Zooming in on abnormal local and global processing biases after stroke: Frequency, lateralization, and associations with cognitive functions

OBJECTIVES

The 'attentional spotlight' can be adjusted depending on the task requirements, resulting in processing information at either the local or global level. Stroke can lead to local or global processing biases, or the inability to simultaneously attend both levels. In this study, we assessed the (1) prevalence of abnormal local and global biases following stroke, (2) differences between left- and right-sided brain damaged patients, and (3) relations between local and global interference, the ability to attend local and global levels simultaneously, and lateralized attention, search organization, search speed, visuo-construction, executive functioning, and verbal (working) memory.

METHODS

Stroke patients admitted for inpatient rehabilitation completed directed (N = 192 total; N = 46 left-sided/N = 48 right-sided lesion) and divided (N = 258 total; N = 67 left-sided/N = 66 right-sided lesion) local-global processing tasks, as well as a conventional neuropsychological assessment. Processing biases and interference effects were separately computed for directed and divided tasks.

RESULTS

On the local-global tasks, 7.8-10.9% of patients showed an abnormal local bias and 6.3-8.3% an abnormal global bias for directed attention, and 5.4-10.1% an abnormal local bias and 6.6-15.9% an abnormal global bias for divided attention. There was no significant difference between patients with left- and right-sided brain damage. There was a moderate positive relation between local interference and search speed, and a small positive relation between global interference and neglect.

CONCLUSIONS

Abnormal local and global biases can occur after stroke and might relate to a range of cognitive functions. A specific bias might require a different approach in assessment, psycho-education, and treatment.

A Case Report and Review: Charles Bonnet Syndrome Plus With Dementia

Introduction

Charles Bonnet Syndrome (CBS) refers to visual hallucinations in visually impaired patients without psychiatric illness who are typically aware that their hallucinations are not real. Rare cases in the literature describe patients with atypical CBS, or CBS plus, who experience hallucinations in the context of sensory deficits but do not meet all of the criteria of a CBS diagnosis. These cases may include hallucinations in more than one sensory modality, including auditory hallucinations, which are thought to arise by a similar pathophysiology to that of the visual hallucinations in CBS. Unfortunately, the clinical criteria for atypical CBS are ambiguous, potentially explaining the rarity of the diagnosis. In addition, certain features of atypical CBS may make the condition particularly prone to misdiagnosis.

Case Presentation

We report a case of atypical CBS in a 67-year-old white male patient presenting with visual and auditory hallucinations that were improved by reassurance. Alongside this case presentation, we provide a review of atypical CBS cases in the literature to compare the diverse features of the syndrome. For this review, we included cases of atypical CBS or CBS plus within the past 20 years for which we could obtain the full text.

Conclusion

Clearer guidelines for the diagnosis of atypical CBS and greater attention to the disorder could substantially improve the management of patients presenting with hallucinations. A broader differential diagnosis including atypical CBS for elderly patients with new-onset hallucinations could help clinicians and patients avoid unnecessary medical workup and treatment.

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

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

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

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

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

A First Step Toward the Operationalization of the Learned Non-Use Phenomenon: A Delphi Study

BACKGROUND

The negative discrepancy between residual functional capacity and reduced use of the contralesional hand, frequently observed after a brain lesion, has been termed Learned Non-Use (LNU) and is thought to depend on the interaction of neuronal mechanisms during recovery and learning-dependent mechanisms.

OBJECTIVE

Albeit the LNU phenomenon is generally accepted to exist, currently, no transdisciplinary definition exists. Furthermore, although therapeutic approaches are implemented in clinical practice targeting LNU, no standardized diagnostic routine is described in the available literature. Our objective was to reach consensus regarding a definition as well as synthesize knowledge about the current diagnostic procedures.

METHODS

We used a structured group communication following the Delphi method among clinical and scientific experts in the field, knowledge from both, the work with patient populations and with animal models.

RESULTS

Consensus was reached regarding a transdisciplinary definition of the LNU phenomenon. Furthermore, the mode and strategy of the diagnostic process, as well as the sources of information and outcome parameters relevant for the clinical decision making, were described with a wide range showing the current lack of a consistent universal diagnostic approach.

CONCLUSIONS

The need for the development of a structured diagnostic procedure and its implementation into clinical practice is emphasized. Moreover, it exists a striking gap between the prevailing hypotheses regarding the mechanisms underlying the LNU phenomenon and the actual evidence. Therefore, basic research is needed to bridge between bedside and bench and eventually improve clinical decision making and further development of interventional strategies beyond the field of stroke rehabilitation.

Treatment of spatial neglect in clinical practice: A nationwide survey

OBJECTIVES

Clinical research has documented a range of evidence-based treatment approaches for spatial neglect (SN), but there is a lack of research on the implementation of treatment into clinical practice. The purpose of this study is to describe the current clinical practice of SN treatment across healthcare sectors including involved professions, methods, timing and sources of evidence.

