Chronic Pain Management: Old Problem with New Technology Solutions

In 2019, chronic pain was included in the International Classification of Disease-11 database as an independent condition. Chronic pain is defined as “pain that persists or recurs for longer than 3 months”. It is multifactorial, with biological, psychological, and social factors contributing to the pain syndrome. In somecircumstances, chronic pain can be further divided by causality, such as secondary to cancer, trauma, or neuropathy, to name a few of the most common causes. The United States Center for Disease Control and Prevention estimates that at least 20 percent of adults suffer from chronic pain. Moreover, alarge systematic review of global epidemiological data attributed chronic low back pain and migraines as leading causes of disabilityworldwide.

Traditionally, opioids have been the cornerstone of pharmacological management for chronic pain. However, given the physiologic and behavioral impact of long-term opioid use, as well as the high potential for abuse, alternative management strategies for chronic pain are imperative. This is particularly true given the minimal to modest impact of non-opioid pharmacological adjuvants and interventional procedures on opioid consumption in patients with chronic pain. Since the use of technology-based solutions is increasingly popular throughout Medicine, its potential application in the field of pain management is no exception. As such, we briefly explore fivepromising technologies that may influence the future of chronic pain management.

1. Virtual Reality (VR):

 A new and promising modality for managingchronic pain utilizes specialized headsets and earphones that allow users to be immersed in a simulated environment. The software generates serene landscapes and allows users to fully interact with the virtual world. Indeed, the use of a 5-minute VR session in established patients (n=30) at a chronic pain clinic was shown to reduce pain by 33 percent after the immersive virtual experience, when compared to baseline. Moreover, in a randomized, controlled study of patients with breast cancer (n=80), the addition of VR to morphine resulted in significantly better anxiety and pain control, compared to morphine alone. The future for VR in Medicine is promising, given the rapid pace of improvements in the “realness” of virtual interactions, and plummeting costs of such advanced technology due to the online gaming industry. By focusing on developing applications that are compatible with existing VR platforms, low costtherapeutic options could be offered to patients with chronic pain.

2. Transcutaneous Electrical Nerve Stimulation (TENS):

In the 1960s, scientists explored the use of electrical nerve stimulation for pain relief. Although promising, the devices were bulky as well as expensive, and applying the required electrodes was a cumbersome process. Recent, high-quality iterations are hand-held devices with multi-use stimulating patches, which typically sell for $20-$25 through large commercial online sellers. Quell® is the first United States Food and Drug Administration (FDA) approved compact TENS device for 24-hour use. Patients can use it during sleep and the modern software permits treatment customization, while tracking response to treatment through pain reporting into the software application. TENS works via transmission of electrical signals via the skin and the postulated mechanism by which it works depends on the intensity of the signal as well as areas stimulated. These devices are thought to activate inhibitory pathways from the central nervous system (CNS) to the periphery. The repeated stimulation offered by TENS devices allows sensitization and can block painful signals from affected areas. Indeed, animal studies suggest that TENS activate receptors that release neurochemicals involved in pain relief. In a narrative review of the literature, Vance et al. state, “TENS has been shown to provide analgesia specifically when applied at a strong, non-painful intensity and [high frequency] HF-TENS may be more effective for people taking opioids”.

3. Electromagnetic Pulse Therapy (EPT):

EPT is a non-invasive technology that uses electromagnetic therapy to interfere with pain pathways. Actipatch®, is an FDA-approved EPT device, marketed for use in patients with chronic joint and muscle pain (8). The device sends low-power, pulsed, short electromagnetic waves at a set frequency to painful sites and interferes peripheral afferent pain mechanisms. Staelin et al., conducted a 7-day trial of EPT in patients with chronic pain (n=1,394) and demonstrated that its use was associated with an average 66 percent reduction in pain at 3-months as well as either reduction or elimination of daily analgesic use. Similar results were reported by Rawe and Kotak (n=5,00). Although both of these studies were open-label, single-arm, registries with post-treatment assessments, the findings are encouraging. Randomized controlled trials are needed to confirm these findings.

4. Radiofrequency Ablation (RFA):

By using targeted pulsed radio waves, RFA involves generating heat around the nerves that supply pain sensation to affected areas. This technology not only modulates various ion channels involved in pain pathways, but also affects various components of the immune system which are known to be involved in chronic pain. RFA treatments have classically been performed in pain clinic procedure suites, where practitioners have used catheters and needles placed under fluoroscopy or ultrasound guidance to target the areas of interest (e.g., back, shoulder, knee).In 2019, the FDA approved Solio Alfa Plus®, which combines radio, light, and infrared energies in a compact, non-invasive device that allows users the freedom to administer sessions in the comfort of their own homes. While RFA has been in use for many years in the clinical setting, this newer technology is promising. However, clinical data is not currently available, and as such, the effectiveness of this device cannot be fully assessed at this time.

5. Infrared Light Therapy:

Light therapy studies date back to the 1960s, but the first clearance for using it in pain management didnot happen until the late 1980s. The FDA approved prescription-only light-emitting diode (LED) therapy in 1994. LumiWave® is an FDA-approved, compact, near-infrared LED therapy device with an indication for treatment of arthritis pain. Light emitted by the device is thought to generate a comfortable level of heat, which causes vasodilation of local blood vessels to improve circulation. Additionally, it is thought that the near-infrared spectrum induces the release of nitric oxide by local tissue to further increase blood flow to promote faster healing of damaged tissue. While the concept is intriguing, and significant anecdotal information is available regarding the effectiveness of LumiWave®, clinical evidence, particularly randomized, control trails are lacking. As such, the utility of LED therapy as an in-home chronic pain management tool is yet to be determined.

Chronic pain is variable in its presentation and causality.Amodality that may provide relief for one patient maybe ineffective in another. However, with advancements in technology, the scope of managing chronic pain is finally moving beyond purely pharmacological interventions. With innovatively designed products, as described above, the hope is to individualize chronic pain management therapies for our patients by offering a range of modalities and finding the product(s) that fits their needs best.