An Open-Source Mirror Visual Feedback Module for Complex Regional Pain Syndrome: A pilot study (Preprint)

BACKGROUND Complex Regional Pain Syndrome (CRPS) is a rare and severe chronic pain condition, with effective treatment options not established for many patients. The underlying pathophysiology is still unclear, but there is a growing appreciation for the role of central mechanisms which have formed the basis for brain based therapies such as transcranial magnetic stimulation and mirror visual feedback (MVF). MVF has been deployed in the treatment of Complex Regional Pain Syndrome (CRPS) using both conventional mirrors and virtual reality (VR). OBJECTIVE To further investigate the use of both conventional mirrors and virtual reality (VR) in the treatment of chronic unilateral upper limb Complex Regional Pain Syndrome (CRPS) patients. Virtual reality has the potential advantage of more flexible and more motivating tasks, as well as the option of tracking patient improvement through the use of movement data. METHODS We used the Virtual Embodiment Lab Open Source Mirror Feedback (VELOS MVF) module in a small pilot study We created a simple environment in immersive virtual reality; designed to be used with consumer virtual reality systems, which allowed left-to-right and right-to-left mirroring in the upper and lower limbs during a simple target-hitting task. We then tested the usability and efficacy of the system in a small sample of CRPS patients at a clinic. RESULTS Nine participants were able to use the system for four or five trials each. We did not find a statistically significant effect on participants’ self-reported average pain scores. No participants quit any trial due to cybersickness. CONCLUSIONS We propose that this module could be a useful starting point for modification and testing for other researchers. Next steps include adapting this module for at-home use, or for use with participants with lower-limb pain.