Effects Of Prism Adaptation Research Articles

Acute effects of prismatic adaptation on penalty kick accuracy and postural control in young soccer players: A pilot study

BackgroundPrismatic adaptation (PA) is a visuomotor technique using prismatic glasses that are capable of moving the visual field and to affect the excitability of certain brain areas. The aim of this pilot study was to explore potential acute effects of PA on penalty kick accuracy and postural control in youth soccer players. MethodsIn this randomized crossover study, seven young male soccer players performed three PA sessions (rightward PA, r-PA; leftward PA, l-PA; sham PA, s-PA) with a washout period of 1-week between them. Immediately before and after each PA session, penalty kick accuracy and postural control were assessed. ResultsWe detected an increase in penalty kick accuracy following PA, regardless of the deviation side of the prismatic glasses (F1,5 = 52.15; p = 0.08; ηp2 = 0.981). In detail, our results showed an increase in the penalty kick accuracy toward the right target of the football goal following r-PA and toward the left target of the football goal following l-PA. We detected a significant effect on the sway path length (F2,12 = 10.42; p = 0.002; ηp2 = 0.635) and the sway average speed (F2,12 = 9.17; p = 0.004; ηp2 = 0.605) parameters in the stabilometric test with open eyes following PA, regardless of the deviation side of the prismatic glasses. In detail, our results showed a significant difference in both the stabilometric parameters (p = 0.016 and p = 0.009, respectively) only following l-PA. ConclusionThe findings of this pilot study indicate that PA could positively affect penalty kick accuracy and postural control suggesting that PA could be used as a visual training technique in athletes.

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.

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.

Non-invasive Brain Stimulation and Prism Adaptation in Art Constructive Errors in Painting.

This study aimed to investigate the influence of neglect and the effect of prism adaptation (PA) combined with continuous Theta-burst transcranial magnetic stimulation (cTBS) on the art constructive errors in painting rehabilitation of stroke patients with neglect. Fourteen patients with neglect and art constructive errors in painting secondary to stroke were randomly assigned to the rehabilitation group and received PA combined with the inhibitory protocol of cTBS over the intact parietal cortex; the control group received PA combined with sham cTBS for two weeks in ten daily sessions. Patients were assessed for art constructive errors in painting in figure copying test (FCT), and coloring test (CT) before and after the intervention. Art constructive errors in painting were classified into omission, deformation, size, neglect of warm colors, and perseveration of errors. Neglect was evaluated using the line bisection task (LBT), figure copying test (FCT), and coloring test (CT). All patients showed a significant improvement in art constructive errors in painting (measured using the pattern of painting' errors in FCT and CT), and neglect (measured using LBT, FCT, and CT) (P<0.05). Omission, neglect of warm colors, and deformation were the most frequent errors. Neglect and rehabilitation influence the painting system in stroke patients. Both approaches improved art constructive errors in painting and neglect symptoms.

Non-pharmacological interventions for spatial neglect or inattention following stroke and other non-progressive brain injury.

Non-pharmacological interventions for spatial neglect or inattention following stroke and other non-progressive brain injury.

Can prism adaptation effects generalize to wheelchair maneuvering?

While prism adaptation (PA) has been recognized as a promising tool for treating spatial neglect, implementation as a standard treatment in clinical care has been lagging. Limited evidence for the generalization of after-effects to everyday activities has been a barrier towards implementation. This study examined whether a home-friendly standardized PA protocol (Peg-the-Mole, PTM) induces after-effects that can transfer to wheelchair maneuvering. We also examined the impact of using constant (1 starting hand position) or variable (3 starting hand positions) training conditions on the transfer of after-effects to wheelchair maneuvering. Sixty participants were randomly assigned to one of four PTM conditions: 1) prisms/constant training; 2) prisms/variable training; 3) sham goggles/constant training; 4) sham goggles/variable training. The use of PTM with rightward shifting prisms induced after-effects on proprioceptive and visual pointing outcome tasks. Groups using PTM with prism goggles showed a leftward shift in their position within a wheelchair course and a reduction in the number of right-sided collisions. The training condition did not have an impact on the transfer of after-effects to wheelchair driving. PTM is a clinically appealing PA protocol that induces after-effects that can transfer to an everyday activity relevant to patients with neglect.

