Does prism adaptation treatment reduce spatial neglect and improve function?

Peii Chen ^1,2* Kimberly Hreha ³ Catrina MacPhee ⁴ Amber Salter ⁵ Gail A Eskes ⁴

• ¹ Kessler Foundation, West Orange, New Jersey, United States
• ² Department of Physical Medicine Rehabilitation, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States
• ³ School of Medicine, Duke University, Durham, North Carolina, United States
• ⁴ Dalhousie University, Halifax, Nova Scotia, Canada
• ⁵ University of Texas Southwestern Medical Center, Dallas, Texas, United States

The potential of using prism adaptation for treating spatial neglect (SN) was questioned when recent meta-analyses found inconsistent evidence. However, analyses of clinical datasets support the use of prism adaptation treatment (PAT) in reducing SN and improving function. The main objective of this review is to evaluate the current state of the evidence of PAT therapeutic effects, identify knowledge gaps, and make suggestions to guide further research and to support clinical decision making. We used the framework of the NIH Stage Model for Behavioral Intervention Development that provides guidance on best practices for developing effective behavioral interventions that can be implemented in real world settings. This Model emphasizes the interplay between mechanisms underlying therapeutic effects (‘who’ should receive the treatment and ‘how’ best does it work?) and considerations of adaptability and feasibility in real-world settings. The present critical review led to the following conclusion: Use of the NIH Stage Model reveals the heterogeneity of PAT studies and challenges in advancing PAT as an effective intervention. Key mechanisms such as prism strength, treatment intensity, arm visibility and activities during treatment, and evaluation methods lack consensus. Therefore, it is essential that clinical research teams continue to collect evidence to determine critical mechanisms and the optimal protocol. Further research identifying the optimal PAT protocol is needed before another meta-analysis on PAT’s clinical efficacy should be conducted again.