Prism Adaptation Research Articles

39 Does Pseudoneglect Modifies The Visuospatial After-Effects Of Vertical Prism Adaptation?

Objective:The prism adaptation (PA) with rightward shifting lenses is a promising rehabilitation technique for left hemispatial neglect. The PA has also been applied in healthy individuals to investigate cognitive mechanism(s) underlining such adaptation. Importantly, studies have suggested that PA may primarily impact the functions of the dorsal or the ventral attentional stream, and we have previously reported that PA to the upward and downward shifting lenses leads to a significant aftereffect in vertical line bisection task. However, this post-adaptation effect, similarly to that seen in the horizontal plane, might have been modified by the presence of the vertical pseudoneglect healthy participants often experience prior to PA. Thus, the aim of this study was to test this hypothesis.Participants and Methods:30 right-handed healthy adults (age M=22,4) performed a computerized line bisection (LB) in vertical and horizontal condition. The bisections were performed twice: before and after PA procedure. Participants took experimental procedure three times, each in at least 24 h of break, each time in one of three conditions of shifting lenses; down, up, control. Both LB tasks (vertical and horizontal) consisted of 24 lines, each centered on 23" touch screen. The participants were asked to find the middle of the line. Throughout the experiment, participants were comfortably seated with their head positioned on a chinrest. Participants were fitted with prismatic goggles that deviated their visual field by 10 degrees. For the adaptation we used the Peg-the-mole procedure consisting of 120 pointing movements.Results:To assess the effect of the vertical PA on landmark judgments we performed a repeated measures ANOVA with direction of PA (upward/downward), the condition of LB (vertical/ horizontal) and pre- vs post adaptation as a between-subjects factor. This analysis revealed a main effect of the direction of PA (p< 0.001) and a main effect of condition (p< 0.001). Overall, however, only adaptation in up-shifting lenses led to significant aftereffects (p<0.05). Further, when we excluded participants who did not exhibited horizontal pseudoneglect in preadaptation LB, the effect of PA in downshifting PA emerged in vertical LB (p<0.05). Further, this group also exhibited the aftereffect of PA in up-shifting lenses for the horizontal (p<0.01) and the vertical LB (p<0.05). Additionally, these participants exhibited a congruent tendency after upward and downward PA, and tended to allocate their attention more upward and rightward.Conclusions:The results of this study confirm that the vertical PA evokes a visuo-spatial bias. Moreover, the PA aftereffect seems to be modified by the presence of the pre-adaptation pseudoneglect. Whereas the mechanism inducing this bias is not fully known, it might be explained in light of the interhemispheric activation-inhibition balance. Both the upward and downward PA may primarily lead to activation of the posterior regions of the right hemisphere, and this activation may result with the upward and rightward bias in the LB task. However, future research with neuroimaging techniques is needed to test this hypothesis.

The effects of prior exposure to prism lenses on de novo motor skill learning.

Motor learning involves plasticity in a network of brain areas across the cortex and cerebellum. Such traces of learning have the potential to affect subsequent learning of other tasks. In some cases, prior learning can interfere with subsequent learning, but it may be possible to potentiate learning of one task with a prior task if they are sufficiently different. Because prism adaptation involves extensive neuroplasticity, we reasoned that the elevated excitability of neurons could increase their readiness to undergo structural changes, and in turn, create an optimal state for learning a subsequent task. We tested this idea, selecting two different forms of learning tasks, asking whether exposure to a sensorimotor adaptation task can improve subsequent de novo motor skill learning. Participants first learned a new visuomotor mapping induced by prism glasses in which prism strength varied trial-to-trial. Immediately after and the next day, we tested participants on a mirror tracing task, a form of de novo skill learning. Prism-trained and control participants both learned the mirror tracing task, with similar reductions in error and increases in distance traced. Both groups also showed evidence of offline performance gains between the end of day 1 and the start of day 2. However, we did not detect differences between groups. Overall, our results do not support the idea that prism adaptation learning can potentiate subsequent de novo learning. We discuss factors that may have contributed to this result.

