# Significant immediate and limited long-term benefit of prism adaptation on spatial neglect: a systematic review and meta-analysis of RCTs

Yuanliang Zhu, Francois Quesque, Daisuke Nishida, Sophie Jacquin-Courtois, Jacques Luaute, Eric Chabanat, Gilles Rode, Yves Rossetti

<figure><img src="image_1.png" /></figure>

## To cite this version:

Yuanliang Zhu, Francois Quesque, Daisuke Nishida, Sophie Jacquin-Courtois, Jacques Luaute, et al.. Significant immediate and limited long-term benefit of prism adaptation on spatial neglect: a systematic review and meta-analysis of RCTs. Annals of Physical and Rehabilitation Medicine, 2025, 68 (7), pp.102022. 10.1016/j.rehab.2025.102022. hal-05452473

HAL Id: hal-05452473

https://hal.science/hal-05452473v1

Submitted on 10 Jan 2026

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

<figure><img src="image_2.png" /></figure>

Distributed under a Creative Commons CC BY 4.0 - Attribution - International License
Meta-analysis

# Significant immediate and limited long-term benefit of prism adaptation on spatial neglect: a systematic review and meta-analysis of RCTs

<figure><img src="image_3.png" /></figure>

YuanLiang Zhu<sup>a,b</sup>, Francois Quesque<sup>b</sup>, Daisuke Nishida<sup>b,c</sup>, Sophie Jacquin-Courtois<sup>d,e</sup>, Jacques Luaute<sup>d,e</sup>, Eric Chabanat<sup>b</sup>, Gilles Rode<sup>d,e</sup>, Yves Rossetti<sup>b,d,e,*</sup>

ARTICLE INFO

Keywords:

Prism adaptation

Spatial neglect

Catherine bergego scale

Behavioral inattention test

Meta-analysis

A B S T R A C T

**Background:** Although prism adaptation (PA) has been applied in spatial neglect (SN) for 27 years, its efficacy remains controversial and lacks consistency.

**Objective:** The first aim was to assess the immediate and long-term effects of PA on SN via meta-analysis of randomized controlled trials (RCTs). The second aim was to identify potential effect modifiers of PA efficacy.

**Methods:** We searched four 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, eight of them reporting CBS data and six for BIT. Immediate PA effects on SN showed a significant improvement for CBS between the PA group (PA/PA + conventional) and control group (shamPA/ shamPA + conventional/only conventional), all studies with prism shift ≥10°, (WMD = -2.13, 95% CI -3.93 to 0.33; P = 0.020), but non-significance for conventional BIT (BIT-C). Long-term benefit was not significant for CBS, while it was significant for BIT-C when the prism shift was ≥10° (n = 2; WMD = 12.37, 95% CI 0.53 to 24.21; P = 0.041). Linear regressions showed non-significant effect modifiers 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 to -0.44; P = 0.019), whereas the subgroup with smaller total exposure showed no significant difference.

**Conclusion:** Even with stringent inclusion criteria, significant 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. The total quantity of prism exposure (°.trials) may be an applicable effect modifier of PA efficacy.

**Trial Registration:** PROSPERO database (registration number: CRD420250650402).

# 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,

**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; M1, primary motor cortex; MBI, modified barthel index; NV, neck vibration; PA, prism adaptation; RCT, randomized controlled trial; SN, spatial neglect; VR, virtual reality; WMD, weighted mean difference

*Corresponding author.

**E-mail addresses:** yuanliang.zhu@inserm.fr (Y. Zhu), francois.quesque@gmail.com (F. Quesque), prix0616@gmail.com (D. Nishida), sophie.courtois@chu-lyon.fr (S. Jacquin-Courtois), jacques.luaute@chu-lyon.fr (J. Luaute), eric.chabanat@chu-lyon.fr (E. Chabanat), gilles.rode@chu-lyon.fr (G. Rode), yves.rossetti@inserm.fr (Y. Rossetti).

<footnote><sup>a</sup> 476 Neurosciences et Cognition, Université Claude Bernard Lyon 1 69675, Bron, France</footnote>

<footnote><sup>b</sup> INSERM U1028 CNRS UMR5292, Trajectoires team, Lyon Neuroscience Research Center (CRNL) 69500, Bron, France</footnote>

<footnote><sup>c</sup> Department of Rehabilitation Medicine, Tokai University 259-1193, Kanaga, Japan</footnote>

<footnote><sup>d</sup> Hospices Civils de Lyon, PAM de reeducation, Hopital Henry Gabrielle, route de Vourles 69565, Saint-Genis-Laval, France</footnote>

<footnote><sup>e</sup> "Mouvement et Handicap" platform, Neurological Hospital, Hospices Civils de Lyon 69500, Bron, France</footnote>
prolonged hospitalization, functional dependence, disability in life activities, and increased risk of falls [4,5]. With rising post-acute care for stroke survivors, the need for validated SN rehabilitation is growing [6].

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 [7–11]. 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 [7]. 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 [11]. 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 [12]. Some scholars argued that PA effects are produced through adaptation to the influence of circuits controlling attention and visuomotor behaviors in the dorsal visual stream, with limited effects on the pervasive perceptual bias characteristic of neglect [13]. However, most studies suggest that PA is not only a low-level perceptual-motor corrective process, but also involves complex neural network remodeling, including the restoration of interhemispheric functional balance, attention, and sensorimotor network plasticity [12,14,15].

Indeed, the 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 [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, numerous 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 stakes of its concrete clinical implications, it is essential to re-examine and comprehensively review the available evidence based on the most rigorous and reliable source of information, ie, RCTs. 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.

