“I Dreamed of My Hands and Arms Moving Again”: A Case Series Investigating the Effect of Immersive Virtual Reality on Phantom Limb Pain Alleviation

Abstract

Phantom limb pain (PLP) is a type of chronic pain that follows limb amputation, brachial plexus avulsion injury, or spinal cord injury. Treating PLP is a well-known challenge. Currently, virtual reality (VR) interventions are attracting increasing attention because they show promising analgesic effects. However, most previous studies of VR interventions were conducted with a limited number of patients in a single trial. Few studies explored questions such as how multiple VR sessions might affect pain over time, or if a patient's ability to move their phantom limb may affect their PLP. Here we recruited five PLP patients to practice two motor tasks for multiple VR sessions over 6 weeks. In VR, patients "inhabit" a virtual body or avatar, and the movements of their intact limbs are mirrored in the avatar, providing them with the illusion that their limbs respond as if they were both intact and functional. We found that repetitive exposure to our VR intervention led to reduced pain and improvements in anxiety, depression, and a sense of embodiment of the virtual body. Importantly, we also found that their ability to move their phantom limbs improved as quantified by shortened motor imagery time with the impaired limb. Although the limited sample size prevents us from performing a correlational analysis, our findings suggest that providing PLP patients with sensorimotor experience for the impaired limb in VR appears to offer long-term benefits for patients and that these benefits may be related to changes in their control of the phantom limbs' movement.

Could Avatar Therapy Enhance Mental Health in Chronic Patients? A Systematic Review

“…For points 1 (year of publication), 2 (country of the study) and 3 (type of study), the following results were extracted (Table 1): the 18 selected studies were published between 2010 and 2020 (38.9%). Many of them (n = 7) were published in 2020 [3,[42][43][44][45][46][47]). The majority of the studies were conducted in the United States (n = 6) [6,25,[43][44][45]48], Australia (n = 4) [3,[49][50][51] and the United Kingdom (n = 4) [42,46,52,53].…”

“…The majority of the studies were conducted in the United States (n = 6) [6,25,[43][44][45]48], Australia (n = 4) [3,[49][50][51] and the United Kingdom (n = 4) [42,46,52,53]. The remaining papers were published in Canada [54], China [47], Ireland [55] and Italy [56]. [6] 2015 USA RCT 1 Cho et al [43] 2020 USA RCT Clarke et al [55] 2019 Ireland Review Dang et al [44] 2020 USA Feasibility study du Sert et al [54] 2018 Canada RCT Falconer et al [52] 2017 England Feasibility study Leff et al [53] 2013 England RCT Pinto et al [48] 2013 USA Pilot testing Robinson-Whelen et al [45] 2020 USA RCT Rus-Calafell et al [46] 2020 England RCT Stewart et al [25] 2010 USA Narrative review Thomas et al [49] 2019 Australia Narrative review Tong et al [47] 2020 China Case series Tongpeth et al [50] 2018 Australia Feasibility pilot testing Triberti et al [56] 2019 Italy Pilot testing Wonggom et al [51] 2019 Australia Review Wonggom et al [3] 2020 Australia RCT 1 RCT: randomized controlled trial.…”

“…Other types of studies used included feasibility studies (n = 2) [44,52], narrative reviews (n = 2) [25,49] and pilot testing (n = 2) [48,56], each corresponding to 11.1%. The least common were feasibility pilot tests (n = 1) [50] and case series (n = 1) [47], each accounting for 5.6% of the total (Table 1).…”

“…In 16.7% of the papers (n = 3) [45,49,52] the viability and acceptability of the use of an avatar was studied. In the remaining studies, the adherence of patients to, and the acceptability of, the intervention were evaluated (n = 1) [44]; the benefits of the intervention were explained (n = 1) [25]; the long-term effects of the interventions based on virtual reality were examined (n = 1) [47]; the opinions of consumers regarding the avatar-based application were studied (n = 1) [43]; the effect of the feeling of presence afforded by having a voice connected to an avatar with regard to the reduction of anxiety was explored (n = 1) [46]; a computerized system that allowed patients to speak to the avatar was developed (n = 1) [53]; the relationship between the personalized avatar and the symptoms of anxiety and depression was explored (n = 1) [56].…”

“…The number of participants ranged from 5, in the paper with the lowest number of subjects [47], to 1535, in a review that compiled information from several studies [55]. In total, 44.4% of the papers (n = 8) [44,45,48,50,[52][53][54]56] included between 10 and 30 participants (Table 2).…”