People with spatial neglect have difficulty attending to one side of space, which can affect their ability to carry out many everyday tasks and reduce independence. We examined the evidence for any type of nonpharmacological intervention.1
We searched for randomized controlled trials of any nonpharmacological intervention versus any control specifically aimed at spatial neglect, searching 6 databases including MEDLINE, Embase, CINAHL, and international trials registers in October 2020. Review authors independently assessed risk of bias of included trials and extracted data and assessed the quality of evidence for each outcome using the Grading of Recommendations, Assessment, Development and Evaluations approach. We categorized interventions into 8 broad types through iterative discussion. Our primary outcome was longer term functional ability in activities of daily living (ADL), that is, ≥1 month after the end of intervention.
We included 65 small randomized controlled trials (1951 participants); 43 provided data for meta-analyses. All included people with stroke, one included 3 participants with nonstroke brain injury, and only 7 included participants with left brain damage. All evidence is very low quality, with very low certainty. There were only 2 low risk of bias trials and no adequately powered definitive trials. None reported patient involvement in design or reporting. Outcome measurement focused on cognitive tests and short-term effects; 58 of 65 trials measured ADL using different methods and 16 measured it longer term. Other meaningful outcomes were rarely reported.
Four intervention types measured our primary outcome:
Visual interventions (training eye movements or scanning): 17 trials (n=398). No evidence of effect on ADL from visual interventions (2 trials, 55 participants; standardized mean difference, −0.04 [95% CI, −0.57 to 0.49]).
Noninvasive brain stimulation: 17 trials (n=467). No evidence of effect on ADL from noninvasive brain stimulation (3 trials, 92 participants; standardized mean difference, 0.35 [95% CI, −0.08 to 0.77]).
Body awareness (increasing awareness of affected side): 12 trials (n=447). Very low certainty evidence suggesting possible benefit on ADL from body awareness interventions (5 trials, 125 participants; standardized mean difference, 0.61 [95% CI, 0.24–0.97]).
Prism adaptation training: 8 trials (n=257). No evidence of effect on ADL from prism adaptation (2 trials, 39 participants; standardized mean difference, −0.29 [95% CI, −0.93 to 0.35]).
Four intervention types did not provide data on longer term ADL: electrical stimulation, 8 trials (n=270); mental function (increasing mental processing skills), 7 trials (n=170); movement (of the arm/body), 6 trials (n=220); and acupuncture, 2 trials (n=104).
Despite 65 trials (1951 participants), evidence of benefit/risk of nonpharmacological intervention to improve longer term functional ability remains very uncertain due to study quality. No rehabilitation approach can be supported or refuted over any other based on current evidence.
Implications for Clinical Practice and Future Research
No strategy for neglect rehabilitation has been researched through fully powered randomized controlled trials. One way to improve the quality of research is by involving patients in trial design and management. Clinicians should continue to follow national clinical guidelines and are strongly encouraged to participate in trials.
This article is based on a Cochrane Review published in The Cochrane Library 2021, Issue 7, doi: 10.1002/14651858.CD003586.pub4/full (see www.thecochranelibrary.com for information). Cochrane Reviews are regularly updated as new evidence emerges and in response to feedback, and The Cochrane Library should be consulted for the most recent version of the review. This review was supported by the Cochrane Stroke Review Group.
Sources of Funding
National Institute for Health Research (NIHR) Development and Skills Enhancement Award, United Kingdom: funded Verity Longley; The Stroke Association, United Kingdom: part-funded Audrey Bowen and Christine Hazelton; NIHR NETSCC Incentive Award, United Kingdom: awarded to Audrey Bowen for the update.