MATERIAL AND METHODS

This is the second part of a nationwide, anonymous, open Internet survey that was conducted among healthcare professionals in Denmark on assessment and treatment of SN.

RESULTS

A total of 525 healthcare professionals participated in the survey of which 411 (78.3%) reported that SN treatment was provided at their workplace. Occupational and physiotherapist were most often involved in the treatment, most commonly characterized by training of activities of daily living (ADL), sensoric stimulation and cueing. Less frequently reported were evidence-based methods such as prism adaptation and visual scanning. The overall intensity of the SN treatment varied considerably across sectors and might consequently be inadequate. A minority of the participants consulted clinical research evidence in their choice of SN treatment approaches.

CONCLUSIONS

There is a profound lack of dissemination and translation of clinical research into current clinical practice, which unarguably leads to an underuse of evidence-based treatment approaches in SN rehabilitation. The results call for international multidisciplinary clinical guidelines for the treatment of SN at different stages of rehabilitation and the tailoring of treatment approaches to the individual patient.

Spectral Overlays for Reading Difficulties: Oculomotor Function and Reading Efficiency Among Children and Adolescents With Visual Stress

This study analyzed the effects of spectral overlays on ocular motility during reading among a clinical group of children and adolescents experiencing visual–perceptual distortions of text. We reviewed the records of 323 eye-hospital patients diagnosed with visual stress and divided this participant sample into two age-based cohorts: children ( n =  184; Mean [ M] age = 10.1, standard deviation [ SD]  =  1.3 years) and adolescents ( n =  139; M age = 14.6, SD = 1.5 years). We used a Visagraph III Eye-Movement Recording System to record ocular motor efficiency while reading with and without spectral overlays, and we examined the following parameters: (a) Fixations, (b) Regressions, (c) Span of Recognition, (d) Reading Rate, (e) Relative Efficiency, and (f) Comprehension. Our results showed that using one or some combination of 10 participant-selected spectral overlays immediately and significantly ( p <  .001) reduced the number of Fixations and Regressions per 100 words, while there were significant ( p <  .001) gains in positive factors such as Span of Recognition, Reading Rate, Relative Efficiency, and Comprehension. Our findings indicate that spectral filtering can be an effective tool for helping many young patients who experience visual–perceptual distortions while reading. Future expanded research employing eye-tracking technology is clearly needed.

Increased Cognitive Load Reveals Unilateral Neglect and Altitudinal Extinction in Chronic Stroke

OBJECTIVE

Neuropsychological studies suggest that the ability to compensate for the presence of spatial neglect highly depends on the attentional resources a patient can rely on. The present research aimed to study neglect in situations where attentional resources are limited due to multitasking.

METHOD

We examined two patients more than 3 years after a right-hemispheric stroke. Both had received neuropsychological rehabilitation for left neglect and did not show any impairment in standard tests. We used a dual-task paradigm combining a peripheral target detection task with a central shape recognition task. Peripheral targets could appear in left/right positions but also in lower/upper positions.

RESULTS

In patient #1, dual-task condition exacerbated left neglect and extinction. Patient #2 did not show any sign of neglect along the horizontal axis, but omitted half of the lower targets when they were presented simultaneously with upper targets under dual-task condition. This behavior reflects altitudinal extinction as the detection of single targets appearing either in upper or lower position was preserved.

CONCLUSION

The present findings show that dual-tasking is a sensitive tool for the quantitative and qualitative assessment of spatial attention deficits, which are often overlooked by standard methods, especially in chronic stage. (JINS, 2019, 25, 644-653).

Effects of Neck Taping in the Treatment of Hemispatial Neglect in Chronic Stroke Patients: A Pilot, Single Blind, Randomized Controlled Trial

Background and objectives: Hemispatial neglect is a common consequence of stroke, with an estimated incidence of 23%. Interventions for treating hemispatial neglect may be categorized as either top-down or bottom-up processing. The aim of top-down approaches is to train the person to voluntarily compensate for their neglect. Such approaches require awareness of the disorder and a high level of active participation by the patient. Differently, bottom-up approaches are based on manipulation of a patient’s sensory environment and so require less awareness of behavioral bias. In line with the latter, it is conceivable that elastic therapeutic taping applied to the left neck surface may provide bottom-up inputs that reduce hemispatial neglect symptoms. The aim of this study was to assess the effect of therapeutic neck taping on visuo-spatial abilities, neck motion, and kinesthetic sensibility in chronic stroke patients with hemispatial neglect. Materials and Methods: After randomization, 12 chronic stroke patients with hemispatial neglect received 30 consecutive days of real (treatment group) or sham (control group) neck taping. The outcomes were as follows: Stars Cancellation Test; neck active range of motion; Letter Cancellation Test; Comb and Razor Test; Cervical Joint Position Error Test evaluated before and after one month of taping. Results: Between-group comparison showed significant differences only for the Cervical Joint Position Error Test after treatment (p = 0.009). Conclusions: Our preliminary findings support the hypothesis that neck taping might improve cervicocephalic kinesthetic sensibility in chronic stroke patients with hemispatial neglect. Further studies are needed to strengthen our results and better investigate the effects of elastic therapeutic taping on visuo-spatial abilities in stroke patients with hemispatial neglect.