Homonymous hemianopia and visual neglect: Part II ― rehabilitation

This article is the second part of a literary review of the most common and difficult to differentiate between visualspatial disorders, namely, homonymous hemianopia and unilateral spatial neglect, which occur after a right hemisphere stroke. In the first part of the review, the phenomenology of these disorders, diagnostic methods, and criteria for their difference were comprehensively explored.
 The second part highlights modern methods of rehabilitation based on the recommendations of the World Federation for Neurorehabilitation. For the rehabilitation of homonymous hemianopia, the following interventions are recommended: saccadic training, hemianopic reading training, restorative visual field training, etc. For the rehabilitation of the neglect syndrome, the following interventions are encouraged: visual scanning training, optokinetic/smooth pursuit therapy, prism adaptation, eye patching, noninvasive brain stimulation, etc.
 Recommendations on the methods and timing of their implementation are presented, and modern clinical studies are highlighted. In addition, the innovative methods of eye tracking and virtual reality are described.
 The information presented herein is sent to rehabilitation medicine specialists.

Slower rates of prism adaptation but intact aftereffects in patients with early to mid-stage Parkinson's disease

There is currently mixed evidence on the effect of Parkinson's disease on motor adaptation. Some studies report that patients display adaptation comparable to age-matched controls, while others report a complete inability to adapt to novel sensory perturbations. Here, early to mid-stage Parkinson's patients were recruited to perform a prism adaptation task. When compared to controls, patients showed slower rates of initial adaptation but intact aftereffects. These results support the suggestion that patients with early to mid-stage Parkinson's disease display intact adaptation driven by sensory prediction errors, as shown by the intact aftereffect. But impaired facilitation of performance through cognitive strategies informed by task error, as shown by the impaired initial adaptation. These results support recent studies that suggest that patients with Parkinson's disease retain the ability to perform visuomotor adaptation, but display altered use of cognitive strategies to aid performance and generalises these previous findings to the classical prism adaptation task.

Prism adaptation during balance standing enhances the transfer after-effect on standing postural displacement

Prism adaptation (PA) is a sensorimotor adaptation paradigm that induces after-effects of adapted tasks and transfer after-effects of non-adapted tasks. Previous studies showed inconsistent results of transfer after-effects of adaptation to a leftward prismatic shift on the center-of-pressure (COP) displacement during eyes-closed standing. Challenging balance during PA increases the generalization of the internal model to untrained movements, resulting in increased transfer after-effects. The present study aimed to investigate the transfer after-effects of PA with challenging balance on standing postural displacement. Thirty healthy young adults were grouped into floor standing and balance-disc standing groups during leftward PA and pointed to targets while adapting to a leftward visual shift (30 diopters) for 20 min. After leftward PA, both groups had a significant rightward displacement of straight-ahead pointing with eyes closed. However, the COP position during eyes-closed standing with feet-closed was significantly displaced rightward only in the balance-disc standing group after leftward PA. These results show that challenging balance might increase the somatosensory and proprioceptive information for standing postural control, resulting in increased transfer after-effects of leftward PA on rightward standing postural displacement.

Investigating premotor reaching biases after prism adaptation

ABSTRACT Prism adaptation (PA) is both a visuomotor learning task and potential treatment for spatial neglect after stroke. While PA’s aftereffects can improve neglect symptoms, therapeutic benefits vary across individuals, possibly due to differences in neglect subtypes. Neglect symptoms can be described along an information processing pathway, yielding perceptual (input) and premotor (output) neglect subtypes. There is some evidence that PA mainly benefits persons with premotor neglect. We investigated whether PA modulates the premotor stage of information processing by examining whether PA could induce a premotor bias in healthy adults. We measured perceptual and premotor biases using a speeded reach task that compares the initiation time of leftward and rightward reaches to lateralized targets from different hand start positions. Using a randomized mixed experimental design, 30 right-handed healthy adults completed this speeded reach task before and after either left-shifting (n = 15) or right-shifting (n = 15) PA. As hypothesized, left-shifting PA speeded initiation time specifically for reaches in the rightward direction, regardless of target location (p = .02, ηp 2 = .18), suggesting that PA induced a premotor bias in the direction of the prism aftereffect. These findings have implications for PA’s underlying mechanisms, which can inform visuomotor learning theories and PA’s use as a treatment for spatial neglect.

