Search pattern in a verbally reported visual scanning test in patients showing spatial neglect

2002 ◽  
Vol 8 (3) ◽  
pp. 382-394 ◽  
Author(s):  
HANS SAMUELSSON ◽  
E.K. ELISABETH HJELMQUIST ◽  
CHRISTER JENSEN ◽  
CHRISTIAN BLOMSTRAND
Keyword(s):  
Right Hemisphere ◽  
Repeated Reading ◽  
Spatial Neglect ◽  
Search Pattern ◽  
Common Finding ◽  
Repeated Readings ◽  
Stroke Patients ◽  
Visuospatial Neglect ◽  
Normal Controls

The present study of right hemisphere stroke patients showed that presence of visuospatial neglect in conventional neglect tests at the postacute stage was strongly associated with an aberrant search pattern in a verbally reported visuo-perceptual scanning test. Compared with normal controls, patients with visuospatial neglect showed a greater proportion of repeated readings of the same target, shorter search sequences, more shifts between horizontal, vertical, and diagonal search, and lower proportion of horizontal search. The relation between spatial neglect and a deficient search pattern was strongly influenced by the asymmetric allocation of attention in the scanning test, with the exception for the proportion of repeated reading which was not influenced by this asymmetry. At follow-up, a significant recovery was noted in the neglect group for the proportion of repeated readings and for the asymmetry in the allocation of attention. However, a high number of omitted targets in the search test was still a common finding in the neglect group and it was suggested that a non-lateralized attentional deficit may have played an important role behind the ineffective search at this point of time. (JINS, 2002, 8, 382–394.)

scholarly journals Left egocentric neglect in early subacute right-stroke patients is related to damage of the superior longitudinal fasciculus

2021 ◽  
Author(s):  
Barbara Spanò ◽  
Davide Nardo ◽  
Giovanni Giulietti ◽  
Alessandro Matano ◽  
Ilenia Salsano ◽  
...  
Keyword(s):  
White Matter ◽  
Right Hemisphere ◽  
Neural Substrates ◽  
Spatial Neglect ◽  
Stroke Patients ◽  
Superior Longitudinal Fasciculus ◽  
Unilateral Spatial Neglect ◽  
Object Based ◽  
The Right ◽  
The Relationship

AbstractA typical consequence of stroke in the right hemisphere is unilateral spatial neglect. Distinct forms of neglect have been described, such as space-based (egocentric) and object-based (allocentric) neglect. However, the relationship between these two forms of neglect is still far from being understood, as well as their neural substrates. Here, we further explore this issue by using voxel lesion symptoms mapping (VLSM) analyses on a large sample of early subacute right-stroke patients assessed with the Apples Cancellation Test. This is a sensitive test that simultaneously measures both egocentric and allocentric neglect. Behaviourally, we found no correlation between egocentric and allocentric performance, indicating independent mechanisms supporting the two forms of neglect. This was confirmed by the VLSM analysis that pointed out a link between a damage in the superior longitudinal fasciculus and left egocentric neglect. By contrast, no association was found between brain damage and left allocentric neglect. These results indicate a higher probability to observe egocentric neglect as a consequence of white matter damages in the superior longitudinal fasciculus, while allocentric neglect appears more “globally” related to the whole lesion map. Overall, these findings on early subacute right-stroke patients highlight the role played by white matter integrity in sustaining attention-related operations within an egocentric frame of reference.

scholarly journals Spatial neglect in the digital age – Influence of presentation format on patients' test behavior

2021 ◽  
Author(s):  
Hannah Rosenzopf ◽  
Christoph Sperber ◽  
Franz Wortha ◽  
Daniel Wiesen ◽  
Annika Muth ◽  
...  
Keyword(s):  
Machine Learning ◽  
Test Scores ◽  
Right Hemisphere ◽  
Search Behavior ◽  
Spatial Neglect ◽  
Presentation Format ◽  
Stroke Patients ◽  
Test Behavior ◽  
Paper And Pencil ◽  
Behavioral Markers

