Robust immediate and limited long-term benefit of prism adaptation on spatial neglect: A Systematic Review and Meta-Analysis of outcomes and predictors

Robust immediate and limited long-term benefit of prism adaptation on spatial neglect: A Systematic Review and Meta-Analysis of outcomes and predictors | medRxiv /* */ /* */ <!-- <!-- /*! * yepnope1.5.4 * (c) WTFPL, GPLv2 */ (function(a,b,c){function d(a){return"[object Function]"==o.call(a)}function e(a){return"string"==typeof a}function f(){}function g(a){return!a||"loaded"==a||"complete"==a||"uninitialized"==a}function h(){var a=p.shift();q=1,a?a.t?m(function(){("c"==a.t?B.injectCss:B.injectJs)(a.s,0,a.a,a.x,a.e,1)},0):(a(),h()):q=0}function i(a,c,d,e,f,i,j){function k(b){if(!o&&g(l.readyState)&&(u.r=o=1,!q&&h(),l.onload=l.onreadystatechange=null,b)){"img"!=a&&m(function(){t.removeChild(l)},50);for(var d in y[c])y[c].hasOwnProperty(d)&&y[c][d].onload()}}var j=j||B.errorTimeout,l=b.createElement(a),o=0,r=0,u={t:d,s:c,e:f,a:i,x:j};1===y[c]&&(r=1,y[c]=[]),"object"==a?l.data=c:(l.src=c,l.type=a),l.width=l.height="0",l.onerror=l.onload=l.onreadystatechange=function(){k.call(this,r)},p.splice(e,0,u),"img"!=a&&(r||2===y[c]?(t.insertBefore(l,s?null:n),m(k,j)):y[c].push(l))}function j(a,b,c,d,f){return q=0,b=b||"j",e(a)?i("c"==b?v:u,a,b,this.i++,c,d,f):(p.splice(this.i++,0,a),1==p.length&&h()),this}function k(){var a=B;return a.loader={load:j,i:0},a}var l=b.documentElement,m=a.setTimeout,n=b.getElementsByTagName("script")[0],o={}.toString,p=[],q=0,r="MozAppearance"in l.style,s=r&&!!b.createRange().compareNode,t=s?l:n.parentNode,l=a.opera&&"[object Opera]"==o.call(a.opera),l=!!b.attachEvent&&!l,u=r?"object":l?"script":"img",v=l?"script":u,w=Array.isArray||function(a){return"[object Array]"==o.call(a)},x=[],y={},z={timeout:function(a,b){return b.length&&(a.timeout=b[0]),a}},A,B;B=function(a){function b(a){var a=a.split("!"),b=x.length,c=a.pop(),d=a.length,c={url:c,origUrl:c,prefixes:a},e,f,g;for(f=0;f<d;f++)g=a[f].split("="),(e=z[g.shift()])&&(c=e(c,g));for(f=0;f<b;f++)c=x[f](c);return c}function g(a,e,f,g,h){var i=b(a),j=i.autoCallback;i.url.split(".").pop().split("?").shift(),i.bypass||(e&&(e=d(e)?e:e[a]||e[g]||e[a.split("/").pop().split("?")[0]]),i.instead?i.instead(a,e,f,g,h):(y[i.url]?i.noexec=!0:y[i.url]=1,f.load(i.url,i.forceCSS||!i.forceJS&&"css"==i.url.split(".").pop().split("?").shift()?"c":c,i.noexec,i.attrs,i.timeout),(d(e)||d(j))&&f.load(function(){k(),e&&e(i.origUrl,h,g),j&&j(i.origUrl,h,g),y[i.url]=2})))}function h(a,b){function c(a,c){if(a){if(e(a))c||(j=function(){var a=[].slice.call(arguments);k.apply(this,a),l()}),g(a,j,b,0,h);else if(Object(a)===a)for(n in m=function(){var b=0,c;for(c in a)a.hasOwnProperty(c)&&b++;return b}(),a)a.hasOwnProperty(n)&&(!c&&!--m&&(d(j)?j=function(){var a=[].slice.call(arguments);k.apply(this,a),l()}:j[n]=function(a){return function(){var b=[].slice.call(arguments);a&&a.apply(this,b),l()}}(k[n])),g(a[n],j,b,n,h))}else!c&&l()}var h=!!a.test,i=a.load||a.both,j=a.callback||f,k=j,l=a.complete||f,m,n;c(h?a.yep:a.nope,!!i),i&&c(i)}var i,j,l=this.yepnope.loader;if(e(a))g(a,0,l,0);else if(w(a))for(i=0;i (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0];var j=d.createElement(s);var dl=l!='dataLayer'?'&l='+l:'';j.src='//www.googletagmanager.com/gtm.js?id='+i+dl;j.type='text/javascript';j.async=true;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-P4HH5NV'); Skip to main content Home About Submit ALERTS / RSS Search for this keyword Advanced Search Robust immediate and limited long-term benefit of prism adaptation on spatial neglect: A Systematic Review and Meta-Analysis of outcomes and predictors View ORCID Profile YuanLiang Zhu , Francois Quesque , Daisuke Nishida , Sophie Jacquin-Courtois , Jacques. Luaute , Eric Chabanat , Gilles Rode , Yves Rossetti doi: https://doi.org/10.1101/2025.06.09.25329277 YuanLiang Zhu a Neurosciences et Cognition ED476, Université Claude Bernard Lyon 1 , 69675, Bron, France b INSERM U1028 CNRS UMR5292, Trajectoires team, Lyon Neuroscience Research Center (CRNL) , 69500, Bron, France Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for YuanLiang Zhu Francois Quesque b INSERM U1028 CNRS UMR5292, Trajectoires team, Lyon Neuroscience Research Center (CRNL) , 69500, Bron, France Find this author on Google Scholar Find this author on PubMed Search for this author on this site Daisuke Nishida b INSERM U1028 CNRS UMR5292, Trajectoires team, Lyon Neuroscience Research Center (CRNL) , 69500, Bron, France c Department of Rehabilitation Medicine, Tokai University , 259-1193, Kanaga, Japan Find this author on Google Scholar Find this author on PubMed Search for this author on this site Sophie Jacquin-Courtois d Hospices Civils de Lyon, PAM de reeducation, Hopital Henry Gabrielle, route de Vourles , 69565, Saint-Genis-Laval, France e “Mouvement et Handicap” platform, Neurological Hospital, Hospices Civils de Lyon , 69500, Bron, France Find this author on Google Scholar Find this author on PubMed Search for this author on this site Jacques. Luaute d Hospices Civils de Lyon, PAM de reeducation, Hopital Henry Gabrielle, route de Vourles , 69565, Saint-Genis-Laval, France e “Mouvement et Handicap” platform, Neurological Hospital, Hospices Civils de Lyon , 69500, Bron, France Find this author on Google Scholar Find this author on PubMed Search for this author on this site Eric Chabanat b INSERM U1028 CNRS UMR5292, Trajectoires team, Lyon Neuroscience Research Center (CRNL) , 69500, Bron, France Find this author on Google Scholar Find this author on PubMed Search for this author on this site Gilles Rode d Hospices Civils de Lyon, PAM de reeducation, Hopital Henry Gabrielle, route de Vourles , 69565, Saint-Genis-Laval, France e “Mouvement et Handicap” platform, Neurological Hospital, Hospices Civils de Lyon , 69500, Bron, France Find this author on Google Scholar Find this author on PubMed Search for this author on this site Yves Rossetti b INSERM U1028 CNRS UMR5292, Trajectoires team, Lyon Neuroscience Research Center (CRNL) , 69500, Bron, France d Hospices Civils de Lyon, PAM de reeducation, Hopital Henry Gabrielle, route de Vourles , 69565, Saint-Genis-Laval, France e “Mouvement et Handicap” platform, Neurological Hospital, Hospices Civils de Lyon , 69500, Bron, France Find this author on Google Scholar Find this author on PubMed Search for this author on this site For correspondence: yves.rossetti{at}inserm.fr Abstract Full Text Info/History Metrics Supplementary material Data/Code Preview PDF Abstract Objective The first aim was to assess the immediate and long-term effects of prism adaptation (PA) on spatial neglect (SN) via meta-analysis of randomized controlled trials (RCTs). The second aim was to identify potential predictive factors of PA efficacy. Methods We searched 4 databases up to March 2025 for RCTs comparing PA or PA+conventional vs. shamPA or shamPA+conventional or only conventional in participants with SN, and assessing behavioral or neuropsychological tests (such as Catherine Bergego Scale (CBS) and Behavioral Inattention Test (BIT)). Cochrane risk-of-bias assessment tool and random-effects meta-analysis were used, and effect size was reported as Weighted Mean Difference (WMD) with 95%CI. Results Only 10 RCTs (356 participants) could be included, 8 of them reporting CBS data and 6 for BIT. Immediate PA effects on SN showed a significant improvement for CBS between the PA group and control group (all studies with prism shift ≥10°, WMD= −2.13, 95%CI: [−3.93, −0.33], P<0.05), while non-significance for BIT-C. Long-term benefit was not significant for CBS, while significant for BIT-C when the prism shift was ≥10° (WMD= 12.37, 95%CI: [0.53, 24.21], P<0.05). Linear regressions showed non-significant predictive factors among the participant characteristics or PA intervention parameters. Subgroup analyses for CBS showed a significant immediate improvement in the larger total quantity of prism exposure (number of total trials × prism shift) subgroup (WMD= −2.73, 95%CI: [−5.01, −0.44], P<0.05), whereas subgroup with smaller total exposure showed non-significance. Conclusion Even with stringent inclusion criteria, robust effects of PA on SN were observed in the short-term CBS (all studies with prism shift ≥10°), mainly derived from studies with total exposure ≥11250°·trials. A significant improvement for long-term BIT-C was observed when the prism shift was ≥10° (n=2, with 4000°·trials and 21600°·trials). The total quantity of prism exposure (°·trials) may be a useful predictive efficacy factor of efficacy. 