Prism adaptation therapy in spatial neglect: The importance of connectional anatomy

The meta-analysis conducted by Székely et al. described the lack of beneficial effect of prism adaptation in neglect patients. The authors concluded that the results did “not support the routine use of prism adaptation as a therapy for spatial neglect”. However, a possible nuance to this conclusion could be that the response (or lack thereof) of neglect patients to prism adaptation may actually depend on the connectional anatomy of their lesion. We develop this idea in our commentary, in order to offer a more balanced perspective on the implications of the findings obtained by Székely et al.

Temporal Relationship between Impairment of Cerebellar Motor Learning and Deterioration of Ataxia in Patients with Cerebellar Degeneration.

Ataxia and impaired motor learning are both fundamental features in diseases affecting the cerebellum. However, it remains unclarified whether motor learning is impaired only when ataxia clearly manifests, nor it is known whether the progression of ataxia, the speed of which often varies among patients with the same disease, can be monitored by examining motor learning. We evaluated motor learning and ataxia at intervals of several months in 40 patients with degenerative conditions [i.e., multiple system atrophy (MSA), Machado-Joseph disease (MJD)/spinocerebellar ataxia type 3 (SCA3), SCA6, and SCA31]. Motor learning was quantified as the adaptability index (AI) in the prism adaptation task and ataxia was scored using the Scale for the Assessment and Rating of Ataxia (SARA). We found that AI decreased most markedly in both MSA-C and MSA-P, moderately in MJD, and mildly in SCA6 and SCA31. Overall, the AI decrease occurred more rapidly than the SARA score increase. Interestingly, AIs remained normal in purely parkinsonian MSA-P patients (n = 4), but they dropped into the ataxia range when these patients started to show ataxia. The decrease in AI during follow-up (dAI/dt) was significant in patients with SARA scores < 10.5 compared with patients with SARA scores ≥ 10.5, indicating that AI is particularly useful for diagnosing the earlier phase of cerebellar degeneration. We conclude that AI is a useful marker for progressions of cerebellar diseases, and that evaluating the motor learning of patients can be particularly valuable for detecting cerebellar impairment, which is often masked by parkinsonisms and other signs.

The Effect of Cognitive Style on Individual Differences in Prismatic Adaptation: A Pilot Study

Prism adaptation (PA) is a well-known and widely used technique for rehabilitating unilateral spatial neglect and studying sensory-motor plasticity. However, there is conflicting evidence in the literature regarding its effectiveness which may arise from differences in the type of prisms used, clinical characteristics of the patients, and the procedure used in training. Individual differences may play a role in PA effectiveness in rehabilitating neglect, affecting both its development and its effects. Field-dependent/independent cognitive style is a pervasive characteristic of individual functioning, affecting how environmental information is processed. Here, we tested the hypothesis that cognitive style plays a role in PA efficacy by submitting to a protocol of prism adaptation to 38 health participants, who were classified as field-dependent (FD, N = 19) or field-independent (FI, N = 19), by using the Embedded Figure Test. Results show that during the exposure phase, FI individuals needed a lesser number of pointing movements to reduce the deviation error than FD individuals. However, there are no differences in the extinction of sensory-motor and cognitive after-effects. These results suggest that prismatic adaptation is affected by individuals' cognitive style since FI individuals will need fewer trials to reach adaptation and this could explain why using this rehabilitation technique with a unique, standard protocol is not always effective.

