses (subtraction analysis, disconnection maps) suggest that the peripersonal space distortions would be more frequently associated with lesions involving the parietal operculum and white matter frontoparietal connections. Moreover, patients reported altered feelings towards the affected limb, which were associated with right brain damage, proprioceptive deficits and a lower cognitive profile. These results reveal implicit and explicit distortions involving metric body representation, peripersonal space representation and the perception of the affected limb in chronic stroke patients. These findings might have important clinical implications for the longitudinal monitoring and the treatments of often-neglected deficits in body perception and representation.

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.

Clinical course of left spatial neglect with a focus on the assessment of stimulus-driven attention

We developed Stimulus-driven Attention Tests (SAT) for a patient with unilateral spatial neglect (USN) and longitudinally investigated the results and compared them to two conventional assessments. The patient suffered a right putaminal hemorrhage resulting in left-side USN. On the 12th, 22nd, and 28th days from the onset, the Behavioral Inattention Test (BIT) and the Catherine Bergego Scale (CBS), which are conventional USN assessments, and our two Stimulus-driven Attention Tests (SAT-1 and SAT-2) were performed. Our assessment tests comprise two tasks in which participants respond to suddenly appearing stimuli and to a target stimulus among distractors. A longitudinal comparison of all assessments was performed to observe the clinical course of the USN. On the 12th day, scores were low on the BIT, CBS, and both SATs, but on the 22nd day, BIT improved above the cutoff; however, the CBS and SATs did not improve. On the 28th day, response to a target stimulus among distractors in the SAT remained low, and CBS scores did not change significantly. We were able to detect USN with the SAT when the participant showed improvement on the paper-and-pencil tests. Moreover, the number of distractors in the SAT was thought to reveal covert USN.

Fine-tuning and Personalization of EEG-based Neglect Detection in Stroke Patients

Spatial neglect (SN) is a neurological disorder that causes inattention to visual stimuli in the contralesional visual field, stemming from unilateral brain injury such as stroke. The current gold standard method of SN assessment, the conventional Behavioral Inattention Test (BIT-C), is highly variable and inconsistent in its results. In our previous work, we built an augmented reality (AR)-based BCI to overcome the limitations of the BIT-C and classified between neglected and non-neglected targets with high accuracy. Our previous approach included personalization of the neglect detection classifier but the process required rigorous retraining from scratch and time-consuming feature selection for each participant. Future steps of our work will require rapid personalization of the neglect classifier; therefore, in this paper, we investigate fine-tuning of a neural network model to hasten the personalization process.

Interaction between spatial neglect and attention deficit in patients with right hemisphere damage

Unilateral spatial neglect (USN) was originally regarded as a parietal syndrome, but it has become evident that USN is a disturbance in the widespread attention network. Here, we focused on an interaction between spatial neglect and non-spatial aspect of attention deficit, and aimed to establish a novel evaluation approach based on the characteristics of the spatial distribution of reaction times. We tested 174 patients with right hemisphere damage and divided them based on their prescreening scores on the Behavioral Inattention Test (BIT): (1) USN++ (n = 79: BIT<131), (2) USN+ (n = 47: BIT≥131 with history of USN), and (3) RHD (n = 48: without neglect symptom). The patients were asked to conduct a touch panel-based pointing task toward 2D-arranged (seven columns × five rows) circular targets on a PC monitor, and the reaction time to each object was recorded. To evaluate aspects of attention deficit and neglect symptoms, we calculated the total average of the reaction time for all objects (RT_mean) and the ratios of the right and left space (L/R_ratio), respectively. The results revealed that RT_mean and L/R_ratio can be regarded as independent evaluation parameters for attention deficit and neglect symptoms, respectively. Voxel-based lesion-symptom mapping based on RT_mean and L/R_ratio values revealed relevant lesions with attention-related brain areas (middle temporal gyrus, angular gyrus, and inferior frontal gyrus), and neglect-related brain areas (superior temporal gyrus and superior longitudinal fascicules). A cluster analysis with Gaussian mixture model detected six different states of USN with an interaction between neglect symptoms and attention deficit. Interestingly, the recovery process after USN can be properly explained by the transition pattern from one cluster to another. Our results suggest that a novel evaluation approach to distinguish between neglect symptoms and attention deficit, namely the characterization of the interaction between RT_mean and L/R_ratio, provides useful information for understanding pathological features of USN.