There are significant factors affecting the efficacy of PA intervention on SN. Especially the diversity of PA intervention designs (not only prism intensity, but also number of trials, frequency, number of sessions, etc) [9–11], and individual differences among participants; in

particular, the variety of brain lesion topography and size) [36,37]. These are also the primary sources of heterogeneity across studies. As clinicians currently face difficulties in interpreting contradictions and debates in the literature, it is timely and necessary to provide more straightforward guidelines for clinical practice. Therefore, we chose to make a significant step forward, building on previous meta-analyses along three main lines: (1) including only RCTs and distinguishing between immediate and long-term effects of PA on SN, (2) identifying which of the physical parameters of PA interventions are effect modifiers of PA efficacy. Notably, PA efficacy may not only be influenced by a single parameter but may also be related to the overall intervention dose (eg, ‘total quantity of prism exposure’) [38], and (3) analyzing the impact of available participant characteristics on PA efficacy on SN, to gain further guidance for future studies and forthcoming 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 [39]. 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" OR "apoplexy neglect" OR "visual neglect" OR "sensory neglect" OR "perceptual disorder" OR "hemisensory neglect"). The search strategies for each database are shown in Table S1. 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 (PA group); C (comparison): sham PA/sham PA + conventional treatment/only conventional treatment (control group); 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 tasks; 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 articles, meta-analyses, case reports, protocols, meetings, summaries, conference abstracts, 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. We 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 S2), we only focused on CBS and BIT, which are also the two most 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 [40]. Also, the CBS has been shown to have good reliability, validity, and sensitivity to changes in the rehabilitation process of people with SN [41,42]. Therefore, it was chosen as the primary outcome in our study. The BIT was used to assess the perceptual and spatial cognitive motor systems [43]. Considering its insufficient sensitivity and limited ecological validity, it was used as the secondary outcome in our study [41].

### 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 zero points (no neglect) to three points (severe neglect), and with a final maximum score of 30 points [40].

### 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 six items with a maximum score of 146; while BIT-B assesses ADLs and has nine items with a maximum score of 81. The lower the score, the more severe the visuo-spatial impairment, and a total BIT score of <196 indicates SN [43].

## 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 (<24 h after the end of treatment) and long-term (>1 month after the end of treatment). Data were averaged when multiple data points were available at a specific time.

Treatment effects were reported as weighted mean differences (WMD) with 95 % confidence intervals (CI) [45]. The I² statistic was used to assess heterogeneity, with 0 % indicating no observed heterogeneity, low >25 %, moderate >50 %, and high >75 % heterogeneity [46]. Considering the small sample size and clinical heterogeneity across studies (eg, participant characteristics, 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 discuss further 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

Given the limited number of included studies in each condition (n≤7 in short- and long-term), it was not statistically appropriate to conduct meta-regression analysis (Cochrane). Also, 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 primary outcome, CBS, with the largest number of studies included. To exploratorily identify whether participants' basic characteristics (average age and days after stroke) were associated with CBS improvement. Whether specific PA intervention parameters, ie, 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 modify the CBS improvement.

When available, individual results of short- and long-term CBS changes were calculated as follows: Result = ΔPA group – ΔControl group, ie, 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 >57 trials were achieved in 20 mins (e.g., 60 trials in <10 min in Rossetti et al, 1998), ie, >11250°.trials. Thus, it was included in the larger total exposure group in the subgroup analyses.

## 2.10. Subgroup analyses

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.) [35], suggesting a crucial role of larger prism shift (≥10°) in the effects of PA. 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.) [38]. 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 in the literature search, and 731 articles remained after excluding duplicate articles. Based on the inclusion and exclusion criteria, 14 articles were included. Original data from 3 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]. Eight studies adopted a single PA intervention compared to sham PA [25-28,47-50], while two for combined interventions (PA + functional electrical stimulation [FES]/neck vibration [NV]) compared to only FES/NV intervention, and were included in the analyses of short-term effects on CBS [33,34]. The data screening process is shown in Fig. 1, and the characteristics of the included literature are shown in Table 1.
<figure><img src="image_4.png" /><figcaption>Fig. 1. Flowchart of the study screening process. Out of the 1394 studies considered, only 10 were finally included in the present analysis.</figcaption></figure>

## 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 of these articles are double-blind [26,28,48,50]. Three studies provided limited information regarding the specific blinding implementation. Choi et al. [34] stated that the study was a single-blind design but did not provide how blinding was implemented. Choi et al, and Mancuso et al, [33,49] did not mention any blinding information. Regarding transparency in reporting on the management and implementation of outcomes measurement, some studies like Nys et al., Mizuno et al., Rode et al., and Choi et al. [25,26,33,34,48] mentioned that the intervention and assessment were conducted by trained occupational therapists, but without further implementation details (self-assessment or observer-rated). Mancuso (2016) did not report on who implemented the intervention or outcome assessment, nor the specific implementation details on the outcome assessment procedures [49]. None of the included studies explicitly reported whether culturally validated or translated versions of outcomes were used. 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) [26,27,47–50].

## 3.3. Outcomes

### 3.3.1. Main outcome-CBS

Seven articles were included for the immediate effect of PA intervention, 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 to -0.33; *P* = 0.020; *I*² = 65%).

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 to 1.03; *P* = 0.656; *I*² = 0%).

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 (I² > 50%), while the heterogeneity of the long-term analysis was 0%. Influence analysis showed the research by Umeonwuka et al. [28] was the main source of heterogeneity in short-term CBS. After exclusion,

the heterogeneity (I²) of short-term CBS decreased from 65.0 % to 21 %, and the effects remained statistically significant (WMD = -1.38, 95% CI -2.70 to -0.06; *P* = 0.04; *I*² = 21%). After further excluding the study by Choi et al. [34], the heterogeneity (I²) decreased from 21 % to 4 %, with remaining significance (WMD = -1.92, 95% CI -3.34 to -0.50; *P* = 0.008; *I*² = 4%), suggesting the stability of the result. Therefore, we decided to retain those two studies (Umeonwuka et al and Choi et al) [28,34] 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 to 40.54; *P* = 0.124; *I*² = 80%) [Fig. 4a]. Only one study described BIT-B for immediate effects [48].

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: 22.1) and control (average BIT-C score improvement: 19.75) groups [25,47,48]. The meta-analysis found no significant difference between the two groups (WMD = 8.67, 95% CI -0.63 to 17.98; *P* = 0.068; *I*² = 0%) [Fig. 4b]. Only 1 study 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. [28] explained most heterogeneity of the short-term CBS (I² decreased from 80% 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 to 19.89; *P* = 0.263; *I*² = 0%). Therefore, we decided to retain this study [28].

For long-term BIT-C, although no statistical heterogeneity was observed (I² = 0%), influence analysis showed that the study by Mizuno et al. [48] had little impact on combined results, as its exclusion maintained the effect non-significant (WMD = 3.39, 95% CI -10.32 to 17.09; *P* = 0.628; *I*² = 0%). In addition, leave-one-out analysis found that excluding the study by Turton et al. [47] altered the effect size to statistically significant (WMD = 12.37, 95% CI 0.53 to 24.21; *P* = 0.041; *I*² = 0%).