Prism adaptation in patients with unilateral lesion of the parietal or cerebellar cortex: A pilot study on two single cases using a concurrent exposure procedure

Neuroimaging studies showed that prism adaptation (PA), a widely used tool for the rehabilitation of neglect, involves a wide network of brain regions including the parietal cortex and the cerebellum. In particular, the parietal cortex has been suggested to mediate the initial stage of PA through conscious compensatory mechanisms as a reaction to the deviation induced by PA. The cerebellum, on the other side, intervenes in sensory errors prediction to update internal models in later stages. It has been suggested that two mechanisms may underlie PA effects: recalibration, a strategic cognitive process occurring in the initial stages of PA, and realignment, a fully automatic reorganization of spatial maps emerging later and more slowly in time. The parietal lobe has been proposed to be involved mainly in the recalibration whereas the realignment would be carried over by the cerebellum. Previous studies have investigated the effects of a lesion involving either the cerebellum or the parietal lobe in PA taking into account both realignment and recalibration processes. Conversely, no studies have compared the performance of a patient with a cerebellar lesion to that of a patient with a parietal lesion. In the present study, we used a recently developed technique for digital PA to test for differences in visuomotor learning after a single session of PA in a patient with parietal and a patient with cerebellar lesions, respectively. The PA procedure, in this case, includes a digital pointing task based on a concurrent exposure technique, which allows patients to fully see their arm during the pointing task. This procedure has been shown to be as effective as the terminal exposure condition in neglect rehabilitation albeit different processes take place during concurrent exposure condition compared to the most used terminal exposure (allowing to see only the final part of the movement). Patients’ performances were compared to that of a control group. A single session of PA was administered to 1) a patient (BC) with left parieto-occipital lesion involving superior parietal lobe (SPL) and inferior parietal lobe (IPL), 2) a patient (TGM) with a stroke in the territory sub-served by the superior cerebellar artery (SCA) , and 3) 14 healthy controls (HC).The task included three conditions: before wearing prismatic goggles (pre-exposure), while wearing prisms (exposure) and after removing the goggles (post-exposure). Mean deviations were calculated for the following phases: pre-exposure, early-exposure, late-exposure, post-exposure. The presence of after-effect was calculated as the difference between pre-exposure and post-exposure conditions. For each of these conditions, patients’ performance was compared to that of the control group by using a modified Crawford t-test. We found that the patient with the parietal lesion had a significantly different performance in the late-exposure and in the post-exposure compared to both HC and the patient with the cerebellar lesion. Conversely, no differences were observed between TGM and HC across all the conditions.Our results show an increase in the magnitude of the adaptation during the late stage of PA in the patient with the parietal lesion whereas no differences in the performance between the cerebellar patient and the controls were found. These results confirm previous studies suggesting that the parietal cortex is an important node of a wider network involved in PA effect. Furthermore, results concerning the cerebellar patient suggest that visuomotor learning is not affected by lesions of the SCA territory when a concurrent exposure is used as, in such case, it less relies on sensory errors prediction to update internal models. Results are discussed considering the novelty of the applied PA technique.

Quantification and Rehabilitation of Unilateral Spatial Neglect in Immersive Virtual Reality: A Validation Study in Healthy Subjects.

Unilateral spatial neglect is a common sensorimotor disorder following the occurrence of a stroke, for which prismatic adaptation is a promising rehabilitation method. However, the use of prisms for rehabilitation often requires the use of specific equipment that may not be available in clinics. To address this limitation, we developed a new software package that allows for the quantification and rehabilitation of unilateral spatial neglect using immersive virtual reality. In this study, we compared the effects of virtual and real prisms in healthy subjects and evaluated the performance of our virtual reality tool (HTC Vive) against a validated motion capture tool. Ten healthy subjects were randomly exposed to virtual and real prisms, and measurements were taken before and after exposure. Our findings indicate that virtual prisms are at least as effective as real prisms in inducing aftereffects (4.39° ± 2.91° with the virtual prisms compared to 4.30° ± 3.49° with the real prisms), but that these effects were not sustained beyond 2 h regardless of exposure modality. The virtual measurements obtained with our software showed excellent metrological qualities (ICC = 0.95, error = 0.52° ± 1.18°), demonstrating its validity and reliability for quantifying deviation during pointing movements. Overall, our results suggest that our virtual reality software (Virtualis, Montpellier, France) could provide an easy and reliable means of quantifying and rehabilitating spatial neglect. Further validation of these results is required in individuals with unilateral spatial neglect.

