Chronic pain has been a niggling thorn in the side of modern medicine for quite some time now. Around 28 million people in the UK experience chronic pain, defined by the NHS as pain that persists for more than 12 weeks despite medication or treatment.
While many chronic pain patients have taken medication for years to try and ease their symptoms, popping paracetamol is no longer advised to treat the problem. According to guidance issued in April this year by the UK National Institute for Health and Care Excellence (Nice), chronic pain should not be treated with painkillers, including paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), benzodiazepines or opioids.
This, NICE says, is due to the lack of evidence these drugs can make any difference to a patient’s quality of life, pain or psychological distress, but an established link to harm and addiction.
Instead, the organisation has recommended the use of antidepressants to achieve moderate pain relief. While the exact mechanism of action has yet to be fully understood, it’s thought that antidepressants may increase the number of pain-reducing neurotransmitters in the spinal cord, providing chronic pain patients with moderate relief.
With painkillers off of the cards, some patients are turning to neuromodulation to manage their condition.
Neuromodulation is defined as any technology that acts directly upon the nerves, modulating their activity through the direct delivery of electricity – meaning a cochlear implant counts as a neuromodulation device. But the technology is most often thought of in the context of chronic pain relief, one of its most common applications.
“My earliest recollection of a pain issue was around the age of 12,” NuroKor CEO Rick Rowan says. “I was given over-the-counter painkillers and told to have a hot bath. The pain escalated in my teens and through to my early adult years.
“I would go into such severe pain and spasm I sometimes could not get off the floor or get out of bed and I’d be there for days. When I would have an episode, I would take terribly dangerous cocktails of drugs in the hope that I would get some relief. It would do almost nothing.”
Rowan’s decades-long experience with chronic pain led him to found NuroKor after stumbling upon bioelectronic research during his search for solutions. The company’s stick-on wearable devices, about the size of a watch face, are designed to stimulate the nerves to relieve acute and chronic pain.
How does NuroKor’s technology work?
“The mechanism of action is a contentious one because there are a number of theories and, within that, a number of mechanisms of action are thought to work simultaneously – there’s not one single thing,” says Rowan.
NuroKor uses three different types of transcutaneous neuromodulation to stimulate the nerves and relieve pain, depending on the settings selected by the user. The first, transcutaneous peripheral nerve stimulation (TPNS) acts on skin-level, affecting shallow, surface-level nerve endings.
Meanwhile, neuromuscular stimulation works deeper to TPNS, typically applied at a higher amplitude and neuromodulating within muscle tissue to relieve pain.
Finally, microcurrent stimulation (MCS) uses a very low current, usually between 1uA and 1000uA or millionths of an ampere and is thought to work at a cellular level to reduce pain. As of yet, it’s unclear exactly how MCS works in practice, but a number of studies have demonstrated that it can have an impact on pain management and can have anti-inflammatory benefits.
The three modes can be used interchangeably by a patient depending on their treatment goals.
“Depending on the type of pain that you’re trying to target, you will have a particular formulation or a set of programmes almost specifically for that type of pain,” says NuroKor director of business and technical development Chloe Stockwell-Clark. “Each of the three modalities have completely different mechanisms of action and completely different reasons why you would use them.”
Can neuromodulation help minimise opioid use?
As chronic pain patients are advised to move away from painkiller-based interventions, neuromodulation could become an increasingly common way for patients to manage their condition.
NuroKor chief medical officer Dr Ashish Shetty says: “When you have pain in a certain part of your body and you take a pill, it works by inhibiting the effect of pain-signalling enzymes in the brain. It doesn’t differentiate between your hand and another part of your body. It’s not very specific. With neuromodulation, we can focus directly on the area that hurts.”
Of course, no treatment is one-size-fits-all, and many chronic pain patients could still receive some benefit from painkillers – particularly those for whom a physical root cause of their pain can be identified, which for many people with chronic pain can prove evasive.
“As pain specialists, we have to make a choice of whether it is appropriate for a patient to have pain relief,” says Dr Simon Thomson, a leading consultant specialising in pain medicine and neuromodulation.
“If there is an organic cause to their pain, like very severe arthritis of the hip, then I will use opiates. But for people with chronic widespread pain which leads to backache, for example, their pain is not going to be affected by opioids, but they will still build up to be tolerant of and dependent on them.”
NuroKor recently surveyed more than 100 of its users and found that more than 91% experienced a significant reduction or total elimination of pain with a 50% to 85% reduction in the use of pain medication.
The company is currently set to enter into an initial study with around 30 participants at Life Sciences Hub Wales, evaluating the use of the technology for self-management of chronic pain in patients awaiting total knee arthroplasty as a result of osteoarthritis.
The six-month project also involves collaboration with the University of Wales Trinity Saint David’s Assistive Technologies Innovation Centre and the TriTech Institute at Hywel Dda University Health Board.
NuroKor: the evidence so far
To date, NuroKor has yet to publish an official peer-reviewed study into the efficacy of its product – something which is fairly common with smaller medtechs that might not have the financial resources to conduct large-scale trials but can still hinder confidence in their claims.
Thomson says: “With all of these companies [in the neuromodulation space] if they want to be taken seriously then I think they’ve got to invest in high-quality, properly-powered studies.”
Still, a growing body of scientific evidence does suggest that the bioelectrical mechanisms in NuroKor products can effectively reduce pain intensity and the need for analgesic relief, particularly when it comes to studies on the efficacy of implanted devices such as spinal cord stimulators.
Shetty says: “There is a saying, extraordinary claim means extraordinary proof. With NuroKor’s devices, you have something that is cheap and non-invasive with very few side effects, so to a degree, you don’t need a lot of studies to be done. You have little to lose, versus a £50,000 spinal cord surgery where you really do need a good evidence base before I operate on you if you have pain.
“There are enough studies to mechanistically prove that electricity helps with pain. What NuroKor’s device is doing here is trying to do so without the surgery. The evidence base for external neuromodulation in general is lacking, but in our current practice we continue to use it with good benefits.”
The technology is currently available over-the-counter in the UK but will become available on a prescription basis in the US next month. Rowan says that the firm also has a Drug Tariff application pending in the UK and is in discussions with a number of potential distribution partners within the NHS, and is hoping to see a UK prescription network launch early in 2022.
Rowan says: “We don’t want to get too heavily focused just on validation because, without sounding too arrogant, we’re no longer interested in debating whether or not this works.”