## 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 and days after stroke and PA
<table><caption>**Table 1**

Characteristics of the included articles.</caption><thead><tr><th rowspan="3">Studies</th><th rowspan="3">Disease type<br>(hemisphere side)</th><th colspan="10">Groups</th><th rowspan="3">PA intervention parameters</th><th rowspan="3">Outcomes: CBS/BIT only<br>(Assessment time)</th></tr><tr><th colspan="5">PA group</th><th colspan="5">Control group</th></tr><tr><th>Sample size</th><th>Age: mean (SD)/range</th><th>Gender (M/F)</th><th>Mean time post stroke (days): mean (SD)/range</th><th>Intervention</th><th>Sample size</th><th>Age: mean (SD)/range</th><th>Gender (M/F)</th><th>Mean time post stroke (days): mean (SD)/range</th><th>Intervention</th></tr></thead><tbody><tr><td>Nys 2008<br>[25]</td><td>stroke- neglect<br>(R hemisphere)</td><td>10</td><td>63.6 (13.8)</td><td>7/3</td><td>8.8 (5.3)</td><td>10°-right</td><td>6</td><td>61.5 (11.0)</td><td>3/3</td><td>11.2 (6.4)</td><td>0°</td><td>30mins/session, 4 consecutive days<br>Total sessions: 4<br>Total exposure: 4000°-trials</td><td>Immediate: No<br>Long term: BIT-C<br>(1 month after the end of treatment)</td></tr><tr><td>Turton 2010<br>[47]</td><td>stroke- neglect<br>(R hemisphere)</td><td>16</td><td>72 (14)</td><td>8/8</td><td>45 (23)</td><td>6°-right</td><td>18</td><td>71 (14)</td><td>11/7</td><td>47 (39)</td><td>0°</td><td>Once/weekday, for 2 weeks<br>Total sessions: 10<br>Total exposure: 5400°-trials</td><td>Immediate: No<br>Long term: CBS, BIT-C<br>(8 weeks after the end of treatment)</td></tr><tr><td>Mizuno 2011<br>[48]<br>(multicenter,<br>double blind)</td><td>stroke- neglect<br>(R hemisphere)</td><td>18</td><td>66.0 (11.5)</td><td>12/6</td><td>67.1 (18.4)</td><td>12°-right</td><td>20</td><td>66.6 (7.7)</td><td>15/5</td><td>64.4 (20.9)</td><td>0°</td><td>20 mins/session, twice/day, 5 days/week, for 2 weeks<br>Total sessions: 20<br>Total exposure: 21600°-trials</td><td>Immediate: CBS, BIT-C, BIT-B<br>(after the end of treatment)<br>Long term: CBS, BIT-C, BIT-B<br>(discharge)</td></tr><tr><td>Rode 2015<br>[26]<br>(double blind)</td><td>stroke- neglect<br>(R hemisphere)</td><td>9</td><td>55.2 (11.9)</td><td>5/4</td><td>51 (17.4)</td><td>10°-right</td><td>9</td><td>61.7 (12.9)</td><td>5/4</td><td>52.2 (19.3)</td><td>0°</td><td>6–10 mins/session, once/week, for 4 weeks<br>Total sessions: 4<br>Total exposure: 3200°-trials</td><td>Immediate: No<br>Long term: total BIT<br>(5 months after the end of treatment)</td></tr><tr><td>Mancuso<br>2016[49]<br>(multicenter)</td><td>stroke- neglect<br>(R hemisphere)</td><td>23</td><td>67.48 (9.40)</td><td>17/6</td><td>66.3 (43.52)</td><td>10°-right</td><td>17</td><td>62.88<br>(12.55)</td><td>11/6</td><td>51.24<br>(26.67)</td><td>0°</td><td>20 mins/session, twice/day, 5 days/week, for two weeks<br>Total sessions: 20<br>Total exposure: 18000°-trials</td><td>Immediate: CBS, BIT-C<br>(after the end of treatment)<br>Long term: CBS<br>(4 weeks after the end of treatment)</td></tr><tr><td>Ten Brink<br>2017[50]<br>(double blind)</td><td>stroke- neglect<br>(R, L hemisphere,<br>bilateral)</td><td>34</td><td>59.31 (14.45)</td><td>25/9</td><td>41.5 (39.00)</td><td>10°-right</td><td>35</td><td>61.48<br>(13.37)</td><td>24/11</td><td>37 (37)</td><td>0°</td><td>Once/working day, for 2 weeks<br>Total sessions: 10<br>Total exposure: 10000°-trials</td><td>Immediate: CBS<br>(after the end of treatment)<br>Long term: CBS<br>(4 weeks after the end of treatment)</td></tr><tr><td>Choi 2019<br>[33]</td><td>stroke- neglect<br>(R hemisphere)</td><td>10</td><td>62.90 (8.64)</td><td>6/4</td><td>30 days:1<br>30-60 days: 6<br>60-90 days: 3</td><td>15°-right + FES</td><td>10</td><td>66.00<br>(12.09)</td><td>3/7</td><td>30 days:2<br>30-60 days: 5<br>60-90 days: 3</td><td>only FES</td><td>20 mins (15° PE + FES)/day, 5 times/week, for 3 weeks<br>Total sessions: 15<br>Total exposure: 22500°-trials</td><td>Immediate: CBS<br>(after the end of treatment)<br>Long term: No</td></tr><tr><td>Vilimovsky<br>2021[27]<br>(double blind)</td><td>21 stroke-neglect<br>2 TBI-neglect<br>(R/L hemisphere)</td><td>12</td><td>47.5-55</td><td>5/7</td><td>38.5-74</td><td>11.4°-right</td><td>11</td><td>53–61</td><td>5/6</td><td>35–79</td><td>0°</td><td>15–20 minutes/once,<br>10 sessions for 2 weeks<br>Total sessions: 10<br>Total exposure: 6840°-trials</td><td>Immediate: CBS<br>(after the end of treatment)<br>Long term: CBS<br>(4 weeks after the end of treatment)</td></tr><tr><td>Choi 2022<br>[34]<br>(multicenter)</td><td>stroke- neglect<br>(R hemisphere)</td><td>12</td><td>62.9 (8.64)</td><td>7/5</td><td>267.6 (79.2)</td><td>10°-right + NV</td><td>12</td><td>67.70 (9.76)</td><td>4/8</td><td>291 (94.8)</td><td>only NV</td><td>20 mins (10° PE + NV)/ day, 5 times/week, for 4 weeks<br>Total sessions: 20<br>Total exposure: 20000°-trials</td><td>Immediate: CBS<br>(after the end of treatment)<br>Long term: No</td></tr><tr><td>Umeonwuka<br>2023[28]<br>(double blind)</td><td>stroke- neglect<br>(R hemisphere)</td><td>37</td><td>51.78 (13.06)</td><td>17/20</td><td>26-56</td><td>11.4°-right</td><td>37</td><td>46.51<br>(13.56)</td><td>20/17</td><td>28–47</td><td>0°</td><td>30 mins/session, once/day, every weekday, over 16 days<br>Total sessions: 12<br>Total exposure: 12312°-trials</td><td>Immediate: CBS, BIT-C<br>(after the end of treatment)<br>Long term: No</td></tr></tbody></table>