Age-related changes to electroencephalographic markers of visuomotor error processing and learning in prism adaptation

Aging is associated with changes in cognitive function, including declines in learning, memory, and executive function. Prism adaptation (PA) is a useful paradigm to measure changes in explicit and implicit mechanisms of visuo-motor learning with age, but the neural correlates are not well understood. In the present study, we used PA to investigate visuo-motor learning and error processing in older adults. Twenty older adults (56–85 yrs) and 20 younger adults (18–33 yrs) underwent a goal-oriented reaching task while wearing prism goggles as continuous EEG was recorded to examine neural correlates of error detection. We examined behavioural measures of PA, as well as ERP components previously found associated with the early and late phases of adaptation to visual distortion caused by the prism goggles. Our results indicate important age-related behavioural and neurophysiological differences. Older adults reached more slowly than younger adults but showed the same accuracy throughout the prism exposure. Older adults also displayed larger aftereffects, indicating preserved visuomotor adaptation. EEG results indicated similar initial error processing in older and younger adults, as measured by the feedback error related negativity (FRN). As seen previously in young adults, the P3a and P3b declined over the prism exposure phase in both groups. Older adults displayed reduced P3a amplitude compared to the younger group in the early phase of adaptation, however, suggesting reduced attentional orienting. Finally, the older group exhibited a greater P3b amplitude compared to the younger group in the later phases of adaptation, potentially a marker of enhanced context updating underlying spatial realignment, leading to their larger aftereffect. Implications for age-related learning differences and clinical applications are discussed.

Prism Adaptation Treatment for Right-Sided and Left-Sided Spatial Neglect: A Retrospective Case-Matched Study

ObjectiveTo compare the effectiveness of prism adaptation treatment (PAT) between patients with right- and left-sided spatial neglect (SN). DesignRetrospective case-matched design. SettingInpatient rehabilitation hospitals and facilities. ParticipantsA total of 118 participants were selected from a clinical dataset of 4256 patients from multiple facilities across the United States. Patients with right-sided SN (median age: 71.0 [63.5-78.5] years; 47.5% female; 84.8% stroke, 10.1% traumatic/nontraumatic brain injury) were matched 1:1 with patients with left-sided SN (median age: 70.0 [63.0-78.0] years; 49.2% female; 86.4% stroke, 11.8% traumatic/nontraumatic brain injury) based on age, neglect severity, overall functional ability at admission, and number of PAT sessions completed during their hospital stay. InterventionPrism adaptation treatment. Main Outcome MeasuresPrimary outcomes were pre–post change on the Kessler Foundation Neglect Assessment Process (KF-NAP) and the Functional Independence Measure (FIM). Secondary outcomes were whether the minimal clinically important difference was achieved for pre–post change on the FIM. ResultsWe found greater KF-NAP gain for patients with right-sided SN than those with left-sided SN (Z = 2.38, P=.018). We found no differences between patients with right-sided and left-sided SN for Total FIM gain (Z=–0.204, P=.838), Motor FIM gain (Z=–0.331, P=.741), or Cognitive FIM gain (Z=–0.191, P=.849). ConclusionsOur findings suggest PAT is a viable treatment for patients with right-sided SN just as it is for patients with left-sided SN. Therefore, we suggest prioritizing PAT within the inpatient rehabilitation setting as a treatment to improve SN symptoms regardless of brain lesion side.

Outcomes of Bilateral Lateral Rectus Tucking in Patients with Divergence Insufficiency

