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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.

Transcranial static magnetic stimulation (tSMS) has been known to reduce human cortical excitability. Here, we investigated whether tSMS would modulate visuo-spatial cognition in healthy humans. Subjects performed a visuo-spatial task requiring judgements about the symmetry of pre-bisected lines. Visual stimuli consisted of symmetrically or asymmetrically transected lines, tachystoscopically presented for 150 ms on a computer monitor. Task performance was examined before, immediately after, and 10 min after tSMS/sham stimulation of 20 min over the posterior parietal cortex (PPC: P4 from the international 10–20 system) or superior temporal gyrus (STG: C6). Nine out of 16 subjects misjudged pre-bisected lines by consistently underestimating the length of the right-side segment (judging lines to be exactly pre-bisected when the transector was located to the left of the midpoint, or judging the left-side segment to be longer when the transector was located at the midpoint). In these subjects showing a leftward bias, tSMS over the right STG reduced the magnitude of the leftward bias. This did not occur with tSMS over the right PPC or sham stimulation. In the remaining right-biased subjects, no intervention effect was observed with any stimulation. Our findings indicate that application of tSMS over the right STG modulates visuo-spatial cognition in healthy adults.

A 75-year-old woman presented with acute behavioural change. She was well until 6 hours prior, when she looked bizarrely while on cooking. Her son spoke to her and noticed that she was staring at her right side. He approached her from her left side and talked to her, but she did not seem to notice

Working memory (WM) is known to be impaired in patients with stroke experiencing unilateral spatial neglect (USN). Here, we examined in a systematic manner three WM components: memory of object identity, memory of object location, and binding between object identity and location. Moreover, we used two different retention intervals to isolate maintenance from other mnemonic and perceptual processes. Fourteen USN first-event stroke patients with right-hemisphere damage were tested in two different WM experiments using long and short retention intervals and an analog response scale. Patients exhibited more identification errors for items displayed on the contralesional side. Localization errors were also more prominent in the contralesional side, especially after a long retention interval. These localization errors were often a result of swap errors, that is, erroneous localizations of correctly identified contralesional objects in correctly memorized locations of ipsilesional objects. We conclude that a key WM deficit in USN is a lateralized impairment in binding between the identity of an object and its spatial tag.

Background The occurrence of unilateral spatial neglect (USN) in non-hemiplegic right-hemisphere damaged patients is rare. Earlier studies of such patients revealed a significant advantage when typical neglect tests were performed by the patient's left hand as compared to the dominant right hand. The mechanism underlying this "output-mode effect" remains elusive. Methods We analyzed the temporal dynamics of this effect using line-bisection task in 9 non-hemiplegic stroke patients with left-USN. Results In 4 patients tested shortly after stroke onset (≤ 6 weeks), the impact of hand laterality was variable (left-hand advantage in one patient; right-hand advantage in 2 patients; similar performance in both hands in one patient). Only later (> 6 weeks) a clear advantage of the left hand emerged in the majority of patients, similar to the earlier reports which were all based on late testing. Conclusions We found variable dynamics in the expression of the output-mode effect in the first weeks following stroke onset, which may reflect changes of inter-hemispheric balance, related to recovery processes. We propose that therapeutic interventions aiming to manipulate the inter-hemispheric balance (e.g., by non-invasive brain stimulation) take into account the existence of such dynamics and their highly variate nature.

A short period of adaptation to a prismatic shift of the visual field to the right briefly but significantly improves left unilateral spatial neglect. Additionally, prism adaptation affects multiple modalities, including processes of vision, auditory spatial attention, and sound localization. This non-randomized, single-center, controlled trial aimed to examine the immediate effects of prism adaptation on the sound-localization abilities of patients with left unilateral spatial neglect using a simple source localization test. Subjects were divided by self-allocation into a prism-adaptation group (n = 11) and a control group (n = 12). At baseline, patients with left unilateral spatial neglect showed a rightward deviation tendency in the left space. This tendency to right-sided bias in the left space was attenuated after prism adaptation. However, no changes were observed in the right space of patients with left unilateral spatial neglect after prism adaptation, or in the control group. Our results suggest that prism adaptation improves not only vision and proprioception but also auditory attention in the left space of patients with left unilateral spatial neglect. Our findings demonstrate that a single session of prism adaptation can significantly improve sound localization in patients with left unilateral spatial neglect. However, in this study, it was not possible to accurately determine whether the mechanism was a chronic change in head orientation or a readjustment of the spatial representation of the brain; thus, further studies need to be considered.