Abbreviations = BIT, behavioral inattention test; BIT-B, behavioral BIT; BIT-C, conventional BIT; CBS, Catherine Bergego scale; FES, functional electrical stimulation; L, left; NV, neck vibration; PA, prism adaptation; PE, prism exposure; R, right; TBI, traumatic brain injury.

<footnote># Total quantity of prism exposure (number of total trials x prism shift).</footnote>
<figure><img src="image_5.png" /><figcaption>**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.</figcaption></figure>

intervention improvements (Table S3). None of the PA intervention parameters reached statistical significance either (Table S3). The scatter plot (Figure. 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 to -0.33; P = 0.020; I² = 65%, [Figs. 3a and 5a]) [27,28,33,34,48–50]. Only one study was included in the long-term CBS when the prism shift was <10°, while three studies had a prism shift of ≥10° and showed a non-significant difference (WMD = -0.34, 95% CI -1.74 to 1.07; P = 0.638; I² = 0% [Fig. 5b]) [27,47,48,50].

Based on the subgroup results for the total exposure, in short-term CBS, two studies were included in the subgroup of <11250°trials and showed non-significance (WMD = -0.50, 95% CI -2.75 to 1.75; P = 0.663; I² = 0% [Fig. 6a]) [27,50]. Five studies were included in the ≥11250°trials subgroup and showed statistical significance (WMD = -2.73, 95% CI -5.01 to -0.44; P = 0.019; I² = 72% [Fig. 6a]) [28,33,34,48,49]. After excluding the studies by Umeonwuka et al. and Choi et al. [28,34] to address heterogeneity, the effect size remained significant (WMD = -2.81, 95% CI -4.57 to -1.05; P = 0.002; I² = 0%).

For long-term CBS, there were three studies included in the <11250°trials subgroup and showed non-significance (WMD = -0.03, 95% CI -1.63 to 1.57; P = 0.968; I² = 0% [Fig. 6b]) [27,47,50]; only one study was included in the ≥11250°trials subgroup [48].

### 4. Discussion

Our main aim was to provide a comprehensive and reliable meta-analysis of RCTs investigating the effects of PA on SN. Compared with the four previous meta-analyses on a 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 (ie, <24 h) and long-term (ie, >1 month) effects of PA on CBS and BIT. Taken altogether, a significant immediate benefit was shown in CBS. The prism regime influenced the pooled effect on long-term BIT-C. 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 effect modifiers of PA efficacy that could account for variability in results. It preliminarily addressed 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 participant characteristics on PA intervention
<figure><img src="image_6.png" /><figcaption>Fig. 3. The effects of PA for main outcome-CBS. (a). Short-term effects (seven 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.</figcaption></figure>

Therefore, we hope that this study can provide preliminary
exploratory insights into the "dose-response" mechanism of PA interven-
tion and provide a reference for further research directions. The follow-
ing discussion will first address the global findings from meta-analysis
on CBS and BIT and then discuss effect-modifying 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 (I² > 50%). The study by Umeonwuka et al. [28] was the primary source of the
<figure><img src="image_7.png" /></figure>

<figure><img src="image_8.png" /><figcaption>**Fig. 4.** The effect of PA for secondary outcome-BIT. (a). Short-term effects. For BIT-C (three studies; n = 152), 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.</figcaption></figure>
<figure><img src="image_9.png" /></figure>

<figure><img src="image_10.png" /><figcaption>**Fig. 5.** The subgroup analyses for the effects of prism shift (°) on CBS. (a). Short-term subgroup analysis. All seven studies (n = 288) with ≥10° prism shift showed significant improvement between the 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.</figcaption></figure>

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, eg, a distinct 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) [28]. The study by Choi et al. [34] 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
<figure><img src="image_11.png" /></figure>

<figure><img src="image_12.png" /><figcaption>**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; Five 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.</figcaption></figure>
influencing factor for short-term efficacy. Interestingly, the results of the subgroup analysis provided some reference values (see the Physical effect modifiers of PA efficacy section).

The effect size of long-term BIT-C was affected by Turton et al.'s [47] study, possibly because of its minor prism shift (6°). After its exclusion, the effect sizes of the remaining two articles (prism shift ≥10°) showed statistical significance [25,48]. This trend suggested that the slight prism shift used in this study may have weakened the overall effect of long-term BIT-C.

Moreover, the potential heterogeneity may also arise from some other aspects, such as different SN definitions, individual heterogeneity (eg, severity of SN, brain lesion), and management and implementation of outcome measurements, as the same outcomes may be assessed using different measurement methods across studies. In addition, except for the physical parameters of PA intervention, the specific PA intervention implementation may also contribute to potential heterogeneity. For example, some RCTs employed terminal trajectory exposure (only fingertips at the table's edge) [28,33,34,48,49], while others used concurrent exposure (entire trajectory except initial phase) [25-27,47,50]. Although existing literature found no significant difference between these two exposure conditions in participants' sensorimotor performance and neuropsychological outcomes, such variations may still contribute to potential heterogeneity [51]. Moreover, some studies measured the after-effects of PA and even excluded participants who did not produce detectable after-effects [25-27,50], while other studies, unlike recommended, did not measure the after-effects at all or did not report the relevant results [28,33,34,47-49]. These differences may also increase the heterogeneity between samples.