Purpose: Divergence insufficiency is characterized by esotropia at far distance with symptomatic diplopia, minimal or no deviation at near distance, and full ocular duction and version. We analyzed the results of bilateral lateral rectus (BLR) tucking in patients with divergence insufficiency.Methods: Surgery was performed on patients with persistent distance diplopia with esotropia for at least 6 months after diplopia onset. The surgical results were evaluated after BLR tucking based on the maximum angle of deviation at distance among all the angles of deviation measured repeatedly, including the results of the prism adaptation test (PAT).Results: 24 patients were included. The average follow-up period was 14 months (1-48 months). The maximum deviations measured by alternate prism and cover test before surgery were 24.79 ± 8.15 prism diopter (PD) at far distance and 15.45 ± 9.30 PD at near distance. The PAT revealed that, the far distance deviation increased to 28.50 ± 7.77 PD and that at near distance to 25.88 ± 8.07 PD, but the difference between the two values fell to less than 3 PD on average. In 14 patients (58%), followed-up for up to 1 year, we noted no recurrence of diplopia or esotropia, or near distance overcorrection, with the exception of one patient who developed diplopia recurrence at far distance.Conclusions: BLR tucking guided by the maximum distance deviation of the 1 hour PAT affords stable results in patients with divergence insufficiency without overcorrection at near distance or undercorrection at far distance.

Surgical Outcomes with and without Prism Adaptation of Cases with Acute Acquired Comitant Esotropia Related to Prolonged Digital Device Use.

To analyze surgical results of 32 cases with acute acquired comitant esotropia (AACE) related to prolonged use of digital devices (DDs). Medical records of cases with AACE related to prolonged use of DDs that had undergone surgery were retrospectively revised. Complete medical history and full ophthalmological examinations before and surgery were obtained for all cases. All cases also underwent neurological examinations using brain and orbital imaging. Motor success was considered as alignment within 10 prism diopters (Δ) at both near and distance. Sensory success was defined as stereopsis ≤60 arcsec. Nineteen cases (Group S) underwent surgery alone and 13 cases were treated with surgery and prism adaptation (Group S+P). Motor and sensory outcomes were compared between groups. Mean age at first visit was 22.0 ± 9.0 years and mean daily use of DDs use was 6.3 ± 3.4 hours. Mean angle of preoperative alignment for distance and near were 26.5 ± 13.0Δ and 24.6 ± 16.4Δ, respectively. Surgery was performed at a mean of 23.3 ±3.5 years old and mean angle of alignment at final examination for distance and near were 5.8 ± 7.7Δ and 3.5 ± 5.7Δ, respectively. Final motor and sensory success rate were 84% and 53%, respectively. No significant differences in motor or sensory outcomes were evident between groups at initial or last visit. Favorable motor and sensory outcomes were achieved with surgical intervention with and without prism adaptation for AACT related to prolonged use of DDs.

Comparison of Prism Adaptation Effects in Children, Younger Adults, and Older Adults

Comparison of Prism Adaptation Effects in Children, Younger Adults, and Older Adults

Effects of prism adaptation and visual scanning training on perceptual and response bias in unilateral spatial neglect

ABSTRACT In some patients with unilateral spatial neglect, symptoms reflect impaired lateralized spatial attention and representation (perceptual bias) whereas in others the inability to respond to stimuli located in contralesional space (response bias). Here, we investigated whether prismatic adaptation (PA) and visual scanning training (VST) differentially affect perceptual and response bias and whether rehabilitation outcome depends on the type of bias underlying symptoms. Two groups of neglect patients in the subacute phase were evaluated before, immediately after, and two weeks following 10 days of PA (n = 9) or VST (n = 9). Standard neuropsychological tests (i.e., Behavioural Inattentional Test, Diller cancellation test, and Line Bisection test) were administered to assess neglect symptoms, while the Landmark task was used to disentangle perceptual and response biases. Performance on the Landmark task revealed that PA was more effective in improving the perceptual bias, while VST mainly modulated the response bias. Neuropsychological tests performance suggested that VST is better suited to modulate neglect in patients with response bias, while PA may be effective in patients with both types of bias. These findings may offer novel insights into the efficacy of PA and VST in the rehabilitation of perceptual and response biases in patients with neglect.

Inter-Task Transfer of Prism Adaptation through Motor Imagery.

