Pain, in its very essence, is a universal experience, yet unique to each individual. It has been defined as ‘an unpleasant sensory and emotional experience associated with actual or potential tissue damage’ by the International Association for the Study of Pain (IASP) and is broadly classified as acute or chronic depending on its duration of persistence.
The Burden of Pain
Pain, both acute and chronic, afflicts nearly 116 million adults in the United States alone, more than the number of individuals affected by heart disease, diabetes, and cancer combined. A study carried out by the Institute of Medicine estimates the annual economic burden of chronic pain in adults to be a staggering 530-630 billion USD. Despite pain’s widespread prevalence and overwhelming cost to the healthcare system, the biology of pain and its most appropriate treatment options still largely elude scientists and clinicians. The standard of care for the management of acute and chronic pain involves the use of therapeutic drugs broadly classified into three categories: non-opioid analgesics, opioids, and additional adjuvant analgesic drugs.
There is no single universal treatment for pain, and some can have unwanted consequences. Opioids, in particular, while initially highly effective at treating both acute and chronic pain, come with a plethora of severely detrimental side effects such as tolerance, dependence, respiratory distress, or hypersensitivity to painful stimuli after long-term use. These side effects put patients at an increased risk of substance abuse disorders affecting nearly 2.1 million Americans annually and resulted in 47,000 opioid-related deaths in 2017. Further, this epidemic of opioid overuse created a burgeoning economic burden of 95 billion USD. Combined, these reasons strongly advocate for the swift development of new and alternative pain management therapies.
Co-Opting Technology for Treatment
Non-pharmacological treatment options are extremely appealing, and current pain treatments include regional anesthetic interventions, rehabilitative physical therapy, cognitive behavioral therapy, and complementary and alternative medicines such as acupuncture, chiropractic spinal manipulation, magnets, massage therapy, yoga, and dietary supplements. Further, the rapid rise of digital technology in healthcare and mindfulness applications means these options are also being co-opted as behavioral therapy for pain management. An area that has seen profound growth due to technological advancements and which could potentially supplement pain treatment is virtual reality (VR).
VR Distracts From Pain
In the last decade, VR has gone from the realms of science fiction to a multibillion-dollar industry. It involves immersing a user in an alternative three-dimensional environment, thereby making the user temporarily unaware of their actual surroundings and environment. Since human beings are capable of processing only a limited number of stimuli at any given time, focusing a person’s attention on alternative stimuli can make them temporarily unaware of their current surroundings and any additional sensations that they may be experiencing.
This distraction model is where the power of VR can be exploited to divert a patient’s attention from a painful event to another more immersive and pain-free experience. In fact, functional magnetic resonance imaging studies of pain and the brain have supported these claims. Healthy patients subjected to painful stimuli along with a VR intervention demonstrated lower neurological activity in the regions of the brain known to be involved in the perception of pain. This immersive quality of VR makes it strongly suited to be adopted for pain management in cooperation with traditional pharmacological and other complementary treatment options.
Advent of VR in Pain Management
The application of VR for pain management was pioneered in 1996. Hunter Hoffman and David Patterson at the Harborview Burn Center in Seattle used VR as distraction therapy while changing the dressings (associated with acute pain episodes) on patients with third degree burns. The patients reported a 10-40% reduction in pain perception, thus providing the first proof of concept for this therapeutic modality. However, bulky equipment, suboptimal computing power, and massive costs associated with creating a basic virtual environment proved to be significant barriers for this technology to be widely accepted as a treatment option. In the past decade, both the hardware and software technologies required to create a virtual environment have advanced radically with a basic VR system easily available for personal use at less than $500, making this technology extremely accessible as a supplemental means to ease pain.
Modern VR and Pain Management
Riding this wave of improved VR technology and reduced costs, several companies have entered the VR and pain management market. Within this growing sector, there is variety in the products offered and patient populations served. Several companies, such as Firsthand Technology, AppliedVR, and XRHealth, cater to a broad range of adult pain conditions, such as chronic pain, labor-induced pain, and acute pain episodes during hospitalizations.