### 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 [52].

For BIT-C, among the three included studies (all used ≥10° shifting and ≥11250°·trials), the multicenter study by Mizuno et al. [48] did not show a greater short-term improvement in the PA group compared with the control group. Participants in this study were categorized into moderate and severe SN based on BIT-B (≥55 vs <55) [48]. However, three limitations cannot be ruled out: uneven sample distribution (moderate SN, n = 22; severe SN, n = 9) may have led to potential subject selection bias; and possible ceiling effects in outcome measurement caused by inter-group heterogeneity of BIT-C baseline in severe SN (89.0 ± 32.1 in PA vs 46.4 ± 26.2 in control group) [48]. These factors may affect the detection power for inter-group effects, especially in the severe SN subgroup. Another multicenter study by Mancuso et al. [49] showed greater improvement for all outcomes in the PA group than in the control group, but the difference was not statistically significant. They attributed this to the generally severe SN among participants rather than to the treatment or assessment tool [49]. In the single-center study by Umeonwuka et al. [28], the enrolled participants also had moderate to severe SN at baseline, and a significant difference between the two groups was observed. They indicated that participants with preserved cognitive function were more likely to achieve substantial improvements after PA intervention, while other participant characteristics (eg, days post-stroke, age, and type and side of stroke) showed no significant correlation [28]. The inconsistencies in results across the studies may also be attributed to the fact that single-center studies have greater controllability in potential confounding factors (eg, sample composition, consistency of intervention implementation, and uniformity of assessment criteria). Combined with the larger sample size (n = 74) in Umeonwuka et al. [28], these factors may further improve the detection power of effects between groups.

In summary, future studies should aim to minimize inter-sample heterogeneity. Both the SN severity and cognitive ability may also be

crucial factors for PA intervention response, and therefore deserve consideration and control.

### 4.1.3. Long-term effect of PA on SN

For CBS, four studies were included, and no significant long-term effects were observed, which is consistent with the meta-analysis results of Li et al and Qiu et al [29,31]. Among the four studies, two applied PA intervention for 10 sessions over 2 weeks (with 10° shifting and 10000°·trials; 11.4° shifting and 6840°·trials, respectively), and excluded participants without after-effects or with after-effects <3 cm, and both evaluated follow-up effects at 4 weeks after the end of intervention [27,50]. No significance was observed in either study [27,50]. Another study used a prism with 6° shifting (5400°·trials), and assessed outcomes at 8 weeks after the end of treatment, and also observed non-significant improvement [47]. It remains unclear whether these results were due to the low total exposure doses of PA intervention or to intra- and inter-group heterogeneity in sample characteristics in each study (eg, different lesion sites, different SN severity, and different stages), which may have affected the power to detect differences between groups [27,47,50]. The study by Mizuno et al. [48] employed a larger total exposure (21600°·trials), reported a positive trend in the PA group on CBS, but it did not reach statistical significance. However, a significant improvement in FIM was observed from the end of the PA intervention until discharge in the moderate SN subgroup, suggesting a long-term effect of PA intervention on ADL [48].

For BIT-C, three studies were included in the analyses, and a significant improvement was observed when the prism shift was ≥10° (n = 2, studies by Nys et al and Mizuno et al) [25,48]. However, this effect was mainly driven by the study of Mizuno et al. [48], as reflected in its higher weight and significant confidence interval. Notably, Mizuno et al. [48] found a significant BIT-C improvement only in the moderate SN subgroup, but not in the severe SN subgroup. The lack of benefit in severe SN may be related to uneven sample distribution and baseline differences between groups (as discussed above) [48]. In addition, this study employed a larger total exposure (21,600°·trials), which may have contributed to the observed improvement [48]. The study by Nys et al. [25] assessed immediate effects on other outcomes (line bisection, star cancellation, etc), while BIT-C was only measured at 1-month follow-up. Although significant immediate benefits were observed in the PA group, no long-term effects were found for all outcomes [25]. This may be related to its relatively lower PA intervention doses (four sessions; 4000°·trials), which might be insufficient to produce lasting effects [25]. Similarly, one study by Rode et al. [26] applied PA intervention with 10° shifting, four sessions across 4 weeks, with small total exposure (3200°·trials), also failed to find significant long-term improvement on total BIT. Given the limited sample size and potential confounders, future studies should employ more rigorous designs with larger samples and stratified subgroup models (eg, by lesion location and severity) to better identify the PA intervention benefits and potential responders.

## 4.2. Other outcomes for the effect of PA on SN

Most of the 10 RCTs included at least two outcomes assessing the PA efficacy. In addition to 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 can detect the changes in participants' attention allocation after
PA intervention [53,54]. 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 [16,55]. virtual reality (VR) neglect tests could simulate real-life scenarios through VR technology to measure people's allocation of attention on the neglect side [56]. 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 [54,57]. Additionally, for a given outcome measure, the standardization of management and specific implementation is also critical for the comparability of studies and the reliability of conclusions [58].

### 4.3. Physical effect modifiers of PA efficacy

Two main types of parameters may be involved in the efficacy of PA interventions. First, the physical parameters and regime of prism exposure conditions affect sensorimotor after-effects and should therefore impact, in turn, the expansion of PA to therapeutic cognitive effects. Second, the individual deficit and lesion should also modify the response to 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 [9–11]. One should expect that the PA efficacy on SN also relates to some of these physical parameters [8,59]. PA intervention with sufficient prism strength and repeated, frequent training (reflecting a larger total exposure) may improve symptoms, with lasting effects beyond eye-hand coordination and visuomotor behavior [12,30,58]. For example, Gammeri R et al. [8] suggested that the visuomotor adaptation induced by low-power prisms (ie, 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 [8]. Similarly, Naito et al. [35] suggested that a larger prism shift ≥10° was a crucial factor in eliciting prism adaptation effects. 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. This may be due to the limited sample size and sample heterogeneity.