The non-dominant hemisphere supports visuospatial and social cognition. Its injury is at the origin of the unilateral spatial neglect. The preliminary objectives of this thesis were (1) to propose a taxonomy of the brain functions supported by the right hemisphere ; (2) to harmonize the functional anatomy with the neuropsychological and clinical semiology datas for each function ; (3) to harmonize the anatomical nomenclature between dissection and imaging studies ; (4) to harmonize the anatomical nomenclature of the main white matter fascicle : the arcuate fasciculus. The main goal of this thesis was (5) to improveour knowledge of the anatomy of the ventral network of attention, which is a cortical functional network identified by resting state MRI, involved in visuospatial cognition. By processing resting state MRI data from 50 subjects, we were able to describe the end points of the ventral attention network. We then used the ventral attention network endpoints as seed regions, for the in-vivo tractography, as well as ex-vivo Klingler’s method. We were thus able to define the fiber bundles supporting the ventral attention network. It include the superior longitudinal fasciculus in its third portion (SLF III) and the arcuate fasciculus. The development of a specific neuropsychological test stimulating the ventral attention network remains to be achieved. In this way, we have published studies (6) aiming at the use of virtual reality headsets in awake brainsurgery, to perform new neuropsychological tests dedicated to the exploration of the right hemisphere cognitive functions.This thesis work has been valued by 7 publications, 1 article submitted and the development of a neuropsychological test using virtual reality in awake brain surgery., L’hémisphère non dominant supporte la cognition visuo-spatiale et sociale. Sont atteinte est à l’origine du syndrome d’héminégligence. Les objectifs préliminaires de cette thèse étaient (1) de proposer une taxonomie des fonctions cérébrales supportées par l’hémisphère droit ; (2) d’harmoniser les données d’anatomie fonctionnelle avec les données neuropsychologiques et de sémiologie clinique de ces fonctions. (3) d’harmoniser la nomenclature anatomique entre les études de dissections et d’imagerie de l’hémisphère droit. (4) d’harmoniser la nomenclature anatomique du principal faisceau de substance blanche : le faisceau arqué. Le principal but de cette thèse était (5) d’approfondir nos connaissances sur l’anatomie du réseau ventral de l’attention, qui est un réseau fonctionnel cortical identifié par l’IRM de repos, impliqué dans la cognition visuo-spatiale. En traitant les données d’IRM fonctionnelle de repos de 50 sujets, nous avons pu décrire les localisations corticales du réseau ventral de l’attention dans notre cohorte de sujets sains. Nous avons ensuite utilisé les zones corticales du réseau ventral de l’attention comme régions germes, pour l’étude des fibres blanches in-vivo (tractographie), ainsi que sur des cerveaux par méthode de Klingler (ex-vivo). Nous avons pu ainsi définir les faisceaux de fibres blanches du réseau ventral de l’attention. Ces faisceaux comprennent le faisceau longitudinal dans sa troisième portion (SLF III) et le faisceau arqué droits. Le développement d’un test neuropsychologique spécifique stimulant le réseau ventral de l’attention reste à concrétiser pour pouvoir réaliser cette chirurgie éveillée. Dans ce sens, nous avons publié des travaux (6) visant à l’utilisation des lunettes de réalité virtuelle en condition de chirurgie éveillée, pour réaliser de nouveaux tests neuropsychologiques dédiés à l’exploration des fonctions cognitives de l’hémisphère droit. Ce travail de Thèse a été valorisé par 7 publications, 1 article soumis et le développement d’un test neuropsychologique utilisant la réalité virtuelle en chirurgie éveillée cérébrale.

