Application of virtual reality technology improves the functionality of brain networks in individuals experiencing pain

Abstract

Medical procedures are inherently invasive and carry the risk of inducing pain to the mind and body. Recently, efforts have been made to alleviate the discomfort associated with invasive medical procedures through the use of virtual reality (VR) technology. VR has been demonstrated to be an effective treatment for pain associated with medical procedures, as well as for chronic pain conditions for which no effective treatment has been established. The precise mechanism by which the diversion from reality facilitated by VR contributes to the diminution of pain and anxiety has yet to be elucidated. However, the provision of positive images through VR-based visual stimulation may enhance the functionality of brain networks. The salience network is diminished, while the default mode network is enhanced. Additionally, the medial prefrontal cortex may establish a stronger connection with the default mode network, which could result in a reduction of pain and anxiety. Further research into the potential of VR technology to alleviate pain could lead to a reduction in the number of individuals who overdose on painkillers and contribute to positive change in the medical field.

Key Words: Virtual reality; Pain; Anxiety; Salience network; Default mode network

Core Tip: Recently, efforts have been made to reduce the discomfort associated with invasive medical procedures through the use of virtual reality (VR) technology. Furthermore, VR has been demonstrated to be an effective treatment for chronic pain, for which no effective treatment has been established. Visual input of positive images may effectively alter functional brain networks. Pain and anxiety may be reduced by decreasing activity in the salience network and by allowing the medial prefrontal cortex to establish strong connections with the default mode network. VR technology can change brain networks and reduce pain and anxiety.

TO THE EDITOR

Virtual reality in medicine

Invasive medical procedures induce pain and anxiety. It would be beneficial for patients if they could reduce the pain and anxiety associated with medical procedures without causing physical side effects. Virtual reality (VR) technology offers a potential solution to this seemingly intractable problem. I found the paper by Zhang et al[1], titled "The effects of combining static cartoons and dynamic virtual environments on preoperative anxiety in preschool children undergoing surgery", to be particularly intriguing. The objective of their study was to simulate a warm and friendly atmosphere based on children's natural needs and interests through the use of static cartoons and a dynamic virtual environment, effectively distracting children during preoperative preparation. Their findings indicated that the integration of static cartoons and a dynamic virtual environment was efficacious in reducing anxiety in preschool children undergoing surgery and stabilizing vital signs during anesthesia induction, comparable to midazolam[1]. A meta-analysis also indicated that VR is an effective method for reducing preoperative anxiety in children[2]. A recent study demonstrated that the utilization of VR in the emergency department resulted in a reduction in pain and anxiety during laceration closure, thereby suggesting its efficacy in the management of acute trauma[3]. Furthermore, VR has been demonstrated to be an effective intervention for reducing pain and anxiety associated with tooth extraction, a procedure that induces noxious stimuli[4]. We are also studying whether application of VR technology can reduce patient pain during invasive dental procedures, as placebo and nocebo effects are likely to occur during tooth extraction[5]. However, Cochrane reviews found low-certainty and very low-certainty evidence that VR is effective in reducing the intensity of acute pain in children[6]. Therefore, future well-designed, large, high-quality trials will examine the effects of VR on acute pain.

The application of VR technology is expected to be effective not only for acute pain, but also for chronic pain of unknown cause. Chronic back pain is a prevalent condition among adults, with the severity of pain and the degree of disability being correlated with a reduction in quality of life. In a program designed to reduce chronic pain, VR-assisted rehabilitation has been demonstrated to be an effective intervention for improving pain[7]. A study of healthy subjects demonstrated that VR-assisted exercise resulted in a reduction in sympathetic tone and pain perception[8]. In this manner, VR is efficacious in avoiding pain and anxiety that are commonly associated with invasive phenomena on the body.

Virtual reality and brain networks

The mechanisms by which VR reduces pain and anxiety remain unclear. Pain is a complex phenomenon that cannot be adequately explained by sensory information received by the brain as painful stimuli. In 2020, the definition of pain was revised to include the following: "An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage"[9]. Pain is a complex phenomenon that involves various brain functions, including somatic sensation and emotion, and is caused by changes in the brain function. The formation of brain functions is contingent upon functional connectivity between disparate neural regions, which are collectively referred to as a large-scale brain network. The functional brain network consists of at least seven major networks: Sensorimotor system, visual system, limbic system, dorsal attention network, central executive network (CEN), default mode network (DMN), and salience network (SN). In patients with chronic pain, the use of VR has been shown to result in enhanced pain relief. This is accompanied by a strengthening of the connections between the visual cortex and the CEN including the medial prefrontal cortex, while the connections between the medial prefrontal cortex and the anterior cingulate cortex, a component of the SN, are reduced[10]. Furthermore, VR may enhance the DMN and the connectivity between DMN and medial prefrontal cortex, resulting in pain relief[11]. It is possible that VR may stimulate the visual cortex, resulting in decreased connectivity between the SN and frontal regions and increased connectivity between the DMN and frontal regions.

Conclusions and future work

The use of VR goggles has been demonstrated to relieve pain and anxiety in patients undergoing medical procedures. The use of such technology to distract patients may result in a reduction in painkillers required. It has been demonstrated that positive visual stimuli can effectively improve the brain network connectivity. However, the changes in brain networks that occur when VR prevents or improves pain or anxiety have not been fully elucidated. By elucidating the mechanism by which VR-induced changes in brain networks contribute to the prevention and improvement of pain, VR technology could be used more effectively to alleviate pain.