1. Introduction Spatial neglect (SN), a lateralized neuropsychological disorder of spatial cognition, has a prevalence of over 50% in the first weeks and months after a stroke[ 1 ]. It may result in an abnormal bias toward the space ipsilateral to the injured cerebral hemisphere, so that people pay little or no attention to the contralateral side (not a primary sensory or motor deficit) to real or imagined space, and are less likely to orient sensory receptors and actions toward this side of space[ 2 , 3 ]. SN (rather than overall stroke severity) predicts poor functional recovery, prolonged hospitalization, functional dependence, disability in life activities, and increased risk of falls[ 4 – 6 ]. With rising post-acute care for stroke survivors, the need for validated SN rehabilitation is growing[ 7 ]. Prism adaptation (PA), a promising intervention to reduce SN symptoms and improve functional prognosis, was first applied to SN rehabilitation by Rossetti and colleagues in 1998[ 8 – 12 ]. They found that the signs of SN on visuomotor tasks significantly improved in the PA group after a few minutes of prism exposure to a right-shifted prism, compared to the control group[ 8 ]. In the early phase (exposure) of the classic PA paradigm, individuals’ entire visual field will be deflected due to the refraction of prisms (optical shift), and their reaching movements are biased toward the virtual target when they are asked to point at a visual target (direct effect of prisms). Over trial repetition, they can gradually improve performance through error reduction until restoring a normal level of performance (error compensation process). When prisms are removed, visuomotor errors in the direction opposite to the optical shift should be observed (after-effect) and measured to quantify the amount of adaptation[ 12 ]. This intervention is thought to bias the egocentric reference and increase spatial perception/attention on the affected side of participants with SN[ 9 ]. In recent years, some studies on the underlying neurophysiological mechanisms of PA have gradually revealed how it works[ 13 ]. These studies suggest that PA is not only a perceptual-motor corrective process, but also involves complex neural network remodeling, including the restoration of interhemispheric functional balance, attention and sensorimotor network remodeling[ 13 – 15 ]. Indeed, generalization of PA after-effects has been reported for numerous domains such as wheel-chair driving[ 16 ], dichotic listening[ 17 ], and beyond SN to posture[ 18 ], spatial dysgraphia[ 19 ], or number cognition[ 20 ]. This extraordinary expansion from a sensory-motor process to cognitive representations allowed the prediction of a good generalization of PA to neglect rehabilitation[ 21 ]. Accordingly, improvement of activities of daily living (ADL) has also been reported e.g.[ 22 , 23 ]. However, case reports and randomized controlled trials (RCTs, widely regarded as the gold standard of study design in health and medical research) do not necessarily lead to similar conclusions[ 24 ]. In the past 27 years since PA was first applied in SN, a lot of RCTs have been conducted[ 25 – 28 ]. However, the results of these studies remain controversial and insufficiently consistent[ 29 ]. Therefore, it is of prime importance to determine the short-term beneficial effects and long-term efficacy of PA on SN[ 30 ]. Three meta-analyses related to this topic have been published previously, with data extracted up to 30 December 2019, 31 January 2020 and 31 June 2021, respectively[ 29 , 31 , 32 ]. Several new high-quality RCTs with inconsistent results have been published in recent years[ 27 , 28 , 33 , 34 ]. Given the current debate on PA efficacy on SN and the stake of its concrete clinical implications, it is necessary and timely to re-examine and comprehensively review the available evidence based on the most rigorous and reliable source of information, i.e. randomized controlled clinical trials. During the revision process of the present report, a related meta-analysis published in March 2025 (data extracted up to April 2024), reported a significant short-term effect of PA intervention on SN outcomes (BIT-C and cancellation tasks), and found that larger prism shift (≥10° shift) was a crucial factor in eliciting PA intervention effects[ 35 ]. This has important guiding significance for future clinical research. However, this meta-analysis mainly focused on the short-term effect of PA on SN, and the impact of intervention timing (acute or chronic stroke), PA protocol (concurrent PA or terminal PA), and a single PA intervention parameter (prism magnitude) on the PA efficacy on SN. Therefore, we aimed to make an important expansion based on previous meta-analyses. We performed a meta-analysis specifically including RCTs published before 2025 and distinguished between immediate and long-term effects of PA on SN. Two main sources of variability of PA efficacy have been identified: the physical parameters of PA intervention (e.g., prism strength, number of sessions etc.), and the participant characteristics (especially the variety of brain lesion topography and size). Therefore, our secondary goal was to identify which of the physical parameters of PA interventions provide a predictive value of its efficacy. Notably, PA efficacy may not only be influenced by a single parameter but may also be related to the overall intervention dose (e.g., ‘total quantity of prism exposure’)[ 36 ]. Additionally, the impact of available participant characteristics on the PA efficacy on SN was analyzed to search for further guidance for future studies and clinical applications. 2. Methods The authors followed the PRISMA2020 and Cochrane guidelines for Systematic Reviews of Interventions. This meta-analysis study was registered in Prospero in February 2025 (CRD420250650402). 2.1 Literature search Based on PRISMA guidelines, a comprehensive literature search was performed in four databases (PubMed, Cochrane, Embase, and Web of Science) up to March 2025[ 37 ]. The search terms were (‘prism adaptation’ OR ‘prism exposure’ OR ‘prism glasses’) AND (‘unilateral neglect OR ‘unilateral spatial neglect’ OR ‘hemispatial neglect’ OR ‘visuospatial neglect’ OR ‘neglect’). The search was conducted by two authors (YLZ, FQ) independently, and no disparity was identified. 2.2 Selection criteria and study selection Two authors (YLZ, FQ) independently screened the studies based on the inclusion criteria. A third author (YR) solved potential disagreements. The inclusion criteria were as follows according to PICOS: P (participants): participants with SN; I (intervention): PA/PA + conventional treatment; C (comparison): sham PA/sham PA + conventional treatment/only conventional treatment; O (outcome): containing behavioral or neuropsychological tests, such as the Catherine Bergego Scale (CBS), Behavioral Inattention Test (BIT), Functional Independence Measure (FIM), Dynamic and Static Task; S (study design): RCT. The exclusion criteria were as follows: no PA; no baseline measurement; no RCT; no behavioral or neuropsychological assessment; data not available or without mean, SD/SEM; Excluded studies included review article, meta-analysis, case report, protocol, meeting, summary, conference abstract, and animal trials. 2.3 Data extraction Two authors (YLZ, YR) independently extracted the following data: study design, the number of participants, age, gender, time post-stroke/injury, intervention in each group, PA intervention parameters, and outcomes (assessment time). 2.4 Outcome assessment During article screening, we did not intentionally restrict the type of outcomes and included all studies that reported behavioral or neuropsychological tests, such as CBS, BIT, Bells Test, scene copying test, FIM, Dynamic Task (Wheelchair Navigation Task), and Static Task (shape cancellation task). As the number of data points available for other reported outcomes was insufficient to support meaningful meta-analysis (n ≤ 2, Table S1), we only focused on CBS and BIT, which are also the two most commonly used scales for assessing neglect. The CBS could assess aspects of participants’ perceptual and motor dysfunction separately, as well as awareness of the impact of SN on daily living skills[ 38 , 39 ]. It has been shown to have good reliability, validity and sensitivity to changes in the rehabilitation process of participants with SN[ 40 ]. Therefore, it was chosen as the main outcome in our study. The BIT was widely used to assess the perceptual and spatial cognitive motor systems[ 41 ]. Considering its insufficient sensitivity and limited ecological validity, it was used as the secondary outcome in our study[ 41 , 42 ]. 2.4.1 Main outcome The CBS includes 10 real-life situations that capture various aspects of ADL (grooming, eating, dressing etc.), with each task ranging from 0 points (no neglect) to 3 points (severe neglect), and with a final maximum score of 30 points[ 38 , 39 ]. 2.4.2 Secondary outcome The BIT is usually divided into two categories: conventional BIT (BIT-C) and behavioral BIT (BIT-B)[ 43 ]. BIT-C is used to assess the severity of visual neglect and has 6 items with a maximum score of 146; while BIT-B assesses ADLs and has 9 items with a maximum score of 81. The lower the score, the more severe the visual impairment, and a total BIT score of less than 196 indicates SN. 2.5 Assessment of risk of bias The Cochrane risk-of-bias assessment tool was used to assess potential risk bias[ 44 ]. Two authors (YLZ, DN) independently assessed the risk of bias. A third author (EC) joined in the discussion to resolve disagreements, achieving consensus in all cases. 2.6 Meta-analysis Meta-analysis was performed using Stata 16.0, based on the evaluation time after intervention: immediate (1 month after the end of treatment). Data were averaged when multiple data points were available at a certain time. Treatment effects were reported as Weighted Mean Differences (WMD) with 95% confidence intervals (CI)[ 45 ]. The I 2 statistic was used to assess heterogeneity, with 0% indicating no observed heterogeneity, >25%, >50%, and >75% indicating low, moderate, and high heterogeneity, respectively[ 46 ]. Considering the small sample size, and clinical heterogeneity across studies (e.g. participant characteristic, study design, or different PA intervention parameters), we employed a random-effects model for all meta-analyses independent of observed I² statistics[ 45 ]. 