Novel Treatment Approach to Contraversive Pushing after Acute Stroke: A Case Report

Purpose: The purpose of this case report is to provide an alternative treatment approach to pushing behavior (PB), adapting widely used equipment for persons with stroke demonstrating such behaviour. The aim is to change their graviceptive experience during interventions while performing repeated stepping and righting practice to resolve PB more quickly. Client Description: The subject is a man aged 56 years who sustained a right middle-cerebral-artery ischemic stroke. He entered in-patient rehabilitation from an acute care hospital 7 days post-stroke. Intervention: Lateral stepping with body weight-supported treadmill training (LS-BWSTT) was used such that the subject stepped laterally toward the uninvolved side. Measures and Outcome: Scores on the Scale for Contraversive Pushing and the FIM were recorded at regular intervals. After intervention, the subject demonstrated decreased PB and improved function. Implications: The individual's PB improved after LS-BWSTT. LS-BWSTT is a novel treatment intervention that could be considered in future clinical decision making using evidence-based principles.

Effect of eye patching in rehabilitation of hemispatial neglect

Eye patching (EP; monocular or right hemifield) has been proposed to improve visuospatial attention to the ignored field in patients with hemispatial neglect. The aim of this paper is to review the literature on the effects of EP in hemispatial neglect after stroke in order to convey evidence-based recommendations to clinicians in stroke rehabilitation. Thirteen intervention studies were selected from the Medline, EMBASE, Scopus, Cochrane Library, CINAHL, PsychINFO, EBRSR, and Health Star databases. Methodological quality was defined according to the Physiotherapy Evidence Database. Overall, seven studies used monocular EP, five used right hemifield patching, and one compared right monocular with right hemifield patching. Seven studies compared normal viewing to monocular or hemifield patching conditions. Six studies included a period of treatment. As to the monocular EP, four studies reported positive effects of right monocular patching. One study showed an improvement in hemispatial neglect with left monocular patching. Two studies found no superiority of right vs. left monocular patching. One study found no effects of right monocular patching. As to the right hemifield EP, one study showed improvements in neglect after right hemifield patching. Three studies found that right hemifield patching combined with another rehabilitation technique was more effective than that treatment alone. One study found no differences between right hemifield patching combined with another treatment and that treatment alone. One study found the same effect between right hemifield patching alone and another rehabilitation technique. Our results globally tend to support the usefulness of right hemifield EP in clinical practice. In order to define a level of evidence with the standard rehabilitation evidence rating tools, further properly powered randomized controlled trials or meta-analysis are needed.

Development of visual-motor perception in pupils with expressive writing disorder and pupils without expressive writing disorder: a comparative statistical analysis

BACKGROUND

Learning disability is one of the most noticed subjects for behavioral specialists. Most of thelearning difficulties are caused by senso-motor development and neurological organization. The main purposeof the present research is to examine the role of delayed perceptual-motor development and brain damage inorigination of expressive writing disorder (EWD).

METHODS

The studied sample is 89 pupils divided into two groups, one of which is pupils with expressivewriting disorder (n=43) and the other is pupils without expressive writing disorder (n=46), consisted of secondand third grade elementary school students. First of all, students with EWD are selected through dictation testand intelligence test, and then the two groups, students with and without EWD, would take the Bender Gestalttest. The average score of perceptual visual-motor development and brain damage of two groups is comparedusing T test for independent groups and χ2 test.

RESULTS

Results show that there is a significant difference in perceptual visual-motor development betweenstudents with EWD and students without EWD (p<0.01). Based on the results, perceptual-motor development ofstudents with EWD is lower than students without EWD. There is no significant difference in brain damagebetween those with EWD and healthy people, (p> 0.05).

CONCLUSION

Based on our findings it could be concluded that those who are relatively more developed thantheir peers, in terms of visual-motor perception, are more successful in education, especially in expressive writing.

Non-pharmacological interventions for perceptual disorders following stroke and other adult-acquired, non-progressive brain injury

BACKGROUND

Stroke and other adult-acquired brain injury may impair perception leading to distress and increased dependence on others. Perceptual rehabilitation includes functional training, sensory stimulation, strategy training and task repetition.