Neglect is a disabling neuropsychological syndrome that is frequently observed following right-hemispheric stroke. Affected individuals often present with multiple attentional deficits, ranging from reduced orienting towards contralesional space to a generalized impairment in maintaining attention over time. Although a degree of spontaneous recovery occurs in most patients, in some individuals this condition can be treatment-resistant with prominent ongoing non-spatial deficits. Further, there is a large inter-individual variability in response to different therapeutic approaches. Given its potential to alter neuronal excitability and affect neuroplasticity, non-invasive brain stimulation is a promising tool that could potentially be utilized to facilitate recovery. However, there are many outstanding questions regarding its implementation in this heterogeneous patient group. Here we provide a critical overview of the available evidence on the use of non-invasive electrical brain stimulation, focussing on transcranial direct current stimulation (tDCS), to improve neglect and associated attentional deficits after right-hemispheric stroke. At present, there is insufficient robust evidence supporting the clinical use of tDCS to alleviate symptoms of neglect. Future research would benefit from careful study design, enhanced precision of electrical montages, multi-modal approaches exploring predictors of response, tailored dose-control applications and increased efforts to evaluate standalone tDCS versus its incorporation into combination therapy.

Highlights • EEG-SVD topographies correlate with signatures of stroke. • They are robust over repeated measurements and new patient samples. • They correlate with the major signs of unilateral spatial neglect., Theoretical advances in the neurosciences are leading to the development of an increasing number of proposed interventions for the enhancement of functional recovery after brain damage. Integration of these novel approaches in clinical practice depends on the availability of reliable, simple, and sensitive biomarkers of impairment level and extent of recovery, to enable an informed clinical-decision process. However, the neuropsychological tests currently in use do not tap into the complex neural re-organization process that occurs after brain insult and its modulation by treatment. Here we show that topographical analysis of resting-state electroencephalography (rsEEG) patterns using singular value decomposition (SVD) could be used to capture these processes. In two groups of subacute stroke patients, we show reliable detection of deviant neurophysiological patterns over repeated measurement sessions on separate days. These patterns generalized across patients groups. Additionally, they maintained a significant association with ipsilesional attention bias, discriminating patients with spatial neglect of different severity levels. The sensitivity and reliability of these rsEEG topographical analyses support their use as a tool for monitoring natural and treatment-induced recovery in the rehabilitation process.

International audience; Caloric vestibular stimulation (CVS) can temporarily reduce visuospatial neglect and related symptoms. The present study examined the effect of CVS on representational neglect during free exploration of the map of France. We asked patients to name cities they could mentally “see” on the map of France, without giving them any directional instructions related to the left or right sides of the map. In right brain damaged patients with left visuospatial neglect, the mental representation of the map was asymmetrical (favoring the right side). After stimulation, neglect patients named more towns on the left side of the map, leading to a significant reduction in map representation asymmetry. Our findings are consistent with previous studies on visuospatial neglect and are in favor of a central effect of vestibular stimulation on mechanisms involved in space representation.

Movement and perception interact continuously in daily activities. Motor output changes the outside world and affect perceptual representations. Similarly, perception has consequences on movement. Nevertheless, how movement and perception influence each other and share information is still an open question. Mappings from movement to perceptual outcome and vice versa change continuously throughout life. For example, a cerebrovascular accident (stroke) elicits in the nervous system a complex series of reorganization processes at various levels and with different temporal scales. Functional recovery after a stroke seems to be mediated by use-dependent reorganization of the preserved neural circuitry. The goal of this thesis is to discuss how interaction with the environment can influence the progress of both sensorimotor performance and neuromotor recovery. I investigate how individuals develop an implicit knowledge of the ways motor outputs regularly correlate with changes in sensory inputs, by interacting with the environment and experiencing the perceptual consequences of self-generated movements. Further, I applied this paradigm to model the exercise-based neurorehabilitation in stroke survivors, which aims at gradually improving both perceptual and motor performance through repeated exercise. The scientific findings of this thesis indicate that motor learning resolve visual perceptual uncertainty and contributes to persistent changes in visual and somatosensory perception. Moreover, computational neurorehabilitation may help to identify the underlying mechanisms of both motor and perceptual recovery, and may lead to more personalized therapies.

Caloric vestibular stimulation (CVS) can temporarily reduce visuospatial neglect and related symptoms. The present study examined the effect of CVS on representational neglect during free exploration of the map of France. We asked patients to name cities they could mentally &ldquo, see&rdquo, on the map of France, without giving them any directional instructions related to the left or right sides of the map. In right brain damaged patients with left visuospatial neglect, the mental representation of the map was asymmetrical (favoring the right side). After stimulation, neglect patients named more towns on the left side of the map, leading to a significant reduction in map representation asymmetry. Our findings are consistent with previous studies on visuospatial neglect and are in favor of a central effect of vestibular stimulation on mechanisms involved in space representation.