2.7 Sensitivity analyses In Stata 16.0, we used influence analysis and leave-one-out analysis to execute sensitivity analyses, to assess the robustness and reliability of the combined results, and to further discuss potential sources of heterogeneity and their impact on the results. 2.8 Publication bias Publication bias could be assessed by using funnel plot asymmetry testing (including Egger’s test) when ≥10 studies were included[ 45 ], while this threshold was not met in our study (n ≤7 in short-/long-term). 2.9 Univariate linear regression analyses Due to the limited number of BIT-C reports (only three studies each included in short- and long-term), we only conducted univariate linear regression analyses (JASP-Jeffreys’s Amazing Statistics Program software) for the main outcome-CBS, with the largest number of studies included. To exploratorily identify whether participants’ basic characteristics (average age and days after stroke) and specific PA intervention parameters, i.e. prism shift (°), number of trials (during prism exposure), number of sessions of each study, total number of trials (number of trials × number of sessions), frequency (/day), number of PA intervention days, total duration of the PA intervention (days elapsed between the first-to-last sessions), and the total quantity of prism exposure (hereafter referred to as “total exposure”, calculated as number of total trials × prism optical shift) might predict CBS improvement. When available, individual results of short- and long-term CBS changes were calculated as follows: Result = ΔPA group – ΔControl group, i.e., ΔPA group = (Post-intervention value of PA group – Pre-intervention value of PA group), ΔControl group = (Post-intervention value of control group – Pre-intervention value of control group). As the total number of data points was only 11, the short-term and long-term CBS scores were pooled in this tentative analysis. Each study’s sample size was used as a weight variable in the analyses. One study was excluded from the regression analyses for the number of trials, number of total trials and total exposure due to missing information on specific trial numbers per session[ 34 ]. Based on the available information (20 sessions of 20 min exposure to a 10° shift), we assumed that much more than 57 trials were achieved in 20 mins (e.g., 60 trials in less than 10 min in Rossetti et al. 1998), i.e. >11250°·trials. Thus, it was included in the larger total exposure group in the subgroup analyses. 2.10 Subgroup analyses Although no significant predictive factors were identified by regression analyses (see Results 3.4 section), we conducted exploratory subgroup analyses for two PA intervention parameters based on prior evidence. The first parameter was prism shift, based on the dose-response relationship identified in the most recent meta-analysis (Naito et al. 2025), suggesting a crucial role of larger prism shift (≥10°) in the effects of PA[ 35 ]. Studies were accordingly categorized into two subgroups: larger prism shift (≥10°) and smaller prism shift (<10°) subgroups. The second parameter was total exposure (number of total trials × prism shift), based on the idea that it could provide insight into the overall PA intervention dosage (Michel et al. 2007)[ 36 ]. According to half of its maximum value (22500°·trials) among the included studies, studies were divided into two subgroups: larger (≥11250°·trials) and smaller total exposure (<11250°·trials). Given the limited sample size for BIT (n ≤ 3 for each subgroup), we only performed regime subgroup analyses on CBS. 3. Results 3.1 Characteristics of the studies In total, 1394 articles were found after literature searching, and 731 articles remained after excluding duplicate articles. Based on the inclusion and exclusion criteria, 14 articles were finally included. Original data from three articles remained unavailable after we contacted the corresponding author twice. In one of the articles, no information was provided about the randomization of participants. Therefore, we gathered comprehensive information from 10 remaining articles (published from 2008 to 2023)[ 25 – 28 , 33 , 34 , 47 – 50 ]. The data screening process is shown in Fig. 1 , and the basic characteristics of the included literature are shown in Table 1 . Download figure Open in new tab Fig. 1 Flowchart of the study screening process. Out of the 1394 studies considered, only 10 were finally included in the present analysis. View this table: View inline View popup Download powerpoint Table 1: Basic characteristics of the included articles. 3.2 Risk-of-bias assessment results All 10 articles included in this study are RCTs on the effect of PA on SN, and five articles among them are double-blind[ 26 , 28 , 48 , 50 ]. Six articles had incomplete data, but most of them explained the tenable reasons and reported sufficient data to calculate the standardized effect size for the outcome measures ( Fig. 2 ). Download figure Open in new tab Fig. 2 The risk-of-bias. a) Risk of bias graph: each risk of bias item across all included studies. b) Risk of bias summary: a detailed summary of each risk of bias item for each included study. 3.3 Outcomes 3.3.1 Main outcome—CBS For the immediate effect of PA intervention, a total of seven articles were included, with a total of 288 participants, of which 146 were in the PA group (average CBS score improvement: 6.53) and 142 were in the control group (average CBS score improvement: 4.08)[ 27 , 28 , 33 , 34 , 48 – 50 ]. As shown in Fig. 3a , the meta-analysis found that the PA group showed greater improvement than the sham group (WMD= −2.13, 95% CI: [−3.93, −0.33], P <0.05). Download figure Open in new tab Fig. 3 The effects of PA for main outcome-CBS. a). Short-term effects (7 studies included, n=288). The PA group showed significantly higher scores than controls (P <0.05), indicating PA’s immediate beneficial effect on CBS in SN participants. b). Long-term effects (four studies included, n=164), no significant long-term effects of PA on SN were observed (P <0.05). *: P <0.05; CBS: Catherine Bergego Scale; PA: prism adaptation; SN: spatial neglect. For the long-term effect, four articles with a total of 164 participants were included, 80 in the PA group (average CBS score improvement: 6.68) and 84 in the control group (average CBS score improvement: 6.39)[ 27 , 47 , 48 , 50 ]. The meta-analysis ( Fig. 3b ) found no significant difference between the two groups (WMD= −0.30, 95%CI: [−1.63, 1.03], P >0.05). 3.3.1.1. Sensitivity analyses of the main outcome — CBS According to the analyses in CBS, we observed high heterogeneity in the short-term analysis (I 2 > 50%), while the heterogeneity of the long-term analysis was 0%. Influence analysis showed the research by Umeonwuka et al. (2023) was the main source of heterogeneity in short-term CBS. After exclusion, the heterogeneity (I 2 ) of short-term CBS decreased from 65.0% to 21.2%, and the effects remained statistically significant (WMD = −1.38, 95%CI: [−2.70, −0.06], P <0.05). After further excluding the study by Choi et al. (2022), the heterogeneity (I 2 ) decreased from 21.2% to 4%, with remaining significance (WMD = −1.92, 95%CI: [−3.34, −0.50], P <0.01), showing the robustness of this result. Therefore, we decided to retain those two studies (Umeonwuka et al. and Choi et al.) to maintain the integrity of the evidence. 3.3.2 Secondary outcome—BIT For the immediate effect for BIT-C, there were three articles with a total of 152 participants included, 78 in the PA group (average BIT-C score improvement: 25.40) and 74 in the control group (average BIT-C score improvement: 7.29)[ 28 , 48 , 49 ]. However, the meta-analysis didn’t reach statistical significance between the two groups (WMD= 17.84, 95% CI: [−4.87, 40.54], P >0.05; Fig. 4a ). Only one study described BIT-B for immediate effects[ 48 ]. Download figure Open in new tab Fig. 4 The effect of PA for secondary outcome-BIT. a). Short-term effects. For BIT-C (n=152, 3 studies), no significant difference was found between the PA group and the control group. Only one study reported BIT-B. b). Long-term effects. Three studies evaluated BIT-C (n=88), no significant long-term effects of PA on SN were observed. Limited data on BIT-B and total BIT from one study only. BIT: Behavioral Inattention Test; BIT-B: behavioral BIT; BIT-C: conventional BIT; PA: prism adaptation; SN: spatial neglect. For the long-term effect, three articles evaluated BIT-C, including 88 participants in total—44 participants in both PA (average BIT-C score improvement: 46.83) and control (average BIT-C score improvement: 43.60) groups[ 25 , 47 , 48 ]. The meta-analysis found no significant difference between the two groups (WMD= 10.51, 95%CI: [−0.96, 21.99], P >0.05; Fig. 4b ). Only one study each was included in BIT-B and Total BIT[ 26 , 48 ]. 