Remapping Body Representation Using Virtual Reality in Chronic Neuropathic Pain: Systematic Review.

Background: Chronic neuropathic pain (CNP) is a common consequence of neurological conditions such as spinal cord injury (SCI), complex regional pain syndrome (CRPS), and phantom limb pain (PLP). These conditions are often associated with distorted body representation (BR) and altered sensory processing. Virtual reality (VR) offers immersive, multisensory experiences that can modulate attention, recalibrate BR, and potentially alleviate pain.

Objective: This systematic review aims to synthesize evidence on the use of VR-based interventions for managing CNP in patients with neurological conditions. It explores how VR can influence pain perception through body remapping. Furthermore, this review seeks to identify gaps in current research, offering recommendations for future research directions and clinical applications.

Methods: We performed a comprehensive literature search in PubMed, Web of Science, and Scopus for studies published between January 2014 and December 2024. We included original studies that examined VR interventions in patients with neurological conditions and CNP, assessing pain reduction, improvements in BR, or functional recovery. We excluded reviews, animal model studies, migraine-related studies, and those lacking a clear VR intervention or relevant clinical outcome data. The quality of the included studies was evaluated using the revised Cochrane Risk of Bias Tool for Randomized Trials and the Cochrane Risk of Bias in Nonrandomized Studies of Interventions tool. Given the heterogeneity in study design, VR protocols, and outcome measures, a qualitative synthesis approach was adopted based on the synthesis without meta-analysis framework.

Results: Ten studies-both randomized controlled trials and uncontrolled experimental designs-met the inclusion criteria. These studies focused on the application of VR in SCI (n=4, 40%), CRPS (n=4, 40%), and PLP (n=2, 20%), using interventions such as immersive VR, mirror visual feedback, visuotactile stimulation, and virtual body illusions. Sample sizes ranged from 9 to 70 participants, with varying degrees of neurological impairment. Most of the studies (n=7, 70%) reported substantial reductions in pain intensity and improvements in embodiment and perceived body ownership. In SCI, combining VR with neuromodulation techniques enhanced analgesic effects. In CRPS, modifying the visual appearance of the affected limb improved body image and decreased pain perception. In PLP, kinesthetic and visual feedback delivered through VR environments significantly reduced PLP and improved movement representation.

Conclusions: Overall, the quality of evidence ranged from moderate to low, mainly due to small sample sizes, protocol heterogeneity, and risk of bias. Evidence regarding adherence to VR therapy was particularly limited. Nonetheless, VR shows strong potential as a noninvasive, patient-tailored therapeutic tool for CNP. VR could provide innovative and engaging strategies to reduce pain and enhance functional outcomes in populations with neurological conditions. Future research should focus on developing standardized protocols and conducting large-scale, high-quality trials to validate VR's long-term efficacy and integration into routine clinical practice.

Trial Registration: PROSPERO CRD42024606150; https://www.crd.york.ac.uk/PROSPERO/view/CRD42024606150.