For the long-term effects of PA, the available data did not allow 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 with <11250°·trials) and showed no statistically significant effect. For BIT-C, the pooled analysis for two studies with ≥10° showed considerable improvement (identical to the finding after excluding Turton et al in Section 3.3.2.1), which points to the critical role of the larger prism shift. As mentioned above, this result was mainly driven by the study of Mizuno et al. [48]. They applied a larger total exposure (21600°·trials). For the effect of the total exposure, 3 studies for CBS, and two studies for BIT-C with <11250°·trials were included, and both led 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. Our subgroup analysis of short-term CBS suggests that the variable of total exposure warrants further exploration in future research.

The importance of cumulative dose has also been confirmed in other studies. Frassinetti et al. [60] (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. But it is unclear whether this effect lasted beyond 5 weeks because the study did not include longer-term follow-up [60]. A similar PA intervention procedure-with a 10° shift, 180 trials/session over 2 weeks was confirmed and extended in the study by Serino et al. [61] (21 participants with moderate to severe SN), but with a reduced frequency (once/day) and consequently a lower total exposure (18000°·trials), that resulted in improvements in SN symptoms that lasted up to 6 months. In addition, Shiraishi et al. [62] conducted an 8-week PA intervention (with 15° shifting, 50 mins/session, 4.2 times per week) in SN participants (chronic phase). They observed effects that lasted up to 6 weeks after prism removal. 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) [62]. Therefore, not only pointing performance, but also various activities while wearing prismatic glasses may potentiate the effects of PA on SN [62]. 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 [62]. 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 [55,63,64]. For example, in the studies of Hyun-Se Choi et al. [33,34] in 2019 and 2022, they reported, separately, that the effect of PA intervention combined with FES/NV on SN was better than that of PA or FES/NV alone. 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.

We also suggest that future studies should measure and report the error reduction curve during prism exposure as well as the after-effects of PA. The participant's ability to correct pointing movements during prism exposure in the first week of intervention could predict SN recovery [61]. Moreover, the failure to detect after-effects may indicate that the participants' sensorimotor adaptation mechanisms are impaired and merely demonstrates that no adaptation at all was obtained [11,12,58].

### 4.4. Individual effect modifiers of PA efficacy

Some studies have suggested that younger participants have better SN functional recovery after PA intervention [28,65]. Earlier PA intervention after stroke may also improve participants' response to PA [37,65]. However, according to our regression results, no significant correlations were found between 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 (eg, middle-aged vs elderly; acute and subacute vs chronic); 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 RCTs 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. [28] 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). Participants with preserved cognitive functions are more likely to learn new tasks, follow instructions, and participate in PA intervention, which relies on attention and visual-motor coordination [28,66]. Therefore, cognitive preservation may serve as a prognostic factor of SN [28]. 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. Participants with moderate SN tend to have greater potential for brain plasticity and learning abilities than those with severe SN, and therefore are more likely to respond to PA intervention [48]. The severity of SN is related to the area and volume of the brain injury [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 (supporting signal transmission across the hemisphere) may be a key condition for the PA efficacy on SN [74,75]. For example, Lunven et al. [37] found that PA may improve SN by tapping sensorimotor or prefrontal circuits more anterior to the corpus callosum. The cerebellar-parietal network forms a hierarchical interaction with the medial temporal and prefrontal regions and plays a key role in the efficacy of PA [12,76]. The former participates in compensating for terminal errors during the prism exposure and in developing sensorimotor after-effects (the foundation and core level of PA), forming a bottom-up connection with the latter to consolidate newly acquired visual-motor conversions further, ultimately achieving cognitive expansion effects (the highest level of PA plasticity) [12,76,77]. Additionally, the primary motor cortex (M1) may facilitate PA acquisition and storage through latent changes that persist after behavioral training [76]. Moreover, it serves as an anatomical-functional interface between low- and high-order PA-related mechanisms and hence merits greater attention in subsequent research [76].

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 area, as well as the structural and functional characteristics of the brain's connectivity [48,52,67]. It is also essential for future studies to consider the effect of interactions between participants' characteristics and PA intervention parameters.

## 5. Limitation

Although meta-analyses have intrinsic limitations, they provide helpful information about therapeutic efficacy [78]. The stringent RCT inclusion criteria applied in our study had some limitations. First, we only included RCTs in this field, which risks missing some high-quality articles from non-RCTs and subsequently underestimating the therapeutic potential of PA. Subsequently, the small sample size may reduce statistical power and increase the risk of both Type I (false positive) and Type II (false negative) errors. Small sample size may also amplify the influence of study-level biases (e.g. variation in intervention protocols

and methodological heterogeneity), potentially compromising the generalizability of the findings.

## 6. Conclusion

Given the current debate on PA, this meta-analysis applied stringent inclusion criteria. Although 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), the pooled effects were mainly driven by the study with a larger total exposure (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 effect modifier for efficacy, which needs to be verified in future studies.

At present, there are still knowledge gaps and a lack of consensus in terms of participants' inclusion criteria, outcome management and assessment, and PA intervention protocol and its specific implementation. These aspects still need to be investigated and then standardized through further studies, with consideration of individual heterogeneity. We agree with Chen et al. [58] that only on this basis can the efficacy of PA be more accurately evaluated.

## 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.

## Declaration of generative AI and AI-assisted technologies in the writing process

The authors declare that no AI/AI-assisted technologies were used in the writing process.

## Declarations of competing interest

None.

## 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.

## Acknowledgments

The authors wish to thank Sonia Alouche, Anne Cheylus, Alexandre Foncelle, Eric Koun and Frederic Volland for their excellent and agreeable technical assistance.

## Supplementary materials

Supplementary material associated with this article can be found in the online version at doi:10.1016/j.rehab.2025.102022.
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. doi: 10.1038/nn1574.

[2] Heilman KM, Valenstein E. Mechanisms underlying hemispatial neglect. Ann Neurol 1979;5:166–70. doi: 10.1002/ana.410050210.

[3] Rode G, Pagliari C, Huchon L, Rossetti Y, Pisella L. Semiology of neglect: an update. Ann Phys Rehabil Med 2017;60:177–85. doi: 10.1016/j.rehab.2016.03.003.

[4] 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. doi: 10.3389/fnhum.2013.00182.

[5] Di Monaco M, Schintu S, Dotta M, et al. 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. doi: 10.1016/j.apmr.2011.03.018.

[6] Barrett AM, Burkholder S. Monocular patching in subjects with right-hemisphere stroke affects perceptual-attentional bias. J Rehabil Res Dev 2006;43:337–46. doi: 10.1682/jrrd.2005.01.0015.