3.3.2.1 Sensitivity analyses of the secondary outcome — BIT The study by Umeonwuka et al. (2023) explained most heterogeneity of the short-term CBS (I² decreased from 80.1% to 0% after its exclusion). However, the statistical conclusion of the retained two studies in short-term BIT-C remained non-significance (WMD= 7.23, 95% CI: [−5.42, 19.89], P >0.05). Therefore, we decided to retain this study. For long-term BIT-C, although no statistical heterogeneity was observed (I² = 0%), influence analysis showed that the study by Mizuno et al. (2011) had little impact on combined results, as its exclusion maintained the effect non-significant (WMD = −1.67, 95%CI: [−28.66, 25.33], P >0.05). In addition, leave-one-out analysis found that excluding the study by Turton et al. (2010) altered the effect size to statistically significant (WMD = 12.37, 95% CI: [0.53, 24.21], P <0.05). 3.4 Univariate linear regression analyses for the main outcome—CBS The regression analyses results revealed that there were no significant correlations between the age/days after stroke and PA intervention improvements (Table S2). None of the PA intervention parameters reached statistical significance either (Table S2). The scatter plot (Fig. S1) shows the improvements in the score of CBS benefits found for PA intervention as a function of physical intervention parameters. 3.5 Subgroup analyses for the main outcome—CBS For the effect of prism shift, all seven studies included in short-term CBS utilized larger prism shift (≥10°), so results are identical to the findings in Section 3.3.1 (WMD = −2.13, 95%CI: [−3.93, −0.33], P <0.05)[ 27 , 28 , 33 , 34 , 48 – 50 ]. Only one study was included in the long-term CBS when the prism shift was 0.05; Fig. 5b )[ 27 , 47 , 48 , 50 ]. Download figure Open in new tab Fig. 5 The subgroup analyses for the effects of prism shift (°) on CBS. a). Short-term subgroup analysis. All included seven studies (n=288, 7 studies) with ≥10° prism shift, and showed significant improvement between two groups (P >0.05). b). Long-term subgroup analysis. Only one study included in prism shift <10° subgroup, while other three studies (n=130) with ≥10° showed non-significance. *: P <0.05; CBS: Catherine Bergego Scale. Based on the subgroup results for the total exposure, in short-term CBS, two studies were included in the subgroup of 0.05; Fig. 6a )[ 27 , 50 ]. Five studies were included in the ≥11250°·trials subgroup and showed statistical significance (WMD = −2.73, 95%CI: [−5.01, −0.44], P <0.05; Fig. 6a )[ 28 , 33 , 34 , 48 , 49 ]. After excluding the studies by Umeonwuka et al. (2023) and Choi et al. (2022) to address heterogeneity, the effect size remained significant (WMD = −2.81, 95%CI: [−4.57, −1.05], P <0.01). For long-term CBS, there were three studies included in the 0.05; Fig. 6b )[ 27 , 47 , 50 ]; only one study was included in the ≥11250°·trials subgroup[ 48 ]. Download figure Open in new tab Fig. 6 The subgroup analyses for the effects of total quantity of prism exposure (°·trial) on CBS. a). Short-term subgroup analysis. Two studies (n=92) included in <11250°·trial subgroup, showed non-significance; Three studies (n=196) with ≥11250°·trial showed significant improvement (P <0.05). b). Long-term subgroup analysis. Three studies (n=126) included in <11250°·trial subgroup, showed non-significance; Only one study with ≥11250°·trial. *: P <0.05; CBS: Catherine Bergego Scale. 4 Discussion Our main aim was to provide a robust and reliable meta-analysis of RCTs investigating the effects of PA on SN. Compared with the four previous meta-analyses on the similar topic, we included the latest RCTs in this field up to March 2025, according to strict inclusion criteria. We distinguished between the short-term (i.e. 1 month) effects of PA on CBS and BIT. Taken altogether, a significant immediate benefit was shown in CBS. The pooled effect on long-term BIT-C was influenced by the prism regime. No significant difference was observed for either the long-term CBS or the short-term BIT-C. For BIT-B, there was only one article providing data for the immediate efficacy and one for the long-term effect of BIT-B and total BIT, which was insufficient to assess effectiveness. This study also discussed the potential predictive factor of PA efficacy that could account for result variability, and also preliminarily discussed the correlation of PA efficacy with participant characteristics (especially brain damage) in SN. To our knowledge, we provide the first meta-analysis that simultaneously analyzes the effect of assessment time, PA intervention parameters, and patient characteristics on PA intervention effects. Therefore, we hope that this study can provide preliminary exploratory insights into the “dose-response” mechanism of PA intervention and provide a reference for further research directions. The following discussion will first address the global meta-analysis results on CBS and BIT and then discuss predictive parameters for PA efficacy. 4.1 The effect of PA on SN 4.1.1 Potential source of heterogeneity In terms of the effect of PA on SN, analyses of both short-term CBS and short-term BIT showed relatively high heterogeneity (I 2 > 50%). The study by Umeonwuka et al. was the main source of the heterogeneity in both short-term CBS and short-term BIT-C. The heterogeneity may stem from its characteristics that were different from those of other studies, e.g., a different design characteristic (single-center), younger participants (average age: 49.15 ± 13.31 years), fewer days after stroke (average: 39.25 ± 7.25 days), and the PA intervention parameters ( Table 1 ). The study by Choi et al. also contributed to the heterogeneity of short-term CBS, presumably because most of the participants in this study were in the chronic stage of stroke (mean days after stroke: 279.30 ± 87.35 vs. <90 days in others). However, excluding these two studies had no impact on the conclusions. Based on the characteristics of the remaining studies, and combining the results of sensitivity and regression analyses, it was not feasible to fully identify a specific influencing factor for short-term efficacy. Interestingly, the results of the subgroup analysis provided some reference value (see the Physical predictive factors of PA efficacy section). The effect size of long-term BIT-C was affected by Turton et al.’s study, possibly because of its smaller prism shift (6°). After its exclusion, the effect sizes of the remaining two articles (prism shift ≥10°) showed statistical significance. This trend suggested that the small prism shift used in this study may have weakened the overall effect of long-term BIT-C. 4.1.2 short-term effect of PA on SN The CBS and BIT scales were used to assess different aspects of the affected individuals with SN. For CBS, we obtained a significant short-term benefit of PA intervention, supporting the short-term efficacy of PA in ADL for participants with SN. The effects of PA intervention may thus translate into improvements in ADL for participants with SN[ 51 ]. For BIT-C, three studies were included in this meta-analysis[ 28 , 48 , 49 ]. In the study by Umeonwuka et al., they found that the BIT-C scores of the PA intervention group were significantly higher than those of the control group[ 28 ]. In the second study by Mizuno et al., they interestingly split the participants based on the SN severity and evaluated the effect of PA in BIT-C separately[ 48 ]. They found an obvious effect of PA on neglect symptoms and ADL in mild SN but no significant effect in severe SN. When analyzing the pooled group, the observed positive trend did not reach statistical significance. In another study following a similar procedure, they found that both groups showed a significant improvement in outcomes, but no statistical difference between the groups, even though the experimental group had higher improvement in all outcomes[ 49 ]. Overall, only three studies reported the immediate effect of PA on SN in terms of BIT-C, and the small sample size may increase the risk of undetected effects due to insufficient power. More large sample sizes and multicenter studies are needed to validate the results in the future. 4.1.3 Long-term effect of PA on SN In the global meta-analysis, no significant long-term effects of PA on SN were observed in CBS and BIT. This result is similar to the meta-analysis results of Li et al. and Qiu et al[ 29 , 31 ]. The small sample size (a limitation also noted in the meta-analyses by Li et al. and Qiu et al.), may reduce statistical power[ 29 , 31 ]. Although a significant improvement for BIT-C was observed when the prism shift was ≥10° (n=2), the sample size remained limited. We therefore agree with their conclusion that more rigorous studies with larger sample sizes exploring the dose of PA interventions are needed in the future to determine its benefits. 