Made available in DSpace on 2020-12-10T19:59:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01. Added 1 bitstream(s) on 2021-07-15T15:25:04Z : No. of bitstreams: 1 S1807-59322020000100233.pdf: 372062 bytes, checksum: dbd940041cab20ff0e0470637d09e7ec (MD5) OBJECTIVE: Unilateral spatial neglect (USN) results in a consistent and exaggerated spatial asymmetry in the processing of information about the body or space due to an acquired brain injury. There are several USN tests for clinical diagnosis, but none of them are validated in Brazil. The aim was to obtain normative values from a healthy sample in Brazil and to evaluate the effects of demographic variables on USN tests. METHODS: This was a cross-sectional study performed with 150 neurologically healthy individuals. USN was evaluated using the line cancelation (LC), star cancelation (SC), and line bisection (LB) tests in the A3 (29.7 x 42.0 cm) sheet format. RESULTS: In LC, 143 participants had 0 omissions, and the occurrence of failure was significantly associated with aging (OR=1.1[1.02-1.2]; p=0.012). In SC, 145 participants had fewer than 1 omission, and the occurrence of failure was significantly associated with aging (OR=1.07[1.03-1.11]; p < 0.001). In LB, deviations were the lowest for those with the highest level of education (r=0.20; p=0.015), and the deviation was 9.5 mm. CONCLUSION: The cutoff points presented in this study may be indicative of USN, but due to performance differences based on age, we suggest using different norm scores for different age groups. These norm scores can be used in the clinic immediately for USN diagnosis. Univ Fed Triangulo Mineiro UFTM, Dept Fisioterapia Aplicada, Uberaba, MG, Brazil Univ Estadual Paulista UNESP, Fac Med Botucatu, Neurocirurgia, Botucatu, SP, Brazil Univ Estadual Paulista, Hosp Clin, Fac Med Botucatu,UNESP, Serv Atencao & Referencia Alcool & Drogas SARAD, Botucatu, SP, Brazil Univ Fed Triangulo Mineiro UFTM, Pos Grad Educ Fis Biomecan & Controle Motor, Uberaba, MG, Brazil Univ Estadual Paulista, Dept Saude Publ, UNESP, Botucatu, SP, Brazil Univ Paulita, UNESP, Fac Med Botucatu, Dept Neurol Psicol & Psiquiatria, Botucatu, SP, Brazil Univ Estadual Paulista UNESP, Fac Med Botucatu, Neurocirurgia, Botucatu, SP, Brazil Univ Estadual Paulista, Hosp Clin, Fac Med Botucatu,UNESP, Serv Atencao & Referencia Alcool & Drogas SARAD, Botucatu, SP, Brazil Univ Estadual Paulista, Dept Saude Publ, UNESP, Botucatu, SP, Brazil Univ Paulita, UNESP, Fac Med Botucatu, Dept Neurol Psicol & Psiquiatria, Botucatu, SP, Brazil

In human–computer interactions, higher-level visuospatial function is likely needed to effectively use the interface. The aim of this study is to clarify whether individuals with visuospatial defec...

Background and Purpose: Unilateral spatial neglect (USN) is often observed in ischemic stroke patients suffered their right parietal lobe. USN is an obstacle to undergo rehabilitation smoothly, then might influence the recovery of activities of daily living (ADL) after stroke. We aimed to clarify the association between the presence of USN after ischemic stroke and the ADL improvement. Methods: Consecutive patients with first-ever ischemic stroke and left limb paralysis who admitted to within 7 days from onset during February 2011 and March 2019 were included. Patients met the following criteria were excluded: mRS ≥3 before onset, NIHSS >15 on admission, without left limb paralysis, and missing NIHSS or functional independence measure (FIM) score on admission. Multiple regression analysis was performed to investigate the association between FIM efficiency score of acute phase and following factors: age, sex, acute reperfusion therapy (using an intravenous infusion of recombinant tissue plasminogen activator and/or endovascular therapy), FIM score on admission, and other clinical characteristics. All data were collected retrospectively using our electrical health record. Results: 721 ischemic stroke patients with left limb paralysis (320 women, median age 76) were included. Median FIM efficiency score was significantly lower in patients with USN than without USN (n=240, 481; 0.83 vs 1.63, respectively). Multiple regression analysis showed that USN, age, and acute reperfusion therapy were significant prognostic factors of FIM efficiency (coefficient and 95% confidence interval [CI]: -0.135 [-0.771 to -0.153], -0.106 [-0.022 to -0.002], and 0.224 [0.136 to 0.305], respectively). Conclusions: USN significantly influence the recovery of ADL after ischemic stroke. Clinicians should adequately evaluate USN after stroke and undergo USN-specific rehabilitation for them to optimize the effect of post-stroke rehabilitation. USN-specific rehabilitation might lead to better FIM efficiency.