[7] Rossetti Y, Rode G, Pisella L, et al. Prism adaptation to a rightward optical deviation rehabilitates left hemispatial neglect. Nature 1998;395:166–9. doi: 10.1038/25988.

[8] Gammeri R, Iacono C, Ricci R, Salatino A. Unilateral spatial neglect after stroke: current insights. Neuropsychiatr Dis Treat 2020;16:131–52. doi: 10.2147/ndt.S171461.

[9] Jeannerod M, Rossetti Y. Visuomotor coordination as a dissociable visual function: experimental and clinical evidence. Baillieres Clin Neurol 1993;2:439–60.

[10] Redding GM, Wallace B. Prism adaptation in alternately exposed hands. Atten Percept Psychophys 2013;75:1168–85. doi: 10.3758/s13414-013-0467-4.

[11] Prablanc C, Panico F, Fleury L, et al. Adapting terminology: clarifying prism adaptation vocabulary, concepts, and methods. Neur Res 2020;153:8–21. doi: 10.1016/j.neures.2019.03.003.

[12] 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. doi: 10.1016/j.cortex.2019.10.003.

[13] Striemer CL, Danckert JA. Through a prism darkly: re-evaluating prisms and neglect. Trends Cogn Sci 2010;14:308–16. doi: 10.1016/j.tics.2010.04.001.

[14] Carter AR, Barrett AM. Recent advances in treatment of spatial neglect: networks and neuropsychology. Exp Rev Neurotherapeut 2023;23:587–601. doi: 10.1080/14737175.2023.2217886.

[15] Clarke S, Crottaz-Herbette S. Modulation of visual attention by prismatic adaptation. Neuropsychologia 2016;92:31–41. doi: 10.1016/j.neuropsychologia.2016.06.022.

[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. doi: 10.1016/j.cortex.2006.06.003.

[17] Jacquin-Courtois S, Rode G, Pavani F, et al. Effect of prism adaptation on left dichotic listening deficit in neglect patients: glasses to hear better? Brain 2010;133:895–908. doi: 10.1093/brain/awp327.

[18] Tilikete C, Rode G, Rossetti Y, et al. Prism adaptation to rightward optical deviation improves postural imbalance in left-hemiparetic patients. Curr Biol 2001;11:524–8. doi: 10.1016/s0960-9822(01)00151-8.

[19] Rode G, Pisella L, Marsal L, et al. Prism adaptation improves spatial dysgraphia following right brain damage. Neuropsychologia 2006;44:2487–93. doi: 10.1016/j.neuropsychologia.2006.04.002.

[20] Rossetti Y, Jacquin-Courtois S, Rode G, et al. 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. doi: 10.1111/j.0956-7976.2004.00696.x.

[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. doi: 10.1016/s0079-6123(03)42019-0.

[22] Pisella L, Rode G, Farnè A, Boisson D, Rossetti Y. Dissociation long lasting improvements of straight-ahead pointing and line bisection tasks in two hemi neglect patients. Neuropsychologia 2002;40:327–34. doi: 10.1016/s0028-3932 (01)00107-5.

[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. doi: 10.1080/02643290500202755.

[24] Azouvi P, Jacquin-Courtois S, Luauté J. Rehabilitation of unilateral neglect: evidence-based medicine. Ann Phys Rehabil Med 2017;60:191–7. doi: 10.1016/j.rehab.2016.10.006.

[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. Restor Neurol Neur 2008;26:1–12.

[26] Rode G, Lacour S, Jacquin-Courtois S, et al. Long-term sensorimotor and therapeutical effects of a mild regime of prism adaptation in spatial neglect. A double-blind RCT essay. Ann Phys Rehabil Med 2015;58:40–53. doi: 10.1016/j.rehab.2014.10.004.

[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. doi: 10.1371/journal.pone.0245425.

[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. Neuropsychol Rehabil 2023;33:1624–49. doi: 10.1080/ 09602011.2022.2131582.

[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;100:584–91. doi: 10.1097/phm.0000000000001598.

[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 fMRI studies 2021;11: doi: 10.3390/brainsci11111468.

[31] Qiu H, Wang J, Yi W, et al. Effects of prism adaptation on unilateral neglect after stroke: an updated meta-analysis of randomized controlled trials. Am J Phys Med Rehabil 2021;100:259–65. doi: 10.1097/phm.0000000000001557.

[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. doi: 10.1016/j.neuropsychologia.2023.108566.

[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 Res Persp 2019;10:265–73. doi: 10.2417/j.phrp.2019.10.5.02.

[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. Int J Environ Res Public Health 2022;19:10. doi: 10.3390/ijerph192013479.

[35] Naito Y, Koshino Y, Ota H, 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. doi: 10.2340/jrm. v57.42542.

[36] Goedert KM, Chen P, Foundas AL, Barrett AM. Frontal lesions predict response to prism adaptation treatment in spatial neglect: a randomised controlled study. Neuro-psychol Rehabil 2020;30:32–53. doi: 10.1080/09602011.2018.1448287.

[37] Lunven M, Rode G, Bourlon C, et al. Anatomical predictors of successful prism adaptation in chronic visual neglect. Cortex 2019;120:629–41. doi: 10.1016/j.cort. 2018.12.004.

[38] 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. doi: 10.1162/joc n.2007.19.2.341.

[39] Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372:n71. doi: 10.1136/bmj.n71.

[40] Bergego C, Azouvi P, Samuel C, et al. Validation d'une échelle d'évaluation fonctionnelle de l'heminegligence dans la vie quotidienne: l'échelle CB. Ann éadaptation. Med Phys 1995;38:183–9.

[41] Azouvi P. The ecological assessment of unilateral neglect. Ann Phys Rehabil Med 2017;60:186–90. doi: 10.1016/j.rehab.2015.12.005.

[42] Marques CLS, de Souza JT, Gonçalves MG, et al. Validation of the Catherine Bergego Scale in patients with unilateral spatial neglect after stroke. Dement Neuropsychol 2019;13:82–8. doi: 10.1590/1980-57642018dn13-010009.

[43] Wilson B, Cockburn J, Halligan P. Development of a behavioral test of visuospatial neglect. Arch Phys Med Rehabil 1987;68:98–102.

[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. doi: 10.1186/s13643-019-1001-0.