4.2 Other outcomes for the effect of PA on SN Practically, each of the 10 RCTs included at least 2 outcomes assessing the PA efficacy. Except for the most frequently reported outcomes—CBS and BIT, there are also some other meaningful behavioral or neuropsychological outcomes for evaluating the PA efficacy reported in some of these 10 RCTs (such as FIM, Albert Test, Bells Test, Wheelchair Navigation Task, and scene copying task). These outcomes mainly focus on the evaluation of independence in daily life, visual-spatial attention, cognitive-motor coordination, and spatial perception for participants with SN. However, since the number of articles reporting these outcomes is insufficient for meta-analysis (n ≤ 2), we only focused on CBS and BIT. In future RCT studies, more attention could be paid to diverse, highly reliable and sensitive outcomes to assess the treatment effect of PA on SN. For example, the Albert test and the Bells test are highly sensitive to SN and are able to detect the changes in participants’ attention allocation after PA intervention[ 52 , 53 ]. Dynamic tasks and situational simulation-type tests—such as gardening or flea-market tasks, and Wheelchair Navigation—are also helpful in assessing spatial attention in a dynamic environment in people with SN[ 16 , 54 ]. Virtual Reality (VR) Neglect Tests could simulate real-life scenarios through VR technology to measure people’s allocation of attention on the neglect side[ 55 ]. When sample size and expected effect sizes allow, evaluation across multiple different tests is more sensitive than any single test alone and should also be encouraged in future studies[ 53 , 56 ]. 4.3 Physical predictors of PA efficacy Two main types of parameters may be involved in the PA interventions efficacy. First, the physical parameters and regime of prism exposure conditions affect sensorimotor after-effects and should therefore affect in turn the expansion of PA to therapeutic cognitive effects. Second, the individual deficit and lesion should also convey a predictive value of therapeutic interventions. The sensorimotor effects of PA are closely related to the parameters of prism intervention, including the degree of prism shift, the number of trials/exposure duration (during prism exposure), frequency (/days), as well as the number of sessions and duration (days) of the PA intervention[ 10 – 12 ]. One should expect that the PA efficacy on SN also relates to some of these physical parameters[ 9 , 57 ]. For example, Gammeri R et al. suggested that the visuomotor adaptation induced by low-power prisms (i.e., shifting the visual field by 5°, 6°, or 10°) might be insufficient to produce detectable effects in all participants. They argued that higher-power prisms (such as 10°, 12° or above) may be more likely to reach critical therapeutic thresholds, producing significant PA effects[ 9 ]. Similarly, Naito et al. (2025) suggested that a larger prism shift ≥10° was a crucial factor in eliciting prism adaptation effects[ 35 ]. However, in our analyses, we found that simply satisfying this parameter was not enough to guarantee efficacy. Specifically, for short-term CBS (all included articles with ≥10° prism shift), the effect size only made a significant benefit when the total exposure was ≥11250°·trials. We also observed that for the three included studies for short-term BIT-C, the prism shift was ≥10° and the total exposure was ≥11250°·trials. However, the results did not reach statistical significance maybe due to the limited sample size. For the long-term effects of PA, the available data did not enable us to explore all combinations of outcomes, prism shift, and total exposure. For CBS, three studies were included in the prism shift ≥10° subgroup (two of which with <11250°·trials) and showed no statistically significant effect. For BIT-C, two studies with ≥10° showed significant improvement (identical to the finding after excluding Turton et al. in Section 3.3.2 .1), which points to the important role of the larger prism shift. However, it was not available to determine the independent contribution of the larger total exposure due to its substantial disparity across those two studies (with 4000°·trials and 21600°·trials). For the effect of the total exposure, three and two studies with <11250°·trials were included for CBS and BIT-C, respectively, and both leading to non-significant results (the result for BIT-C was identical to the finding after excluding Mizuno et al. in Section 3.3.2 .1). The effect of larger total exposure in long-term CBS and BIT-C was uncertain in our analysis because each included only one study. The existing evidence is insufficient to confirm the long-term clinical benefits of a larger total exposure. There is still a lack of data to explore the effects of smaller prism shifts. Our subgroup analysis of short-term CBS suggested that the variable of the total exposure warrants further exploration in future research. The importance of cumulative dose has also been confirmed in other studies. Frassinetti et al. (not RCT) conducted a 2-week PA intervention on SN participants (with a 10° shift, 180 trials-20 mins/session, twice/day, 20 sessions in total, 36000°·trials for the total exposure), and the improvements in SN were still observed 5 weeks after the intervention[ 58 ]. But it is unclear whether this effect lasted beyond 5 weeks because the study did not include longer-term follow-up. In addition, Shiraishi et al. conducted an 8-week PA intervention (with 15° shifting, 50 mins/session, 4.2 times per week) in SN participants and observed that the effects lasted up to 6 weeks after prism removal[ 59 ]. Notably, in this latter study, instead of pointing performance, various activities were performed while exposed to the prism glasses: toss rings (10-15 min), pegboard exercise (10-15 min), and a ball throwing/dart game (20-30 min). Therefore, not only pointing performance but also various activities while wearing prismatic glasses may be important factors in observing the effects of PA on SN[ 59 ]. In summary, this study combined a stronger-than-average prism strength, a large number of sessions and greater and more ecological activities during prism exposure, leading to a long-lasting benefit. Finally, we may only preliminarily speculate that a larger total exposure and diversifying task arrangements should be encouraged in future studies to expect long-term beneficial effects in participants with SN. In addition, the combination of different interventions may be more effective in treating SN than a single intervention[ 54 , 60 – 62 ]. For example, in the studies of Hyun-Se Choi et al. in 2019 and 2022, they reported separately that the effect of PA intervention combined with functional electrical stimulation (FES)/neck vibration (NV) on SN was better than that of PA or FES/NV alone[ 33 , 34 ]. However, they did not follow up to observe the long-term effects of PA on SN. Hence, in future studies, more high-quality, longer-term RCTs are needed to observe the effect of PA on SN. It can be a separate prism intervention, including not only pointing tasks but also various activities while exposed to the prism glasses. PA combined with other interventions should also be investigated to combine several mechanisms of action. 4.4 Individual predictive factors of PA efficacy Some studies have suggested that younger participants have better SN functional recovery after PA intervention[ 28 , 63 ]. Earlier PA intervention after stroke may also improve participants’ response to PA[ 63 – 65 ]. However, according to our regression results, no significant correlations were found between the age or days after stroke and the benefits of PA intervention on SN. It is worth noting that we could only conduct analyses for them based on group mean values. Subgroup analyses of age/days post-stroke were also not undertaken because subgroup classifications could only follow broad criteria (e.g., middle-aged vs. elderly; acute, subacute vs. chronic), and only one study could be included in the chronic stage. More information at the individual level should also be encouraged in future studies to explore the relevance of such information to the efficacy of PA intervention on SN. It is important to consider that the participants’ deficits and lesions may also affect the treatment outcome. One of the possible reasons for the discrepancy between case reports and RCT and for the variability of RCT outcomes is that responders and non-responders have been described. Numerous articles have reported the link between the improvement of symptoms and the characteristics of brain damage in people with SN. For example, Umeonwuka et al. reported that the BIT-C was not only related to the treatment allocation but also related to the cognitive ability (for each unit increase in cognitive ability (Mini-Mental State Examination score), the recovery rate increased by 1.5 after controlling for confounders)[ 28 ]. In another study, Kamakura CK et al. found that the BIT-C was also related to the degree of white matter lesions[ 66 ]. Among the studies included in our meta-analyses, several articles (e.g.,[ 25 , 47 , 49 ]) did not report and/or discuss participants’ cognitive abilities and/or specifics of brain damage. It is therefore possible that confounding variables contributed to the lack of significance observed. Additionally, the PA efficacy is also correlated with the severity of SN. As shown in the RCT by Mizuno et al., PA intervention significantly improved neglect symptoms and ADL in participants with mild SN, but not in severe ones. This may be due to greater potential for brain plasticity and learning abilities in participants with mild SN than in severe ones[ 48 ]. The severity of SN is related to the brain injury area and volume[ 67 , 68 ]. More extensive brain damage is more likely to impact multiple brain circuits, thereby reducing compensatory capacity and affecting