Prism adaptation effects in complex regional pain syndrome: A therapo-physiological single case experimental design exploratory report

ABSTRACT Complex Regional Pain Syndrome (CRPS) is an invalidating chronic condition that can occur after an acute peripheral lesion. Prism adaptation therapy is regarded as a promising tool to improve chronic pain in this syndrome but the mechanisms which lead to pain amelioration remain unknown. In this exploratory report we performed a retrospective analysis of longitudinal data collected from a single, atypical patient, who showed hyper-attention toward her affected (left) hand. Repeated assessments of pain and spatial neglect made during the course of the prism adaptation treatment revealed differential contributions of the two hands to adaptation-induced pain reduction. Treatment response appeared to be associated with a relative modification of the spatial behaviour of the two hands. This case study provides a new example of pain relief following prismatic deviation away from the pathological side.

Combined virtual reality and haptic robotics induce space and movement invariant sensorimotor adaptation

Prism adaptation is a method for studying visuomotor plasticity in healthy individuals, as well as for rehabilitating patients suffering spatial neglect. We developed a new set-up based on virtual-reality (VR) and haptic-robotics allowing us to induce sensorimotor adaptation and to reproduce the effect of prism adaptation in a more ecologically valid, yet experimentally controlled context. Participants were exposed to an immersive VR environment while controlling a virtual hand via a robotic-haptic device to reach virtual objects. During training, a rotational shift was induced between the position of the participant's real hand and that of the virtual hand in order to trigger sensorimotor recalibration. The use of VR and haptic-robotics allowed us to simulate and test multiple components of sensorimotor adaptation: training either peripersonal or extrapersonal space and testing generalization for the non-trained sector of space, and using active versus robot-guided reaching movements. Results from 60 neurologically intact participants show that participants exposed to the virtual shift were able to quickly adapt their reaching movements to aim correctly at the target objects. When the shift was removed, participants showed a systematic deviation of their movements during open-loop tasks in the direction opposite to that of the shift, which generalized to un-trained portions of space and occurred also when their movements were robotically-guided during the adaptation. Interestingly, follow-up questionnaires revealed that when the adaptation training was robotically-guided, participants were largely unaware of the mismatch between their hand and the virtual hand's position. The stability of the aftereffects, despite the changing experimental parameters, suggests that the induced sensory-motor adaptation does not rely on low-level processing of sensory stimuli during the training, but taps into high-level representations of space. Importantly, the flexibility of the trained space and the option of robotically-guided movements open novel possibilities of fine-tuning the training to patients’ level of spatial and motor impairment, thus possibly resulting in a better outcome.

Effects of Prism Adaptation for Unilateral Spatial Neglect After Stroke: A Systematic Review and Meta-Analysis.

The aim of the study was to assess effects of prism adaptation on unilateral spatial neglect poststroke. Searching databases and referring to randomized controlled trial until December 30, 2019. There were two reviewers who searched some key words such as unilateral spatial neglect and prism adaptation, and only randomized controlled trial was included. There were two evaluators who screened literature and data regarding research design, treatment plan, etc. Assessment tool recommended in Cochrane Reviewers' Handbook 5.1.0 was adopted to assess the risks of bias of randomized controlled trial, and Revman 5.3 software was used for meta-analysis. Mean differences and 95% of confidence intervals were calculated, and heterogeneity was assessed through I2 statistics. Eight randomized controlled trials were included, involving 244 patients of which 130 in experimental group and 114 in control group. According to meta-analysis results, prism adaptation group scored significantly higher than control group in improving Behavioral Inattention Test (mean difference = 8.99, 95% confidence interval = 0.93 to 17.06, P = 0.03) and Star Cancellation Test (mean difference = 3.04, 95% confidence interval = 0.19 to 5.88, P = 0.04). However, there was no significant statistical difference in Catherine Bergego Scale between groups (mean difference = -0.30, 95% confidence interval = -1.83 to 1.23, P = 0.70). The long-term follow-up visits (over 1 mo) appeared no statistical difference in Behavioral Inattention Test scores between the patients of two groups (mean difference = 8.93, 95% confidence interval = -1.98 to 19.84, P = 0.1). Prism adaptation can improve neglect symptoms of patients with unilateral spatial neglect after stroke temporarily.

Effect of prism adaptation in patients with partially accommodative esotropia: clinical findings and surgical outcomes.