Prism adaptation (PA) is a useful method to investigate short-term sensorimotor plasticity. Following active exposure to prisms, individuals show consistent after-effects, probing that they have adapted to the perturbation. Whether after-effects are transferable to another task or remain specific to the task performed under exposure, represents a crucial interest to understand the adaptive processes at work. Motor imagery (MI, i.e., the mental representation of an action without any concomitant execution) offers an original opportunity to investigate the role of cognitive aspects of motor command preparation disregarding actual sensory and motor information related to its execution. The aim of the study was to test whether prism adaptation through MI led to transferable after-effects. Forty-four healthy volunteers were exposed to a rightward prismatic deviation while performing actual (Active group) versus imagined (MI group) pointing movements, or while being inactive (inactive group). Upon prisms removal, in the MI group, only participants with the highest MI abilities (MI+ group) showed consistent after-effects on pointing and, crucially, a significant transfer to throwing. This was not observed in participants with lower MI abilities and in the inactive group. However, a direct comparison of pointing after-effects and transfer to throwing between MI+ and the control inactive group did not show any significant difference. Although this interpretation requires caution, these findings suggest that exposure to intersensory conflict might be responsible for sensory realignment during prism adaptation which could be transferred to another task. This study paves the way for further investigations into MI's potential to develop robust sensorimotor adaptation.

Prism adaptation combined with eye movement training for unilateral spatial neglect after stroke: Study protocol for a single-blind prospective, randomized controlled trial.

Unilateral spatial neglect (USN) is a complex neurological syndrome that often reduces rehabilitation outcomes, prolongs patients' hospital stays, and decreases their quality of life. However, the current therapies for USN have varying efficacy. We will explore a new treatment option that combines prism adaptation (PA) with eye movement training (EMT) for the treatment of USN after stroke. We will conduct a single-blind, prospective, randomized controlled trial to assess the efficacy of the combined intervention (PA & EMT) on USN in an inpatient rehabilitation setting. The study aims to recruit 88 patients with USN after an ischemic or hemorrhagic stroke. Participants will be randomly assigned to the following four groups: (1) PA group (n = 22), (2) EMT group (n = 22), (3) PA and EMT group (n = 22), and (4) control group (n = 22). All groups will receive 10 sessions of interventions over 2 weeks, 5 times per week. Blinded assessors will conduct a baseline assessment, a post-intervention assessment, and a follow-up assessment (2 weeks post-intervention). The primary outcome measure will use the Behavioral Inattention Test-Conventional Subset (BIT-C) and Catherine Bergego Scale (CBS) to assess the levels of USN. Secondary outcome measures will assess the patient's ability to perform activities of daily living using the Modified Barthel Index (MBI). Patients who completed all treatment and assessment sessions will be included in the final analysis. This study will explore the effects of 10 sessions of combined interventions (PA & EMT) on USN and functional capacity. This study has the potential to identify a new, evidence-based treatment option and provide new ideas for the treatment of USN. The study protocol has been approved by the Nanchong Central Hospital. Written informed consent will be obtained from all the participants. The results of this study will be disseminated to the public through scientific conferences and a peer-reviewed journal. ChiCTR, ChiCTR2100049482. Registered on 2 August 2021, http://www.chictr.org.cn/showproj.aspx?proj=130823.

Virtual Reality in the Rehabilitation of Cognitive Impairment after Stroke

Virtual reality (VR) is seen by some as a tool that may greatly improve, or even revolutionize cognitive rehabilitation. VR offers distinct advantages compared to classic rehabilitation using paper-and-pencil or computer-based training, such as immersion, the feeling of presence, embodiment of virtual players, ecological and multisensory stimulation. We here review recent clinical studies examining the effects of VR training in patients with stroke-induced cognitive deficits. Several trials reported evidence that VR training improves general cognition compared to standard cognitive training. However, the evidence remains controversial, as some of these studies had a high risk of bias. Regarding mood, there is some indication that immersive training improves depression scores in stroke patients, but the number of studies examining mood changes is very low. Finally, in the domain of spatial cognition the development of specific intervention techniques such as virtual prism adaptation provide avenues for clinical interventions, though well-controlled clinical trials are lacking. Together, the available evidence suggests that VR has the potential to improve rehabilitation particularly in domains requiring repetitive training in an immersed, ecological setting, or when a mismatch between body frames and the environment is created. Controlled clinical studies are required to examine the specific advantages of VR compared to classic interventions.