the therapeutic effect of PA[ 68 ]. One study found that SN severity is associated with a widespread decline in functional connectivity of attention, motor and auditory network nodes to the contralateral brain, and that these changes were observed mainly in right-hemisphere stroke participants[ 67 , 69 ]. Another functional magnetic resonance imaging study revealed that SN severity is linked to the decreased connectivity of the right basal forebrain to the brainstem and basal ganglia, coupled with increased connectivity of the left frontal, temporal, and parietal arousal and attention network regions[ 67 , 70 ]. PA may improve neglect symptoms by rebalancing intra- and inter-hemispheric network activity via acting on intact nodes of the damaged network, homologous nodes in the undamaged hemisphere, or both[ 71 – 73 ]. The white matter integrity between hemispheres may be a key condition for the PA efficacy on SN[ 66 , 74 ]. For example, Lunven et al. found that PA may improve SN by tapping sensorimotor or prefrontal circuits more anterior to the corpus callosum[ 75 ]. Additionally, structures such as medial temporal lobe structures, the anterior cerebellar cortex, and obviously, the occipital lobe also play a significant role in the effect of PA on SN[ 76 – 78 ]. Given the important role of cerebello-parietal connections in PA (contributing to both recalibration and realignment), it is not surprising that a similar key role of these connections has been found for the therapeutic effects of PA[ 13 , 79 ]. In future studies, for a better understanding of the effects of PA on SN and the mechanisms behind it, it is necessary to define the severity of SN, the associated deficits, the brain injury aera, as well as the structural and functional characteristics of the brain’s connectivity[ 48 , 51 , 67 ]. It is also important for future studies to consider the effect of interactions between participants’ characteristics and PA intervention parameters. 5. Limitation Although meta-analyses also have intrinsic limitations, they provide useful information about therapeutic efficacy[ 80 ]. The stringent RCT inclusion criteria applied in our study had some counterpart risks in terms of limitations. First, some high-quality reports may have been excluded. Subsequently, the small sample size may lower statistical power. This is one of the possible reasons why we did not find significant results for long-term CBS and short-term BIT and why we could not determine which parameters play a significant independent predictive role in the therapeutic effect of PA. It was also not feasible to examine the interaction between potential factors affecting treatment outcomes due to the limited sample size. 6. Conclusion Given the current debate on PA, this meta-analysis applied stringent inclusion criteria. Despite the fact that only 10 RCTs were included in our study and only two outcomes (CBS and BIT) could be evaluated, we found a significant short-term benefit of PA on SN for the functional scale CBS (all studies with prism shift ≥10°), with effects mainly derived from studies with a total exposure of ≥11250°·trials. A significant improvement for long-term BIT-C was observed when the prism shift was ≥10° (n=2, with 4000°·trials and 21600°·trials). Long-term effects on CBS and short-term effects on BIT-C did not reach statistical significance. These results provide evidence for the therapeutic potential of PA intervention, and suggest that the total quantity of PA exposure may be a useful predictive factor for efficacy. Declarations of interest None Data Availability All data produced in the present study are available upon reasonable request to the authors Funding This work was supported by the China Scholarship Council, the Agence Nationale de la Recherche (ANR) [grant numbers ANR-23-JSTD-0001, 2023], Inserm, CNRS, Hospices Civils de Lyon, and Université de Lyon. Author’s contribution YuanLiang Zhu designed the study and wrote the protocol. Author YuanLiang Zhu, Francois Quesque and Yves Rossetti managed the literature searches and analyses. Authors YuanLiang Zhu, Daisuke Nishida, Eric Chabanat and Yves Rossetti undertook the statistical analysis, and author YuanLiang Zhu wrote the first draft of the manuscript. Daisuke Nishida, Francois Quesque, Sophie Jacquin-Courtois, Jacques. Luaute, Gilles Rode and Yves Rossetti reviewed and edited the manuscript. Francois Quesque and Yves Rossetti supervised the research. All authors contributed to and approved the final manuscript. List of all Additional Materials Fig. S1: Scatter plot of linear regression-physical intervention parameters. Normalized benefit scores are pitted against two potential parameters. Each point corresponds to either short-term or long-term effects of PA on CBS benefit scores. The size of the points reflects the sample size of each study, the larger the sample size, the larger the point size (four bins were used: 10-19; 20-39; 40-59; 60-79). a). Prism strength: 9/11 data points exhibit better scores after PA intervention compared to the control group. b). Total quantity of prism exposure: 8/10 data points exhibit better scores). Although the regression line between outcome and prism shift/total quantity of prism exposure has a positive slope, as one may expect, this trend did not reach significance. CBS: Catherine Bergego Scale; PA: prism adaptation. Table S1: The number of data points available for outcomes. Table S2: The linear regression analyses-the predictive ability of participants’ basic characteristics (average age and days after stroke) and different PA intervention parameters on SN improvement (main outcome-CBS). PRISMA checklist. Acknowledgments The authors wish to thank Sonia Alouche, Anne Cheylus, Alexandre Foncelle, Eric Koun and Frederic Volland for their excellent and agreeable technical assistance. Abbreviations ADL activities of daily living BIT Behavioral Inattention Test BIT-B behavioral BIT BIT-C conventional BIT CBS Catherine Bergego Scale CI Confidence Intervals FIM Functional Independence Measure FES functional electrical stimulation MBI Modified Barthel Index NV neck vibration PA prism adaptation RCT randomized controlled trial SN spatial neglect VR Virtual Reality WMD Weighted Mean Difference. Reference [1]. ↵ Corbetta M , Kincade MJ , Lewis C , Snyder AZ , Sapir A . Neural basis and recovery of spatial attention deficits in spatial neglect . Nat Neurosci 2005 ; 8 : 1603 – 10 . OpenUrl CrossRef PubMed Web of Science [2]. ↵ Heilman KM , Valenstein E . Mechanisms underlying hemispatial neglect . Ann Neurol 1979 ; 5 : 166 – 70 . OpenUrl CrossRef PubMed Web of Science [3]. ↵ Rode G , Pagliari C , Huchon L , Rossetti Y , Pisella L . Semiology of neglect: An update . Ann Phys Rehabil Med 2017 ; 60 : 177 – 185 . OpenUrl CrossRef PubMed [4]. ↵ Di Monaco M , Schintu S , Dotta M , Barba S , Tappero R , Gindri P . Severity of unilateral spatial neglect is an independent predictor of functional outcome after acute inpatient rehabilitation in individuals with right hemispheric stroke . Arch Phys Med Rehabil 2011 ; 92 : 1250 – 6 . OpenUrl CrossRef PubMed [5]. Czernuszenko A , Członkowska A . Risk factors for falls in stroke patients during inpatient rehabilitation . Clin Rehabil 2009 ; 23 : 176 – 88 . OpenUrl CrossRef PubMed Web of Science [6]. ↵ Nijboer T , van de Port I , Schepers V , Post M , Visser-Meily A . Predicting functional outcome after stroke: the influence of neglect on basic activities in daily living . Front Hum Neurosci 2013 ; 7 : 182 . [7]. ↵ Barrett AM , Burkholder S . Monocular patching in subjects with right-hemisphere stroke affects perceptual-attentional bias . J Rehabil Res Dev 2006 ; 43 : 337 – 46 . OpenUrl CrossRef PubMed [8]. ↵ Rossetti Y , Rode G , Pisella L , Farné A , Li L , Boisson D , et al. Prism adaptation to a rightward optical deviation rehabilitates left hemispatial neglect . Nature 1998 ; 395 : 166 – 9 . OpenUrl CrossRef PubMed Web of Science [9]. ↵ Gammeri R , Iacono C , Ricci R , Salatino A . Unilateral Spatial Neglect After Stroke: Current Insights . Neuropsychiatr Dis Treat 2020 ; 16 : 131 – 152 . OpenUrl CrossRef PubMed [10]. ↵ Jeannerod M , Rossetti Y . Visuomotor coordination as a dissociable visual function: experimental and clinical evidence . Baillieres Clin Neurol 1993 ; 2 : 439 – 60 . OpenUrl PubMed Web of Science [11]. Redding GM , Wallace B. Prism adaptation in alternately exposed hands . Atten Percept Psychophys 2013 ; 75 : 1168 – 85 . OpenUrl PubMed [12]. ↵ Prablanc C , Panico F , Fleury L , Pisella L , Nijboer T , Kitazawa S , et al. Adapting terminology: clarifying prism adaptation vocabulary, concepts, and methods . Neuroscience Research 2020 ; 153 : 8 – 21 . OpenUrl PubMed [13]. ↵ Panico F , Rossetti Y , Trojano L . On the mechanisms underlying Prism Adaptation: A review of neuro-imaging and neuro-stimulation studies . Cortex 2020 ; 123 : 57 – 71 . OpenUrl CrossRef PubMed [14]. Carter AR , Barrett AM . Recent advances in treatment of spatial neglect: networks and neuropsychology . Expert Review of Neurotherapeutics 2023 ; 23 : 587 – 601 . OpenUrl PubMed [15]. ↵ Clarke S , Crottaz-Herbette S . Modulation of visual attention by prismatic adaptation . Neuropsychologia 2016 ; 92 : 31 – 41 . OpenUrl CrossRef PubMed [16]. ↵ Jacquin-Courtois S , Rode G , Pisella L , Boisson D , Rossetti Y . Wheel-chair