Computerization of diagnostic neglect tests can deepen our knowledge of neglect specific abnormalities, by effortlessly providing additional behavioral markers that are hardly extractable from existing paper-and-pencil versions. However, so far it is not known whether the digitization and/or a change in size format impact neglect patients' search behavior and test scores and thus require adjustments of cut-off criteria. We compared the Center of cancellation (CoC) measure of right hemisphere stroke patients with spatial neglect in two cancellation tasks across different modalities (paper-and-pencil vs. digital) and display sizes (small, medium, large). We found that the CoC measure did neither vary considerably between paper-and-pencil versus digital versions, nor between different digital size formats. The CoC derived from cancellation tasks thus seems robust to test digitization. A further aim of the present study was to evaluate three additional parameters of search behavior which became available through digitization. We observed slower search behavior, increased distance between two consecutively identified items, and signs of a more strategic search for neglect patients than control patients without neglect. Machine learning classifications indicated that - beyond the CoC measure - the latter three variables can help to differentiate stroke patients with spatial neglect from those without.

scholarly journals Sensorimotor cortex forms prism adaptation memories in older adults and stroke patients

2020 ◽  
Author(s):  
Gershon Spitz ◽  
Pierre Petitet ◽  
Janet Bultitude ◽  
Alessandro Farnè ◽  
Jacques Luaute ◽  
...  
Keyword(s):  
Sensorimotor Cortex ◽  
Right Hemisphere ◽  
State Space Model ◽  
Prism Adaptation ◽  
Spatial Neglect ◽  
Behavioural Intervention ◽  
Stroke Survivors ◽  
Stroke Patients ◽  
After Effect ◽  
The Brain

AbstractStroke is the largest cause of complex disability in adults. Approximately half of right-hemisphere stroke survivors suffer spatial neglect–an inability to voluntarily orient to people or objects in contralesional space. Neglect is a significant impediment to successful community reintegration. Prism adaptation (PA) is a promising behavioural intervention that can alleviate symptoms of spatial neglect. PA induces a leftward pointing bias–the prism after-effect (AE). In neglect, the prism AE generalises to improve other sensory, motor, and cognitive domains. Although the formation of an AE is a key index in neglect, we do not yet know where it is formed in the brain. Here, we used a novel computational fMRI-based approach to study, for the first time, the brain circuits that mediate the formation of PA in stroke survivors and age matched controls. Healthy individuals (n = 17) and stroke patients (n = 11) performed prism adaptation during fMRI. Temporal signatures of memory formation were extracted from the behavioural data using a state-space model and regressed against the fMRI data. This revealed that, in both groups, fMRI signal in left sensorimotor cortex correlated with the gradual formation of the prism after-effect during adaptation. This indicates that the sensorimotor cortex may be a useful target for neuromodulation that aims to improve the persistence of therapeutic prism after effects.

Anosognosia for Hemiplegia in Stroke Rehabilitation

2001 ◽  
Vol 15 (3) ◽  
pp. 213-222 ◽  
Author(s):  
Adina Hartman-Maeir ◽  
Nachum Soroker ◽  
Noomi Katz
Keyword(s):  
Right Hemisphere ◽  
Significant Risk ◽  
Spatial Neglect ◽  
Implicit Measure ◽  
Safety Measures ◽  
Attentional Deficits ◽  
Temporal Lobes ◽  
Right Hemisphere Damage ◽  
Underlying Mechanisms

