Prism Adaptation Treatment Improves Inpatient Rehabilitation Outcome in Individuals With Spatial Neglect: A Retrospective Matched Control Study

Prism adaptation treatment improves spatial neglect after severe traumatic brain injury: A case series

BACKROUND

Spatial neglect (SN) after traumatic brain injury (TBI) is common, hindering rehabilitation progress and functional outcomes. Most research has focused on SN treatment after stroke with few published instances of post-TBI SN treated using prism adaptation treatment (PAT) in inpatient rehabilitation.

OBJECTIVE

This case series characterizes the dose, after-effect, and treatment response of PAT in patients with SN after severe TBI.

METHODS

Six patients exhibiting severe (n = 2), moderate (n = 2), or mild (n = 2) SN after severe TBI received 5 to 10 PAT sessions during their inpatient rehabilitation stay. Functional improvement in SN was measured by the Catherine Bergego Scale (CBS).

RESULTS

Patients presented with a mean initial CBS score of 16.8 (range: 8.8-24.3). Prism after-effect was present after PAT. Following 5-10 sessions, the mean CBS score improved by 11.6 points to 5.2 (range: 7.8-21.8); the change in initial versus final CBS scores was significant (P = 0.031).

CONCLUSION

This study is the first to demonstrate prism after-effect and functional SN improvement in individual patients with TBI. Patients showed a clinically meaningful improvement in mild, moderate, and severe SN following 5 to 10 PAT sessions. Additional studies are needed to assess tolerability, benefit, and optimal PAT dose for SN after TBI.

Prism Adaptation Treatment Predicts Improved Rehabilitation Responses in Stroke Patients with Spatial Neglect

Spatial neglect (SN) impedes functional recovery after stroke, leading to reduced rehabilitation gains and slowed recovery. The objective of the present study was to investigate whether integrating prism adaptation treatment (PAT) into a highly intensive rehabilitation program eliminates the negative impact of spatial neglect on functional and motor recovery. We examined clinical data of the 355 consecutive first-time stroke patients admitted to a sub-acute inpatient neurorehabilitation program that integrated PAT. The 7-item Motor Functional Independence Measure, Berg Balance Scale, and Motor Activity Log were used as main outcome measures. We found that 84 patients (23.7%) had SN, as defined by a positive score on the Catherine Bergego Scale via the Kessler Foundation Neglect Assessment Process (KF-NAP^®). Although 71 patients (85%) received PAT, the presence of SN at baseline, regardless of PAT completion, was associated with lower functional independence, higher risk of falls, and a lower functional level of the affected upper limb both at admission and at discharge. The severity of SN was associated with inferior rehabilitation outcomes. Nonetheless, patients with SN who received PAT had similar rehabilitation gains compared to patients without SN. Thus, the present study suggests that integrating PAT in an intensive rehabilitation program will result in improved responses to regular therapies in patients with SN.

Impacts of Prism Adaptation Treatment on Spatial Neglect and Rehabilitation Outcome: Dosage Matters

We examined whether number of prism adaptation treatment (PAT) sessions in regular clinical practice would predict spatial neglect (SN) improvement and rehabilitation outcomes. We reviewed clinical records from 16 U.S. rehabilitation hospitals where neurological patients were assessed for SN using the Catherine Bergego Scale (CBS) and if SN was detected, and may have received PAT. Multiple linear regression was used to predict CBS Change (indicating SN improvement) in 520 patients who received PAT while considering age, sex, diagnosis, time post diagnosis, CBS at baseline, neglected side of space, and length of stay. Another set of regression models including the same variables and adding Function Independent Measure (FIM®) at admission was used to predict FIM Gains (indicating rehabilitation outcomes) in 1720 patients receiving PAT or not. We found that greater number of PAT sessions predicted greater CBS Change, especially in patients with moderate-to-severe neglect. Number of PAT sessions also positively correlated with Total FIM, Motor FIM, and Cognitive FIM Gains regardless of SN severity classification at baseline. Furthermore, number of PAT sessions predicted CBS Change and FIM Gains among patients completing ≤8 PAT sessions but not among patients with ≥8 sessions, who however, showed greater CBS Change with increased PAT frequency (i.e., fewer days between two consecutive sessions). Receiving more once-daily PAT sessions predicted greater improvement in SN and rehabilitation outcomes. Receiving PAT at a higher frequency for 8 or more sessions predicted better SN improvement. Thus, dosage matters. The study provides practice-based evidence that PAT is appropriate for inpatient rehabilitation.

Visuomotor misalignment induced through immersive virtual reality to improve spatial neglect: a case-series study

One evidence-based treatment for spatial neglect is prism adaptation (PA) treatment. PA after-effects, i.e., the implicit shifts in the arm reaching position toward the neglected side of space after prism removal, are considered fundamental to PA treatment effects. In the present study, the arm reaching position was shifted through a visuomotor misalignment procedure using immersive virtual reality (VR). To examine whether this procedure might have a beneficial impact on spatial neglect, we conducted a multi-baseline experiment in three individuals with chronic left-sided neglect post stroke. Improved spatial neglect was observed in all participants immediately after 5 sessions with two rounds in each. Two participants demonstrated lasting or continuous improvement two weeks later. Participants' pattern of brain lesions did not appear to clearly explain performance differences. The findings suggest that VR-induced visuomotor misalignment may improve spatial neglect immediately after a multi-session treatment course. The optimal number of sessions will be determined by future studies with a larger sample size, which may also elucidate the number of sessions sufficient for sustained improvement in most patients. Further investigations will identify the neural mechanisms underlying VR-induced visuomotor misalignment, which may or may not be identical to PA after-effects.

