Virtual Reality Therapy for Pain
Lynn R. Webster, M.D.
Vice President, Scientific Affairs
AUGUST 15, 2018
Twenty percent of the world’s population lives with chronic pain. Opioids have long been the fallback option for moderate-to-severe chronic pain treatment, because more effective and affordable options are not available. The growing opioid crisis has led away from the use of opioids to treat chronic pain and toward an urgent need for safer and more effective pain treatments.
One such treatment may be Virtual Reality (VR). Over the past 20 years, an expansive amount of research has examined ways to use VR for recreation, in aviation, and for employee training. Advances in technology have caused VR to migrate from entertainment to medical applications with considerable research into its potential effect on pain.
What Virtual Reality Is
Because of the rapid growth of VR research, there is some confusion about what VR is. A simple definition is that VR is a computer-generated world that simulates real-life experience through senses and perception. A person who uses VR equipment is able to “look around” the artificial world, move around in it, and interact with virtual features or even thoughts. This effect is commonly created by a VR headset consisting of a head-mounted display with a small screen that is positioned in front of the eyes.
The immersive, realistic environment of VR can be whimsical and entertaining, as with VR video games. In the 1990s, when VR became commercially available for the general public, it was perceived by the public as a way to live out virtual fantasies and was mostly used for entertainment. That aspect of VR made its way into a well-crafted, very funny episode of the television situation comedy, “Mad About You,” featuring Paul Reiser and Helen Hunt as fictional New York City-based newlyweds.
But VR also has its serious side. Great technology advances have shown that VR may reduce activation in certain areas of the brain. This is illustrated in fMRI studies, such as one involving burn pain during medical procedures, a source of some of the worst pain in medical settings. VR has the ability to help the brain change and adapt to computer-generated experiences that would be painful or otherwise difficult in ordinary physical reality. This is why VR might have therapeutic value.
Virtual Reality and Acute Pain
VR has been studied mostly for treatment of acute pain, primarily in the form of Distraction Therapy (DT). Simply described, the concept says:
- Pain requires attention
- People have limited capacity for paying attention
- A person immersed in a pleasurable VR world has less attention left over for processing pain signals in the body
It is not uncommon for studies of acute pain to report pain reduction of up to 50%, but the effect is short-lived. Most studies offer little evidence that DT can provide the lasting analgesic benefit that is needed for chronic pain.
Virtual Reality Neuropsychological Therapy and Chronic Pain
Lasting pain relief may be possible by combining VR technology with cognitive behavioral therapy (CBT), a well-studied and recommended psychosocial intervention for pain. A new concept introduced by a Silicon Valley company, CongnifSense, attempts to integrate VR with CBT. The company calls this proprietary approach Virtual Reality Neuropsychological Therapy (VRNT). VRNT is aimed not at distraction but at helping the brain unlearn chronic pain.
VRNT provides patients with “experiential learning” or “experiential training” in the form of simulation. Experts in the field report that, in contrast to didactic learning, experiential learning is far more effective. An example of didactic learning would be reading about how to dance, whereas experiential learning would be getting out on the floor and trying out the steps. The experiential learning process, which is implicit or subconscious, is 7 times as effective as explicit learning. Going beyond standard VR, VRNT is a software system or platform that will allow updating to improve the treatment modules as knowledge is acquired.
To understand how VRNT may work for chronic pain, we need to review at a high level what chronic pain is and how it differs from acute pain. Acute pain comes on suddenly and is expected to resolve when healing is complete. Acute pain episodes can recur. But chronic pain is not a series of acute pain episodes. Chronic pain persists past the expected healing period and becomes a disease by working changes in the central nervous system. A growing body of evidence shows that chronic pain is mediated in different parts of the brain than acute pain.