Most of these companies create novel VR experiences that can ease patient suffering during painful episodes. They have partnered with external hardware producers to obtain VR headsets, which are then programmed with particular experiences, depending on the requirements of the patient and the healthcare provider. All of these companies work primarily with hospitals to introduce their therapeutic applications through physicians and pain management teams in an inpatient setting. As of now, none offers a direct-to-consumer product.
One of the earliest companies in this sector is the Seattle-based Firsthand Technology. They have two applications, Cool! and Glow!, that let users interact with different virtual environments wherein they can either traverse a virtual world playing paintball with otters or gather butterflies in an evening setting. These immersive environments are focused on reducing pain and stress in patients during medical procedures or with chronic conditions. Firsthand’s applications are compatible with multiple VR systems such as the Oculus, HTC Vive, or the Windows mixed reality headsets.
AppliedVR, which was started in 2015, currently has eight distraction applications and has taken its virtual therapies to over 30,000 patients in 250 hospitals across eight countries. AppliedVR initially partnered with Dr. Brennan Spiegel of Cedars-Sinai Medical Center to carry out a controlled clinical trial in a cohort of 100 patients. Patients exposed to VR therapy reported a significant reduction in their pain levels as compared to patients in the control group who received an intervention in the form of 2D video viewed on 14-inch screen. Dr. Tashjian, the first author on the study, cautioned that “while the improvements were significant, further randomized trials still need to be performed to confirm the efficacy of this mode of therapy.” He also mentioned that adoption of the technology in older patients was a little slower as compared to a younger cohort, an important consideration to keep in mind for the creators of these experiences.
XRHealth has two applications for pain management which are accompanied with real-time data analytics that can be accessed by physicians to design and modify every patient’s treatment individually. Because of the sensitive nature of patient data collection, XRHealth is at the forefront of getting their applications registered with the FDA as FDA/CE Registered Medical Applications to follow HIPAA guidelines.
KindVR focuses primarily on pediatric pain and anxiety management during both disease and medical procedures. KindVR initially partnered with Dr. Anne Marsh at UCSF Benioff Children’s Hospital (Oakland) to design calming experiences for pediatric sickle cell patients undergoing acute pain episodes known as a vaso-oclusive crisis. A non-controlled small clinical trial was carried out in these patients to examine whether a VR intervention could act as an adjuvant for better pain management. Regarding this clinical trial, Dr. Marsh said: “We did a 15-minute VR session in addition to the standard pain medication that the patients were already getting, and we reassessed their pain to check if things had changed at all. In fact, things had changed – (1) The patients loved it and they ask for it when they come back in. (2) It was effective – it decreased their pain score and they reported having fewer areas of their body impacted by pain. (3) We did not notice any untoward side effects – none of them experienced any headaches, dizziness, or visual disturbances. It was very well tolerated. So, to have that to layer into our toolset was a great thing.” Building on the positive outcomes from this trial, KindVR has extended its program to 35 hospitals across the United States with clinical trials being held at eight of these sites.
Watch and Wait: A Promising Field with More to Prove
Given the largely encouraging results from a handful of clinical studies and the urgent need for alternative therapeutics for pain management, there definitely exists a niche to be filled by the rapid scaling of VR in this space. In fact, to underscore the importance of devising novel therapeutics for pain management and substance use disorders, the National Institute for Drug Abuse also recently issued a request for applications for “Virtual Reality Tools to Enhance Evidence Based Treatment of Substance Use Disorders.”
Most of the companies in this space are in the nascent stages of their product development as physicians and venture capital firms await the results of multiple studies currently in the early phases of clinical trials. Additionally, the VR industry still has several hurdles to jump in terms of uncovering whether there are any harmful side effects of prolonged usage of a digital technology, implementing a new technology at already under-resourced hospitals, developing a standardized treatment regimen, and working out insurance coverage for such treatment options.
The current market share of VR in healthcare stands at 1.78 billion USD and is predicted to grow to 6.1 billion USD by 2026. Intense investment in this sector would be instrumental in allowing the companies to scale up the technology to make it more accessible to both patients and their pain management physicians. While VR is not the ultimate panacea for effective pain management, its use could provide physicians with an additional novel and relatively safe instrument in their diminishing treatment toolbox to alleviate pain.
Tanvi Sinha, PhD is a Postdoctoral Scholar at the Cardiovascular Research Institute at the University of California, San Francisco.