Clinical presentation of strokes confined to the insula: a systematic review of literature

BACKGROUND AND PURPOSE

The insular cortex serves a wide variety of functions in humans, ranging from sensory and affective processing to high-level cognition. Hence, insular dysfunction may result in several different presentations. Ischemic strokes limited to the insular territory are rare and deserve a better characterization, to be quickly recognized and to receive the appropriate treatment (e.g. thrombolysis).

METHODS

We reviewed studies on patients with a first-ever acute stroke restricted to the insula. We searched in the Medline database the keywords "insular stroke" and "insular infarction", to identify previously published cases. Afterwards, the results were divided depending on the specific insular region affected by the stroke: anterior insular cortex (AIC), posterior insular cortex (PIC) or total insula cortex (TIC). Finally, a review of the clinical correlates associated with each region was performed.

RESULTS

We identified 25 reports including a total of 49 patients (59.7 ± 15.5 years, 48% male) from systematic review of the literature. The most common clinical phenotypes were motor and somatosensory deficits, dysarthria, aphasia and a vestibular-like syndrome. Atypical presentations were also common and included dysphagia, awareness deficits, gustatory disturbances, dysautonomia, neuropsychiatric or auditory disturbances and headache.

CONCLUSIONS

The clinical presentation of insular strokes is heterogeneous; however, an insular stroke should be suspected when vestibular-like, somatosensory, speech or language disturbances are combined in the same patient. Further studies are needed to improve our understanding of more atypical presentations.

Prevalence of spatial neglect post-stroke: A systematic review

OBJECTIVE

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Neuronavigated 1 Hz rTMS of the left angular gyrus combined with visuospatial therapy in post-stroke neglect

BACKGROUND

Visuospatial neglect (VSN) may be caused by an inter-hemispheric imbalance of neural activity after brain injury. Repetitive transcranial magnetic stimulation (rTMS) allows rebalancing restoration to a certain degree, relieving neglect symptoms.

OBJECTIVE

This study investigates the therapeutic effect of 1 Hz rTMS applied over the left angular gyrus combined with visual scanning training in patients with left VSN in the subacute stroke phase.

METHODS

Twenty-eight patients with VSN were randomly assigned to either experimental (fifteen sessions of rTMS consisted of 1800 magnetic pulses delivered to the left angular gyrus with a neuronavigation control), or control group (fifteen sessions of sham stimulation), followed by visual scanning training. VSN severity was assessed both before and after treatment with a 3-month follow up employing the Behavioural Inattention Test and functional measures.

RESULTS

No statistically significant differences were detected in outcome measures between the rTMS and sham groups after completion of 3-week therapy and at 3-month follow up. The magnitude of stimulation effects was not associated either with lesion volume, its location, or baseline motor threshold.

CONCLUSIONS

Our study did not confirm efficacy of 1 Hz rTMS over the angular gyrus as an adjuvant method to visual scanning training in patients with VSN in the subacute stroke.

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.

The presence and prediction of lateralized inattention 7 years post-stroke

OBJECTIVE

Lateralized inattention is a typical sign of neglect and related to poor functional outcome. Knowledge of the long-term course of this phenomenon is limited. The purpose of this study was to investigate presence and predictors for signs of lateralized inattention 7 years after stroke.

METHODS

From a cohort of acute ischemic stroke patients, aged 18-69 years (n = 297), a consecutive series of 188 survivors without recurrent stroke at follow-up 7 years later were included. Within the first week after stroke onset, stroke severity was assessed according to the Scandinavian Stroke Scale. Target omissions, asymmetry of omissions, and perceptual speed according to Star- and Letter Cancellation Tests were also assessed. Presence of lateralized inattention at the 7-year follow-up was investigated with the Star- and Letter Cancellation Tests and with the neglect item in the National Institutes of Health Stroke Scale.

RESULTS

At the follow-up, 22 (11.7%) participants had lateralized inattention and the multivariable regression showed that independent significant baseline predictors were total omissions in target cancellations (P < .001) and inferior baseline performance on visual processing speed (P = .008).

CONCLUSION

About one of ten individuals exhibited signs of lateralized inattention 7 years after stroke. Baseline performance in perceptual processing speed and target omissions independently predicted presence of late signs of lateralized inattention. This is the first time processing speed is recognized as a significant predictor of lateralized inattention several years after the stroke incidence, indicating that the longitudinal course of processing speed following stroke is a critical subject for future research.

Transcranial electric stimulation optimizes the balance of visual attention across space

OBJECTIVE

Transcranial direct current stimulation (tDCS) provides a way to modulate spatial attention by enhancing the ratio of neural activity between the left and right hemispheres, with a potential benefit for the rehabilitation of visual neglect.