OBJECTIVES

To examine the evidence for improvement in activities of daily living (ADL) six months post randomisation for active intervention versus placebo or no treatment.

SEARCH STRATEGY

We searched the trials registers of the Cochrane Stroke Group and the Cochrane Infectious Diseases Group (May 2009) but not the Injuries Group, the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, Issue 3), MEDLINE (1950 to August 2009), EMBASE (1980 to August 2009), CINAHL (1982 to August 2009), PsycINFO (1974 to August 2009), REHABDATA and PsycBITE (May to June 2009). We also searched trials and research registers, handsearched journals, searched reference lists and contacted authors.

SELECTION CRITERIA

Randomised controlled trials of adult stroke or acquired brain injury. Our definition of perception excluded visual field deficits, neglect/inattention and apraxia.

DATA COLLECTION AND ANALYSIS

One review author assessed titles, abstracts and keywords for eligibility. At least two review authors independently extracted data. We requested unclear or missing information from corresponding authors.

MAIN RESULTS

We included six single-site trials in rehabilitation settings, involving 338 participants. Four trials included people with only stroke. All studies provided sensory stimulation, sometimes with another intervention. Sensory stimulation typically involved practising tasks that required visuo-perceptual processing with occupational therapist assistance. Repetition was never used and only one study included functional training. No trials provided data on longer term improvement in ADL scores. Only three trials provided any data suitable for analysis. Two of these trials compared active to placebo intervention. There was no evidence of a difference in ADL scores at the scheduled end of intervention: mean difference (95% confidence interval (CI)) was 0.9 (-1.6 to 3.5) points on a self-care ADL scale in one study and odds ratio (95% CI) was 1.3 (0.56 to 3.1) for passing a driving test in the other, both in favour of active intervention. The trial that compared two active interventions did not find evidence of difference in any of the review outcomes.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support or refute the view that perceptual interventions are effective. Future studies should be sufficiently large, include a standard care comparison and measure longer term functional outcomes. People with impaired perception problems should continue to receive neurorehabilitation according to clinical guidelines.

Brain networks of spatial awareness: evidence from diffusion tensor imaging tractography

Left unilateral neglect, a dramatic condition which impairs awareness of left-sided events, has been classically reported after right hemisphere cortical lesions involving the inferior parietal region. More recently, the involvement of long range white matter tracts has been highlighted, consistent with the idea that awareness of events occurring in space depends on the coordinated activity of anatomically distributed brain regions. Damage to the superior longitudinal fasciculus (SLF), linking parietal to frontal cortical regions, or to the inferior longitudinal fasciculus (ILF), connecting occipital and temporal lobes, has been described in neglect patients. In this study, four right-handed patients with right hemisphere strokes underwent a high definition anatomical MRI with diffusion tensor imaging (DTI) sequences and a pencil and paper neglect battery of tests. We used DTI tractography to visualise the SLF, ILF and the inferior fronto-occipital fasciculus (IFOF), a pathway running the depth of the temporal lobe, not hitherto associated with neglect. Two patients with cortical involvement of the inferior parietal and superior temporal regions, but intact and symmetrical fasciculi, showed no signs of neglect. The other two patients with signs of left neglect had superficial damage to the inferior parietal cortex and white matter damage involving the IFOF. These findings suggest that superficial damage to the inferior parietal cortex per se may not be sufficient to produce visual neglect. In some cases, a lesion to the direct connections between ventral occipital and frontal regions (ie, IFOF) may contribute to the manifestation of neglect by impairing the top down modulation of visual areas from the frontal cortex.

Visual hemispatial neglect, re-assessed

Increased computer use in clinical settings offers an opportunity to develop new neuropsychological tests that exploit the control computers have over stimulus dimensions and timing. However, before adopting new tools, empirical validation is necessary. In the current study, our aims were twofold: to describe a computerized adaptive procedure with broad potential for neuropsychological investigations, and to demonstrate its implementation in testing for visual hemispatial neglect. Visual search results from adaptive psychophysical procedures are reported from 12 healthy individuals and 23 individuals with unilateral brain injury. Healthy individuals reveal spatially symmetric performance on adaptive search measures. In patients, psychophysical outcomes (as well as those from standard paper-and-pencil search tasks) reveal visual hemispatial neglect. Consistent with previous empirical studies of hemispatial neglect, lateralized impairments in adaptive conjunction search are greater than in adaptive feature search tasks. Furthermore, those with right hemisphere damage show greater lateralized deficits in conjunction search than do those with left hemisphere damage. We argue that adaptive tests, which automatically adjust to each individual's performance level, are efficient methods for both clinical evaluations and neuropsychological investigations and have the potential to detect subtle deficits even in chronic stages, when flagrant clinical signs have frequently resolved.