To assess the effects of prism adaptation on the surgical outcomes of individuals with partially accommodative esotropia (PAET). The medical records of 51 patients with PAET who were managed surgically at single referral center were retrospectively reviewed. Patients were divided into two groups according to prism adaptation. Data about sex, age, initial angle of deviation, final angle of deviation, stereoacuity, surgical dosage, and follow-up periods were collected. The main outcome of this study was motor outcomes at 12months. Eighteen patients had a history of prism adaptation (PA group) and 33 did not (augmented surgery group, AS group). One year after surgery, 12 (66.7%) patients in the PA group and 21 (63.6%) in the AS group achieved an angle of deviation less than 5 PD. The surgical success rate in both groups did not significantly differ (p = 1). After the first prism adaptation test, six patients had an angle of deviation similar to the previous angle; however, 12 patients had larger angle, and consequently required additional prism (prism builder). Two (33.3%) patients who were prism non-builders had deviation less than 5 PD during the final visit. However, among the prism builders, four (57.1%) and five (100%) patients who had prism added once and more than once, respectively, had less than 5 PD deviation during the final visit (p = 0.03). No significant differences were observed in terms of surgical outcomes between both groups. Nonetheless, in PA group, prism builders have better surgical outcomes than non-builders.

Prism adaptation treatment for upper-limb complex regional pain syndrome: a double-blind randomized controlled trial.

Initial evidence suggested that people with complex regional pain syndrome (CRPS) have reduced attention to the affected side of their body and the surrounding space, which might be related to pain and other clinical symptoms. Three previous unblinded, uncontrolled studies showed pain relief after treatment with prism adaptation, an intervention that has been used to counter lateralised attention bias in brain-lesioned patients. To provide a robust test of its effectiveness for CRPS, we conducted a double-blind randomized controlled trial of prism adaptation for unilateral upper-limb CRPS-I. Forty-nine eligible adults with CRPS were randomized to undergo 2 weeks of twice-daily home-based prism adaptation treatment (n = 23) or sham treatment (n = 26). Outcomes were assessed in person 4 weeks before and immediately before treatment, and immediately after and 4 weeks after treatment. Long-term postal follow-ups were conducted 3 and 6 months after treatment. We examined the effects of prism adaptation vs sham treatment on current pain intensity and the CRPS symptom severity score (primary outcomes), as well as sensory, motor, and autonomic functions, self-reported psychological functioning, and experimentally tested neuropsychological functions (secondary outcomes). We found no evidence that primary or secondary outcomes differed between the prism adaptation and sham treatment groups when tested at either time point after treatment. Overall, CRPS severity significantly decreased over time for both groups, but we found no benefits of prism adaptation beyond sham treatment. Our findings do not support the efficacy of prism adaptation treatment for relieving upper-limb CRPS-I. This trial was prospectively registered (ISRCTN46828292).

Effects of Prism Adaptation on Unilateral Neglect After Stroke: An Updated Meta-Analysis of Randomized Controlled Trials.

The aim of this study was to investigate the effects of prism adaptation (PA) on unilateral neglect after stroke. Randomized clinical trials, published up to January 31, 2020, comparing PA with neutral goggles or no goggles were systematically searched and included. Two independent reviewers performed data extraction and assessed the quality of studies using the Physiotherapy Evidence Database scale. A total of seven randomized trials, involving 211 participants, satisfied the inclusion criteria. There was no significant immediate benefit of PA as measured by Behavioral Inattention Test (BIT) (weighted mean difference [WMD], 5.10; [95% confidence interval (CI), -6.68 to 16.88]), behavioral subset (BIT-B; WMD, 3.40 [95% CI, -3.97 to 10.76), conventional subset (BIT-C; WMD, 9.98 [95% CI, -0.42 to 20.38]), and Catherine Bergego Scale (WMD, -0.52 [95% CI, -1.98 to 0.93]). No statistical difference was observed between PA and control on the long-term effect (BIT: WMD, 1.92 [95% CI, -9.34 to 13.18]; BIT-B: WMD, -3.28 [95% CI, -11.89 to 5.34]; BIT-C: WMD, 2.66 [95% CI, -10.35 to 11.67]; Catherine Bergego Scale: WMD, -1.22 [95% CI, -3.05 to 0.62]). PA did not show a greater improvement on neglect symptoms in post-stroke patients with unilateral neglect, compared with placebo or no treatment. These findings do not support the routine use of PA in patients with unilateral neglect after stroke.