The influence of clinical characteristics on prism adaptation training in visuospatial neglect: A post-hoc analysis of a randomized controlled trial

Previous studies indicate that the effect of prism adaptation training (PAT) on unilateral neglect may depend on clinical characteristics. In this explorative work, we re-analyzed data from a previously conducted randomized controlled trial (N = 23) to investigate whether age, etiology, severity of motor impairments, and visual field deficits affect the efficacy of PAT. Additionally, we reviewed PAT studies that reported lesion maps and distinguished responders from non-responders. We transferred these maps into a common standard brain and added data from 12 patients from our study. We found patients suffering from subarachnoid bleeding appeared to show stronger functional recovery than those with intracranial hemorrhage or cortical infarction. Furthermore, patients with visual field deficits and those with more severe contralateral motor impairments had larger after-effect sizes but did not differ in treatment effects. In addition, patients with parietal lesions showed reduced recovery, whereas patients with lesions in the basal ganglia recovered better. We conclude that PAT (in its current form) is effective when fronto-subcortical areas are involved but it may not be the best choice when parietal regions are affected. Overall, the present work adds to the understanding on the effects of clinical characteristics on PAT.

Prism Adaptation Treatment of Spatial Neglect: Feasibility During Inpatient Rehabilitation and Identification of Patients Most Likely to Benefit

Objective

Spatial Neglect is prevalent among stroke survivors, yet few treatments have evidence supporting efficacy. This study examines the feasibility of Prism Adaptation Treatment (PAT) within an inpatient rehabilitation facility and the degree by which PAT improves symptoms of spatial neglect and functional independence among sub-acute survivors of right hemispheric stroke.

Design

In this retrospective cohort study, 37 right hemispheric stroke patients were identified as having received at least 4 PAT sessions during their inpatient stay. Spatial neglect and functional independence levels of patients in the PAT cohort were compared to a matched active control group comprised of rehabilitation patients receiving alternative therapies to address neglect admitted during the same time period.

Results

Most patients received the full recommended 10 sessions of PAT (average sessions completed = 8.6). A higher percentage of severe neglect patients receiving PAT (69%) displayed clinically significant gains on FIM (≥22 points) compared to those receiving alternative treatments (6%). Patients with mild or moderate neglect in the PAT cohort did not exhibit greater benefit than controls.

Conclusion

Provision of PAT for treatment of spatial neglect in right hemispheric stroke patients was feasible during the inpatient rehabilitation admission. Patients with severe neglect showed the most benefit from PAT.

Clinical Trial Registration

This study was registered as a retrospective observational study on Itab Clinical Trials.gov. NCT04977219.

The Implementation Process of Two Evidence-Based Protocols: A Spatial Neglect Network Initiative

Introduction

Spatial neglect, a neurocognitive disorder of lateralized spatial attention, is prevalent among stroke survivors especially in inpatient rehabilitation facilities (IRFs). The ultimate goal of the project was to improve spatial neglect care in inpatient rehabilitation and trained as many OTs as possible using both tools in their regular practices as the means to achieve our overall objective. Therefore, we conducted a project aimed at implementing two evidence-based protocols, one for assessment (KF-NAP®) and the other for treatment (KF-PAT®), and share the implementation process, which included barriers and facilitators identified during and after the process, and implementation outcomes.

Methods

Sixteen IRFs were involved. The Knowledge-To-Action Cycle was used to describe the process of knowledge inquiry (training), translating knowledge (implementation) and evaluating the use of knowledge in clinical practice (outcomes). Barriers and strategies were reported using the Consolidated Framework for Implementation Research and identified through a survey, after the study concluded.

Results

Thirty-two therapists at the participating sites were trained to some level of the KF-NAP and KF-PAT. Throughout the project and also once after it finished, different barriers were identified by researchers and clinicians, who then determined together actions to eliminate or minimize the barriers. For example, multiple sites reported: "not having time to train other staff at their hospital due to high patient volume and other responsibilities."

Discussion

The project shared our implementation process which demonstrated the importance of using implementation methods and incorporating a researcher-clinician partnership, not only for knowledge generation but also knowledge translation. Frequent communications and exchanging information with stakeholders at different levels, may be determinant to the success of each implementation phase. Further research is needed.

Neural Mechanisms of Prism Adaptation in Healthy Adults and Individuals with Spatial Neglect after Unilateral Stroke: A Review of fMRI Studies

Functional disability due to spatial neglect hinders recovery in up to 30% of stroke survivors. Prism adaptation treatment (PAT) may alleviate the disabling consequences of spatial neglect, but we do not yet know why some individuals show much better outcomes following PAT than others. The goal of this scoping review and meta-analysis was to investigate the neural mechanisms underlying prism adaptation (PA). We conducted both quantitative and qualitative analyses across fMRI studies investigating brain activity before, during, and after PA, in healthy individuals and patients with right or left brain damage (RBD or LBD) due to stroke. In healthy adults, PA was linked with activity in posterior parietal and cerebellar clusters, reduced bilateral parieto-frontal connectivity, and increased fronto-limbic and sensorimotor network connectivity. In contrast, RBD individuals with spatial neglect relied on different circuits, including an activity cluster in the intact left occipital cortex. This finding is consistent with a shift in hemispheric dominance in spatial processing to the left hemisphere. However, more studies are needed to clarify the contribution of lesion location and load on the circuits involved in PA after unilateral brain damage. Future studies are also needed to clarify the relationship of decreasing resting state functional connectivity (rsFC) to visuomotor function.