Visual unilateral spatial neglect (VUSN) is a neuropsychological condition commonly experienced after stroke whereby patients are unable to attend to stimuli on the controlesional side of their space. VUSN can occur in the personal, peripersonal, and/or extrapersonal portion of patient’s space. Traditional paper-and-pencil neuropsychological tests are widely used to evaluate VUSN, but they assess peripersonal VUSN. Instead, personal and extrapersonal neglect are less easily evaluated. The aim of this study was to present normative values for the Visual Scanning Test (VST), a new neuropsychological tool to quantitatively assess the extrapersonal VUSN. Eighty-six healthy subjects took part in the study (61 female), with a mean age of 52.8 years (SD = 17.0) and a mean of 14.0 years of education (SD = 5.2). The VST involved a visual search for a target between similar visual distractors, projected in the far space. The test was administered twice to each participant, with an interval of 2 weeks. From the recorded data, it was possible to obtain indexes related to the reaction times and to the accuracy of the performance on the VST. Multiple linear regression analysis revealed that age and education significantly influenced VST-derived indexes. From the regression analysis, a correction grid for raw scores was built. Adjusted scores were then ranked, and by means of a non-parametric procedure, tolerance limits (both outer and inner one-sided) were defined. The present study provided normative data for the VST in an Italian population useful for both clinical and research purposes. ClinicalTrials.gov ID: NCT03931798

The non-dominant hemisphere supports visuospatial and social cognition. Its injury is at the origin of the unilateral spatial neglect. The preliminary objectives of this thesis were (1) to propose a taxonomy of the brain functions supported by the right hemisphere ; (2) to harmonize the functional anatomy with the neuropsychological and clinical semiology datas for each function ; (3) to harmonize the anatomical nomenclature between dissection and imaging studies ; (4) to harmonize the anatomical nomenclature of the main white matter fascicle : the arcuate fasciculus. The main goal of this thesis was (5) to improveour knowledge of the anatomy of the ventral network of attention, which is a cortical functional network identified by resting state MRI, involved in visuospatial cognition. By processing resting state MRI data from 50 subjects, we were able to describe the end points of the ventral attention network. We then used the ventral attention network endpoints as seed regions, for the in-vivo tractography, as well as ex-vivo Klingler’s method. We were thus able to define the fiber bundles supporting the ventral attention network. It include the superior longitudinal fasciculus in its third portion (SLF III) and the arcuate fasciculus. The development of a specific neuropsychological test stimulating the ventral attention network remains to be achieved. In this way, we have published studies (6) aiming at the use of virtual reality headsets in awake brainsurgery, to perform new neuropsychological tests dedicated to the exploration of the right hemisphere cognitive functions.This thesis work has been valued by 7 publications, 1 article submitted and the development of a neuropsychological test using virtual reality in awake brain surgery., L’hémisphère non dominant supporte la cognition visuo-spatiale et sociale. Sont atteinte est à l’origine du syndrome d’héminégligence. Les objectifs préliminaires de cette thèse étaient (1) de proposer une taxonomie des fonctions cérébrales supportées par l’hémisphère droit ; (2) d’harmoniser les données d’anatomie fonctionnelle avec les données neuropsychologiques et de sémiologie clinique de ces fonctions. (3) d’harmoniser la nomenclature anatomique entre les études de dissections et d’imagerie de l’hémisphère droit. (4) d’harmoniser la nomenclature anatomique du principal faisceau de substance blanche : le faisceau arqué. Le principal but de cette thèse était (5) d’approfondir nos connaissances sur l’anatomie du réseau ventral de l’attention, qui est un réseau fonctionnel cortical identifié par l’IRM de repos, impliqué dans la cognition visuo-spatiale. En traitant les données d’IRM fonctionnelle de repos de 50 sujets, nous avons pu décrire les localisations corticales du réseau ventral de l’attention dans notre cohorte de sujets sains. Nous avons ensuite utilisé les zones corticales du réseau ventral de l’attention comme régions germes, pour l’étude des fibres blanches in-vivo (tractographie), ainsi que sur des cerveaux par méthode de Klingler (ex-vivo). Nous avons pu ainsi définir les faisceaux de fibres blanches du réseau ventral de l’attention. Ces faisceaux comprennent le faisceau longitudinal dans sa troisième portion (SLF III) et le faisceau arqué droits. Le développement d’un test neuropsychologique spécifique stimulant le réseau ventral de l’attention reste à concrétiser pour pouvoir réaliser cette chirurgie éveillée. Dans ce sens, nous avons publié des travaux (6) visant à l’utilisation des lunettes de réalité virtuelle en condition de chirurgie éveillée, pour réaliser de nouveaux tests neuropsychologiques dédiés à l’exploration des fonctions cognitives de l’hémisphère droit. Ce travail de Thèse a été valorisé par 7 publications, 1 article soumis et le développement d’un test neuropsychologique utilisant la réalité virtuelle en chirurgie éveillée cérébrale.