driving improvement following visuo-manual prism adaptation . Cortex 2008 ; 44 : 90 – 6 . OpenUrl CrossRef PubMed Web of Science [17]. ↵ Jacquin-Courtois S , Rode G , Pavani F , O’Shea J , Giard MH , Boisson D , et al. Effect of prism adaptation on left dichotic listening deficit in neglect patients: glasses to hear better? Brain 2010 ; 133 : 895 – 908 . OpenUrl CrossRef PubMed Web of Science [18]. ↵ Tilikete C , Rode G , Rossetti Y , Pichon J , Li L , Boisson D . Prism adaptation to rightward optical deviation improves postural imbalance in left-hemiparetic patients . Curr Biol 2001 ; 11 : 524 – 8 . OpenUrl CrossRef PubMed Web of Science [19]. ↵ Rode G , Pisella L , Marsal L , Mercier S , Rossetti Y , Boisson D . Prism adaptation improves spatial dysgraphia following right brain damage . Neuropsychologia 2006 ; 44 : 2487 – 93 . OpenUrl CrossRef PubMed Web of Science [20]. ↵ Rossetti Y , Jacquin-Courtois S , Rode G , Ota H , Michel C , Boisson D . Does action make the link between number and space representation? Visuo-manual adaptation improves number bisection in unilateral neglect . Psychol Sci 2004 ; 15 : 426 – 30 . OpenUrl CrossRef PubMed Web of Science [21]. ↵ Rode G , Pisella L , Rossetti Y , Farnè A , Boisson D . Bottom-up transfer of sensory-motor plasticity to recovery of spatial cognition: visuomotor adaptation and spatial neglect . Prog Brain Res 2003 ; 142 : 273 – 87 . OpenUrl PubMed [22]. ↵ Pisella L , Rode G , Farnè A , Boisson D , Rossetti Y . Dissociated long lasting improvements of straight-ahead pointing and line bisection tasks in two hemineglect patients . Neuropsychologia 2002 ; 40 : 327 – 34 . OpenUrl CrossRef PubMed Web of Science [23]. ↵ Humphreys GW , Watelet A , Riddoch MJ . Long-term effects of prism adaptation in chronic visual neglect: A single case study . Cogn Neuropsychol 2006 ; 23 : 463 – 78 . OpenUrl PubMed [24]. ↵ Azouvi P , Jacquin-Courtois S , Luauté J . Rehabilitation of unilateral neglect: Evidence-based medicine . Annals of Physical and Rehabilitation Medicine 2017 ; 60 : 191 – 197 . OpenUrl [25]. ↵ Nys GMS , De Haan EHF , Kunneman A , De Kort PLM , Dijkerman HC . Acute neglect rehabilitation using repetitive prism adaptation: A randomized placebo-controlled trial . Restorative Neurology and Neuroscience 2008 ; 26 : 1 – 12 . OpenUrl PubMed Web of Science [26]. ↵ Rode G , Lacour S , Jacquin-Courtois S , Pisella L , Michel C , Revol P , et al. Long-term sensorimotor and therapeutical effects of a mild regime of prism adaptation in spatial neglect. A double-blind RCT essay . Annals of physical and rehabilitation medicine 2015 ; 58 : 40 – 53 . OpenUrl [27]. ↵ Vilimovsky T , Chen P , Hoidekrova K , Petioky J , Harsa P . Prism adaptation treatment to address spatial neglect in an intensive rehabilitation program: A randomized pilot and feasibility trial . PLoS ONE 2021 ; 16 . [28]. ↵ Umeonwuka CI , Roos R , Ntsiea V . Clinical and demographic predictors of unilateral spatial neglect recovery after prism therapy among stroke survivors in the sub-acute phase of recovery . Neuropsychological rehabilitation 2023 ; 33 : 1624 – 1649 . OpenUrl PubMed [29]. ↵ Li J , Li L , Yang Y , Chen S . Effects of Prism Adaptation for Unilateral Spatial Neglect After Stroke: A Systematic Review and Meta-Analysis . Am J Phys Med Rehabil 2021 ; 100 : 584 – 591 . OpenUrl PubMed [30]. ↵ Boukrina O , Chen P . Neural Mechanisms of Prism Adaptation in Healthy Adults and Individuals with Spatial Neglect after Unilateral Stroke: A Review of fMRI Studies . Brain Sci 2021 ; 11 . [31]. ↵ Qiu H , Wang J , Yi W , Yin Z , Wang H , Li J . Effects of Prism Adaptation on Unilateral Neglect After Stroke: An Updated Meta-Analysis of Randomized Controlled Trials . Am J Phys Med Rehabil 2021 ; 100 : 259 – 265 . OpenUrl PubMed [32]. ↵ Székely O , Ten Brink AF , Mitchell AG , Bultitude JH , McIntosh RD . No short-term treatment effect of prism adaptation for spatial neglect: An inclusive meta-analysis . Neuropsychologia 2023 ; 189 . [33]. ↵ Choi HS , Kim DJ , Yang YA . The effect of a complex intervention program for unilateral neglect in patients with acute-phase stroke: A randomized controlled trial . Osong Public Health and Research Perspectives 2019 ; 10 : 265 – 273 . OpenUrl [34]. ↵ Choi HS , Lee BM . A Complex Intervention Integrating Prism Adaptation and Neck Vibration for Unilateral Neglect in Patients of Chronic Stroke: A Randomised Controlled Trial . International Journal of Environmental Research and Public Health 2022 ; 19 : 10 . [35]. ↵ Naito Y , Koshino Y , Ota H , Piano M , Watanabe A , Inagaki Y , et al. Short-term effect of prism adaptation treatment on severity of unilateral spatial neglect following right hemispheric stroke: a systematic review and meta-analysis . J Rehabil Med 2025 ; 57 : jrm42542 . OpenUrl PubMed [36]. ↵ Michel C , Pisella L , Prablanc C , Rode G , Rossetti Y . Enhancing visuomotor adaptation by reducing error signals: single-step (aware) versus multiple-step (unaware) exposure to wedge prisms . J Cogn Neurosci 2007 ; 19 : 341 – 50 . OpenUrl CrossRef PubMed Web of Science [37]. ↵ Page MJ , McKenzie JE , Bossuyt PM , Boutron I , Hoffmann TC , Mulrow CD , et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews . BMJ 2021 ; 372 : n71 . [38]. ↵ Azouvi P . Functional Consequences and Awareness of Unilateral Neglect: Study of an Evaluation Scale . Neuropsychological Rehabilitation 1996 ; 6 : 133 – 150 . OpenUrl [39]. ↵ Azouvi P , Olivier S , de Montety G , Samuel C , Louis-Dreyfus A , Tesio L . Behavioral assessment of unilateral neglect: study of the psychometric properties of the Catherine Bergego Scale . Arch Phys Med Rehabil 2003 ; 84 : 51 – 7 . OpenUrl CrossRef PubMed Web of Science [40]. ↵ Azouvi P . The ecological assessment of unilateral neglect . Ann Phys Rehabil Med 2017 ; 60 : 186 – 190 . OpenUrl CrossRef PubMed [41]. ↵ Marques CLS , de Souza JT , Gonçalves MG , da Silva TR , da Costa RDM , Modolo GP , et al. Validation of the Catherine Bergego Scale in patients with unilateral spatial neglect after stroke . Dement Neuropsychol 2019 ; 13 : 82 – 88 . OpenUrl PubMed [42]. ↵ Bergego C , Azouvi P , Samuel C , et al. Validation d’une échelle d’évaluation fonctionnelle de l’héminégligence dans la vie quotidienne: l’échelle CB. Ann éadaptation . Med Phys 1995 ; 38 : 183 – 189 . OpenUrl [43]. ↵ Wilson B , Cockburn J , Halligan P . Development of a behavioral test of visuospatial neglect . Arch Phys Med Rehabil 1987 ; 68 : 98 – 102 . OpenUrl PubMed Web of Science [44]. ↵ Delaney J , Cui R , Engel A . Risk of bias judgements and strength of conclusions in meta-evidence from the Cochrane Colorectal Cancer Group . Syst Rev 2019 ; 8 : 90 . [45]. ↵ Higgins JPT TJ , Chandler J , Cumpston M , Li T , Page MJ , Welch VA (editors). Cochrane Handbook for Systematic Reviews of Interventions version 6.5 (updated August 2024). 6.5 ed. Cochrane , 2024 . [46]. ↵ Huedo-Medina TB , Sánchez-Meca J , Marín-Martínez F , Botella J . Assessing heterogeneity in meta-analysis: Q statistic or I2 index? Psychol Methods 2006 ; 11 : 193 – 206 . OpenUrl CrossRef PubMed Web of Science [47]. ↵ Turton AJ , O’Leary K , Gabb J , Woodward R , Gilchrist ID . A single blinded randomised controlled pilot trial of prism adaptation for improving self-care in stroke patients with neglect . Neuropsychological Rehabilitation 2010 ; 20 : 180 – 196 . OpenUrl PubMed [48]. ↵ Mizuno K , Tsuji T , Takebayashi T , Fujiwara T , Hase K , Liu M . Prism adaptation therapy enhances rehabilitation of stroke patients with unilateral spatial neglect: A randomized, controlled trial . Neurorehabilitation and Neural Repair 2011 ; 25 : 711 – 720 . OpenUrl [49]. ↵ Mauro M , Donatella C . Efficacy of Prisms in Neglect Treatment: A Randomized Single Blind Study . International Journal of Physical Medicine & Rehabilitation 2016 ; 4 . [50]. ↵ Ten Brink AF , Visser-Meily JMA , Schut MJ , Kouwenhoven M , Eijsackers ALH , Nijboer TCW . Prism Adaptation in Rehabilitation? No Additional Effects of Prism Adaptation on Neglect Recovery in the Subacute Phase Poststroke: A Randomized Controlled Trial . Neurorehabilitation and Neural Repair 2017 ; 31 : 1017 – 1028 . OpenUrl [51]. ↵ Champod AS , Frank RC , Taylor K , Eskes GA . The effects of prism adaptation on daily life activities in patients with visuospatial neglect: a systematic review . Neuropsychol Rehabil 2018 ; 28 : 491 – 514 . OpenUrl PubMed [52]. ↵ Albert ML . A simple test of visual neglect . Neurology 1973 ; 23 : 658 – 64 . OpenUrl CrossRef PubMed [53]. ↵ Azouvi P , Samuel C , Louis-Dreyfus A , Bernati T , Bartolomeo P , Beis JM , et al. Sensitivity of clinical and behavioural tests of spatial neglect after right hemisphere stroke . J Neurol Neurosurg Psychiatry 2002 ; 73 : 160 – 6 . OpenUrl Abstract / FREE Full Text [54]. ↵ O’Shea J , Revol P , Cousijn H , Near J , Petitet P , Jacquin-Courtois S , et al. Induced sensorimotor cortex plasticity remediates chronic treatment-resistant visual neglect . Elife 2017 ; 6 . [55]. ↵ Painter DR , Norwood MF , Marsh CH , Hine T , Woodman C , Libera M , et al. Virtual reality gameplay classification illustrates the multidimensionality of visuospatial neglect . Brain Commun 2024 ; 6 : fcae145 . OpenUrl [56]. ↵ Ten Brink AF , Visser-Meily JMA , Nijboer TCW . Dynamic assessment of visual neglect: The Mobility Assessment Course as a diagnostic tool . J Clin Exp Neuropsychol 2018 ; 40 : 161 – 172 . OpenUrl PubMed [57]. ↵ Jacquin-Courtois S , Rode G Fau - Pavani F, Pavani F Fau - O’Shea J, O’Shea J Fau - Giard MH, Giard Mh Fau - Boisson D, Boisson D Fau - Rossetti Y , et al. Effect of prism adaptation on left dichotic listening deficit in neglect patients: glasses to hear better ? 