METHODS

We tested the effect of bilateral tDCS in healthy individuals performing a visual detection task. This protocol consists in the positioning of the anode and cathode on mirror positions over the left and right parietal areas. The stimulation was repeated over three days to maximize the chance to observe a bias to the hemispace controlateral to the anode.

RESULTS

Compared to a sham treatment, left anodal - right cathodal stimulation enhanced attention across the full range of space, since the first day with no build-up effect on the next days, and modified the balance of left-right omissions when stimuli appeared at the same time.

CONCLUSION

Bilateral tDCS improved detection in both visual fields, with no privileged processing of one side, except when concurrent stimuli were presented. The results provide partial support to the hemispheric rivalry hypothesis.

SIGNIFICANCE

The technique has the potential to boost attention in neglect patients but should be used as an adjuvant rather than as an alternative to functional rehabilitation.

Novel characterization of subjective visual vertical in patients with unilateral spatial neglect

Visual vertical (VV), visually perceived direction of gravity, is widely measured to assess the vestibular function and visuospatial cognition. VV has been assessed by comparing orientation and variability of measured values separately between subject groups. However, changes in orientation and variability often differ in patients with unilateral spatial neglect (USN). Here, we developed a novel classification of VV that combines orientation and variability and characterized the effects of USN on VV. Forty-three subacute stroke patients with or without USN (USN+, n = 17; USN-, n = 26) and 33 age-matched controls were included in the study. In darkness, a luminous line, initially tilted at 30° either to the left or right, gradually rotated towards the vertical. The VV was defined as the deviation of the subjectively-perceived vertical from the true vertical. The new classification demonstrated that, while the majority of USN + patients (14/17) exhibited large variability, nine showed normal orientation and five showed greater contra-lesional deviation of orientation, suggesting different underlying mechanisms for orientation and variability. Further analyses revealed VV deviation to the initial tilt in all groups. However, the deviation in USN + was larger and more variable, indicating attentional disorders. Such characterization would contribute to individually specified clinical rehabilitation.

Mirror Therapy in Stroke Rehabilitation: Current Perspectives

In contrast to varied therapy approaches, mirror therapy (MT) can be used even in completely plegic stroke survivors, as it uses visual stimuli for producing a desired response in the affected limb. MT has been studied to have effects not just on motor impairments but also on sensations, visuospatial neglect, and pain after stroke. This paper attempts to systematically review and present the current perspectives on mirror therapy and its application in stroke rehabilitation, and dosage, feasibility and acceptability in stroke rehabilitation. An electronic database search across Google, PubMed, Web of Science, etc., generated 3871 results. After screening them based on the inclusion and exclusion criteria, we included 28 studies in this review. The data collected were divided on the basis of application in stroke rehabilitation, modes of intervention delivery, and types of control and outcome assessment. We found that most studies intervened for upper limb motor impairments post stroke. Studies were equally distributed between intervention in chronic and acute phases post stroke with therapy durations lasting between 1 and 8 weeks. MT showed definitive motor and sensory improvements although the extent of improvements in sensory impairments and hemineglect is limited. MT proves to be an effective and feasible approach to rehabilitate post-stroke survivors in the acute, sub-acute, and chronic phases of stroke, although its long-term effects and impact on activities of daily living need to be analysed extensively.

Frontal lesions predict response to prism adaptation treatment in spatial neglect: A randomised controlled study

Spatial neglect commonly follows right hemisphere stroke. It is defined as impaired contralesional stimulus detection, response, or action, causing functional disability. While prism adaptation treatment is highly promising to promote functional recovery of spatial neglect, not all individuals respond. Consistent with a primary effect of prism adaptation on spatial movements, we previously demonstrated that functional improvement after prism adaptation treatment is linked to frontal lobe lesions. However, that study was a treatment-only study with no randomised control group. The current study randomised individuals with spatial neglect to receive 10 days of prism adaptation treatment or to receive only standard care (control group). Replicating our earlier results, we found that the presence of frontal lesions moderated response to prism adaptation treatment: among prism-treated patients, only those with frontal lesions demonstrated functional improvements in their neglect symptoms. Conversely, among individuals in the standard care control group, the presence of frontal lesions did not modify recovery. These results suggest that further research is needed on how frontal lesions may predict response to prism adaptation treatment. Additionally, the results help elucidate the neural network involved in spatial movement and could be used to aid decisions about treatment.