[45] Higgins JPT TJ, Chandler J, Cumpston M., Li T., Page MJ., Welch V.A. 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. doi: 10.1037/1082-989x.11.2.193.

[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. Neuropsychol Rehabil 2010;20:180–96. doi: 10.1080/ 09602010903040683.

[48] Mizuno K, Tsuji T, Takebayashi T, et al. Prism adaptation therapy enhances rehabilitation of stroke patients with unilateral spatial neglect: a randomized, controlled trial. Neurorehabil Neural Rep 2011;25:711–20. doi: 10.1177/1545968311407516.

[49] Mauro M, Donatella C. Efficacy of prisms in neglect treatment: a randomized single blind study. Int J Phys Med Rehabil 2016;4. doi: 10.4172/2329-9096.1000355.

[50] Ten Brink AF, Visser-Meily JMA, Schut MJ, et al. Prism adaptation in rehabilitation: No additional effects of Prism adaptation on neglect recovery in the subacute phase poststroke: a randomized controlled trial. Neurorehabil Neural Rep 2017;31:1017–28. doi: 10.1177/1545968317744277.

[51] Facchin A, Bultitude JH, Mornati G, Peverelli M, Daini R. A comparison of prism adaptation with terminal versus concurrent exposure on sensorimotor changes and spatial neglect. Neuropsychol Rehabil 2020;30:613–40. doi: 10.1080/09602011.2018.1484374.

[52] 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. doi: 10.1080/09602011.2016.1182032.

[53] Albert ML. A simple test of visual neglect. Neurology 1973;23:658–64. doi: 10.1212/ wnl.23.6.658.

[54] Azouvi P, Samuel C, Louis-Dreyfus A, et al. Sensitivity of clinical and behavioural tests of spatial neglect after right hemisphere stroke. J Neurol Neurosurg Psychiatry 2002;73:160–6. doi: 10.1136/jnnp.73.2.160.

[55] O'Shea J, Revol P, Cousijn H, et al. Induced sensorimotor cortex plasticity remediates chronic treatment-resistant visual neglect. Elife 2017;6. doi: 10.7554/eLife.26602.

[56] Painter DR, Norwood MF, Marsh CH, et al. Virtual reality gameplay classification illustrates the multidimensionality of visuospatial neglect. Brain Commun 2024;6: fcae145. doi: 10.1093/braincomms/fcae145.

[57] 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;40:161–72. doi: 10.1080/13803395.2017.1324562.

[58] Chen P, Hreha K, MacPhee C, Salter A, Eskes GA. Does prism adaptation treatment reduce spatial neglect and improve function? Front Rehabil Sci 2025;6:1539887. doi: 10.3389/fresc.2025.1539887.
[59] Jacquin-Courtois S., Rode G Fau - Pavani F., Pavani F. Fau-O'Shea J., et al. Effect of prism adaptation on left dichotic listening deficit in neglect patients: glasses to hear better? 2010.

[60] Frassinetti F, Angeli V, Meneghello F, Avanzi S, Lădavas E. Long-lasting amelioration of visuospatial neglect by prism adaptation. Brain 2002;125:608-23. doi: 10.1093/brain/awf056.

[61] Serino A, Bonifazi S, Pierfederici L, Lădavas E. Neglect treatment by prism adaptation: what recovers and for how long. Neuropsychol Rehabil 2007;17:657-87. doi: 10.1080/09602010601052006.

[62] 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.

[63] Saevarsson S, Halsband U, Kristjansson A. Designing rehabilitation programs for neglect: could 2 be >1+1? Appl Neuropsychol 2011;18:95-106. doi: 10.1080/09084282.2010.547774.

[64] 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. doi: 10.1136/jnnp.73.4.412.

[65] Chen P, Hreha K, Gonzalez-Snyder C, et al. Impacts of Prism adaptation treatment on spatial neglect and rehabilitation outcome: dosage matters. Neurorehabil Neural Rep 2022;36:500-13. doi: 10.1177/15459683221107891.

[66] Ward NS, Brown MM, Thompson AJ, Frackowiak RS. Neural correlates of motor recovery after stroke: a longitudinal fMRI study. Brain 2003;126:2476-96. doi: 10.1093/brain/awg245.

[67] Durfee AZ, Hillis AE. Unilateral spatial neglect recovery poststroke. Stroke 2023;54:10-9. doi: 10.1161/strokeaha.122.041710.

[68] Bartolomeo P. From competition to cooperation: visual neglect across the hemispheres. Rev Neurol 2021;177:1104-11. doi: 10.1016/j.neurol.2021.07.015.

[69] Baldassarre A, Ramsey L, Hacker CL, et al. Large-scale changes in network interactions as a physiological signature of spatial neglect. Brain 2014;137:3267-83. doi: 10.1093/brain/awu297.

[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;53:930-8. doi: 10.1161/strokeaha.121.035733.

[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. doi: 10.1016/j.neuropsychologia.2016.08.002.

[72] Crottaz-Herbette S, Fornari E, Notter MP, et al. Reshaping the brain after stroke: the effect of prismatic adaptation in patients with right brain damage. Neuropsychologia 2017;104:54-63. doi: 10.1016/j.neuropsychologia.2017.08.005.

[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;49:107-19. doi: 10.1016/j.cortex.2011.10.009.

[74] Kamakura CK, Ueno Y, Sakai Y, et al. White matter lesions and cognitive impairment may be related to recovery from unilateral spatial neglect after stroke. J Neurol Sci 2017;379:241-6.

[75] Lunven M, Toba MN, Bartolomeo P. Prism adaptation therapy in spatial neglect: the importance of connectional anatomy. Neuropsychologia 2023;188. doi: 10.1016/j.neuropsychologia.2023.108640.

[76] Panico F, Fleury L, Trojano L, Rossetti Y. Prism adaptation in M1. J Cogn Neurosci 2021;33:563-73. doi: 10.1162/jocn_a_01668.

[77] Schintu S, Gotts SJ, Freedberg M, Shomstein S, Wassermann EM. Effective connectivity underlying neural and behavioral components of prism adaptation. Front Psychol 2022;13:915260. doi: 10.3389/fpsyg.2022.915260.

[78] Lee YH. An overview of meta-analysis for clinicians. Korean J Intern Med 2018;33:277-83. doi: 10.3904/kjim.2016.195.