For example, some chronic back pain is mediated, in part, through the frontostriatal system, which also mediates emotional and motivational circuits, fear, avoidance, catastrophizing, depression, and even addiction and the placebo effect. On the other hand, phantom limb pain seems to be largely mediated through the spinothalamic system, leading to a maladapted centralized body image that may involve primary nociception, hypersensitivity, and allodynia.
In most cases when chronic pain develops, maladaptive changes occur in the associated brain regions or in the central processing of nociception. When this happens, behaviors also change in an attempt to adapt to the new normal of chronic pain. The result is dysfunctional and non-productive behavior including avoidance, fear, anxiety, and anger. These types of behaviors can inhibit the person’s ability to adjust to particular situations.
Although they are often used to reduce anxiety, maladaptive behaviors may prevent someone from adapting or coping well with the demands and stresses of life. Maladaptive behaviors are targeted for modification in CBT.
Powering Virtual Reality Neuropsychological Therapy with Cognitive Behavioral Therapy
VRNT combines the power and immersion experience of VR with principles of CBT. The self-distancing, self-efficacy, and fear extinction tools of CBT help patients manage thoughts, feelings, and perceptions. At a fundamental level, CBT drives the potency of VRNT.
CBT draws on the belief that numerous maladaptive learning cycles contribute to the chronification of pain. Often, these cycles occur in the subconscious as implicit learning.
One well-known cycle is the Fear-Avoidance Learning Cycle (Figure 1). This model shows the propensity for the patient to develop chronic pain as a function of the patient’s propensity to fear pain. It works like this: When an injury causes pain, if there is a lot of fear (red cycle), the patient tends to catastrophize, leading to hyper-vigilance, avoidance, disuse, depression, and disability, all of which worsen the pain experience. In contrast, if there is little fear (green cycle), the patient tends to confront the fear of pain and recover more quickly.
Figure 1: Fear-Avoidance Learning Cycle
Source: J.W.S. Vlayen, S.J. Linton et al., 2012
To provide a lasting reduction of chronic pain, we have to disrupt this negative (red) cycle and lead the patient toward a more positive (green) cycle as illustrated in Figure 2. This is exactly what VRNT proposes to do. The goal behind VRNT is to interrupt the maladaptive learning process by providing an experiential approach. It leverages modes of action from CBT focused on self-efficacy, fear-extinction, and self-distancing.
Figure 2: Virtual Reality Neuropsychological Therapy’s Potential to Interrupt and Replace Maladaptive Learning Cycles
Source: J.W.S. Vlayen, S.J. Linton et al., 2012
A Conventional Virtual Reality Experience
Cool! is one of the current VR videos used for pain treatment. Figure 3 is a screenshot of the video that a patient would see. The video redirects the mind’s attention from the experience of pain, but when the distraction ends the pain returns quickly.
Figure 3. Conventional Virtual Reality with Cool!
A Virtual Reality Neuropsychological Therapy Experience
The VRNT system contains two steps. In the first, the patient first uses tools of the VR system to draw a representation of the pain as a fully active three-dimensional avatar with visual and audio controls. The second step allows the patient to manipulate the pain using one of several healing modes during which the patient is guided through various approaches for reframing his or her experience of, and relationship with, the pain. During this period, the brain is learning.
Figure 4 shows what a patient would see through a VRNT device. This image combines the avatar a patient would see with the patient actually using the device.
Figure 4. Virtual Reality Neuropsychological Therapy Experience
A still image from a VR demo shown at the International Conference on Opioids at Harvard Medical School on June 11, 2018
Repeated applications of VRNT are expected to improve chronic pain for extended intervals in contrast to the temporary benefits most VR therapies currently provide. It is plausible that a home unit, with programming by a psychologist or other trained medical expert, will have the capacity to offer pain relief comparable to today’s pharmacotherapies.
VRNT is only one of dozens of VR technologies being studied to treat chronic pain. With further research, VR therapies may help reduce dependence on opioid prescriptions and contribute to solving the opioid crisis. Only time and additional research will tell.