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.

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

OBJECTIVE

Visual spatial neglect (VSN) is a disorder of spatial-temporal attention, often as a result of traumatic brain injury, including stroke. Accumulating evidence suggests that the recovery from VSN follows a very predictable pattern. In this study, we aimed to determine the specific electrophysiology readout that might have predictive value for recovery from VSN in the typical early events, including the recovery rate of visual processing, within the first four weeks of recovery.

METHODS

This was a prospective study of 18 right ischemic stroke patients with VSN who performed a visual cue-target task within 3 days after stroke. The patients were divided into two groups according to their outcome. We compared behavioral data, the amplitudes and latencies of ERP components（P1, N1, and P300） between patients with persistent-VSN (P-VSN) and those with rapid recovery-VSN (R-VSN).

RESULTS

The amplitudes and latencies of the P1 and N1 components were not significantly influenced by the validity of the cue-based expectancy (all p > 0.05). However, a longer mean P300 latency evoked an effective cue (p < 0.001), and there was a significant difference between the P-VSN and R-VSN groups when using the left target (left hemisphere, p = 0.014; right hemisphere, p = 0.027). The recovery rate found in our study (18.75% at four weeks after stroke) was lower than that of previously reported studies.

CONCLUSIONS

Our findings support the use of the event-related potential as a tool for investigating rapid recovery from VSN after stroke and suggest that other factors, such as an asymmetrical omission toward the contralateral side or impairment in the temporal processing capacity, might also be potential biomarkers of recovery.

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.

Distorted gaze direction input to attentional priority map in spatial neglect

A contribution of the gaze signals to the attention imbalance in spatial neglect is presumed. Direct evidence however, is still lacking. Theoretical models for spatial attention posit an internal representation of locations that are selected in the competition for neural processing resources – an attentional priority map. Following up on our recent research showing an imbalance in the allocation of attention after an oculoproprioceptive perturbation in healthy volunteers, we investigated here whether the lesion in spatial neglect distorts the gaze direction input to this representation.

Information about one's own direction of gaze is critical for the coordinate transformation between retinotopic and hand proprioceptive locations. To assess the gaze direction input to the attentional priority map, patients with left spatial neglect performed a cross-modal attention task in their normal, right hemispace. They discriminated visual targets whose location was cued by the patient's right index finger hidden from view. The locus of attention in response to the cue was defined as the location with the largest decrease in reaction time for visual discrimination in the presence vs. absence of the cue. In two control groups consisting of healthy elderly and patients with a right hemisphere lesion without neglect, the loci of attention were at the exact location of the cues. In contrast, neglect patients allocated attention at 0.5⁰-2⁰ rightward of the finger for all tested locations. A control task using reaching to visual targets in the absence of visual hand feedback ruled out a general error in visual localization. These findings demonstrate that in spatial neglect the gaze direction input to the attentional priority map is distorted. This observation supports the emerging view that attention and gaze are coupled and suggests that interventions that target gaze signals could alleviate spatial neglect.

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The mechanisms of left inattention in spatial neglect are incompletely understood.

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Attention loci in visual space are displaced to the right of somatosensory cues.

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This indicates a distorted gaze direction input to the attentional priority map.

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Distorted gaze direction input could lead to left-right attention imbalance.

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.

Rehabilitation in chronic spatial neglect strengthens resting-state connectivity

OBJECTIVES

Rehabilitation of patients with chronic visuospatial neglect is underexplored, and little is known about neural mechanisms that can be exploited to promote recovery. In this study, we present data on resting-state functional connectivity within the dorsal attention network (DAN) in chronic neglect patients as they underwent training in a virtual reality (VR) environment that improved left-side awareness.

METHODS

The study included 13 patients with visuospatial neglect persisting more than six months after a right-sided stroke. The patients underwent resting-state functional magnetic resonance imaging (fMRI). Scans were collected at baseline and after five weeks of intense training. We specifically examined resting-state functional connectivity within the DAN. In addition, using spatial concordance correlation, we compared changes in the spatial topology of the DAN with that of other networks.

RESULTS

We found a longitudinal increase in interhemispheric functional connectivity between the right frontal eye field and the left intraparietal sulcus following training (before: 0.33 ± 0.17 [mean ± SD]; after: 0.45 ± 0.13; P = 0.004). The spatial concordance analyses indicated that training influenced the DAN connectivity more than any of the other networks.