Digital solutions for unilateral spatial neglect (USN) assessment and treatment are nowadays of great interest, because of both the possibility of combining them with other rehabilitation practices, and the easy-to-understand data and indicators they collect. The ReMoVES platform, developed in DITEN laboratories, is conceived in the Assistive Technologies framework and provides motor and cognitive exergames and activities to be performed in conjunction with traditional rehabilitation. In this work, two case-studies, related to the USN rehabilitation, are presented. The combination of cognitive therapy, delivered by the ReMoVES platform, and transcranial direct-current stimulation (tDCS) technique was used as rehabilitation treatment for both the patients. Data collected at the beginning or at the end of the rehabilitation process, or also during the treatment sessions, are shown and discussed in this paper. This work is a preliminary part of a wider one, that will be conducted involving many different rehabilitation centers, aimed at proving the validity of such an approach to USN treatments.

Individuals with left unilateral spatial neglect (USN) following a right hemisphere lesion show difficulty in orienting their attention toward stimuli presented on the left. In normal cognition, others' gaze direction and a pointing arrow naturally guide visual attention. Here, we explore a method to identify patients who may benefit from these skills as a base for compensation during rehabilitation. We tested gaze and arrow cueing effects in 26 healthy participants and in 13 patients with USN. Our data show that brain injuries causing USN do not affect gaze and arrow cueing in a consistent manner from one patient to another.

Prism adaptation (PA) is a technique that induces a temporary change of the alignment between different reference frames. This technique has been shown to reduce many signs of unilateral spatial neglect (USN). Two procedures of prism adaptation have been used. In concurrent exposure participants can see their arm and hand during the movement trajectory, and during terminal exposure, participants can see only the most distal few centimetres. Because the two exposures elicit different proportions of visual and proprioceptive realignment, they could present different rehabilitation efficacies. We compared these procedures in 12 USN patients and 12 healthy participants who performed one session of PA with concurrent exposure and one session with terminal exposure. We compared the effects of the two exposure types on sensorimotor outcomes (visual subjective straight ahead, proprioceptive subjective straight ahead, open loop pointing, and error correction during exposure) and neglect outcomes. We found no significant differences in the effects of the two exposure types on sensorimotor performance of patients and controls, nor on patients’ neuropsychological outcomes. Compared with controls, USN patients showed a significant rightward bias in visual subjective straight ahead pre-adaptation, a slower rate of error correction during prism exposure, and some evidence that visual and proprioceptive shift could be influenced by their neglect. Based on these results, we recommend that prism adaptation be conducted with concurrent exposure for easiness of execution.

Unilateral spatial neglect (USN), a highly prevalent and disabling post-stroke deficit, severely affects functional mobility. Visual perceptual abilities (VPAs) are essential in activities involving mobility. However, whether and to what extent post-stroke USN affects VPAs and how they contribute to mobility impairments remains unclear.To estimate the extent to which VPAs in left and right visual hemispaces are (1) affected in post-stroke USN; and (2) contribute to goal-directed locomotion.Individuals with (USN+,Higher discrimination thresholds were found for all VPAs in the USN+ group compared to USN- and HC groups (Deficits in VPAs may account for the functional difficulties experienced by individuals with post-stroke USN. Psychophysical tests used in the present study offer important advantages and can be implemented to enhance USN diagnostics and rehabilitation.