Investigating prismatic adaptation effects in handgrip strength and in plantar pressure in healthy subjects

BackgroundPrismatic Adaptation (PA) is a visuomotor procedure inducing a shift of the visual field that has been shown to modulate activation of a number of brain areas, in posterior (i.e. parietal cortex) and anterior regions (i.e. frontal cortex). This neuromodulation could be useful to study neural mechanisms associated with either postural measures such as the distribution of plantar pressure or to the generation of muscle strength. Indeed, plantar pressure distribution is associated to activation of high-level cognitive mechanisms taking place within the posterior regions of the brain dorsal stream, especially of the right hemisphere. Conversely, hand force mostly rely on sensorimotor mechanisms, fulfilled by anterior regions of the brain and involving both hemispheres. Research questionSince PA effects have been reported to affect both sensorimotor and higher level cognitive processes, is it possible to hypothesize a modulation of both hands strenght and plantar pressure after PA? MethodsForty-six healthy subjects (male = 23; mean age = 25 ± 3 years) were randomly divided into two groups: a leftward prismatic adaptation group (l-PA) and a rightward prismatic adaptation group (r-PA). Hand strength and plantar pressure were assessed, immediately before and after PA, using the handgrip task and baropodometric measurement, respectively. ResultsBoth l-PA and r-PA induced a significant decrease of strength in the hand contralateral to the lenses deviation side. Only r-PA was associated with an increase of the forefoot plantar pressure in both feet. Modulation of interhemispheric inhibitory processes at sensorimotor and higher cognitive level may account for the present results. SignificancePA exerts effects on body posture and hand strength relying on different mechanisms. The PA effects on hand strength are probably related to the modulation of interhemispheric inhibition of sensorimotor processes, involving both hemispheres. The PA effects on body posture are probably related to modulation of body representation, involving mainly the right hemisphere.

Effects of Prism Adaptation on Reference Systems for Extrapersonal Space in Neglect Patients.

Up to now, rehabilitation of unilateral spatial neglect has focused on egocentric forms of neglect, whereas less is known about the possibility to improve allocentric deficits. The present study aimed to examine the efficacy of prism adaptation (PA) training on patients with different forms of neglect: egocentric, allocentric, or mixed. Twenty-eight patients were assessed with specific neglect tests before (T0) and after (T1) 10 sessions of PA training. Performance in the Apples Cancellation test was used to identify patients with egocentric (n = 6), allocentric (n = 5), or mixed (n = 17) forms of neglect. In the overall group of patients, PA training produced significant improvements in performance across different neglect tests. In terms of the egocentric–allocentric distinction, the training was effective in reducing omissions in the left part of space in the Apples Cancellation test both for patients with egocentric neglect and mixed neglect. By contrast, errors of commissions (marking the inability to detect the left part of the target stimulus, i.e., allocentric neglect) remained unchanged after PA in patients with allocentric neglect and actually increased marginally in patients with mixed neglect. The PA training is effective in improving egocentric neglect, while it is ineffective on the allocentric form of the disturbance. Notably, the allocentric component of neglect is frequently impaired, although this is most often in conjunction with the egocentric impairment, yielding the mixed form of neglect. This stresses the importance of developing exercises tuned to improving allocentric neglect.

The Effect of a Complex Intervention Program for Unilateral Neglect in Patients with Acute-Phase Stroke: A Randomized Controlled Trial.

ObjectivesThe purpose of this study was to examine the combined effects of Prism Adaptation (PA) plus functional electrical stimulation (FES) on stroke patients with unilateral neglect, and suggest a new intervention method for acute-phase stroke patients.MethodsThere were 30 patients included in this study from April to October 2016 that had unilateral neglect whilst hospitalized following a stroke (diagnosed by a professional). The participants, who were patients receiving occupational therapy, understood the purpose of the study and agreed to participate. The patients were randomly divided into 3 groups: PA plus FES group (Group A), PA group (Group B), and FES group (Group C). Treatments lasted for 50 minutes per day, 5 times per week, for 3 weeks in total. Reevaluation was conducted after 3 weeks of intervention.ResultsAll 3 groups showed unilateral neglect reduction after the intervention, but PA plus FES (complex intervention method) was more effective than PA or FES alone [effect size: Motor-free Visual Perception Test (0.80), Albert test (0.98), CBS (0.92)].ConclusionThe results of this study support further studies to examine complex intervention for the treatment of unilateral neglect.

Prisms adaptation improves haptic object discrimination in hemispatial neglect

Neglect manifestations are typically explored in the visual modality. Although they are less commonly investigated tactile deficits also exist, and the aim of this study was to explore neglect in this modality. A haptic object discrimination task was designed to assess whether or not shape perception is impaired in seven right brain damaged patients with or without neglect. Each patient's performance on the object discrimination task was assessed before and after a brief period of prism adaptation, a bottom-up rehabilitation technique known to improve neglect symptoms. The results suggest that a haptic deficit – in the form of substantially more left errors – is present only in patients with neglect. Following prism adaptation, the left bias error rates in neglect patients were substantially reduced, and were similar to those observed in patients without neglect. Moreover, the haptic processing of the right side of objects also improved slightly. This finding suggests an expansion of the effects of prism adaptation to the unexposed, tactile modality supporting the cross-modal central effect hypothesis.