Objective: The purpose of this study was to investigate anosognosia for hemiple gia (AHP) in the rehabilitation phase after onset of stroke. Methods: Forty-six hemi plegic stroke patients, 29 with right hemisphere damage (RHD) and 17 with left hemi sphere damage (LHD) were evaluated ∼1 month after onset of stroke. Anosognosia was evaluated with an implicit measure designed to assess anosognosic behaviors (choosing between unimanual and bimanual tasks), in addition to a traditional ex plicit verbal measure. Results: AHP was found m 28% of the RHD and 24% of the LHD group. The majority of patients with AHP in the RHD group had large lesions involving the frontal, parietal, or temporal lobes and had coexisting sensory deficits and unilateral spatial neglect, whereas the LHD patients with AHP had predominantly small subcortical lesions and no sensory or attentional deficits. The functional out comes of AHP patients in both hemisphere groups revealed their inability to retain safety measures at discharge from rehabilitation (p < 0.036) and their need for assis tance in basic and instrumental activities of daily living at follow-up. Conclusions: AHP presents a significant risk for negative functional outcome in stroke rehabilita tion. The underlying mechanisms of AHP may be different for left and right hemi sphere patients, therefore requiring different intervention approaches. Key Words: Anosognosia—Cerebrovascular accident—Rehabilitation outcome.

scholarly journals Body size perception in stroke patients with paresis

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252596
Author(s):  
Azam Shahvaroughi-Farahani ◽  
Sally A. Linkenauger ◽  
Betty J. Mohler ◽  
Simone C. Behrens ◽  
Katrin E. Giel ◽  
...  
Keyword(s):  
Body Size ◽  
Right Hemisphere ◽  
Peripersonal Space ◽  
Spatial Neglect ◽  
Size Perception ◽  
Stroke Patients ◽  
Action Capability ◽  
Ability To Act ◽  
Neurological Patients ◽  
Initial Injury

Recent studies have suggested that people’s intent and ability to act also can influence their perception of their bodies’ peripersonal space. Vice versa one could assume that the inability to reach toward and grasp an object might have an impact on the subject’s perception of reaching distance. Here we tested this prediction by investigating body size and action capability perception of neurological patients suffering from arm paresis after stroke, comparing 32 right-brain-damaged patients (13 with left-sided arm paresis without additional spatial neglect, 10 with left-sided arm paresis and additional spatial neglect, 9 patients had neither arm paresis nor neglect) and 27 healthy controls. Nineteen of the group of right hemisphere stroke patients could be re-examined about five months after initial injury. Arm length was estimated in three different methodological approaches: explicit visual, explicit tactile/proprioceptive, and implicit reaching. Results fulfilled the working hypothesis. Patients with an arm paresis indeed perceived their bodies differently. We found a transient overestimation of the length of the contralesional, paretic arm after stroke. Body size and action capability perception for the extremities thus indeed seem to be tightly linked in humans.

scholarly journals Dissociating ego- and allocentric neglect after stroke: prevalence, laterality and outcome predictors

2017 ◽  
Author(s):  
Nele Demeyere ◽  
Celine R. Gillebert
Keyword(s):  
Acute Stroke ◽  
Outcome Predictors ◽  
Spatial Bias ◽  
Stroke Patients ◽  
Visuospatial Neglect ◽  
Double Dissociation ◽  
Stroke Prevalence ◽  
Cognitive Screen ◽  
Contralesional Side

AbstractVisuospatial neglect is a neuropsychological condition commonly experienced after stroke, whereby a patient is unable to attend to stimuli on their contralesional side. We aimed to investigate whether egocentric and allocentric neglect are functionally dissociable and differ in prevalence, laterality and outcome predictors. A consecutive sample of 366 acute stroke patients completed the Broken Hearts test from the Oxford Cognitive Screen. A subsample of 160 patients was followed up 6 months later. We evaluated the association between egocentric and allocentric neglect, contrasted the prevalence and severity of left-sided versus right-sided neglect, and determined the predictors of persistence versus recovery at follow up. Clinically, we found a double dissociation between ego- and allocentric neglect, with 50% of the neglect patients showing ‘only’ egocentric neglect and 25% ‘only’ allocentric neglect. Importantly, patients with only allocentric neglect did not demonstrate any egocentric spatial bias in the locations of the allocentric errors. Left-sided egocentric neglect was more prevalent and more severe than right-sided egocentric neglect, though right-sided neglect was still highly prevalent in the acute stroke sample (35%). Leftsided allocentric neglect was more severe but not more prevalent than right-sided allocentric neglect. Overall recovery of neglect was high: 81% of egocentric and 75% of allocentric neglect patients recovered. Severity of neglect was the only significant behavioural measure for predicting recovery at 6 months.