CONCLUSION

Intense VR training that improved left-sided awareness in chronic stroke patients also increased sporadic interhemispheric functional connectivity within the DAN. Specifically, a region responsible for saccadic eye movement to the left became more integrated with the left posterior parietal cortex. These results highlight a mechanism that should be exploited in the training of patients with chronic visuospatial neglect.

Is Unilateral Spatial Neglect Associated With Motor Recovery of the Affected Upper Extremity Poststroke? A Systematic Review

BACKGROUND AND PURPOSE

Individuals with stroke often present symptoms of multiple domains, such as weakness of the affected upper extremity (UE) and unilateral spatial neglect (USN), which are both associated with poor functional outcome. The aims of this systematic review were to search and review studies that investigated (1) the relationship between USN and affected UE sensorimotor recovery poststroke and (2) the effectiveness of sensorimotor interventions to improve the affected UE in patients with USN.

METHODS

An electronic search of databases (MEDLINE, EMBASE, CINAHL and Cochrane CENTRAL) was conducted using a combination of the following terms: stroke, USN, and affected UE. Studies meeting the inclusion criteria were rated using a modified version of the Quality Index, and relevant data were extracted.

RESULTS

A total of 850 studies were identified, and 14 were included; 13 studies assessed correlations between USN and the affected UE capacity/recovery, and 1 study assessed an intervention to improve the UE of individuals with USN. An association between presence of USN and UE capacity/recovery was found in most studies and USN did not interfere with recovery of the affected UE in the single experimental study.

CONCLUSIONS

USN is associated with poor UE motor capacity and less UE recovery poststroke. Therefore, these impairments should be considered when planning rehabilitation and discharge. Because USN is a well-researched phenomenon, the lack of studies and insufficient evidence related to UE interventions in individuals with USN was unexpected. These interventions should be developed and researched to improve UE and overall functional outcome poststroke.

Mirror therapy for improving motor function after stroke

BACKGROUND

Mirror therapy is used to improve motor function after stroke. During mirror therapy, a mirror is placed in the person's midsagittal plane, thus reflecting movements of the non-paretic side as if it were the affected side.

OBJECTIVES

To summarise the effectiveness of mirror therapy compared with no treatment, placebo or sham therapy, or other treatments for improving motor function and motor impairment after stroke. We also aimed to assess the effects of mirror therapy on activities of daily living, pain, and visuospatial neglect.

SEARCH METHODS

We searched the Cochrane Stroke Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, AMED, PsycINFO and PEDro (last searched 16 August 2017). We also handsearched relevant conference proceedings, trials and research registers, checked reference lists, and contacted trialists, researchers and experts in our field of study.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and randomised cross-over trials comparing mirror therapy with any control intervention for people after stroke.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials based on the inclusion criteria, documented the methodological quality, assessed risks of bias in the included studies, and extracted data. We assessed the quality of the evidence using the GRADE approach. We analysed the results as standardised mean differences (SMDs) or mean differences (MDs) for continuous variables, and as odds ratios (ORs) for dichotomous variables.

MAIN RESULTS

We included 62 studies with a total of 1982 participants that compared mirror therapy with other interventions. Of these, 57 were randomised controlled trials and five randomised cross-over trials. Participants had a mean age of 59 years (30 to 73 years). Mirror therapy was provided three to seven times a week, between 15 and 60 minutes for each session for two to eight weeks (on average five times a week, 30 minutes a session for four weeks).When compared with all other interventions, we found moderate-quality evidence that mirror therapy has a significant positive effect on motor function (SMD 0.47, 95% CI 0.27 to 0.67; 1173 participants; 36 studies) and motor impairment (SMD 0.49, 95% CI 0.32 to 0.66; 1292 participants; 39 studies). However, effects on motor function are influenced by the type of control intervention. Additionally, based on moderate-quality evidence, mirror therapy may improve activities of daily living (SMD 0.48, 95% CI 0.30 to 0.65; 622 participants; 19 studies). We found low-quality evidence for a significant positive effect on pain (SMD -0.89, 95% CI -1.67 to -0.11; 248 participants; 6 studies) and no clear effect for improving visuospatial neglect (SMD 1.06, 95% CI -0.10 to 2.23; 175 participants; 5 studies). No adverse effects were reported.

AUTHORS' CONCLUSIONS

The results indicate evidence for the effectiveness of mirror therapy for improving upper extremity motor function, motor impairment, activities of daily living, and pain, at least as an adjunct to conventional rehabilitation for people after stroke. Major limitations are small sample sizes and lack of reporting of methodological details, resulting in uncertain evidence quality.