The Effect of Continuous Theta-Burst Transcranial Magnetic Stimulation Combined with Prism Adaptation on the Neglect Recovery in Stroke Patients

Objectives: This study was designed to investigate the effect of prism adaptation (PA) combined with continuous theta-burst transcranial magnetic stimulation (cTBS) on the neglect recovery of stroke patients with unilateral neglect. Methods: A total of 14 stroke patients with unilateral neglect were randomly assigned to 2 groups including an intervention group undergone PA combined with cTBS over the left intact parietal cortex and a control group. PA combined with sham cTBS was perfomed for 2 weeks in 10 daily sessions. Before and after the intervention, patients were evaluated for visuospatial neglect measured using the Star Cancellation Test (SCT), Line Bisection Task (LBT), Figure Copying Test, and Clock Drawing Task. Neurological function was evaluated using the Modified Rankin Scale (MRS). Results: Both groups (PA alone and PA+ cTBS) showed improvement in their neglected symptoms (measured by SCT, LBT, Figure Copying Test, and Clock Drawing Task), and in their disability in the neurological function (measured by MRS) (P< .05). Conclusions: The results of the present study showed that, transcranial magnetic stimulation did not increase the effect of PA on neglect symptoms in stroke patients.

The effect of prism adaptation on state estimates of eye position in the orbit

Prism adaptation (PA) after-effects are assessed using tests that measure changes in sensorimotor systems. After-effects on pointing without feedback to a visual target (open loop pointing – OLP) are traditionally described as being larger than those measured by straight ahead pointing (SAP) with eyes closed, and the difference between them is attributed to a shift in visual localisation. However, neither differences between OLP and SAP, nor shifts in perceptual judgement of visual straight ahead (VSA), are consistently reported. Moreover, since very few studies have directly recorded direction of gaze, an effect of PA on the state estimate of gaze direction has not been reliably documented. The current research aimed to isolate the effects of PA on state estimates of eye position. We measured sensorimotor after-effects through common (OLP, SAP, and VSA) measures, and also recorded eye position and additional after-effect measures to interrogate changes to the oculomotor system and how these might relate to other measures of sensorimotor change. To ascertain if PA's effects on estimates of eye position could be attributed to eye muscle potentiation, we compared the effects of PA to sustained gaze deviation without adaptation. PA induced no effect on visual straight-ahead and no change in direction of gaze, when measured while positioning a target, looking straight ahead in the dark, or looking toward the passively positioned and occluded unexposed hand. We also found that after-effects measured by SAP with the eyes open were larger than SAP with the eyes closed and equal to those observed with OLP. The findings challenge the concept that total adaptation after-effect is a direct sum of arm proprioceptive and visual after-effects as conventionally measured, and suggest that the oculomotor system is altered by prism adaptation only in interaction with an arm motor command when vision is available.

Effect of prism adaptation on neglect hemianesthesia

Prism adaptation (PA) has proven to be effective in alleviating many signs of unilateral spatial neglect (USN). Generally, the principal improvement after PA treatment was found to be in the high-level cognitive function. Nevertheless, some evidence has also been found for it in somatosensory function. We have aimed to test the influence of PA on neglect hemianesthesia, a condition in which the high-level neglect-related deficit mimics hemianesthesia. Twenty-one USN patients were enrolled in the study. Each patient performed two sessions of PA, one with neutral glasses and one with prism glasses using a cross-over design. Sensitivity on the upper limb was tested using two methods. The first task was the sensibility subtest which was derived from the standard clinical examination. The second was the perceptual and motor electro-cutaneous threshold on the forearms using an electro-cutaneous stimulator. Four neuropsychological tests were used to diagnose USN and to check improvement: Star cancellation, Line bisection, Sentence reading and the Comb & Razor test. Comparing prism with sham conditions, our results show significant improvements in double extinction and in the electro-cutaneous perceptual threshold only for the contralesional hand. No improvement was found for the ipsilesional hand, for the motor threshold, and for neutral glasses. Significant improvement was found in personal neglect. Replication of the task in a subgroup of patients confirmed the primary results. The improvements in somatosensory perception together with the amelioration of personal neglect suggest that PA also has a specific effect on the neglect hemianesthesia.