The Effects of Unilateral Visuospatial Neglect on Perception of Müller-Lyer Illusory Figures

Perception ◽  
1995 ◽  
Vol 24 (4) ◽  
pp. 415-433 ◽  
Author(s):  
Jason B Mattingley ◽  
John L Bradshaw ◽  
Judy A Bradshaw
Keyword(s):  
Right Hemisphere ◽  
Spatial Perception ◽  
Baseline Condition ◽  
Visual Features ◽  
Horizontal Line ◽  
Visuospatial Neglect ◽  
Low Level ◽  
Right Hemisphere Damage ◽  
Illusory Perception ◽  
Normal Controls

Left visuospatial neglect after right hemisphere damage is a lateralised disorder of spatial perception and cognition. A study is reported of the extent to which patients with left visuospatial neglect are susceptible to the illusory effects normally elicited by Müller-Lyer figures, in which inducing fins are located on one end or on both ends of a horizontal line. Seven patients with left visuospatial neglect and seven normal controls were tested on a task of horizontal-line bisection in which stimuli consisted of plain lines of three lengths (100, 150, and 200 mm), randomly interleaved with lines with unilateral or bilateral fins. As a group, normals made accurate bisection judgments in the baseline (no-fins) condition, and exhibited significant illusory effects in both the unilateral-fin and the bilateral-fin conditions. In contrast, patients made substantial rightward errors in the baseline condition, consistent with their neglect of the left end of the line. However, as a group, patients still exhibited significant illusory effects with left-sided outward-projecting fins on 100 mm lines and with left-sided inward-projecting fins on 150 mm lines. Moreover, at least one patient exhibited consistent illusory effects both for inward-projecting and for outward-projecting left-sided fins at all line lengths. Normal illusory effects in patients were also obtained with stimuli containing unilateral right-sided and bilateral fins. The existence of such effects with inducing elements on the contralesional extremity of horizontal line stimuli suggests preservation of low-level, perhaps preattentive, perceptual mechanisms responsible for coding elementary visual features. The results may be relevant for an understanding of the influence of attentional factors on illusory perception.

Translation Research for the Rehabilitation of Left Spatial Neglect and Associated Disorders of Attention in Stroke Patients

2008 ◽  
Vol 18 (2) ◽  
pp. 55-65 ◽  
Author(s):  
Nkiruka Arene ◽  
Argye E. Hillis
Keyword(s):  
Theoretical Basis ◽  
Attention Bias ◽  
Spatial Neglect ◽  
Clinical Use ◽  
Stroke Patients ◽  
Translation Research ◽  
Unilateral Neglect ◽  
Assessment And Treatment ◽  
Sound Theoretical Basis ◽  
Review Current

Abstract The syndrome of unilateral neglect, typified by a lateralized attention bias and neglect of contralateral space, is an important cause of morbidity and disability after a stroke. In this review, we discuss the challenges that face researchers attempting to elucidate the mechanisms and effectiveness of rehabilitation treatments. The neglect syndrome is a heterogeneous disorder, and it is not clear which of its symptoms cause ongoing disability. We review current methods of neglect assessment and propose logical approaches to selecting treatments, while acknowledging that further study is still needed before some of these approaches can be translated into routine clinical use. We conclude with systems-level suggestions for hypothesis development that would hopefully form a sound theoretical basis for future approaches to the assessment and treatment of neglect.

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