The objective of this study was to examine visual scanning performance in patients with Unilateral Spatial Neglect (USN) in a visual search task. Thirty-one right hemisphere stroke patients with USN were recruited. They performed a dynamic visual search task with two conditions, with and without distractors, while eye movements were monitored with an eye-tracker. The main goal of the task was to select target stimuli that appeared from the top of the screen and moved vertically downward. Target detection and visual scanning percentage were assessed over two hemispaces (right, left) on two conditions (distractor, no distractor). Most Scanned Regions (MSR) were calculated to analyze the areas of the screen where most points of fixation were directed to. Higher target detection rate and visual scanning percentages were found on the right hemispace on both conditions. From the MSRs we found that participants with a center of attention further to the right of the screen also presented smaller overall MSRs. Right hemisphere stroke patients with USN presented not only a significant rightward bias but reduced overall search areas, implying hyperattention does not only restrict search on the horizontal (right-left) axis but the vertical axis (top-bottom) too.

Spatial neglect syndrome with cerebral lesions is characterized by the ina-bility to orient, report, or respond to relevant visual stimuli contralateral to the lesions. In this study, we investigated the pattern of horizontal visual search in a large space; this search was performed by patients with right hemisphere damage caused by cerebrovascular disease. The neck rotation angle and search time in each increment were continuously recorded during the task, and quantitative data of the measurements were collected. Head position during the visual search task in a large space (%) was then calculated. We set angular bands in increments of 5 degrees from the midline on the left and right sides, and calculated the total search time in each angular band. In patients with unilateral spatial neglect (USN), the search time in the angular band of 5 - 9 on the right side was significantly longer (with USN 16.7%, without USN 4.5%, t = 2.52, df = 16, p < 0.05). Furthermore, in patients with neglect in the leftmost end area in a large space, the search time was significantly shorter in the angular band of 1 - 4 degrees to the left (with neglect 13.1%, without neglect 23.7%, t = 2.13, df = 16, p < 0.05), and tended to be long in the angular band of 5 - 9 to the right. The neck rotation angle and pattern during the search task in a large field deviated slightly to the right, and the search time slightly to the left was short. We believe that these results support the rightward deviation of the search pattern and frame of USN patients.

Unilateral spatial neglect (USN) is characterized by neglect in peripersonal and extrapersonal space, the disparity of which is unknown. We assessed these forms of neglect in a patient with USN. We promoted sight scanning in extrapersonal space and used an eye camera to measure gaze movement. We found left-sided sight scanning in peripersonal space, but right-side-biased sight scanning in extrapersonal space. Additionally, line of sight was corrected when the patient was instructed to look left in extrapersonal space and to focus the line of sight at the center. Gaze measurement thus helped to assess disparities in spatial neglect in USN.

Background/Objective Limb activation is one of the behavioural interventions to improve unilateral spatial neglect (USN). However, the effect of passive limb activation on activities of daily living (ADL) is not clear. This study examined the effect of passive limb activation by functional electrical stimulation (FES) on wheelchair driving for patients with USN, and to discuss the possibility of application of this treatment to occupational therapy. Methods A single subject design-baseline-intervention-baseline (ABA), was applied to 2 stroke patients with USN. Phase A' and A consisted of the wheelchair driving task only. Phase B consisted of the wheelchair driving task with FES. Each phase lasted for 2 weeks. The wheelchair driving task was maneuvering on a square passage in the clockwise and counter clockwise conditions for 8 minutes respectively, and four obstacles were set at each side. FES was applied to the affected forearm extensor muscles. Assessor recorded: 1) The distance participants drove wheelchair for 8 minutes, and 2) The number of collisions with obstacles and the wall, for 10 days. Results For one participant, the distance of maneuvering significantly increased in phase B (p < .05.), and USN on the cognitive test in the extrapersonal space indicated a tendency to improve after phase B. Conclusion Passive limb activation by FES improved wheelchair driving and cognitive performance for patients with USN. It can be used with instruction from occupational therapists to enhance the performance on ADL.