2010 . [58]. ↵ Frassinetti F , Angeli V , Meneghello F , Avanzi S , Làdavas E . Long-lasting amelioration of visuospatial neglect by prism adaptation . Brain 2002 ; 125 : 608 – 23 . OpenUrl CrossRef PubMed Web of Science [59]. ↵ Shiraishi H , Yamakawa Y , Itou A , Muraki T , Asada T. Long-term effects of prism adaptation on chronic neglect after stroke . NeuroRehabilitation 2008 ; 23 : 137 – 51 . OpenUrl PubMed Web of Science [60]. ↵ Saevarsson S , Halsband U , Kristjansson A . Designing rehabilitation programs for neglect: could 2 be more than 1+1? Appl Neuropsychol 2011 ; 18 : 95 – 106 . OpenUrl CrossRef PubMed [61]. Schindler I , Kerkhoff G , Karnath HO , Keller I , Goldenberg G . Neck muscle vibration induces lasting recovery in spatial neglect . J Neurol Neurosurg Psychiatry 2002 ; 73 : 412 – 9 . OpenUrl Abstract / FREE Full Text [62]. ↵ Luauté J , Villeneuve L , Roux A , Nash S , Bar JY , Chabanat E , et al. Adding methylphenidate to prism-adaptation improves outcome in neglect patients. A randomized clinical trial . Cortex 2018 ; 106 : 288 – 298 . OpenUrl PubMed [63]. ↵ Chen P , Hreha K , Gonzalez-Snyder C , Rich TJ , Gillen RW , Parrott D , et al. Impacts of Prism Adaptation Treatment on Spatial Neglect and Rehabilitation Outcome: Dosage Matters . Neurorehabil Neural Repair 2022 ; 36 : 500 – 513 . OpenUrl PubMed [64]. Lunven M , Rode G , Bourlon C , Duret C , Migliaccio R , Chevrillon E , et al. Anatomical predictors of successful prism adaptation in chronic visual neglect . Cortex 2019 ; 120 : 629 – 641 . OpenUrl PubMed [65]. ↵ Chen P , Hreha K , Gonzalez-Snyder C , Rich TJ , Gillen RW , Parrott D , et al. Impacts of Prism Adaptation Treatment on Spatial Neglect and Rehabilitation Outcome: Dosage Matters . Neurorehabilitation and Neural Repair 2022 ; 36 : 500 – 513 . OpenUrl [66]. ↵ Kamakura CK , Ueno Y , Sakai Y , Yoshida H , Aiba S , Hayashi A , et al. White matter lesions and cognitive impairment may be related to recovery from unilateral spatial neglect after stroke . J Neurol Sci 2017 ; 379 : 241 – 246 . OpenUrl CrossRef PubMed [67]. ↵ Durfee AZ , Hillis AE . Unilateral Spatial Neglect Recovery Poststroke . Stroke 2023 ; 54 : 10 – 19 . OpenUrl CrossRef PubMed [68]. ↵ Bartolomeo P . From competition to cooperation: Visual neglect across the hemispheres . Rev Neurol (Paris ) 2021 ; 177 : 1104 – 1111 . OpenUrl PubMed [69]. ↵ Baldassarre A , Ramsey L , Hacker CL , Callejas A , Astafiev SV , Metcalf NV , et al. Large-scale changes in network interactions as a physiological signature of spatial neglect . Brain 2014 ; 137 : 3267 – 83 . OpenUrl CrossRef PubMed [70]. ↵ Boukrina O , Kowalczyk M , Koush Y , Kong Y , Barrett AM . Brain Network Dysfunction in Poststroke Delirium and Spatial Neglect: An fMRI Study . Stroke 2022 ; 53 : 930 – 938 . OpenUrl PubMed [71]. ↵ Chechlacz M , Humphreys GW , Cazzoli D . Spatial and non-spatial aspects of visual attention: Interactive cognitive mechanisms and neural underpinnings . Neuropsychologia 2016 ; 92 : 1 – 6 . OpenUrl PubMed [72]. Crottaz-Herbette S , Fornari E , Notter MP , Bindschaedler C , Manzoni L , Clarke S . Reshaping the brain after stroke: The effect of prismatic adaptation in patients with right brain damage . Neuropsychologia 2017 ; 104 : 54 – 63 . OpenUrl PubMed [73]. ↵ Saj A , Cojan Y , Vocat R , Luauté J , Vuilleumier P . Prism adaptation enhances activity of intact fronto-parietal areas in both hemispheres in neglect patients . Cortex 2013 ; 49 : 107 – 119 . OpenUrl CrossRef PubMed Web of Science [74]. ↵ Lunven M , Toba MN , Bartolomeo P . Prism adaptation therapy in spatial neglect: The importance of connectional anatomy . Neuropsychologia 2023 ; 188 . [75]. ↵ Lunven M , Rode G , Bourlon C , Duret C , Migliaccio R , Chevrillon E , et al. Anatomical predictors of successful prism adaptation in chronic visual neglect . Cortex 2019 ; 120 : 629 – 641 . OpenUrl PubMed [76]. ↵ Chen P , Goedert KM , Shah P , Foundas AL , Barrett AM . Integrity of medial temporal structures may predict better improvement of spatial neglect with prism adaptation treatment . Brain Imaging and Behavior 2014 ; 8 : 346 – 358 . OpenUrl [77]. Pisella L , Rossetti Y , Michel C , Rode G , Boisson D , Pélisson D , et al. Ipsidirectional impairment of prism adaptation after unilateral lesion of anterior cerebellum . Neurology 2005 ; 65 : 150 – 2 . OpenUrl CrossRef PubMed [78]. ↵ Serino A , Angeli V , Frassinetti F , Làdavas E . Mechanisms underlying neglect recovery after prism adaptation . Neuropsychologia 2006 ; 44 : 1068 – 78 . OpenUrl CrossRef PubMed Web of Science [79]. ↵ Saj A , Cojan Y , Assal F , Vuilleumier P . Prism adaptation effect on neural activity and spatial neglect depend on brain lesion site . Cortex 2019 ; 119 : 301 – 311 . OpenUrl PubMed [80]. ↵ Lee YH . An overview of meta-analysis for clinicians . Korean J Intern Med 2018 ; 33 : 277 – 283 . OpenUrl PubMed View the discussion thread. Back to top Previous Next Posted June 10, 2025. Download PDF Supplementary Material Data/Code Email Thank you for your interest in spreading the word about medRxiv. NOTE: Your email address is requested solely to identify you as the sender of this article. Your Email * Your Name * Send To * Enter multiple addresses on separate lines or separate them with commas. You are going to email the following Robust immediate and limited long-term benefit of prism adaptation on spatial neglect: A Systematic Review and Meta-Analysis of outcomes and predictors Message Subject (Your Name) has forwarded a page to you from medRxiv Message Body (Your Name) thought you would like to see this page from the medRxiv website. Your Personal Message CAPTCHA This question is for testing whether or not you are a human visitor and to prevent automated spam submissions. Share Robust immediate and limited long-term benefit of prism adaptation on spatial neglect: A Systematic Review and Meta-Analysis of outcomes and predictors YuanLiang Zhu , Francois Quesque , Daisuke Nishida , Sophie Jacquin-Courtois , Jacques. Luaute , Eric Chabanat , Gilles Rode , Yves Rossetti medRxiv 2025.06.09.25329277; doi: https://doi.org/10.1101/2025.06.09.25329277 Share This Article: Copy Citation Tools Robust immediate and limited long-term benefit of prism adaptation on spatial neglect: A Systematic Review and Meta-Analysis of outcomes and predictors YuanLiang Zhu , Francois Quesque , Daisuke Nishida , Sophie Jacquin-Courtois , Jacques. Luaute , Eric Chabanat , Gilles Rode , Yves Rossetti medRxiv 2025.06.09.25329277; doi: https://doi.org/10.1101/2025.06.09.25329277 Citation Manager Formats BibTeX Bookends EasyBib EndNote (tagged) EndNote 8 (xml) Medlars Mendeley Papers RefWorks Tagged Ref Manager RIS Zotero Tweet Widget Facebook Like Google Plus One Subject Area Rehabilitation Medicine and Physical Therapy Subject Areas All Articles Addiction Medicine (568) Allergy and Immunology (863) Anesthesia (300) Cardiovascular Medicine (4435) Dentistry and Oral Medicine (444) Dermatology (382) Emergency Medicine (608) Endocrinology (including Diabetes Mellitus and Metabolic Disease) (1509) Epidemiology (15229) Forensic Medicine (30) Gastroenterology (1124) Genetic and Genomic Medicine (6600) Geriatric Medicine (668) Health Economics (997) Health Informatics (4538) Health Policy (1368) Health Systems and Quality Improvement (1613) Hematology (541) HIV/AIDS (1264) Infectious Diseases (except HIV/AIDS) (15916) Intensive Care and Critical Care Medicine (1103) Medical Education (623) Medical Ethics (146) Nephrology (667) Neurology (6599) Nursing (346) Nutrition (998) Obstetrics and Gynecology (1144) Occupational and Environmental Health (957) Oncology (3333) Ophthalmology (974) Orthopedics (369) Otolaryngology (420) Pain Medicine (436) Palliative Medicine (130) Pathology (663) Pediatrics (1693) Pharmacology and Therapeutics (691) Primary Care Research (711) Psychiatry and Clinical Psychology (5447) Public and Global Health (9232) Radiology and Imaging (2198) Rehabilitation Medicine and Physical Therapy (1370) Respiratory Medicine (1196) Rheumatology (593) Sexual and Reproductive Health (712) Sports Medicine (530) Surgery (712) Toxicology (99) Transplantation (289) Urology (265) (function(){function c(){var b=a.contentDocument||a.contentWindow.document;if(b){var d=b.createElement('script');d.innerHTML="window.__CF$cv$params={r:'a00d4d4a2ed9aa64',t:'MTc3OTYzNjIxMA=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElementsByTagName('head')[0].appendChild(a);";b.getElementsByTagName('head')[0].appendChild(d)}}if(document.body){var a=document.createElement('iframe');a.height=1;a.width=1;a.style.position='absolute';a.style.top=0;a.style.left=0;a.style.border='none';a.style.visibility='hidden';document.body.appendChild(a);if('loading'!==document.readyState)c();else if(window.addEventListener)document.addEventListener('DOMContentLoaded',c);else{var e=document.onreadystatechange||function(){};document.onreadystatechange=function(b){e(b);'loading'!==document.readyState&&(document.onreadystatechange=e,c())}}}})();