Occurrence and Recovery of Different Neglect-Related Symptoms in Right Hemisphere Infarct Patients during a 1-Year Follow-Up

OBJECTIVES

To examine the occurrence of and recovery from visual neglect-related symptoms with the focus on neglect laterality, ipsilateral orienting bias, and slowed processing speed in right hemisphere (RH) infarct patients during a 1-year follow-up. Furthermore, to propose guidelines for assessing processing speed alongside the Behavioural Inattention Test (BIT).

METHODS

We studied three RH patient groups: neglect (N+), mild left inattention (MLI+), and non-neglect (N-) patients, and healthy controls. The BIT with some additional analyses was conducted at the acute phase and at 6 and 12 months.

RESULTS

The N+ group's BIT score increased and originally lateralized omissions became more evenly distributed during the follow-up. The N+ and MLI+ groups' starting points were more rightward located than the healthy group's at the acute phase and at 6, and partly at 12 months. Patient groups were slower than the controls in performing cancellation tests at the acute phase. The N+ and MLI+ groups remained slower than the controls throughout the follow-up.

CONCLUSIONS

During the first year after RH infarct, originally left-sided manifestation of neglect shifted toward milder non-lateralized attentional deficit. Ipsilateral orienting bias and slowed processing speed appeared to be rather persistent neglect-related symptoms both in neglect patients and patients with initially milder inattention. We propose some effortless, tentative ways of examining processing speed and ipsilateral orienting bias alongside the BIT to better recognize these neglect-related symptoms, and highlight the need to assess and treat patients with initially milder inattention, who have been under-recognized and under-treated in clinical work. (JINS, 2018, 24, 617-628).

Neuroanatomical and behavioural factors associated with the effectiveness of two weekly sessions of prism adaptation in the treatment of unilateral neglect

Among the different interventions to alleviate the symptoms of unilateral neglect, prism adaptation (PA) appears especially promising. To elucidate the contribution of some neuroanatomical and behavioural factors to PA's effectiveness, we conducted a study combining neuropsychological and lesion mapping methods on a group of 19 neglect patients who underwent two sessions of PA during one week and assessed their improvement relative to the baseline until the following week (7-8 days later). Correlation analyses revealed a significant positive relationship between the magnitude of the proprioceptive after-effect and the improvement at the follow-up session in two perceptual tasks requiring motor responses. Conversely, no correlation was found between the proprioceptive after-effect and the improvement in a perceptual task with no motor involvement. This finding suggests that patients' potential to show a prism-related improvement in motor-related tasks might be indicated by the strength of their proprioceptive response (proprioceptive after-effect). As for the neuroanatomical basis of this relationship, subtraction analyses suggested that patients' improvement in perceptual tasks with high motor involvement might be facilitated by the integrity of temporo-parietal areas and the damage of frontal and subcortical areas.

Unilateral spatial neglect in the acute phase of ischemic stroke can predict long-term disability and functional capacity

OBJECTIVE

The aim of this study was to assess the relationship between the degree of unilateral spatial neglect during the acute phase of stroke and long-term functional independence.

METHODS

This was a prospective study of right ischemic stroke patients in which the independent variable was the degree of spatial neglect and the outcome that was measured was functional independence. The potential confounding factors included sex, age, stroke severity, topography of the lesion, risk factors, glycemia and the treatment received. Unilateral spatial neglect was measured using the line cancellation test, the star cancellation test and the line bisection test within 48 hours of the onset of symptoms. Functional independence was measured using the modified Rankin and Barthel scales at 90 days after discharge. The relationship between unilateral spatial neglect and functional independence was analyzed using multiple logistic regression that was corrected for confounding factors.

RESULTS

We studied 60 patients with a median age of 68 (34-89) years, 52% of whom were male and 74% of whom were Caucasian. The risk for moderate to severe disability increased with increasing star cancellation test scores (OR=1.14 [1.03-1.26], p=0.01) corrected for the stroke severity, which was a confounding factor that had a statistically positive association with disability (OR=1.63 [1.13-2.65], p=0.01). The best chance of functional independence decreased with increasing star cancellation test scores (OR=0.86 [0.78-0.96], p=0.006) corrected for the stroke severity, which was a confounding factor that had a statistically negative association with independence (OR=0.66 [0.48-0.92], p=0.017).

CONCLUSION

The severity of unilateral spatial neglect in acute stroke worsens the degree of long-term disability and functional independence.